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MG MGB GT V8 Factory Originals Technical - large aluminum V* engines

Hey guys,
Has anyone tried putting a Ford aluminum 5.0L or a Chevy (VORTEC) aluminum 5.3L in a MGB/C/GT? If so, what kind of modifications are necessary. What kind of power can you expect?

On another note, how much horsepower is too much power for a MGB V8 conversion? Is there a point where what seems to be a small amount of horsepower for a classic muscle car is actually too much horsepower for a 2200 lb. MGB? I mean, will say 350hp or even 400hp tear the car apart or make it go sideways? Any input(on either idea: large aluminum V8 or too much horsepower) would be appreciated. Thanks guys.

Eric Vandermey

You really need to get more specific. Are you talking one of those aluminum 302's, or the mod motor that is bored and stroked to 5.0L? you'll never get a mod motor in an mgb. Don't bother measuring. it will NEVER happen. MG's can handle 400hp at the flywheel. A little chassis stiffening never hurt anything, but I doubt you REALLY need it till you're putting 400hp to the rear wheels.

From a safety standpoint, I really like the idea of adding an additional crossmember from the frame rails to the outer sill. That to me is a good idea.

I have a 73 GT with a LS1 six speed from a 02 Z06 early vette IRS, CCE modified front suspension.
Under the car is a tube frame conecting 8 points on the B tub with 3 stress members in the inside, plus a roll bar that is molded to the contour of the B GT roof and conected to the tube frame. Anything is possible. don't let anyone tell you that you can't do it. Make a plan before you start.
How fast is it?
Blinding fast and yet very streetable. How much? Lots of time and $$$$ but I rather drive my GT than my Pantera or any other performance car that I have.

Dream it, Do it!!!
Oluf J

the Modular ford can be done, but the work involved for the performance makes it a bit pointless. And you would ned expensive chassis modification to hood, inner fenders, etc etc.. the Modular is just a massive motor. You would be metter served wiht a stroked 5.0 or even a 5.8L windsor. the 5.8 would require custom hood work which is much simper than the fenders..

At the same time I have to argue with the HP figures. I know I am just under 300hp and my chassis cannot put it ALL to the ground hard like say a mustang can. I almost bet there are 215 powered cars out there that could keep up with mine due to my traction issues. Now maybe a modern posi rear axle will solve that, maybe not...
Fact is the torque with proper gearing will make these 2400lb cars flat out fly, it is all in the balance. They will screech, squeal and get out of shape, but what is amazing is that during all that they are rocketing forward at incredible speed... Most muscle cars I have seen will either hook hard or roast off the tires depending on what the driver wants them to do..OUr cars are unique in that they just start moving. So it is a double edged sword... sure the chassis can handle the power, the problem is getting GOOD transfer to the ground, THAT is when you start having chassis issues and need to reinforce as a mid HP hard launch will cause more problems than a high HP tire spinning launch..

It may never be like a tuned muscle car, but these cars flat out fly no argumanets out that!!
Larry Embrey


The aluminum 215 engine weighs less than the stock engine, and a Ford 302 only weighs a few pounds more. I agree with Larry - there is just not enough performance gain to be had by going with any of the engines you mentioned to make all the trouble worthwhile. I don't know what the "reasonable" limits of power are from the 215, but 500 "streetable" HP can easily be had from the 302 at a reasonable cost. A bone-stock crate 302 will give you 300 - 350HP.

You can buy an aluminum block for a Ford 302, but they are VERY expensive and the weight reduction is minimal.


If you're determined enough, you can put ANY engine in ANY car. I don't say you'd like the results, but it can be done. I have seen an MG midget with a big block Chevy! Agreed though, the Ford modular motor is simply too big to be a realistic candidate for an MGB. The Chevy engine is really too large as well, but it can make a nice swap with a lot of work.
Dan Masters

In response to the type of engine, I do not have a particular engine in mind. Plus, I am not a mechanic in any way to make major modifications. I was just wondering, because I do like horsepower, and I have not heard of many B/O/P 215's hitting more than 300 hp. I was just wondering about putting ANY American made aluminum engine into the B. I realize one of the advantages of the B/O/P 215 is the relative power to the realized weight reduction, especially compared to a heavy cast iron block. I was just currious as to a way of getting over 300 hp and maybe up to 400 hp into my B. I presently have a stock 215 (or basically stock). It is tuned well enough that I am around 200 hp presently.

It appears, that if I wanted more power, the most recommended engine (besides the BOP 215) would be the Ford 302. In fact I have heard of many people dropping that particular engine in. I was just interested in the thoughts of other enthusiasts. Yes, I understand, that with the proper planning, tools, know-how and budget, that ANY engine can be put in any car. However, as much as I like to dream, I realistically must also consider the cost-reward ratio. Anyways, thanks guys for your input.
Eric Vandermey

The RV8 can make a few hp and the 5.0 has been fitted but now with modified rear suspension.


If you already have the 215 in there, why not go with a buick 300? I think it mounts the same as the 215.

In response to 'how much power can the B chassis handle'..

There is a fellow here in Aust by the name of Mort Fitzgerald who races an MGB v8. It has a 5.2 litre rover engine and must have approx 450hp. The reason I would guess the car has this power level is that it is a front front running car in the Marque sports category. BTW, the other front running cars are current model Porsche 911 GT3, Ferrari 360CS etc etc. This is a vry fast, highly developed vehicle. Still uses leaf springs on the rear!

Photos can be seen at
Look through a couple of links and look for Mort's red v8 roadster.

Yes I already have a nicely tuned BOP 215, and have considered either stroking it with a 300 crank/heads, etc. or simply dropping in a nicely tune Buick 300. However, on a naturally aspired 300 or a Stroked 215, how much horsepower can I really expect to reach?
Eric Vandermey

A Buick 300 with a bit of head work- larger valves- and a mild cam will give you 325 HP at the flywheel, and be streetable enough for 2 hours of traffic traveling a total of 22 miles. That was my ride home last night in the rain. A good electric fan helps.

A more radical cam & larger carb- it has a 500 cfm Edelbrock- and higher compression would get you to 350 HP, plus or minus, at no additional cost as part of the original rebuild. I wanted a totally streetable engine, so I stopped well short of max HP.

As far as hooking up, my car is a GT, a bit heavier than the roadster, & it is almost impossible to spin the tires from a standing start due to the Streetlocker center section in the 3.55 8" Ford rear. I have traction bars, panhard rod & glass springs from Doug Jackson. This car hooks up better than almost anything I have ever driven, but you really need some form of positraction to achieve this.
Jim Stuart

The Chevrolet 5.7 LS1 is all alum. complete engine weights less than the modular Ford and it makes more hp can also be tune for more.

I did look at all of the options. For the money the LS1 will give you more for your buck.

0 to 60 3.2 seconds NOW that is one fast MGB GT and it handles. If my helath permits I will be doing the one lap of America.
Oluf J

I like the idea of a buick 300 with a 340/350 crank. I know its been done, and requires alot of clearance mods, but man, a 350 that drops in on the 215 mounting brackets and all that sounds good to me.


There are a lot of folks who would be very, VERY interested in learning more about your car (myself among them). How about doing us all a really big favor and submiting details and pictures of your car to the British V8 newsletter?

Details for contacting the newsletter can be found at or e-mail me with your address (e-mail or postal) and I'll send you a copy of the newsletter questionaire for you to fill out.
Dan Masters

Will do! It's at the body shop when it it's done will send the completed pictures.

Oluf J

I too would be highly interested in seeing pics of your engine set up. In fact, I would love to see pics of the entire MGBGT project. Please either post a couple pics to this site or email me a pic or two.
Eric Vandermey

Its not a bad idea except that the 4.8/5.3/6.0 Chevys are all iron block, aluminum head. Got one under the bonnet of my GMC. If I had my way, an aluminum 302 is the ticket
Jarrod Hills

An LS1 does sound nice, I'd like to see some pics as well.

"Its not a bad idea except that the 4.8/5.3/6.0 Chevys are all iron block, aluminum head."

Not so, Jarrod.

You must have the 6.0L in your GMC. It is as you describe. The 4.8/5.3L however IS an aluminum block, aluminum head engine. I have the 5.3L in my Silverado. I think it would be great in a conversion, but I am not certain that the dimensions would be suitable.

Carl Floyd

I've had several versions of 302 Ford in my car. Starting with a stock 2bbl w/automatic, then a 325 hp aluminum head upgrade, and now a 400hp 380lb torque stroker and T5. Maybe my age is showing but for 95% of the time it's too much motor.It's hard not to wind it up through the gears every time because it feels/sounds so good, but talk about a cop magnet. The car seems to handle it all well, but of course the tires are not hooking.I think most people would probably be very happy with a max of 350.I gave up serious fuel mileage also, which today is not a good thing.But fortunately it rained all summer so not a lot of seat time....

When I first started driving my GT- 325 HP Buick 300- I was sure this was as much power as anyone could really want. 16,000 miles later, I am wondering what I can do to boost the output without spending all my retirement funds.

Stupid, of course, not enough room for a supercharger unless I remove the A/C compressor or cut a big hole in the hood. Maybe a 400 HP Ford for the next car. Oh yes, I said this was the last V8 I would build....

Is this a sickness? Is there a cure?
Jim Stuart

Oh yes, most definitely a sickness. Completely controllable though, a simple spendthrift trust with heavy restrictions on automotive uses and all income directed into it should do the trick. Might need a judge who's convinced you're something less than perfectly competent though. My oh my what a predicament.
Been thinking lately about replacing the gas struts on the bonnet with air cylinders. Then a source of pressurized gas would be needed to operate them, I expect nitrous oxide would do just fine. Probably could find some other way to use it as long as it's there.....

Jim Blackwood

Dale - I have noticed the same thing. I had the Alum head RV cam motor which was pretty quick and got 17-19mpg even playing around.. Cheap mufflers kept it fairly quiet. Now with the EFI and a true 5.0 cam and block and Alum heads, she is much stronger. The Flowmaster 40series mufflers give her the everyone look at me sound, but the mileage is WAY down to the 12mpg area.. I know she needs to be run on the dyno to tune, but I am not sure what mileage that will bring out...

I still have all stock running gear and I doubt if it can really put down more than 275hp. The funny thing is that even while she is screaching tires, and kicking the tail out she is moving out RIGHT NOW.. I jhave yet to be able to get her to sit still and just roast em off!! In all honesty unless someone goes full blown race prepped chassis and suspension a 302 is more than the car can really use affectively.
Larry Embrey

Don't get me wrong though... If I had the chance and ability to stuff a 351 TT in the car I would do it in a hearbeat!!
Larry Embrey

This thread was discussed between 24/11/2004 and 05/12/2004

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