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MG MGB GT V8 Factory Originals Technical - MGB V8 Conversion

Hey. I have a 77 MGB and i was getting ready to install a 305 chevy engine with a TH350. The engine and tranny are fresh. I was wondering if you guys had any ideas or pointers on putting it together. I was wondering how you guys would go about modding the engine mounts? Also what would be done to suspension?? ANd firewall if anything? What about taking weight off the fornt.
Micheal L.

Although it’s been done, using a small block Chevy is an uncommon MGB conversion because it’s big and heavy, but at least the ’77 MGB does have the bigger engine compartment having the design the factory used for the MGBBT V8.

All you can do to help with the weight issue is to swap as many components out for some made of aluminum. If your motor is ready to go you are probably not anxious to swap intake, heads and certainly not the block. Some weight can be saved by utilizing a high torque starter. I haven’t heard of anybody replacing the springs to compensate for the weight, but there were different MGB springs made with different lengths and springing weights so it’s worth looking into. The farther you set the motor back the better for weight distribution, but that will cause interference with the steering and firewall.

The automatic transmission will save you from having to deal with the clutch and linkages, but will burden the cooling even more.

For motor mounts I’d use the ’77 MGB motor mounts rather than the Chevy mounts and use a design that’s similar to what is used for other MGB conversions. That would be a flat strap bolted to the sides of the block where the Chevy mounts bolted and welded to that at a 30 degree angle a flat piece that is shaped to mate to the MGB mount. That is an over simplification of that mount design, but I gave a quick description of it just to put a picture in your mind.
George Champion

The TH350 won't need a cooler when it only has that much horsepower going through it. As I already have the engine and transmission ready to go. I am not to sure about the motor mounts you are talking about.
Micheal L.

The cooling that George is referring to is engine cooling, I believe.

The size of the automatic transmission pretty well fills the transmission tunnel, leaving little room for under bonnet heat to escape. My 1969 MGC with BW35 autobox suffers from this malady.

Bonnet louvers, *small* cutouts in the inner fenderwells (not *large* ones as the inner fenders are somewhat structural to the MGB unibody construction), and avoiding block-hugger headers may also help with heat build-up under the bonnet.

HTH...

rick
rick ingram

With a 305 and a light car like the MG, no way would I use a TH350 (not that I would use an automatic in a sports car, anyway).

Just because you have the parts doesn't mean you have to use them for this project. As much as I bleed Chevy Orange, it's not the best engine to use in an MGB V8 swap for several reasons. Same for the tranny. The 700R4 is by far the BEST way to go.
Carl Floyd

Michael, the Chevy isn't the engine of choice for most B conversions, but it has been done. There is information and photos of at least one conversion here on the British V8 website. http://www.britishv8.org/Photos-MG-Conversions.htm
As far as cooling for the turbo 350, I wouldn't recommend running any automatic without some form of fluid cooling even on a low horsepower application. Most of the heat generated comes from the torque converter while it is 'slipping' as the energy from the engine is converted into heat instead of motion in the transmission. I've used 60s era Chevy pickup engine mounts on a couple of different conversions and find them easy to work with and relatively small for tight areas. Try to engineer a bolt in mount if possible, makes later removal of the engine easier with the additional clearance available if the mounts can be removed once the weight of the engine is on the hoist. Try front springs from a 75 or later MGB GT, they are the highest rated stock springs and should help hold up the weight of the Chevy.
Bill Young

Hi Guys,

See the Third Edition of Roger Williams' book 'How to give your MGB V8 Power'. This, recently published, book specifically covers US engines both Ford and GM small-block V8s.

Hope this helps.

Peter
P L Hills

Mike,

Here's the link for the latest edition:

http://www.amazon.com/gp/product/1904788939/ref=sr_11_1/002-8191208-6004845?ie=UTF8

Cheers

Pete
Pete Mantell

Mike,
More food for thought! With the sbc V8 engine you'll will most likely require some form of hood modification to get air cleaner clearance. Rover/BOP engines, Chev 60 degree V6 engines and the small block Ford V8 can all be installed without hood mods.
Graham Creswick

Mike,
You will have to relocate the steering column inside the engine bay, requiring probably 3 universal joints and 2 pillow blocks for the intermediate shafts. Alignment and good solid mounts will be critical for smooth rotation. The tranny will very likely require you to cut the transmission tunnel for clearance and you may lose the heater in the process. (Bear in mind, as a unibody this is the main structural member.) There are no headers, you will have to make your own. There are no engine mounts either. The standard starter will probably not fit inside the frame. You will need the most extreme radiator you can shoehorn in, and that may not be enough. Other problems will arise as well. Unless you are an experienced customizer you would do well to reconsider. A number of notably accomplished customizers who as Carl says bleed chevy orange have chosen the small block ford rather than take on the challenge, and for good reason. Please do yourself a real big favor and thoroughly research this swap before you begin cutting metal. You may find that the best course of action is a trade: your chevy parts for some ford or rover parts. Or, if you are a diehard GM fan, think Buick. The 215 is a great choice, and for power the 300 is even better. Plus it can be had with aluminum heads ('64). Want more? It can be stroked with a 340 or 350 crank. That one is a drop in, bolt together swap. What could be easier?

Think about the car you are trying to build and the simplest way to get there. Sad to say, chevy power is not it, and we've all broken down and admitted it.

Now there *is* one really good chevy alternative that you really should consider. The 60 degree V-6. It's up to what, 4 liters or more now? That's one heck of a big engine in a small package, and is well on it's way to the same kind of success the SBC achieved. Best of all, it's a -yep, you guessed it, drop in, bolt together swap.

See, we've done all the hard work for you already. All you have to do is a little trading and you're good to go.

Jim
Jim Blackwood

well what about

http://cgi.ebay.com/ebaymotors/LOW-MILES-4-3L-v-6-sonoma-GMC-S-10-chevy-1993_W0QQcmdZViewItemQQcategoryZ33615QQihZ012QQitemZ220019539800QQrdZ1

or

http://cgi.ebay.com/ebaymotors/Extreme-Build-2-8L-Chevy-V-6-with-BW-T-5-NO-RESERVE_W0QQcmdZViewItemQQcategoryZ33615QQihZ019QQitemZ290021059037QQrdZ1

what about either one of those??

Are those drop in?
Micheal L.

Looks like it to me, but contact Dann Wade at: killerbv6@aol.com
He's one of our resident experts on the V6 swap and can hook you up on the best engine and the best parts.

Jim
Jim Blackwood

Also Bill Guzman at:
bg.gtv6@verizon.net
www.classicconversionseng.com

Jim
Jim Blackwood

Also, I think that 4.3 is a 90 degree engine. Same issues as with the SBC.

Jim
Jim Blackwood

Jim's correct the 4.3L is a 90 degree V. Meaning it is wider than the Buick/Rover or the Ford V8. The 4.3 is basically a V6 version of the 350 Chevy.

If you are going to go to all this trouble why use the 2.8? If you want a V6, and you want to do it on a budget, use a 3.4L from a Camaro. And call Bill Guzman.
Carl Floyd

My shop teacher actually has a new aluminum 3.4 straight from the factory but its missing the intake manifold. Do you know where i can find one i believe the engine is a 2004 or newer. He said i could have it.
Micheal L

If that's a gift, you'd better grab it and growl! Intakes regularly come up on ebay for just about everything, usually quite reasonable. Junkyard is another source, also the guys mentioned below and also Brian McCullough at:
brian@bmcautos.com
http://www.bmcautos.com/

Those three sources will have anything you might need for a V-6 install.

That engine is probably the best one out of the currently available choices for a V-6.

Also check out this BB:
http://www.mgexperience.net/phorum/list.php?40
It's the place where most of the V-6 guys hang out.

Jim
Jim Blackwood

Michael, I bought a 3.4 firebird engine complete with T5 tranny fuel injection wiring harness and computer for 700 bucks. It has 70K miles on it.

Im debating whether to open the engine up or just plunk it in on the motor mounts I bought from classic. BMC also sells the same installation kits.

Forget a 4.3 liter motor, too much rework is necessary.
CW Strong

I actually just found a 2.8L rebuilt with a T5 transmission and computer and wiring harness for 700 bucks. I thought a 2.8 was to small but it has 300hp/300torque and revs up past 6 grand. So i am seriously debating buying it the guy has over 2,500 in the engine alone but no one wants to buy it since its a 2.8 the only downside is the operating range of the cam is 3000-5500 but i think in a car as light as the mg it will be fine around 2000
Micheal L

I am not sure how to wire the computer though
Micheal L

Consider the MegaSquirt fuel injection controller (megasquirt.com) it's probably the hottest setup for a custom car, many advantages. I like it a lot.

Jim
Jim Blackwood

A GM 2.8L making 300hp doesn't sound very streetable.
Carl Floyd

Who's the guy from Indiana that has the yellow rubber bumper car with a small block chevy? I would never go with the sbc myself, due to size and weight, but he had a really nice car! I remember it roaring pretty impressively on the dyno at Putnam Park. I wanted to get some detail photos of his install, but I didn't get any.
Ryan Reis

That's Bill Wheat of Terre Haute.

Chevy 350 with autobox and tuber rear end for an 9" Ford, I believe.

rick
rick ingram

This thread was discussed between 22/08/2006 and 25/08/2006

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