MG Sports Cars

I just became a member of this board. The reason I joined, I am thinking of buying a MGB and installing a chevy engine that I already own. Most of the info here is for the Rover/Buick engine. What publications would you recommend for this project? I would prefer not to have to alter the car, is that possible? I know that the Rover/Buick fits the rubber bumper cars without any modification. The chevy engine has the same dimensions as the Rover/Buick so maybe it will fit without modification. Any info will be appreciated.
Thanks Joe

You'll likely get a ton of answers Joe. There are a few guys who've put a Chevy motor in an MGB, scan the Photo Gallery (above link). It'll make a big difference whether you're talking about a Chevy V6 (e.g., 60* GM motor) or a V8 like the 350. The former is way easier to do w/o any modifications to the body shell. Not sure if a 350 can be done w/o mods or not, but the write ups in the gallery should give you some clues & I'm sure a couple of the guys who've done it will chime in.

Rob

The engine is 327 chevy small block. I have looked in the photo gallery. I need to know does anyone make motor/frame mounts,headers etc. for a MGB/chevy small block motor or is all this custom.
Joe

Joe, to the best of my knowlege there isn't a kit for the SBC into an MGB. The only swaps with a kit or anything resembling one are for the GM 60 degree V6 and the Rover/Buick V8. There is a kit for the Ford 302 in the works, but not ready for release.
For a SBC you'd be pretty much on your own. At least you have other installations to go by so you will know what problems there are and what other builders did to solve them.

I don't know of any good store-bought headers for the Chevy conversion. I think you'll have to make your own or hire someone to do it. Compared to that, motor mounts are easy to make!

Quote:

I would prefer not to have to alter the car, is that possible?

You'd probably be wise to add reinforcements to the chassis. The MGB is a very strong little car by design... but since you're talking about an especially powerful conversion, you especially should be looking for a donor car that's in excellent condition. A high mileage car that's already been through a lot of fatigue cycles, or that has corrosion, or that has dubious-quality repairs should be avoided. A GT would be stronger. A roll cage would be smart. IMHO, you should at least figure on adding strategic stiffeners to the chassis. A sports car chassis can be too heavy, but it can't be too stiff. Keep in mind that the MGB body was a "unit-body" design - so every time you cut sheetmetal you should be thoughtful. Consider replacing whatever you cut out with a replacement structure or reinforcement.

The Chevy V8 can potentially produce a great deal of power... but it will also produce a lot of heat. To end up with a good installation, you'll want to think especially carefully about the cooling system. One rule about cooling systems that we keep coming back to is that maximizing airflow through the radiator is the key to system performance. A bigger radiator, a thicker radiator, a fancy water pump, fancy exhaust coatings, etc. - frankly none of that stuff is anywhere near as important is airflow through the radiator, and the easy way to increase airflow seems to be giving the air a good route OUT of the engine compartment. For that reason, I think it's very sensible to plan on venting the inner-fender aprons. (Run your custom exhaust out through the vent holes. The wheel wells are comparitively low pressure, and the pressure differential will draw air out of the the engine compartment naturally whenever you're moving.) Again though, you'll want to make the holes in the "wings" sensibly small and you should consider reinforcing them with a flange of some sort.

You're already planning of upgrading rear axles aren't you? To end up with an enjoyable, balanced sports car I think you'll want to change gear ratios, add a limited slip differential, and probably make other modifications to help get the power to the road (e.g. "anti-tramp bars", bigger tires, etc.)

Since you're talking about installing an engine that's 200 pounds (or more) heavier than stock, and since nearly all that weight will be on the front axle, IMHO you should be looking hard for weight reduction ideas. The rubber bumper B you're leaning toward starts out heavier and higher than the earlier chrome bumper models... so that doesn't help. You'll surely want to lower the car, and I would probably lose the heavy rubber bumpers.

opinion about choosing conversion projects: I done a lot of automobile projects, and
have come to the conclusion below from a significant schooling in the college of Hard Knocks:

Choose the engine to match the car. Not choose to fit an engine in because you have a car and motor. Sell what you have and get the right stuff

Do a conversion that others have already blazed the trail for.
Projects like you describe with a largish 90degree v8 take a lot of resource and dont give a practical car as a result. In this case, It would mean large expenses and work to jam it in and reengineer the suspension to handle the 'wrong' weight and 'wrong' amount of power. Most projects like that dont get finished, and of the few that do get finished, most are 'frankenmobiles'. It takes a lot of skill, work, and money to go that route and get anywhere worth going and get a car worth having..

Example of a success:

I recently did a 2.8 v6 conversion to a rubber bumper B and it was pretty easy. No cutting, no re-engineering anything. Parts all available and the finished car is a lot of fun to drive. It's balanced well and plenty peppy. I got the s10 pickup for $250, and swapped the s10 T5 for the right transmission. $600 for the other bits and a few weeks and it was running.

Example of a failure:

My son bought a Sunbeam alpine project car with a 229 v6 ( a 90 degree motor) and a pretty paintjob. Never could get it to work well. Just no room for anything. Ran hot. Nose heavy, poor handling. He hHad to change steering, etc etc. Frankenmobile. He gave up. A 60 degree v6 motor would fit in quite well...



Edited 1 time(s). Last edit at 02/01/2008 12:53AM by scot abbott.

There are a couple guys working on SBC conversions, if you have the skills it can be done. Modify an aftermarket set of headers, that sort of thing. But it will add weight to the front of the car in addition to being a real challenge so definitely not a swap for the faint of heart. If you have any doubts, the 215 or Rover is certainly the way to go and provide a good power upgrade path as well. The V6 swaps are fine but if you're thinking SBC I doubt you'll be satisfied with them.

Jim

Joe
If you decide to stay with a SBC, I would use aluminum heads, intake and water pump. It can save quite a bit of weight. This will help the handling.

Bill

Joe, just a couple of observations...having had 4.3 V6 (3/4 of the 350SBC) in an mgb there are several major problems with this setup
1 height of the engine, unless you are willing to have the engine sitting 4 inches above the hood line, you will have to do major surgery on the mgb front crossmember
2 weight of the engine, you will have to make substanial changes to the suspension
3 headers, unless you elect to run the headers through the inner fender (viable option) it is a very close fit between the headers and the chasis rails. Mine were made from several sets of tubular astrovan headers. When the finished product was done, you could barely put a piece of paper between the headers and the chasis rails. If you decide to go the 4.3 route, I have probably the only set of 4.3 headers designed for the mgb.
cheers

Mike & All
First thanks for all the suggestions and info!!!!
You mentioned that your 4.3 chevy had a height problem. If the dimensions of the buick/rover engine are the same as the chevy engine why is there a problem. The chevy pan is a rear sump. I guess I have to see some installations first hand. I believe there is a MG show in Philly some time this year. I will try to attend since I live in New Jersey.
I agree that I should not try to fit the engine to the car, but since I saw the engine had the same dimensions, I thought it may work. Another reason, it is easy to make 350 HP with the chevy. The buick/rover would be expensive to reach that power level. Besides it would be less expensive to buy a TR8 and modify the engine, no swap problems but again power level of 350HP would be expensive. As far a weight is concerned, Alum heads, fiber hood and trunk, remove rubber bumpers and anything to reduce weight to about 2600 lbs without driver. I also was thinking of a TR6 but it looks like it would be to narrow of a fit. Then there is always a ford engine which is a smaller engine and seems to work better for a MG. I am going to continue to explore the use of a chevy engine and look forward to any info/pictures/web site.
Thanks again
Joe

"I saw the engine had the same dimensions"

Not exactly. Take a good look at this car:

[www.britishv8.org]

If you really want a Chevy engine, stuff a LS1 in it.

You might also consider the 350 Buick, as the only things different from a 215 install are headers, overall height and weight. It uses the later BOP bellhousing which is very common. The engine is very light for an iron engine and aluminum heads should be available from TA Performance in a couple years. the additional height is .840" based on the increased deck height of 1.187". This engine in stock 4bbl form gives 375 ft/lbs of torque with 280 hp and can easily go much higher with little effort. Worth looking into.

Jim

Carl/Jim
The reason I want to use a chevy engine if possilble is I already own one. I think if I was going to start with a clean sheet I would go with the ford engine or maybe I should buy a finished project. From what I seen, a kit is available and the ford engine is slightly smaller. Carl thanks for the site info. It does look a little tight, but all V8s look tight, some more than others.
Joe

The LS1 can be done, check out Chris Longos installation...

Mike Maloney,

Curious - after all the work involved, why did you swap your chevy 4.3 for a rover 3.9. I purchased an mgb with a rover 3.9 conversion last April. I like it (same or very close bore/stroke ratio as ford 302 - albeit smaller cubes), but I haven't driven any other conversions (maybe britishv8 2008) yet! If we all had BOPR swaps, it would be somewhat boring - I find all these various engines swaps interesting and entertaining.

Tony


P.S. I'll start a new thread shortly regarding short stroke vs long stroke (that should be interesting ;) and discontinue this hijack.

Let me try this again....

Overall view looks fairly stock.....

RMO 699F Wrote:
-------------------------------------------------------
> The LS1 can be done, check out Chris Longos
> installation...

We are hoping Chris will send some info on his cars to Curtis.

The geometry of the "90degree" motors like the sbc and the 4.3 GM v8 give an engine that will be significantly broader than the 60 degree V6's. This a priori makes for a tight fit in the engine bay,. Sometimes this means changing the steering shaft, and sometimes it means running the headers out through the sides of the engine bay, and so forth. It also means a very large hunk of hot metal jammed into the smallish space, and small ventilation passageways for cooler air to circulate, and short distances for the heat to travel to the passenger compartment. This means cooling issues to address for the motor and/or the passengers. All these are in addition to the weight distribution problems of the heavier hardware in the nose of the car. (read handling problems) . All these issues can be addressed with more time and money, but that is not the hallmark of good engineering. It is more a testimony to using brute force to make up for choices with serious fundamental flaws.

The front wheel drive 60 degree GMV6's can provide about 275 HP, and very little weight penalty, and it is much narrower than the 90 degree motors. These modern motors can be converted to RWD application readily. I drove a late model B with such a setup at Dann Wade's British Car Conversions and its performance is clearly stunning. I think it's a mistake to overlook that direction if you want a REALLY REALLY quick B that handles as well as a B can handle, and it all works well.. There is plenty of room in the engine bay, the car runs cool, etc. I think the reason it works so well is it is based on a choice having very good engineering fundamentals-great power to weight, and good fit in the car

For those with more money than patience, there's the GM v6 which is nearly 3.9 liters, and its output is about 240 HP with 240 ftlp torque in stock form...

Joe,

I am doing a 350 SBC conversion in my '75 MGB. I was going to do the Buick 215/T5, had most, if not all the parts. I decided to try something different and went with an SBC. My '75 was a great running car, I was told at the Colorado emissions that I had the cleanest running MGB's they had seen.
In the Fall of 2006, I pulled the stock engine/tranny and started the conversion. I was told that I would have to move the steering column, cut the tranny tunnel, etc. I did not have to do anything like that! I have a 4 bolt main Vortec 5.7 and a TH 350 tranny installed, a 4 inch thick aluminum tractor radiator, Edelbrock intake, 600 cfm carb, MSD ignititon system, March underdrive pulleys, etc (Dang, I've spent alot of money, despite my "belief" that a 350 would be "cheap" to do, and I am not done yet!). I had to cut the inner fenders (too much metal removed to some observers) and make custom headers to go through the inner fenders and under the car. I started the engine for the first time last weekend! Awesome sound!
I know I have much more weight up front than the car was designed for, but I wanted to do a different V8 than most talked about doing, i.e. the BOP/Rover V8. I am doing a chrome bumper conversion, VDO gauges, Fiero seats, etc. I will also add some reinforcement to the rear end. After I drive the car, I'll look at options for the front end. I did the green stuff brake pads for more braking area, and added the stainless brake lines.
I have corresponded with two guys who have done the SBC, one kept the stock rear end, and he claims it has held up fine after two years of "pushing it hard." The other guy did a Ford 9 inch. I am not the kind of person that likes to smoke the tires a lot, just have some fun and some power at hand, but I'll see how the stock rear holds up at first.
I'd be happy to answer any questions you might have. The guys on this forum are much more experienced than me. This is my first MG (I have built Porsches, Fiats, Alfas), and what feedback you hear about the GM 60 degree V6 is a great conversion to have/do - the weight is much less and the power possibilities are there, too. I will have my driveshaft in a few weeks, and I'll be able to do the "maiden voyage." The car won't be pretty, but will be driveable. Sometime this year, I'll contribute to the "How it was done" collection.
Let me know if you have any questions.

Brad