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MG MGB GT V8 Factory Originals Technical - Larry Embrey's 5.0 Radiator
I was on your web site, very nice BTW, and saw that you are using a late MGB radiator. How well has that worked with your 5.0? Forgive me if this has already been discussed and I missed it.
|So far it has worked ok. when I had it running last I did get a bit on the warm side, that was with STOCK rad and fans.|
This year I have the same rad, but have a pair of 8" ducted puller fans mounted ont he radiator. Seems to have been a big help. In fact I am going to be pulling the Tstat to go with a stock mustang 195* one as it has been running to cool.
HOWEVER - realise that I have lower temps than many of you The hottest I have seen so far this year is 75-80*F which for us is warm.
|David--Im using a 65 Mustang 4 row brass rad and find its fine on highway or underway but tends to get hot in traffic.I have 3 elec fans--! 14 " pusher in front on thermostat and 2- 8 inch pullers in back.-one runs continuously other on manual control.This works ok but I think an aluminum rad would solve all this problem. Actually at speed the enhgine runs a little cool.|
I am amazed Larry can get good cooling with a late stock B rad.
|I think the standard radiator is adequate for most applications. My engine is approx 200hp, and even at 35c in the south of France last summer it was adequate on Autoroutes, but boiled in Nice in a traffic jam.|
I believe that the problem stems from heat trapped under the bonnet, and the biggest fan in the world will not do anything other than build up heat around the engine.
I have fitted louvres towards the rear of the bonnet a la E type , and bent back the lip on the scuttle and raised the centre rear of bonnet to let hot air escape, I spoke to Kenlowe this week and they have suggested a fan at the rear of the engine bay, to draw hot air out (evidently the fit them aftermarket to such cars as the Renault turbo).
I am going to investigate this, there is room between the heater and engine. Has anybody considered this, I understand that there are a number of cars (eg MGF) with extractor fans ?
|How about a remote-operated (cable or something) vent door in the hood/bonnet that you could open when needed?|
Just a thought.
|I have built for my 3.5 liters SD1 slightly tuned this ally radiator, original dimensions but more thick, I have also a watertank, two 250mm électric fan. I have 155mm water pump pulley (OE 175mm)|
|I have a 65 ford falcon radiator mounted as far forward in the engine bay as possible, and a walker 16" puller fan behind it. That fan moves something like 2750 cfm of air. I ducted the bottom of the radiator from the air dam back, and I don't have any cooling problems at all. I have a hard time letting the temperature get up above 190 the setup is so efficient... I can take lots of pics with my digital cam if anyone would like to see what I did.|
I'd be very interested to see how you did the airdam. Are you using openings in your valence as well. Joe
|Justin, I would appreciate any and all pictures of your car.|
|The only reason I tried my stock rad is because my local rad shop guy told me it is plenty to cool the motor. he said the KEY is to keep airflow thru it. a stock MGB rad is a very dense copper rad which are great for cooling, thier weakness is that in our MG's we never get adequete airflow thru them..|
Mine was running under 180 on the freeway at one point, which is why I am going to put the 195tstat in as the eFI wants it around 195*
|An other good reason for use ally rad, it's incredibly light, at the front of car.|
Mike, when you turned back the rear lip on your bonnet did you manage to do it without damaging the paint or kinking the surface. Also, did you have the louvres pressed into the bonnet or did you cut holes and fit ready-made louvres?
|Justin--I too would be interested in seeing pics of your set up.|
Miuchael--I have also raised the back edge of the hood ( bonnet ) to its max to let heat out and have rather large holes in inner fenders for the headers which allows alot of heat out. I do agree its the lack of airflow throught the engine compartment that is the basic problem.As Larry says on the go my car actually runs cool and I have a 195°thermostat installed to keep it at a good operating temp.
I was not able to put 1 large diam puller fan behind rad due to clearance problems.So am interested to see how Justin did his.
|Gil - Yeah I had clearance issues due to depth behind my rad. Last year I actually put the Rad about .5" forward. I used the spacer you find under the mg seats between the rad and the support.|
This year with the switch to the EXPLORER serpentine belt system I have lots more room, the Rad is back in its normal mounting AND I have a set of 8" pullers behind the rad. I have a 16" spal fan I got from a friend. I am not sure if they are custom done for his Co, but I doubt it. I don't have cfm data, but the fan is VERY thin.
|isn't the back edge of the bonnet (hood) a high pressure area? If so, wouldn't opening this area, in fact, push air in and effectively reduce the amount of air passing thru the radiator due to the air being forced into the engine compartment from behind the radiator.|
This is the current thinking on the MGC cooling issue. One of the first things to do is to make sure the real bonnet seal is in place to ensure negative pressure behind the radiator.
69 MGC GT
74 RWA midget
|RM--I have read about this theory of negative pressure area at the back of the bonnet--but --there is no cooling problem at speed. its when idling in traffic so hardly think this is a factor. Whem not moving it definitely allows some heat to escape. just my opinion on this.|
|Gil's right.........we've got to get rid of the hot air when stopped. I can see a heat haze from the louvres and rear bonnet slit....so I know it's coming out...but it's just not fast enough !|
David, I did make a bit of a mess of the lip on the RV8 bonnet, and the chanel on the scuttle, but it doesn't show when the lid is down.
The louvres are ally plates, I was told that it would be very difficult & expensive to press lovres into the steel. I had the bonnet cut to accept them, they fit very neatly under the bonnet edge strengtheners, but after about 5 years the join between the ally and steel is starting to show slightly.
They are about 10"x7" which is as large as I could get to fit on the flat bit each side of the 'hump'.
There is quite a good pic. of it on the X-PowerForum members gallery picture section , my pics are under mikeb.
|Sorry for the delay, I was a bit busy over the weekend. I went out today and took a few pictures of my radiator setup. There are some problems that will be visible in my pics. Mainly, a lot of air can flow around the radiator and into the engine bay while driving. I would have fixed this, but the car is running so cool as it is, that I found no reason to go to all the work. Spal fans suck. I've never seen a decent one. The blades can break off on them too. |
Go here: http://photos.yahoo.com/bmanetd and check the folder "V8 Radiator"
NO giving me crap about some of the other visible problems ok? I didn't install this radiator to pass off as a work of art at a car show. I installed it to cool off the car.
|Justin, thanks for the pics. Nice car. I'd be proud to have it my garage.|
Car looks good and the louvres seem to suit it well. OK, I will investigate the pros and cons (and cost) of having the louvres cut or purchasing ready made. I have some very slight damage to the bonnet so this is probably a good time, plus summer is coming.
I have had the RV8 for 3 years and used to have an occasional cooling problem with the expansion tank filling, overflowing and then continuing to siphon resulting in the loss of 2 or 3 litres of coolant. During last winter we rebuilt the engine with a 90mm stroke crank, balanced the crank and flywheel, new rods and pistons taking it up to 5 litre, adding the stage 3 heads and ported inlet manifold with shorter trumpets and a new ECU chip. I had a new aluminium radiator made which is deeper than the original (coming down to almost level with the crossmember) and added a larger fan, from a Range Rover I think, plus a Japanese (maybe Toyota) fan switch which cuts in at around 95 deg C and if it fails for any reason, it fails safe with the fan continuously running (allegedly).
As you would expect, it goes very well with lots more torque, but no more overheating problems. 1st gear is now redundant and I am considering how to raise the overall gearing but cost may rule that out, for now at least.
I will get the part number of the fan switch and post it and double-check on the fan.
I've recently converted from flap-valve to hotwire......I've fitted 45mm shortened trumpets and a 65mm throttle which I suspect have come from a TVR, it's probably overkill for a 3.5, but I have my sights on something bigger eventually !!
Just had Lambda sensors fitted this week , so I hope to improve on 29mpg I'm currently getting .
Just got the cooling to crack......and we're there
|Justin--Thanks for the pics -I dont have anywhere near that much room between my rad and pulley. My rad is right against the front crosspiece and the back of engine is against the firewall so I need to shrink something --lol.Really I guess the solution is an Alum rad like Dale has. Maybe next winter .|
I'd wondered about that too, I have the 'top-hat'pump pulley and I have barely 1/4" clearance with the radiator, I would love to fit a puller fan, but there is no room.
|I chopped the tray that the oil cooler mounted to. That added at least an inch or two to my clearance. No reason anyone else can't do the same. I've seen quite a few V8's with the same mod. Heck. you could even notch the upperbar (that the hood latches to) and add yourself another 1/4 to 1/2 inch of room. |
The space is there if you're willing to cut.
|Man you guys are having to really fight to get things fit? But, I hope this info helps others starting on a conversion.|
I did not have to do anything to my rad placement, or even my rad (Think I got very lucky on the Rad) THe with a 5.0/302 swap is to use the 96-01 Ford Explorer front accessory set-up. Just cut the ears for the power steering and AC off the left side mount to clear the frame and hood and mount away. I had room for a pair of thick 8" puller fans and still had more room between them and the water pump than I had beetween the water pump and rad core last year, WITH the rad mounted almost 1/2" farther forward. I am Serious the explorer kit is THE way to go, it saves INCHES, gives serpentine belting, so not setting belt tension by hand and comes with a 65A alt (bigger available via aftermarket) And it is all junkyard gettable. Or buy a complete explorer motor, make $$ selling off the intakes and heads and buy the Mustang GT parts like I did. You SHOULD make $$ that way.. hard part is findign the mustang parts as they are 94/95 GT specific.
Hopefully it will not be to tall once I push the engine back up a bit to clear a stock steering rack..
I considered that, but I have a 19 row oil cooler and it is only 1/4" clear of the bottom of the radiator, it would have been possible perhaps to fix it
upright rather than leaning backwards with hindsight, this might have gained me an inch !
|Michael--actually I have 2 puller fans behind the rad--offset so the shallow parts are towards the center and just fit in front of "the top hat " (like that description ) I just couldnt get 1 big puller in as the room is not there in the center area.My rad is about as far forward as possible and I did cut quite a bit of the lower pan away as Justin describes.Larry's suggestion is a good one but I dont want to go back to revamping the whole timing cover etc at this point.But I do have a serpentine belt on my set up and a 94 amp alt to contend with all 3 fans-headlights and wipers( rare occasion ) without having a glowing ign light as I did with a 63 amp alt.|
Hopefully I can get thru this summer without major problems and perhaps install an alum rad next winter.
|I'm still coming back to my theory about hot air being trapped.......an engineer friend of mine came round last night, he was involved with testing radio transmitter fans for efficiency some time ago, and they used smoke generators to test airflow through cabinets.|
I've organised a pair of small fans to fit behind the bonnet louvres ( mine are like an E Type's), I will do some tests before and after fitting them, and report back, hopefully this will provide practical as distinct from theoretical input.
|Michael--this sounds very interesting --I look forward to hearing the results of your tests--thanks --Gil|
|The promised fans have not yet turned up , so my Bank Holiday experiment may have to be postponed until next week.|
|I have experienced all the overheating problems of 90 + deg. traffic jams and used late model larger rad with stock and after market fans and found NO CURE --- UNTIL I installed an enlarged "B-COOL" Aluminum Rad.. It is same stock width but 3 in. longer. The 4 core rad is now 2 with 1.125 in. cores. I have a 13 in. stainless flex fan on the water pump and a 16 in "SPAL" pusher fan with only a man. sw. on the consol|
|I have experienced all the overheating problems of 90 + deg. traffic jams and used late model larger rad with stock and after market fans, added oil coolers and found NO CURE --- UNTIL I installed an enlarged "B-COOL" Aluminum Rad.. It is same stock width but 3 in. longer. The 4 core rad is now 2 with 1.125 in. cores. I have a 13 in. stainless flex fan on the water pump and a 16 in. "SPAL" pusher fan (2350 cfm)with only a man. sw. on the consol. The test was to idol in 90+ weather until the car hit 210 deg. and turn on the fan. After about 1 min., the temp dropped to 180 deg. AND STAYS THERE|
|My experience with different rads led me to the same conclusion as Keith.My first attempt was an early Mustang 3 row.I also have an engine driven fan, a high tech 4 blade unit that could possibly have come from a Farmall "H".Even with my 2 small pusher electric fans it still was not enough at hot idle.Thanks to lottery winnings (no I'm not kidding) I bought a Griffin aluminum rad,the same 2 row design as the B-Cool.That cured all problems with running hot.At the same time I had a buddy fabricate a very nice alum shroud that no doubt helped some as well,so possibly the combination of the two is what did it.But like I always say sometimes,until you go aluminum,you won't be coolin'em......|
This thread was discussed between 20/05/2004 and 30/05/2004
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