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MG MGB GT V8 Factory Originals Technical - V6 questions
|Now before all you folks panic, this is NOT for the MG!! So relax, I will never give up my 5.0!!|
That said I would like to get some info from those of you running V6's. I would like to go Ford V6, but Chevy V6 info would also be usefull.
I am most interested in length, hieght, width info. Stock power, aftermarket hop-ups are also of interest. I am going to want EFI on it, so a lter model donor car would be my target. This would be for a small truck, smooth power and good torque would be my ultimate goals. And NO a V8 will not fit in the truck due to length.
|If I was looking for an all around low cost, parts available, V6, I would pick a GM 4.3 . But I used a GM 3800 Series II V6 in my mgb roadster because of the size and that it was a SFI V6 with 240 Lbs of Torque and 200 HP in it's stock form. Also 1996-2002 Camero/Firebird offer this in RWD.|
|From what I've been able to find there isn't a lot of aftermarket parts for the GM 60* V6. Since you're into fuel injection, the 93-95 F-body 3.4L SFI may be something to consider. Those are RWD engines. There are plenty of GM FWD engines too, which are aluminum head engines. FWIW, iron heads and aluminum heads don't interchange on these engines, nor do iron head pistons interchange with aluminum head pistons - I suppose you could swap them both, but it'd make more sense to just get the type engine you want in the first place.|
I have a full size pick-up with the Vortec 4.3L, and it's without a doubt the most reliable and troublefree engine I've ever had. I've done nothing other than change ignition parts, which may explain why it's still running so well.
|Glenn, A little info here if you want to pick up on it.|
A GM FWD 3.1/3.4 V6 will make more than 200 HP with properly tuned headers. If a person has the entire intake system and heads Extrude Honed you can pick up another 12 to 15 HP. They also lend to turbo applications in their raw form. This can take you to 250 to HP with 5 to 7 lb. boost with out the Extrude Hone process. The header systems for a turbo are a lot simpler and less expensive also. The money you can save with the turbo would be about a third of the cost of regular tuned headers. More boost can be applied if you use an aftermarket ECU. All this is usually less expensive than going with an engine that has not been used in a lot of conversions.
Aluminum heads will work on an iron head engine if you use the whole top end assembly. Some later model roller tappet 3.1/3.4 may not swap. Dann BCC
|Re: Lack of performance parts for the 60 degree 3.4 - True, parts aren't as plentiful as a SBC, but look here:|
You can't go too far with cams on the stock computer controlled engine anyway, becase it relies more on engine vaccum (map) signal to control idle than the TPS. Performance cams with lots of overlap tend to give erratic vaccum, especially at idle and the stock calibrated PCM gets confused.
Carbs, otoh, don't care if lumpy idle is what you are after.
However, throw a Haltech or any other aftermarket ECU into the mix (or a reprogrammed GM ECU) and build your idle on the throttle position sensor and problem solved?...well... alleviated anyway.
So, back on the parts site- forged low compression pistons, strong rods, tap in some oil sprayers for the underside of the pistons and boost the bejesus out of it. (Insert maniacial laughter)
|When it comes to the V6 there are many choices and it all depends on purpose.|
GM choose the 60 degree V6 with the iron head for the truck and F body cars due in PART for the reliability and torque at the botton end needed in the larger and heavier bodys.
If you swap the heads with the alum, then the pistons also have to be replace in order to have an eficient combustion chamber. So... If I had the room and if it's paractical, meaning work involve, then a 90 degree 4.3 GM would be my choice. If the room is limited then the 2.8/3.4 iron head will produde the most torque in the 60 degree V6 version. I have a 3.8 Buick on my Jag MKII great performance with high compression Kenne-bell pistons etc. Truck use is different than auto use, therefore the power should be in lower end and camshaft is very critical, the 3.4 crate engine comes with an ideal cam for botton end torque.
When using a FI system keep the cam duration below 220 @.50 with 110 to 112 overlap, plenty of vacuum to signal the Map. On the Ford category the V6 is too cubersome when it comes to the electrical and items like the pan and bell housing etc. the other choice is a Ford 2.9 60 degree, great engine but heavy with some or 0 aftermarket parts. I have a GT with a 2.8 Ford daily driver.
Chevy 60 V6 parts are availble via the same places as the V8, Aries pistons 11:1 to 12:1 Wiseco also can make a set of pistons, Crane, GM, Comp Cams, Carillo rods, oil pumps, etc..
Interchangeable parts with V8, Valve springs, rods with some mods, rocker arms with mods, vintage tray with mods, intake valves from a buick 3.8 (larger)and many more. High performance parts are not advertise like the V8's you have to ask for them.
We are planing to build a TCRA GT6 class MGB GT with a 2.8/ 3.0 (under 3 liter for GT6 class) 12:1 compression etc. an engine like this can develop 250+ reliable hp with an rpm range of 7500 I would not put this engine on a truck.
Botton line, If you like Fords then consider the 4.0
with lots of work and if you have the room or the 4.3 GM.
If room is limited then consider the 60 degree 3.4 iron head GM you will be surprise.
|Larry, either the small Ford or Chevy v6 60 would probably work in a small truck, they were both used in small trucks from their respective manufacturers. There might be an advantage in using one of the truck setups in that the transmission shifter location and length is different in the truck applications. I'd recommend the Chevy S10 or GMC S15 v6 with a 5 speed. The Chevy is a little shorter than the Ford so clearance will be better and the truck bellhousing has an internal slave for the clutch so clearance around the bell housing would be better.|
|Bill, I've never seen any difference in piston shape between either aluminum head or cast iron. The cast iron head is somewhat wedge shaped in comparison to the "heart shape" of the aluminum heads. The shape of the aluminum heads with larger unshrouded valves help create a better swirl and consequently makes a more desirable combustible mix.The FWD engines have more torque ( 205 ft lb.) Dann|
While there is no apparent difference in shape between the pistons from an aluminum head engine and an iron head engine, there is a difference in piston height. The measurement between the center of the wrist pin and the top of the piston is different, that is why you cannot use the pistons from an aluminum head engine with iron heads. Compression ratio would be too high. Sooo ... you would have to completely dissamble the short block aluminum head engine and replace the pistons. And then you would have still have to deal with the starter issue being on the wrong side. Better to start off with the iron block if that is what you want. Just been down that road and decided to go with 3.4 iron head and block with MPFI and 3.42 rear end. Still trying to decide wheather to use a modified 700r4 (driven an automatic Corvette lately?... with competition cluthes, sprag, servos, etc.) or keep on slamming gears with a 5 speed, the HTOB issue, extra hydraulics and the necessary periodic clutch replacements. Getting older now and the auto really appeals to me. Sorta like Plug'n'Play FWIW Alan.
|I believe the iron head and aluminum head engines use different pushrods too because of the splayed valve arrangement - seems like I read the al head takes two different lengths for intakes and exhausts, and, I don't don't if either are the same as on the iron head motors.|
|Alan, if you use the 700R trans you will have to widen the trans tunnel. I have not done an auto trans conversion, but I have customers who have, and that is what it was relay to me.|
3:42 differential, shift kit in a light car, great combo!
Dan, Alan and Glenn are correct on the pistons and valve train, also the earlier alum head engines had different piston dome. I check it again in the GM performance parts book, just to make sure. Under notes, it's recomdnded not to use the alum heads on the iron head short block or the other way around.
Dan, the debate on which engine-brand produces the best hp-torque # Can go for as long as we will be on this earth and no one who stands in their believes will agree with any other explanation or hp #'s, but There is a logical reason why GM use the iron head V6 engines in the S-F series vehicles or why the off road race trucks use the iron head engines etc. etc.
I am sure that the alum head is a very good engine and produces great torque and hp #'s that are impresive.
I am pleased to hear from someone who at least knows of someone who has put the 700r4 into a "B" Did this person that you heard of, use a 60 degree v6 with the smaller 700r4 case? There are 2 cases that have this designation (700r4) one for the small block 90 degree Chev and one for the 60 degree v6 as found in the Camaros and Firebirds. Do you happen to know how much floor space in the footwell was lost? I realize that the tunnel is real narrow but I would really like to get as much info as possible about the experience of others who have tried this before I get my SAWS-ALL powered up.
|Bill, don't you find it odd that GM would recommend not using aluminum heads on the iron short block? They do it every day with the FWD. Hmmmmm..... Sometimes I think they just throw their technology info up into the air and take a wild grab at it and pass on what info they catch in their hands. :-)|
Alan, I don't get it. Both engines are iron blocks. If the strokes are the same and the deck heights are the same, and the rod lengths are the same then how could there be any difference in the pistons. Some factor would have to change. While I don't deal with a RWD engine something is awry here. What kind of compression are you talking about 10:1? Sounds good to me. Anyway why would you need to change the pistons again? I don't get it.
So should I believe that the FWD iron block has a higher deck height than the RWD? Very interesting. Apparently by what you say the FWD must have a taller, maybe thicker crown on the pistons. I thought both versions had the same stroke. I'll check it out. I don't want to be passing any bad info.
Alan, the starter issue isn't an issue. I use a bell housing that has the starter on the correct side anyway. This is one of the advantages of using a late model low mileage FWD engine. I don't understand why you say the engine would have to be disassembled to replace the pistons. Could you clarify this?
Go to the website www.60degreev6.com. The difference is the location of the hole in the side of the piston for the wrist pin. The engines with the aluminum heads have the hole in a different location on the piston to compensate for the shallow combustion chamber of the aluminum head. If you want to put the aluminum heads on an iron block with the pistons from the iron block you will have a compression ratio of about 15:1. Because the combustion chamber in the iron head is considerably larger than the GEN II aluminum head, a flat top piston is used with the connecting rod wrist pin hole situated lower in the piston,(thus making the top of the piston ride higher up the bore) driving the charge up and into the head. Use the iron head piston with aluminum heads and the small combustion chambe (28cc I think) and the compression goes through the roof. Call GM and ask for the piston part numbers they are diferent for this reason.
|Alan, what I was told, is that it needed to be wider by 1 inch on both sides and a very small amount on the firewall needed to be dress. The trans that he is using is from a Camaro.|
Send me an e-mail and [erhaps I can conect you with him. He is located in Mass.
Dan, I think you misunderstood the statement.
Alan has explain why.
Alum head smaller chamber call fast burn
Iron head larger combustion. Can't not use the same piston.
It's commun pratice by GM to use dish pistons or to relocate the wrisk pin higher or lower to adjust compression.
The 2.8 X11 came with .020 higher wrisk pin, to raise the compression from 8:5 to 8:9.
I will quote the GM performance manual.
"1987 and later Gen II V6/60 Chevrolet with Aluminum cylender heads used dish pistons. This sump design maintains an 8:9 compression ratio with the aluminun cylender heads smaller combustion chamber 28 cc"
This is why you would not use a alum head on a V6 that came with iron head with flat top pistons.
If you change the pistons then the swap would be ok.
"Chevrolet Power" Book Page 172 under piston section
|One more thing...the iron head and aluminum head intakes aren't interchangeable due to the intake paswsages being in different locations. The iron heads have two passages right next to each other whereas the aluminum heads don't.|
Point being that if you use al heads you pretty much have to run some sort of FI since no intakes for carbs are available with the al head intake port spacing.
I wish Currao's book was still in print.
|Well, fellows I really don't know what to say. They would have to either raise the height of the block or lower it when changing wrist pin location on the piston or change strokes. I know they didn't change deck heights because the manifolds exchange perfectly with the heads and there are no gaps in the lower manifold. If there was I have to machine them to fit if the deck was lower.|
Changing compression cannot be achieved by changing pin location by itself. The stroke would have to be changed also. You are speaking of older engines and I am speaking of new. They made three versions of the aluminum heads and at least five versions of the 60įV6. I'm looking at two pistons as I write. The dish on the piston from the aluminum head engine is identical to the iron head engine except for dish depth. There is about 19cc difference in the pistons and the pins are in the exact place. I'm holding a piston from a 2002 GM Venture and a piston for a 1993 3.4 Camaro.
I happen to know that you can use the 3400 aluminum heads on a RWD iron block because I have them installed on a 1993 3.4 Camaro engine along with the entire manifold and push rod assembly from the 2002 3400 FWD as I mentioned earlier. It has a compression ratio of 10.665 to 1 and it runs on hi test pump gas to make it a legal entry. The only change in the heads was to have them Extrude Honed. It was running fine in my autocross/race car the last time I had it out. The reason I used the RWD block was because the flywheel is a little heavier and could handle heat build up better and stored more energy to release at launch for the 60 ft times. I couldn't use the FWD engine block only because the flywheel was to large to accommodate the starter. It turns 13.2 to 13.5 with consistency at 105 mph.
|Dann, I think the key to this dilema lies in the different dish volumes you mentioned.|
I can't speak from experience because I've never seen these things in person - I'm going by what I've read (which doesn't make it factual).
It's my understanding that the aluminum heads have a much smaller combustion chamber than the iron heads. GM's approach was to use pistons with a larger dish volume with the smaller chambered aluminum heads in order to achieve a practical CR. The iron head engines have larger combustion chambers and use flat-top pistons or pistons with a smaller dish volume to create a similar CR.
I don't recall reading anything about different wrist pin heights.
I'm not sure what factory CRs are, but 8.5-8.9 comes to mind.
If you've built a motor with aluminum heads and iron head pistons which gives a CR of 10.665, I'm glad to hear it. From what I've read the CR would jump through the roof, but no actual numbers were given.
Are the 2002 Venture heads GenerationIII heads? Maybe they have a slightly larger combustion chamber than the GenII aluminum heads.
I have to disagree with what you said about changing wrist pin height itself not affecting the CR. If the wrist pin is moved up the piston, the piston will be lower in the block at TDC resulting is less compression. If the wrist pin is lowered (wrist pin height increased) too much the piston would be higher in the block at TDC, possibly high enough to make contact with the head and prevent the crank from turning.
What cam are you using?
You are in denial. Call the GM dealer and ask what the part numbers are for each piston and then ask them if they are interchangeable. Has nothing to do wih "older vs. newer engines" You obviously do not understand basic engine theory if you can state that
" Changing compression cannot be achieved by changing pin location by itself." That's total garbage. As for the fact that you "happen to have" this miracle engine with Aluminum heads and iron block pistons and it runs swell - give me some of that stuff you have been smoking. As for the starter not being an issue because you have the right bellhousing, yeah I got a bellhousing that has a bulge on both sides to allow for mounting the starter on either side. That's not the problem. If you want to mount the starter on the passenger side - you can, AFTER you drill the new holes in the block so that you can bolt it onto the engine, and then shim it so that the starter can engage smoothly with out chewing up the ring or pinion or both.Hopefully you can bore and tap new threads correctly or you scrap the block. Why bother? Get the proper engine for the application. RWD block with iron pistons and heads or put aluminum head pistons on the rods and THEN install aluminum heads. If you need every last eenth degree of power for your B, slice the bugger up and drop in a V10 Viper engine... in other words who cares. I realize you have a business selling "late model" aluminum headed FWD engine conversions - thats great. But the Camaro RWD engines with iron heads were made up until 1995 and are not the antiques that you would have us believe - according to the Q/A page on your website - Something IS awry.... FWIW Alan
|Glenn, thanks for the reply.We may be saying the same thing but more has to be considered.|
If you move the piston pin with out adding or subtracting material at the top of the piston you would either have the piston sticking out above the deck or below the deck the same distance you moved the pin. As I stated before you have to INCREASE THE STROKE OR DECREASE IT OR CHANGE ROD LENGTH to accomodate the change. I was being practical by saying you can't increase the compression because the piston would hit the head. Also what good would it do to have the piston far below the deck just to decrease the compression? The volumetric effiency would suffer and swirl and flame travel would be affected. The heads are from a 2002 Venture. I think we are saying the same thing but in a different way. Thanks for your conversation. Dann
|Alan, every once in a while I get nasty replies from armchair mechanics such as you. You are severely misinformed about almost everything you speak of. You are looking rather foolish to the crew here at the shop. I would like for you to consider the other readers opinion of you at this point. There are at least 15 customers of mine who read these columns and three of them have called me to ridicule you. I suspect your lack of experience and information sources have done you injustice.|
Everything I say about the bell housing is true. I have several in stock if you ever need one. Did I mention that it fits a Ford transmission? A very sweet set up. As for the bell housing with a starter accommodation that "fits" both sides comes from an earlier Camaro. The starter will not fit on the driver side using this bell housing without machining it. I'm sure you never checked this out or you would have said so. I would never "drill or shim" something as precise as an automobile engine. Only a shadetree mechanic and fool would attempt this without a fixture at the least.
You cannot redrill a FWD engine for starter on the passenger side because there isn't enough material. If you don't like the FWD conversion that is your privilege. If you want to use engines that have at least 100,000 miles on them it's your money and your car. Everyone has opinions and I am no different. I would like to debate this further but I would need a more informed and worthy adversary to do so. If it sounds like I'm being a little cocky then it would be one of the few things you got right. You started it. Don't bring a knife to a gunfight the next time you address these columns. Thanks for your input. Dann Wade British Car Conversions.
Won't bother adressing this to Dan (still in denial) however to his customers that he speaks of - Do yourselves a favor and check out the comments and remarks that appear on the MGBV6.com website and the comments and remarks on the Fiero on line service guide website, and V6fbody on line, and the 60degreev6
website,and ThirdGEN.org among countless others. Dan your are an obstinate individual and name calling only diminishes your already small status. And while we are at it why don't you go finish up that atrocious so called webite "Under Construction" just doesn't cut it. I would never buy a product from anyone with an attitude such as yours. While you may have some customers I'll bet that they are not repeat customers. Did you call a GM dealership and inquire about the interchangeability of piston use as we are "discussing"? Noooooo...... What's this childishness about "Knife fight"? Get a grip old fellow. Dinner at Dan's house - Alan is invited.
|Cant' we all just get along?|
Lets see if I got this straight.
Iron Head RWD v. Aluminum Head FWD 3.4:
Same crank throw, same rod length, same bore, same deck height. But the Aluminum head has much less chamber area. So an identical flat top piston with an aluminum head results in a much higher compression ratio because the same volume (bore area x stroke) ends up squished down into a smaller chamber at TDC. So, what to do to keep the compression ratio acceptable: Either (1) dish the piston or (2) keep it flat but shorten the height of the piston as measured from the wrist pin centerline to the top of the piston.
Am I missing something?
|Well, gentleman, after scrolling over this thread a few times, and I admit, not comprehending all of it, I will say this. My car currently resides at Dann's shop. It's 90% finished, and I got the chance to test drive it monday. This baby is SWEET!Dann has been great to work with, and when the B is done, I'm thinking GT for the next project. Regards to all, and feel free to email me.|
|Thanks Alan, Out of respect for the members this forum this will be my last input on this subject. I appreciate your feelings but I believe my attitude was directed at you and NO ONE else. I don't think any of my customers would ever agree with you. I'd rather shoot myself in the foot rather then decieve anyone. At least my reputation for being a stand guy up hasn't been defeated. I would never trust what a dealer would tell me about anything. Their reputation for inaccuracy is always questionable and anyone's accuracy for information can be wrong. I have been wrong many times but I've learned by it, that why my products and work are so darn good. As for my website, a very young dear friend is doing the site for a school project and I am happy to be able to give him the challenge. I'm not pleased that it has taken so long but I am pleased that he is trying so hard to please others. I'm glad that you have visited the site so many times. There are many FAQ's there that could help a person save many dollars by making an informed choice. I would be more then glad to have you at my home for dinner and afterward we could "discuss" the element in question. I won't deceive anyone if I can possibly help it. In the final analysis the world agrees with me if it's really that important of which it is not. I've changed my mind, you could be a worthy adversary if you weren't so doggone emotional! Thanks to Brian and Brian I shall not expel my oratory or apply it to this subject any further, it is beneath me. Thank you, Dann BCC|
|Thanks you Brian C. for your direction in meditation for the previous threads. Dann|
|Brian H. it is truly a VERY sweet car and D... fast! Dann BCC|
|AS far as repeat customers for Dann !!!!!|
I would gladly do business with him again! I am already thinking of another V6 project for a GT and will use Dann again.
Dann has always been extremely helpful and HONORABLE in every way. To me HONOR is the most important trait someone can have and is sadly missing in people today (especially those that also don't understand respect).
The personal attack on Dann was totally uncalled for.
I think the same of Bill Guzman. The civil discourse between Bill and Dann (who have competing conversion kits) is always refreshing and reassuring that differing viewpoints can be aired without the petty personal attacks.
Dann and Bill have both provided an excellent service to this BBS and put in huge amounts of time (and I am sure investment) to come up with their respective conversions. My hats off to them both.
|Thank you Brian Corrigan .. That is all I have ever been trying to say. There are a lot of hot rodders out there who have been trying to find an inexpensive piston form some other GM factory application for exactly this purpose (aluminum heads on a RWD block and a compression ratio of about 9.2 9.5)NO ONE HAS THEM! Have to be custom made (= expense)There are also other issues that will come up with ratios higher that 9.5 or so, e.g. the ECM monitors heat created in the engine, by way of the MAT and CTS and if pre-ignition occurs, the knock sensor tell the ECM to retard the timing by way of the ESC. If you fiddle with the compression ratios by an inordinate amount |
( 9.5+ ) you will get get pre-ignition with todays 92 octane gas. You will have to flash (burn) another PROM chip with the new tables, or buy a custom chip. If you do your own trouble shooting you will neeed a scanner capable of diagnosing OBDII for ANY GM engine built after 1995... read expensive. Brian Mc Cullough of MGBV6 website has a lot of pertinate information on this subject as does CHEVYTHUNDER.com. NUFF SAID..... Damn..... As Dan says " thats all I will say on the subject" "Armchair Mechanic Al"
|Alan, you are correct, I too decided to go with the iron head V6 in part due to the compression.|
The stock piston sets below the deck, changing the pin high will raise the piston almost flush with the deck.
I don't understand what Dann is saying about the block deck high, no such thing Dann. The machinest who is building my engine is very knowledgeable.
The late model 3.4 has pistons with deep valve reliefs
that affects compression.
Dann, perhaps you need to inform yourself a bit better on the subject, and perhaps be a bit polite to others.
|I just got through reading this thread...what a hoot! I can't believe ya'll are even having to have this discussion. If GM is dropping a piston in the bore to lower compression ratio, they are lowering it using a half-assed method. You would never do that in any performance application. The idea is for the quench area of the piston to ALMOST touch the quench area of the head. Dropping the piston would completely blow the designs of both. Would it work...yes. Would it be the most efficient method...hell no! If you are worried about compression ratio, buy pistons to match the cc of the head you want to use. If the head has too small of a combustion chamber for your tastes, open the chambers up a little. Chances are the valves could use a little unshrouding anyway! While you are at it, go ahead and do a quick bowl porting to make the head flow a little better. |
Ya'll need to put a little reason into your buildups. It absolutely amazes me how many of you will spend tons of money for minor things on your buildups, but then feel the need to skimp on pistons. Think about what you REALLY don't want to have to go and change...put your money there first! I would rather have a stout and sound shortblock, followed by heads, then intake and headers....all in order of pain in the ass to change factor!
Please feel free to discard any unused portion of this rant!
|Thank you George Stanley|
Thank you G.P Copes
Thank you Brian Corrigan
Thank you Bill Guzman
Thank you Glenn in Virginia
Dan, fire all those clown mechanics that have been laughing. You can not "just put aluminum heads and intake" (as per your initial post of Oct 23) on an engine that originally came with iron heads without changing the pistons PERIOD. I am NOT "severly misinformed" nor am I "looking foolish"-
quite the opposite.
"Armchair Mechanic Al" (sort of has a nice ring to it ) Might even start a new website with that name and sell MGB v6 conversions... just kidding Dan - my worthy adversary....
|Gee whiz Allan, wasn't I saying what G.P.said all along??? ( scratching my head!) Dann|
|I actually printed this thread to read it carefully.|
1. Yes GM use higher wrist pin on the X-11 Actually is not a half ass way of do it = milling heads or block
2. Some racing teams running Show room stock cheat by having pistons made with higher wrist pins, putting the piston level with the block. Ford did the same with the large 460 ci for different applications.
3. The early iron V6 use different pistons than alum head V6 by using a different piston, which had a dome.
4. Later V6 3.4 they all came with flat top pistons and deep valve reliefs.
If the heads are swap into an iron head block the cr will go up and therefore...bla bla bla.
Now, what difference does all this makes? Nothing.
Use the engine that makes you feel right.
Some like simplicity and others like complexity.
Let's get along without anger.
BTW our racing team name will change to a Dinosaur name, we will come up with a name soon. Since we are going to build a TCRA- GT6 class GT with a 3-liter V6 and a Carb, I think it will deserve a dinosaur name.
|George what engine do you speak of. The late model FWD doesn't have valve reliefs. Dann|
No you were not. Read you own post of Oct 21,24 and Oct 25. You don't seem so adament now. Maybe you were just "misinformed". Keep scratching your head, but do not tell me what I know, from past ACTUAL experience is "misinformed". You asked me to clarify MY statement about the fact that you would have to "disassemble the block (that had iron pistons) and reassemble it with the pistons meant for an engine with aluminum heads IF you wanted to run those aluminum heads and intake on a block that originally came with iron heads and pistons. Still following???... I did - you did not like the fact that you were wrong ("Changing compression cannot be achieved by changing pin location by itself..") No big deal. The only reason I spoke up, was to share some information with the folks out there who are planning to install a 60 degree v6 into their MGB. They are going to be making some $$$$ decisions and correct facts are important to have at this point in determining which way to go FWD or RWD (engine-wise) When I raced Pro stock years ago I used to run a 64 cc head with a flat top piston on a 350 v8 and the compression ratio was 10.3 Had to us 100% or higher octane. Stands to reason if you put an aluminum head on a flat top piston as found in a RWD block, and the aluminum head volume is 28 cc (less than 1/2 of the 64cc I was working with) your compression ratios will be A LOT HIGHER than 10.665. Maybe 15:1 that is all I was saying... which is entirely different from your statement of OCT 21. Them's facts Ma'am. That's what I thought this board was all about ..sharing correct information.
Thanks Bill.. thats what I said. Simple stuff. It is done, and can be done. Don't know for sure but I think that the early domed aluminum piston gave a compression ratio of 11.3 or maybe 12.5 I do know that it would be nice if GM made a piston for the v6 that was 9.5-9.7:1 . THe ECM would probably handle it if it was a MAF system, rather than a speed density with MAP.
Really don't want to argue with Dann, but I won't be bullied to agree to anything that anyone says, when I know for a fact, that their statement was wrong "Just to get along" ( Never did like Rodney King and his whiney lame excuses anyway) And then to be told by this same person I "look foolish" FWIW.. Armchair Mechanic Al (Love the ring of that name.. sorta has a nice lilt to it)
|There's only one way to settle this.|
Y'all mail me all your engine stuff postage paid and I'll get back to you just as soon as I can.
|OK...it was REALLY late when I last posted...so letís see if I can clear any of this up. First, changing any aspect of the piston or the combustion chamber will affect compression ratio. Did GM drop the piston in the bore and leave a big ole space between the top of the piston and the head to lower compression? I have no idea. I do know they have made dumb-assed mistakes such as the Pontiac 301, so almost anything is possible. Would any decent mechanic or machine shop use these methods alter the compression ratio in a performance engine...HELL NO! Any engine I build starts off with the engine deck decked to 0 so it is consistent and lets the design of the piston/combustion chamber do their jobs. This is also why those showroom stock guys 0 deck the block...along with their rules allow certain tolerances on things like stroke, so they also stroke the engines to the very limit of the rules.|
As far as the iron block/Al head thing...people been doing it for years, and it works. Don't know what else to say.
All you have to do is pick your desired CR, pick your head, have block decked to 0 and order the pistons to match your desired CR with desired head. Also, you want to figure how many CCs your head actually has left after you clean up the combustion chamber before you figure piston shape required.
Once again, please feel free to return any unused portion of above rant for a full refund!
OOPS!!! There are times when 0 decking a block are not desired, such as when using Al rods due to the Al stretching more than steel when heated. For that, I am sure Dann has much more knowledge than I do.
|Geeeez, I'm going back to work, I've got a headache!|
The issue is NOT if you can run an aluminum head on an iron block. The issue is.. Can you take the unmodified aluminum heads and manifold from a v6 engine and put them on the same type of v6 engine that originally came with iron heads on it, from the factory, and have it run without compression problems? Dan says you can. I say you can not. Because the combustion volumne in the aluminum cylinder head is very small and the combustion chamber in the iron heads is very large. If you do not change the flat top pistons that came with the iron head engine (this is the bone of contention) to the dished pistons that came with the aluminum head engine(and are designed to work with the fast burm aluminum heads) you will have problems with very high compression ratios. The dog won't run!! This all came about from a remark that was made about "just put the aluminum heads and intake on the iron head engine" I stated that you must also change the pistons to accomadate the different style of combustion chamber of the aluminum heads. You can not hog out the cylinder head you will probably go through the water jacket. You simply need to change the pistons which means disassembling the short block to change the pistons. No big deal but some expense and additional work to make the switch. Got Dann all wound up and the spaghetti hit the wall. Armchair Mechanic Al... See the first posts and read through for some entertainment. Larry Embry see what you started??? HA HA
PS I am sending you some broken flat top pistons and a beat up aluminum cylinder head both from the v6 I blew up. Sorry for the valve marks on the pistons maybe they can be polished out?? I love this board.
|Larry's a Ford guy - you know he's loving this.|
|he he he!! Shush glenn, your ruining it!! It was all part of the master plan to get the Chebby (no offense) guys fighting amongst themselves while I sneak on by in my Ford powered monster heh|
Joking aside, I think I have decided to leave the truck alone for now. IF I go to the trouble of doing an engine swap it WILL get a 5.0, that or I sell it heh.
|Alan, please hush. My stuff works and you have none. Dann|
I never said that your "stuff" didn't work. I just stated the combo, that you said were OK, Doesn't work ! Take some of your own advice and hush up. You have a very poor condesending attitude that doesn't bode well for a fellow dealing with the public. All you have to say is "I stand corrected" or nothing at all . The operative word here is maturity.. Don't bother telling me to hush up. You are right though, I have none(MGB Conversions business or parts)that I offer to the public. I don't need to. Retired. You, on the other hand have a reputation to preserve, and a negative exposure to your business on the internet,should you persist arguing with people when you are clearly wrong. Just drop it Dan, and treat the new info that you have gained from this friendly banter,as "useful". As the mayor of Washington D.C. Marion Barry used to say "Just Get Over It" Enjoy your day. Uncle Al
I never said that your "stuff" didn't work. I just stated the combo, that you said were OK, Doesn't work ! Take some of your own advice and hush up. You have a very poor condesending attitude that doesn't bode well for a fellow dealing with the public. All you have to say is "I stand corrected" or nothing at all . The operative word here is "maturity".. Don't bother telling me to hush up. You are right though, I have none(MGB Conversions business or parts)that I offer to the public. I don't need to. Retired. You, on the other hand have a reputation to preserve, and a negative exposure to your business on the internet,should you persist arguing with people when you are clearly wrong. Just drop it Dan, and treat the new info that you have gained from this friendly banter,as "useful". As the mayor of Washington D.C.- Marion Barry, used to say "Just Get Over It" Enjoy your day. Uncle Al
|Sorry for double post. Laughing so hard, I hit the "submit" button twice.|
|Bad timimg Larry!|
|man!!!, larry, way to stir the pot, but serious, i have a headache from too much tech stuff, i used bill's kit in my car and i love it, goes like he**, either way you go, does not matter, just as long as you all come over to the dark side and go V6, what do you think the odds of having V6 added to the heading on the board right next to the V8? jim|
|What we need is a V6 meet. Here in Tulsa the Cobra, MidAmerica Ford, Porsche, Corvette clubs all have a weekend where they rent the road course at Hallet ($2250 with all insurance, officials and staff) and the Tulsa Drag Strip. Tech sessions could help explain a lot of the discussion on this thread. |
|You guys are cracking me up! It doesn't surprise me that Dann got all defensive instead of trying to get at the root of the disagreement, I mean, no offense meant Dann but that's just so you. But why do you other guys have to just keep egging him on thata way? Well, that's Entertainment ;-)|
That is a great idea. Sooner or later everyone would have a good indication of the benefits and pitfalls of the engine / trans / rear axle choice that they would choose when planning a v6 conversion. MGBV6.com is already a good source (however I am having trouble at this time logging in, as are others, due to the strange BBS they are using)
There is also the subject of the different fuel injection systems that could be adapted to the v6 conversion and directions on how to do so inexpensively. Good stuff for the folks who do not want to have to cut a hole or install a scoop on the hood (bonnet). Alan (see? I can be agreeable)
|Hi Mike. How is your project coming along? I'm glad you mentioned a V6 meet. I think it would be of a great interest and benefit to the curious and owners of the various V6 owners. I gave a seminar in Tennessee this year which had an excellent audience. I have given several in the past few years at different events. Since the endorsement I received from KEN COSTELLO the interest for the V6 conversion has gained a lot more interest. I think the meet should include any V6 conversion and may even a straight 6. |
I sponsored a class for all British conversions at the last Dayton, Ohio British Car Meet. We had a real good turn out for all conversions. The rules were simple. Any major engine, transmission, rear, or suspension qualified the car as long as it wasn't transposed in to any car that of the same manufacturer or country. To compete a vehicle would have to have a British body. Example: A Jag engine in a Healy would not qualify but a Chevy in a Healy would while a Healy in a Chevy would not. We are considering a classification for custom body work too. The purpose of the classification was to get the cars out into view so builders and potential builders could absorb the engineering and had a chance to mingle with other owners and have a chance at competing for prizes.
We had some real interesting cars. The winner was picked by popular vote the first year because I couldn't muster up enough experienced help to make up a judging staff. Next year will be a lot different. The winner was a Morris Minor with a 13 A rotary engine and tranny coupled to a custom drive shaft going driving a stock rear end from the info I gathered. I would like to see a meet in the cental midwest in order to make the trip closer for all coasts. There is a lot of activity in Florida and the South states. I wouldn't want to exclude the V8 boys because a lot of them are really interested in the V6. I would put the emphasis on the V6 marque because the V8 connection usually excludes the V6 in their meet notifications for the most part. I really would like to see a meet more geared to the one I mentioned before in Dayton. I think that would cover just about any British conversion. If I could get my street cars and the racer, the one with the aluminum heads on the 3.4 Camaro sort block, down to Texas I would love a V6 see the meet there. A good time would be late spring maybe? I would like to herar some of your ideas.
|Jim B, thats true actually. :-) I can't resist a good cat fight.|
I had hoped to see you at the Dayton British car meet this summer. Did I miss sending you an email about the subject? It's a short drive for you. It will be hosted by me next year. I'm sure people would like to see your car. Any more plans for you car? BTW, I have a Triumph body of frame in EXCELLENT shape with the frame restored. All for sale. I'm selling it for a customer. Some of the suspension parts are missing. If anyone you know would be interested let me know. Dann BCC
|Bill G, whats your thoughts on a V6 meet. Would love to hear it! |
The project is in storage right now until I can get a new house built. I am really wanting to get going on it!
I will help to arrange a British car conversion meet here in Tulsa if their is enough interest. Tulsa is pretty centrally located for everyone.
Hallet hosts the SCCA Regionals and is also the site for the SCCA Driving School. The Tulsa Drag Strip is also available.
|Dann, I really like the idea. As you may know I am organizing a meet here in Ca. next year, sponsor by our V8 news letter. This meet is for all modified British cars. A V6 only meet sounds great, but my time to travel is somewhat regulated by my activities here in Ca. We now have a sponsor Red Line Oil and we are looking for others for our British car meet next year in July Sept time frame.|
Perhaps you could come to Ca for our meet.
Thanks for the invitation Dann.
|Sorry I had to miss the meet Dann, right now I can't remember whether it was after I blew the head gasket or if there was something else but I do remember it was one of those unavoidable type things. I'm planning on being at the next one though. Over the next month or two I'll have the heads o-ringed and put it back together for spring. I've actually been so busy I haven't even had the time to pull the heads off yet. As for future changes, the big one is the T-bird IRS with inboard brakes and custom bearing carriers (spindles) but I can't even begin to predict when that will be ready to go in the car.|
|Alan, there is no need for a hole in the hood with a carb set-up, everything fits under the hood.|
The FI also fits very nicely.
|Hi Bill |
Thanks for you input regarding the need for a hole in the hood or scoop. I have a question though.. Can you use the carbed v6 engine with the chrome bumper cars and the stock crossmember, and what other modifications are needed? (Carb base milled or a portion removed) It seems that everytime I see a picture of a v6 MGB chrome bumper car, there has been an issue with clearance either at the crank damper and crossmember or at the top of the air cleaner and reinforcing rib under the hood,on the carbed cars. On some of the RB cars I have noticed an inordinate amount of space between the top of the front wheel and the wheel well arch. Probably because of the fact that the frame has been shimmed between the crossmember and the bottom of the frame to gain clearance. I have also noticed in some photos I have seen on the Internet that the owners have used 15 inch wheels to fill in some of the space in the wheel well area by using more "wheel". I have gone with the MPFI instead of the carb route, for these reasons. I may be wrong with my understanding of the facts on this matter (see how nicely I did that Dann?) However I want to keep the wire wheels and the "Blimey! its British" look, so sheer power is not my reason for the interest in MPFI. Just want reliability and the fun of converting the car to full fuel injected with ALDL SES, VAT, automatic cooling fan and functional EGR with an O2 sensor so I can run closed loop.Just want a good highway cruiser at a reasonable RPM, with power to pass in short spaces.
PS I once had a 3.8S Jag and thought about putting a 4.3 TBI into it. Now I wish I would have kept it and done that. Nice ride.
|Great day! Cooler temps, no smoke, no more ashes, and rain in the forecast.|
Yes Alan, I really like my MKII jag with the Buick 3.8. I drove the car for 12 years to work, and club runs, now is in need of front end rebuild and minor detail work. All I need is time.
Alan, the must important part of a swap is deciding the purpose, so your plan will come together, and your choices will become easier. Hp is for magazines and selling purposes, if the 2.8 MIP was good for a 3300 lb car then it should be good for a 2200 lb car. Torque is great on this engines and it comes at a lower rpm where it can be use.
Purpose is the key to a successful outcome. You have yours.
Alan, very good questions. The carb will fit under on the CB, two choices here.
1. Garret makes a top for the Edelbrock manifold that works very nicely; it will allow you the use of a regular air cleaner.
2. You can use a snorkel type top on the carb and attached a cone type air cleaner.
The extra clearance you see is due in part to the weight savings about 29 to 40 lb EST.
With the kit there is no issues with the front cross member. The kit was design for the average person with minimum tools. On the CB the motor mount towers need to be cut off and the minor dressing done next to the steering column to clear the header flange.
Everything is close tolerance. The mounts are outrigger and stager to prevent motion during acceleration, thus closer tolerances can be had.
With the MIP FI will fit just fine under the hood. No cutting to the cross member is necessary, but the clearance is tight without any problems.
If I may.
I just completed the modified stock A- arms that will lower the car 1 inch just by installing the A-arms, and have camber adjustment and are powder coated. Just replace the A-arms set the alignment and go.
They will be out available next week.
I will e-mail you a picture of a 3.4 with TBI all under the hood.
Hope this helps you Alan.
|Alan, I did not see and e-mail address in your posting, if you send an e-mail I will send the picture showiing the 3.4 under the hood.|
|Jim, I understand the T Bird IRS is the route to go for minimum costs and max bennies. Does it have a flange at the yoke or is a U joint? I'm betting our drive shaft will fit if it's a flange. I would like to hear of your progress if you will. Your car could make for stiff competition with the rest of the conversions. I hope you can make it.|
This thread was discussed between 19/10/2003 and 31/10/2003
This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.