MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB GT V8 Factory Originals Technical - chevrolet conversion, LS1?

I have a 1978 mgb that I have been considering doing a v8 conversion on for some time.

This week, I started thinking about small block modern GM V8's such as the LT1 and LS1 out of the Camaro/Firebird/Corvette instead of the traditional route with the 215/rover/etc. that simply bolts in.

I checked out the bbs already and saw a similar posting about the LS1 vs. Ford 5.0, Chevy conversion...

I have a few questions:

1. Will an LS1 fit in the engine bay and with what modifications will I expect with engine mounts, engine bay, headers (a huge concern), exhaust, hood bulge, transmission tunnel... can it be done in essence?

2. What kind of gauges will I have to use to utilize the electronic speed control on the LS1 (ie- how do I set up a modern electronically controlled engine in an mgb and what gauges will work, if the Smiths can't pull it off).

I read up on the LS1 and it seems to be a good deal in terms of HP, weight, size, and cost, and not too hard to find at the salvage yard. I want an engine I can put in my car that has more opportunities for tuning and performance than the 215. But since I have never done a v8 conversion, I may be stepping in over my head (even though all my friends are gearheads and tool around with firebirds, vettes, and camaros from 1967 on up to almost brand new.

Thanks,

Mike
Michael

That much power you will twist that car up. You should be able to fit it. As for power some of those big hevy trans Ams are running in the high 12's at 108 mph (stock) in the 1/4 mile so that could make your MG scary fast (probably weight about 1,000lbs less then those cars). My wife will not le me have any fun like this with my car. I tryed to talk he in to letting me put a LT1 or a 5.0 ford (with a supercharger). Of the two I would go with the LS1 GM has really underated the power on those engines (in firebird and other GM car) they seem to be putting out what the Vets are. Good luck
The G

It can be done, but G hit the nail on the head on a few things. Torque will be a problem. The MG chassis is fairly stout, but 400+ft/lbs is a bit much. An MG with a 302 will weight in at 2000-2100lbs depending on engine accessories and aluminum content. Another issue is getting the power to the road, that may be what saves the chassis, since rather than hooking up and transfering stress to the chassis, the tires will break loos and ease the stress by melting tires..

BUt - It can be done, I have seen pictures of cars with 350's, 454's, etc. It is just a matter of how deep into cutting and rebuilding the engine bay and firewall you are willing to go.

G - let me know if you ever find any way of getting a blower on a 302MGB without cutting up the hood. My motor is in and I see no way of mounting the blower unit, just not enough room under the hood up front.
Larry Embrey

I've searched for the weight on the LS1 without any luck on the net. Have you guys found any true numbers on this. All I keep getting is that "they did it to save weight", well obviously but how much?

Thanks
Luke
Luke Staley

Larry Embrey, (not sure what you meant about hood clearance was it high or space between engine and radiator, if space between the engine in radiator disregard and look at what I wrote about

Maybe not a blower but possible to do a Centrifugal Supercharger from Vortec (A or S trim), Powerdyne, paxton (NOVI 1000), or Procharger (PSC-1), they can be ran with a carb as well. Saleen put the procharger on a 99 Explorer it mounted on the bottom of the engine so it was down and out of the way. That is what I was thinking anyway. They Mount on the front of the engine on either the left or r side and usually do not stick out to far past normal engine items from what I have seen. It would have a lot of top end and not all of the torque down low.
The G

According to my Jim Pace catalog of Goodwrench Engines, the 2000 LS1 MFI aluminum replacement engine is listed at 450lbs. They list two: "Y" and "F" code, both for $4644.80. They also list an LS1 Engine Kit for Camaro's and Firebird's for $5659.95. It is a complete engine with 320 hp and 330 torque, from intake to exhaust. Check their website at www.paceparts.com. Sounds about the same, or a tad heavier than the Ford 5.0L. I think I remember the Ford weighing in at 420 something.
Bob Fish

To keep it under the hood, use an Eaton blower, turn it upside down and set it on the lifter valley pan. Then build an IR/Log manifold above it. Since the Eaton uses a rear inlet you can come off the back for the air or a/f induction. The rest is pretty basic. That should clear the hood with no problem.
Jim Blackwood

Jim, that is about the tightest spot on a ford install. The distrib sits vertically just to the driver side of the crank/cam. About same location as a 215, but straight up/down, the distrib touches the hood. How big is this eaton unit? What is a IR/log manifold? I have a low rise Edelbrock manifold and still had to mill the choke tube off my holley to get it all under the hood..

The idea sounds intruiging, email me with any info you have..
Larry Embrey

Larry,

Have you looked into the centrifugal superchargers?
The G

What do you mean by Centrifugal? The kind that go under the carb or the kind that mount above the Alt and have ducting to the carb? I have see both, with my instal niether will work in "stock" location.. BUT I mighT be able to mount one low on driver side, same place as an alt, but other side of engine..
Larry Embrey

Larry, with the blower inverted as in the later Ford or GM installations, the blower drive is on the right and should clear the distributor. If not, a crank trigger should work. The drive is by serpentine belt, so not much new there. The intake would have to be scratch built, using Individual Runners (IR) going into a plenum (Log) above the blower, which could be made short for more hood clearance if needed, or doubled over for more runner length if not. Might as well add injector bosses at the same time, firing near vertical as in the 4.6L SOHC Ford, or angled in from the outside. A narrow injector spray cone should work well.

The SBC might be more of a challenge due to the dist being in the rear, right in the way of the induction, but again, a crank trigger solves that problem.
Jim Blackwood

Jim,

What happens to the body with all that tq. Those roots type put a lot down across the board. 302 V8 + roots supercharger = twisted mg body. Plus with the SOHC is fuel injected so that would be an issue if he stayed with the carb. A custom intake is going to cost some $$ unless he does everything by himself. Now if you have thing to do this it would be intersting and fun to do. Painless wiring makes a fuelinjection harness for ford engines. So you rig a mounting plate and then tubes to the heads putting the injectors in in the tubes. You would have forced air so everything as far as opimum angles is not huge unless you want the most out of your combo. That way you have your fuel injection. Or how about finding some way of mounting it like the miatas roots where you can have it force air into the carb. Not sure of what you have for room on the sides. But a roots blown MG would be very fun to drive I bet. Just my 2 cents. You can go to a junk yard and get an eaton (M90 I think) off of a Thunderbird super coupe
The G

Might be an M60, that's what they used on the GM's a few years back, but I really don't know. The M90 seems to me it would be about the right size for the 4.6L.

The MGB unibody is surprisingly stiff. As well as surprisingly heavy. Early Mustangs were unibody, right? And they weren't that much heavier. So I don't think you would twist it up too bad, at least not without ample warning. I've run a pretty heavily built Buick 215 and a Turbo Olds 215 without the least sign of twisting, and I haven't heard of problems from the 302's, SBC's or 300 Buick conversions. Might as well push the envelope. I'm sure the Eaton could handle A/F mix, but even a Rover FI system could be adapted, as long as the injector bosses are there. Custom manifolds can be made of about anything from sheetmetal to fiberglass or even wood to be extreme about it. Just takes time and lots of thought, and of course the base needs to support the blower. Aluminum is great if you can weld it, I find an acetylene torch does surprisingly well. But steel is easier for most people, and even copper and brass will do a fine job, if a bit heavier.

I think the idea here is to get it under the hood, so underslung below the manifold is the way to go. There's really not enough room for it anywhere else. I know this because of the one sitting on my Olds 215 Turbo engine. It very much sticks out. The manifold would be an interesting challenge, as the tubes would have to run vertical until they got above the blower, and might even have to be crowded to the outside a little, and I don't think you'd want the injectors running straight out of the tops of them even though that'd probably be the best for the mixture. I wouldn't mind building one if somebody wanted to pay me to do it. You're right though, that would be pricey. But imagine the expressions at the car show!
Jim Blackwood

This thread was discussed between 20/10/2001 and 24/10/2001

MG MGB GT V8 Factory Originals Technical index

This thread is from the archives. Join the live MG MGB GT V8 Factory Originals Technical BBS now