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MG MGB GT V8 Factory Originals Technical - Selling MGB Conversion
|Well gentleman, After sometime, I have decided to abandon my MGB V8 project. I had it on the road and tested it--it was fantastic--but missing something??? It just wasn't vintage enough. So after completing our new house and moving, which took two years out of my MG endeavors, I decided to make the car more vintage. How--Metal dash, mechanical fan, original V8 overdrive transmission, SU carbs, chrome bumpers, stowaway top, etc. I am sure you are getting the picture now. Yup still not vintage enough!|
My first car was a 57 MGA and that was vintage! So--I am going to do an MGA V8. Last summers University Motors party convinced me that it can be done without sacrificing the vintage feel of the old A--moreso if I use SU carbs and the original V8 gearbox. So it is done! I need to get rid of all of the old B stuff. I have put up an add in this BBS's classifieds. A body tub for $500. Hope somebody wanting to do a conversion will benefit by it.
Oh, and don't try to talk me out of this or I may think that you are my wife (yeah, I am crazy)!
|way to go jim. i know exactly how you feel, i sold my bv6 last year and have put my time into the final completion of a 5 year long project on a 1960 mga v6, i have been driving it almost daily now and i love it, much better driving with the top down for me than the b was. jim|
That's great news. I have been working on my A with a Buick 215/T5 for years now. You are one of a handful that will try this. Search Lyle Jacobsen to see some pictures of what to do. Converting an A is far more difficult than any B, trust me. I ended up not cutting the goal post and I have 1/16" clearances in many areas. I can send some picts too.
|jim, i should lend you my copy of the ultimate mg video, when you see that fabulous mga with the complete frontline suspension set up all around and the honda 2.0L s2000 vtec drivetrain you may want to reconsider engines., i know i am, jim|
|Jim - think about using a V6 in the MGA - easier to install and less cutting, with the same power and weight as the 215.|
|Gee, I didn't think I would get this many comments from the dark side. I don't want to use a V-6--sorry guys but it just aint right--God never intended MG's to have two or even one bank of 3 cylinders. Besides I am trying to do this with all MG parts--hence the V8 OD transmission and the SU carbs. Thanks for the good wishes and suggestions but I will stick with my crazy idea. Hey Scott, Thanks for the offer of the pictures--I would be interested in anything that you have. BTW my e-mail address on the header is incorrect. It is firstname.lastname@example.org.|
|jim, i read your post and was not for sure so i checked with my pastor yesterday at service. he says that god surely favors V6's, lots of reference to this in the scriptures, you just probably have not read enough of them: like he created the world in SIX days? not eight, just for starters. time to take in a bible study and than get started on that V6 MGA.|
|To Jim Madson,|
Back away oh dark one lest you beguile me! I just purchased my first V6 auto about 2 months ago. Bought an Audi Cab Quattro for my bride. Has the 3.0 V-6. It really is a beautiful engine. As soon as a lifted the hood (bonnet), I new that my more sensitive side could be tempted--then my bride looked at me with wanton eyes, and it was over. But alas, this one discretion shall not be repeated. I have reunited with my manly manhood, and shall not repeat the V6 incident again. We shall speak of my weakness no more! But then again every time I glance beneath the hood of that Audi........
Please e-mail me any pictures of your in progress conversion. I know that it can be done without chopping the "goal post". Doc Mangles in St Louis did it and I have seen pictures of a right hand drive A with the goal post intact. The trick is what to to with the radiator? What size? How does it attach--frame or body? Is it straight or angled? Downflow or crossflow? These are the (my) questions. So if you can enlighten me with either words or pictures, I would be most grateful.
Please hurry before Jim Madson talks me into a V6!
|James, I'm taking the liberty of sending you a few photos of V6 installations. I hope it is OK with you. I like a V8 too but times have changed.If you like a stock 215 V8 for it's power alone, then your missing about 70 HP that comes free with every converted 3.4 V6. If you want more power from a 215 V8 then that can be done for a bunch of dollars but the same dollars put in a 3.4 equates to much more HP in the end. I'll close here before I write a huge article on the differences.|
I have a number of 3.4L V6 motors here and one 3.9L V8. Come take a look at the difference. If your stuck on the V8, purchase this one and rebuild it... I'm north of Mpls.
Bill Spohn has a website showing his 3.4L V6 conversion in progress. Take a look.
|BMC Brian McCullough|
Please, stop with your requests to go V6. I already have the engine (buick block with P6 heads good for 137 bhp low compression and pump gas), the gearbox (genuine MGB V8 OD also only good for 137 bhp), the rear axle (3.07), the carbs (SU HIF6 on the original style clawfoot manifold also only good for 137 bhp). You see, its not just about power. Its about torque and oh yeah, that wonderful V8 sound. Its about a whole lotta stuff that is deep down in your gut--it says go your own way! My mother always used to counter my childhood requests to do something that the other kids were doing with the question--"Well if everyone is going to jump off a cliff, are you going to also?"
No Mom, I am not!!! I got my own cliff and I'm going to jump off that one.
|BTW, thanks for all the interest and help--that is truly what makes this (B)BS great!!|
We have a 3.4 in our "A" and I used a mid 60's Mustang radiator. It's about the same width as the normal unit but taller so you need to tilt it a bit to make it fit.
I sort of know what you are going through, some 25 odd years ago when I converted my B there were lots of guys around saying "use a v6, it'll be easier, etc, etc..." and there just weren't that many around who had actually done a V8 but I knew it could be done because I'd heard the factory had done it. (But not on a '71! At the time I had no idea how different they were.)
But I resisted the tempters and stuck with the V8 plan and have never regretted it.
On the subject of radiators though, it is not all that expensive to have a custom one built and get exactly what you want. I would recommend a crossflow, perhaps a double crossflow so that both the inlet and outlet are on the same side, and then add a surge tank to keep the air out of the heads. That'll eliminate most of the potential cooling problems.
|Jim Blackwood--Jim, thanks for the encouraging words. I agree with your radiator comments--I also feel that a cross flow is the way to go. When you spoke of the surge tank, did you mean expansion tank?|
|James, no it isn't an expansion tank, it is designed to be run at full pressure and usually is the fill point for the system as well as the highest point in the system so that any air bubbles go there. One other important function is to isolate the pressure cap by putting it on the pump inlet side of the radiator so that it is not subjected to pump outlet pressure which can (and does)purge coolant at higher engine speeds. An unpressurized coolant recovery tank can also be used, which has the effect of keeping the surge tank filled, but if designed well the level in the surge tank can be maintained at about 2/3 full and no recovery tank would be needed. They are most often seen on cross-flow radiator systems but can also be designed for downflow and double crossflow. I have one on my downflow system. The plumbing is more particular and the dynamics more complex but it can be done.|
|James, Go for the V8. It is a lot of work but worth it in the end. My son ('73 MGB 215 V8) and I had our aluminum radiators custom made by Ron Davis Raceing in AZ. I've never had an over heating problem in stop and go traffic in 85 degree heat. Heat in the foot well is another thing, it gets real hot. There are pictures and build details of my MGA on the mgaguru.com web site. Good luck with your project. |
Go with the V8!
Just in the process of siting my 215/3.5 Rover in the chassis - yep it's tight!
After a lot of deliberation over whether to chop the 'goalpost', to get the engine lower (and the front pulley behind the the steering rack), I've compromised by moving the rack forward 2" and chopping 1.5" out of the goalpost . The motor now sits much lower but retains the goalpost.
The only thing I'm not sure about is whether moving the the rack forward will have any detrimental effect on the steering (bump steer etc) - any ideas guys? At the moment it looks like i will have to shorten the trackrods (or ends)
Next up is where to re-route the steering? - its tougher on a RHD!
Rear axle route is Reliant Scimitar (3.07 gears), which is basically a narrow Jag Mk 2 live axle, on coil overs/4 bar set up.
|C J Bond|
Did you move the rack and chop section the goal post?
On my A I cut the 3/4" lip from the heater shelf but didn't cut the main section. I ended up pushing the rack 1/2" straight forward to clear the harmonic balancer and made only 1/4" spacers to put the pulleys beyond the rack. The rack shaft was rotated a few degrees to clear the header. Watch out for bump steer. Changing the angle and length of the tierods will cause some issues. The bellhousing sat on the round frame crossmember so a large mallet made some clearance. Everything fits.
|Nothing sounds like a V8. I have a Mazda rotary in a MGA. All the power I need, easyest swap possible but it just don't sound right. Next swap will be a V8. Wonder if I can Fit a Toyota/Lexus 4.0 vvti.....in a MGA...|
|R J Brown|
|jim, i do agree when i drive my bgt v8 i do like the burble even though i have dual exhausts on my v6 mga. radiators: 2 years ago i purchased a custom made crossflow unit from ron davis with there custom made fan and shroud for about $1000.00. i cannot even began to tell you all the overheating issues i struggled thru 2 summers of driving with, i tried every thing possible including stripping the motor down to insure that the head gaskets were not in backwards, i asked them several times about their calculations of the required size radiator as compared to the size and hp output of my v6, it is over 200 hp. they were adamant that it was enough. as a final item this spring i removed their unit, installed a stock off the shelf adco as referred to by part number from bill spohn with a cheap $40 fan and it runs at 160 all day long? so having a custom made unit is not a requiremnet in my book, but if you want one made for an A i will give you a heck of a deal on a ron davis unit, jim|
|You really need to figure up your radiator sizing requirements on your own for a custom radiator if you want to be sure it is right. Size isn't all that matters. Tube size, count and spacing all play a part as does fin type and count. A well designed small core can easily outperform a less efficient large core. For the MG you should use the most efficient core type available and make the radiator as large as space allows. There are several radiator sites that have good information and a good radiator shop will let you look at the core supplier's catalogs. I had a $400 custom brass radiator made about a dozen years back which used a 5 row core but had 3/8" tubes. The fin count was high but that core was less efficient than a 3 row with 5/8" tubes that I replaced it with later on. It was a custom ordered core and the re-core was about $350. The core manufacturer is really the only one who knows which design is more efficient, the shop guy is generally going to sell you what he is most familiar with. But if you read the catalogs you can be the one to make the informed choice. Also, hype to the contrary notwithstanding, aluminum and brass radiators are very competitive with each other. A well designed brass and a well designed aluminum radiator are going to be so close to equal in use that you wouldn't know the difference so the choice of materials needs to be decided based on other factors.|
Yes I have chopped about 1" out of the goalpost and moved the rack forward. At the moment it is only mocked up and reversable at this stage. Basically, I've moved the rack forward so that the front pulley sits down behind the rack. Am i right in thinking that you have the rack between the pulley and the h. balancer?
My intention was to get the engine as low as possible, avoiding hood clearance problems. What type of air filter do you run with your setup?
Yes, large mallet required for the round crossmember!
Thanks for you advice on the tierods, it has made think again before proceeding.
|C J Bond|
Yes, my Buick 215 is as far down as the round beaten cross member would allow. After leveling the intake, the h balancer was touching the rack. I made wedges that bolted into the stock rack holes that moved the rack 1/2" forward (not up or down) and rotated the steering shaft to clear the tube headers. Adding a 1/2" spacer on the balancer put the pulley groove about 1/4" beyond the rack. In other words the engine is straddling the rack. The bonus was the the steering column was only 1/2" too short now so adding a deeper aftermarket Moss hub + motolita put the wheel in the perfect stock location. I used the stock MGA U-joint and didn't need anything else. For the air filter I bought a 15" (Edelbrock 4 barrel) dropped base and dropped it even more. A 2.5" filter clears the later domed hood by at least 1/4". I crossed bolted the motor mounts to make them more or less solid. One clearance on the steering shaft to frame is 1/32"... Lots of special fabricated brackets and shims were needed.
I used a MGB suspension and I had to shorten the MGA tie rod arms 3/8" due to the different steering arm geometry. If it weren't for an ME degree and a Dad with a machine shop, it probably wouldn't have happened for me.
Revisited the scene of the crime (steering rack) last night, after reading your comments and re-engaged my brain. Put the rack back in its original position and hung the pulley/harmonic balancer over the top (removing an unwanted pulley)and all of a sudden things look at lot more achievable.
Looks like i may be re-welding the goalpost section I (carefully) removed last week.
Thanks very much for your helpful comments.
How about a 'MGA V8 conversions' heading for the board?
|C J Bond|
This thread was discussed between 21/04/2006 and 04/05/2006
This thread is from the archive. The Live MG MGB GT V8 Factory Originals Technical BBS is active now.