MG Sports Cars

engine swaps and other performance upgrades, plus "factory" and Costello V8s

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Aram
Av

(3 posts)

Registered:
05/12/2015 02:46AM

Main British Car:


1971 MGB GT 302 swap
Posted by: Aram
Date: May 12, 2015 03:20AM

Hey guys I'm looking into buying a running 1971 MGB gt tomorrow for a project car. The car currently runs. I have been looking into swapping the motor to a ford 302. I was going to use the kit offered by Mantell. Does this come with everything I need to do the swap including the radiator and everything? If not what else would I need to buy? I was budgeting 4k to do the whole swap would that be enough? I just need the car swapped and to run once I get it running I'll worry about swapping the rear end and mods. I've never took on anything like this before most I've mechanically is lower a car, change oil, belts, oil pan (cracked one cause the car was too low), so I've done minor job. I can't fabricate at all that's why I was going to buy the kit. How hard would this swap be? And does the kit come with detailed instructions? Also can you guys list the parts that won't come with the kit so I can price it all out. Thanks guys.


JWD
Jim Durham
Gig Harbor, Wa.
(103 posts)

Registered:
01/22/2013 11:43AM

Main British Car:
1980 MGB Ford 302 (398.9 HP, 383.2 TQ)

Re: 1971 MGB GT 302 swap
Posted by: JWD
Date: May 12, 2015 09:40AM

Here's write-up that might answer some of your questions - [forum.britishv8.org]


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 1971 MGB GT 302 swap
Posted by: BlownMGB-V8
Date: May 12, 2015 10:21AM

Aram, the '71 is a Mark-II car (CB) and will need some firewall mods to fit the engine in, so you need to know someone who can handle those details or learn to do it yourself, or, go with a later, RB car. Also the Mantell kit uses a RB crossmember IIRC and that means for your '71, matching ride heights front/rear and matching up the steerting column. You need to do some more research. There are other options. The amount of work required depends on the combination you settle on. For instance, the factory installed the Rover V8 in the RB body. The 302 also fits with the crossmember modified and possibly minor other mods. You can check with Pete on that.

Jim


Aram
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(3 posts)

Registered:
05/12/2015 02:46AM

Main British Car:


Re: 1971 MGB GT 302 swap
Posted by: Aram
Date: May 12, 2015 12:11PM

I read about the rover motor, but I was reading parts were getting expensive because it's so old that's why I was thinking about the 302. I read that the rover motor wouldn't need any odification is that true with 71? Are there performance parts available for the rover motor?


BlownMGB-V8
Jim Blackwood
9406 Gunpowder Rd., Florence, KY 41042
(6468 posts)

Registered:
10/23/2007 12:59PM

Main British Car:
1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS

authors avatar
Re: 1971 MGB GT 302 swap
Posted by: BlownMGB-V8
Date: May 12, 2015 02:26PM

Where are you? That makes a difference. The Rover is more common these days in Europe and Australia. The BOPR (Rover) is still a popular swap stateside, primarily due to the larger displacement motors available and the light weight (80 lb difference but the car handles it fine). The Buick 300 is also a good option, inexpensive but a little harder to find.

The CB will require at least one cut in the firewall with either engine and the steering shaft will be close to the exhaust. More often owners move the engine back a bit further, possibly requiring a cut on the other side as well, and sometimes more extreme surgery. Frequently at the least the RB steering universal is fitted, meaning the pinion shaft has to be lengthened, often the later RB firewall cone is also fitted. You'll need a welder/machinist type person to modify the pinion shaft and make sure it runs true.

Jim


Aram
Av

(3 posts)

Registered:
05/12/2015 02:46AM

Main British Car:


Re: 1971 MGB GT 302 swap
Posted by: Aram
Date: May 13, 2015 04:19AM

I'm from California. So both the Buick and the rover swap require me to fabricate at bit correct? Also would a budget of 4k get the job done? After reading some threads I'm thinking it won't. Also these motors don't seem to easy to get any suggestions on where I should look?


MGBV8
Carl Floyd
Kingsport, TN
(4511 posts)

Registered:
10/23/2007 11:32PM

Main British Car:
1979 MGB Buick 215

authors avatar
Re: 1971 MGB GT 302 swap
Posted by: MGBV8
Date: May 13, 2015 10:21AM

With only 4 grand, a used 3.4 v6 might get you close, if you scrounge around & do all the work yourself. I will also only require minor firewall work.

That budget will not include the price of the car, of course. So, buy a very solid car that does not need much.



mgbreis
Ryan Reis
Beatrice, NE
(203 posts)

Registered:
07/16/2008 11:07AM

Main British Car:


Re: 1971 MGB GT 302 swap
Posted by: mgbreis
Date: May 13, 2015 12:04PM

Good advice from Jim and Carl. Just to be clear, there is no completely bolt-in v8 option for your '71 chrome bumper. You can either go with the v6, or you should look for a rubber bumper (74.5 and newer) if you want a bolt-in v8 project.


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