MG Sports Cars

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

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mikes18421
Mike K.

(4 posts)

Registered:
10/27/2008 10:16PM

Main British Car:


1975 MG Midget/ 302 Windsor V8 conversion
Posted by: mikes18421
Date: October 27, 2008 10:28PM

Looking at buying a really nice 75 MG Midget. Body is very nice but the orig 4 cyl engine needs rebuilding. I have been into 5.0L mustangs for a long time and have a few 5.0L drivetrains laying around. What's all involved in converting it over to the 5.0 and T5 trans? It would be a carbed 5.0. Does anyone sell a kit or parts that would aid in this type of conversion? Any advise/help would be great!

Thanks

Mike


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: V6 Midget
Date: October 28, 2008 08:15AM

No kits for Midgets for any engine swap that I know of. The 302 will be a tough fit in a Midget chassis, but can be done if you have small feet! The reason I say that is the footwells in a Midget are pretty small to begin with and you will have to move the engine back and cut into the footwells quite a bit to get it to fit behind the steering rack. That will push the shifter pretty far to the rear, might be better using a case from the S10 Chevy version of the T5 in that case. Plan on modifying the steering shaft quite a bit, you'll need several u-joints and supports to route it around the engine and exhaust.
For front suspension, consider some type of aftermarket installation, perhaps a narrowed Mustang II type in order to get both better brakes but also to get some coil over shocks for the front suspension. Midget coil springs are a small diameter wind and very hard to find replacements for in any spring rate that really works well with a conversion.
Plan on using aluminum heads if you can to get the weight down as well. You're going to have a lot on the front end even with that.
Rear axle choice is up to you, depends a lot on what you use in front as I would think you'd want to keep the lug pattern the same if possible, makes carrying a spare easier. I stayed with 13" wheels for my V6 Midget and kept the stock front discs, so used a Chevy Monza 10 bolt rear narrowed to fit. Vegas and Monza's had the same lug pattern as the Midget and were designed to fit with 13" wheels. A 10 bolt should hold up to a 302 if you don't get too wild.


mikes18421
Mike K.

(4 posts)

Registered:
10/27/2008 10:16PM

Main British Car:


Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: mikes18421
Date: October 28, 2008 09:43AM

Thanks for your reply and advise!!! Looks like doing a V8 is not going to happen. Sounds like it's too involved for me. How does the V6 work?? What type of V6 is most used? How about 4cyl engines? Can the 1800cc MG motor be swapped into the car?? I ask because I know were there is an 1800cc engine sitting around. Does anyone sell performance parts for the MG 1500/1800 engines?? If so where??


Sorry for all the questions. I'm new to this type of car. I've had an itch to get an MG for a long time now but I don't know much about them and what's being done to modify them.

Thanks again for the help!


V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: V6 Midget
Date: October 28, 2008 10:27AM

Mike, the V6 I used and that has also been used by a couple of other guys is the GM 60 degree unit in either 2.8, 3.1, or 3.4 sizes. These came in Camaros, Firebirds, and S10s coupled to T5s. I used a 2.8 from a Camaro and it worked fine. The S10 transmission has the shifter pretty far forward and would really crowd the dash in a Midget, I advise using the Camaro/Firebird unit. As far as other engines, several fours have been installed in this chassis, ranging from a Suzuki to Toyota. Check out the photo section on the newsletter under MGs for the Midgets and under Healey for the Sprites. It really depends on what you want from the car. I like loads of torque for good highway performance, wasn't too worried about extremely light handling for autocross etc, so the heavier and lower reving V6 worked for me. The twin cam fours are screamers and give excellent performance, but of course lack a little of the torque so you'll have to rev them a little tighter. For the minimum of hassle on a swap I like to select an engine that has a bellhousing diameter small enough to fit the chassis without having to alter the footwells, is short enough to clear the firewall and steering, and is low enough to clear the hood. That makes a swap a lot easier if there is minimal sheet metal work and chassis reinforcement to do. If you're not up to speed on fuel injection systems and computers then try to select an engine that has been in production long enough to have earlier versions with carburators and standard distributors that can be fitted to a newer engine to make that area easier.


Moderator
Curtis Jacobson
Colorado USA
(3800 posts)

Registered:
10/12/2007 02:16AM

Main British Car:
71 MGBGT, Buick 215

authors avatar
Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: Moderator
Date: October 28, 2008 10:38AM

Check the MG Midget and Austin-Healey Sprite sections of our website to see lots of pictures of re-engined Spridgets, including Bill's V6. Here's the link directly to Bill's car:
Bill Young's 1973 MG Midget with 1987 Chevy 2.8L V6 MPFI (18 photos)

There are lots of excellent inline-four options too - far more than we show so far in fact, but we'll be adding more soon.

For the very best horsepower-to-weight ratio, it's hard to beet the Mazda rotary engines... although they sound and look funny and they have to be rev'd-up to be at their best, they wouldn't require any change at all to your footwells or tranny tunnel and they'd significantly reduce the weight of your sports car. In my opinion, that's always a good thing! Here's a very nice example:
Brian Kraus's 1976 MG Midget with 1986 Mazda 13B rotary engine (23 photos)
Don't let all Brian's "racecar" features scare you, the engine itself is a relatively easy install. I think Brian even sells conversion motor/tranny mounts if you want to build one similar to his.

We also plan to feature an exceptionally fierce three-rotor turbocharged Sprite very soon. (You can preview pictures of it in the Austin-Healey section of our message board.)

Does anyone sell performance parts for (Triumph) 1500 or MG 1800 ("B-Series") engines? Certainly! These engines are still used in race cars all the time. One of our vendors sponsors specializes in parts for MGB racecars, and will be delighted to talk you through many of the options. His ad comes up approximately every fourth time you look at this message board: John Targett of Targett Motorsports.

Candidly, you probably won't find much love for the 1500 engine on any "MG" message board, and although the A-Series (earlier Midget/Sprite engine) and B-Series (MGA/MGB) engines are remembered fondly, their power-to-weight ratio is pretty lousy unless you invest a lot of money and make them "unstreetable".



Edited 1 time(s). Last edit at 10/28/2008 10:40AM by Moderator.


mikes18421
Mike K.

(4 posts)

Registered:
10/27/2008 10:16PM

Main British Car:


Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: mikes18421
Date: October 28, 2008 10:43AM

With the V6 does the front suspension need to be modefied to a Mustang II or can it be left stock? The footwells don't need to be modified? With your setup what did you have to do to make it work? How about engine mounts?

I'd like to keep the car light but want the car to be pretty quick. I will not be entering into any auto Xing but would like to throw it around on the back roads.

Thanks again for your help


mikes18421
Mike K.

(4 posts)

Registered:
10/27/2008 10:16PM

Main British Car:


Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: mikes18421
Date: October 28, 2008 10:48AM

Thanks curtis for your response and for the links!



V6 Midget
Bill Young
Kansas City, MO
(1337 posts)

Registered:
10/23/2007 09:23AM

Main British Car:
'73 MG Midget V6 , '59 MGA I6 2.8 GM, 4.0 Jeep

authors avatar
Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: V6 Midget
Date: October 28, 2008 04:08PM

Mike, the front suspension doesn't need to be changed for the V6 or for the 4s or rotary that have been mentioned as well, but the stock Spridget brakes are marginal at best for a performance car. Uprated pads help a lot, but add much weight and you'll be pushing the limits. That's one reason I would opt for something like a Mustang II front if I was using a V8. If you position the V6 as I did the foot wells don't need to be changed. The transmission tunnel is raised and enlarged slightly, but the basic frame remains unchanged. Other builders have moved the engine rearwards and lower to obtain hood clearance, but that requires more modifications to the chassis and firewall areas. I opted for minimal firewall and chassis problems by adding clearance in the hood area. I used MPFI so that manifold was tall and extended pretty far forward. I think if you used a small 4 barrel you could keep the hood mods down to a much smaller scoop over the carb. I made my own engine mounts Used Chevy PU V8 mounts on the side and tranny, making adaptors from 1/4" plate and 1" heavy tubing. They bolt to the original Midget engine mount locations in the front. The car has good power and will break the rear tires loose if I try a bit. Top measured speed so far is 95 mph, plenty fast enough for me. The car cruises easily at 75mph in 5th gear and pulls hard when passing or running an entrance ramp to the highway. Handling is nearly neutral with a bit of understeer. Photos from the autocross at Spridget 50 show the car fairly balanced and without too much body lean so the suspension is working pretty well.
IMG_2803.JPG


vegte44
Harry Vander Vegte
West MI
(10 posts)

Registered:
10/21/2008 11:02PM

Main British Car:
73 Midget

Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: vegte44
Date: October 28, 2008 08:50PM

Mike, go to cardomain.com and check out the Austin Healey Sprites. Lot of V8 conversions there. There is one with a 302 stuffed in it. With some planning it can be an easy swap. Nicest thing about small block chevys and fords is that they are the cheapest to play with. Worst case senario: build a tube chassis. People make it sound so hard to do. Chassis building is one of the easiest things to do. Just take your time, measure 3 times, cut once, and make sure your welds are good. I am planning on building two chassises over this next year. One for my drag midget and one for my 63 Falcon convertible.


highmileage
B. D. Howard
LSD (Lower Slower Delaware)
(29 posts)

Registered:
08/10/2010 04:41PM

Main British Car:
Fidget and Jagrolet Fidget -Ford V8 powered Midget, Jag XJ w/ Chevy V8

Re: 1975 MG Midget/ 302 Windsor V8 conversion
Posted by: highmileage
Date: June 17, 2012 10:37PM

Ooops, I just noticed how old this thread is. My bad...


I have a 289 Midget. I didn't build it and neither did the previous owner, so I'm afraid that I can't help you much.

But I do have the car here! Where are you located?

Fidget01.jpg



Edited 1 time(s). Last edit at 06/17/2012 10:42PM by highmileage.


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