Opel GT V8 Project!!!

[Snakes111]

I am currently starting on my project to put a Chevy small block 350 in my 69 Opel gt and was looking for some tips on how to get it ready like beefing up the suspension and or anything else. So if you can help please post thanks.

[GTJIM]

Put 300 lbs of sand on the hood and drive it - that is how your GT will handle with a Chevy cast iron V8 in it ... Nice Huh??

[coolchrisp]

not everyone puts in a V8 for handling. most likely for just goin fast in a straight line.
before you worry about suspension you have to support the hole car! there is alot of threads on here about connecting the front and rear with rocker supports!

[Gumby]

Originally Posted by Snakes111 I am currently starting on my project to put a Chevy small block 350 in my 69 Opel gt and was looking for some tips on how to get it ready like beefing up the suspension and or anything else. So if you can help please post thanks.

My suggestion if you are dead set on a V-8 GT is to use an aluminum rover v-8 instead of the chevy small block, because it is a great deal lighter than the cast iron block.

Like others have said, a quick search of the forums will provide a wealth of information on what to expect in this kind of swap.

Good luck on completing your swap!

[kwilford]

After being a member for almost a year and a half, albeit with only 11 posts, I suspect that you should know to search first, then add to an existing thread, BEFORE you start a new thread, ESPECIALLY in the WRONG Forum (this was in the GT Forum, which is reserved for non-technical topics relating ONLY to the GT, so I moved it to the Engine Swap Forum). Please look around this Forum and THEN ask away.
Thank you for your consideration.

[opelwasp]

You'll need to stop the body twist too, unless you like popping windshields out every time you mash the accelerator. You'll need to tube the chassis, upgrade the brakes so you can actually stop the beast, and also a whole new rear end is a must. The Opel ones just cant take the power.

[Snakes111]

Well i did some more researching and found there are many more things that would need to be done. But i was wondering if there was anyway to make the frame stronger without replacing it with a tubed frame?

[namba209]

Originally Posted by Snakes111 Well i did some more researching and found there are many more things that would need to be done. But i was wondering if there was anyway to make the frame stronger without replacing it with a tubed frame?

Nope, you can't replace the frame, the whole car is the frame, it's a uni-body. You can only add to what's there. Contact JP in FL, or the Gages in OH, they've both done the swaps correctly.

[jeff denton]

I have to tell you, I would not worry about putting a V8 in my chassis, which is the original frame and floor and tunnel and firewall, all very radically stiffened by rollcage galore rising up out of my unpatented Speedway Rocker Panels. The front suspension and rear end would certainly need some help, but I'd bet my bottom dollar that my car could handle 400 horsepower easily! With an aluminum block and heads and careful weight placement/planning, I guarantee you I could make it handle reasonably well, too. Course this is getting into a rather spendy little wet dream here, but I didn't see this thread start with the usual "how much is" baloney. Personally, I still like the Rover/Oldsmobubble V8. I just have always liked that motor. Have seen some neat stuff done with them. Have two of them in my own little collection of bizarre junk. One was in my S10 for a while, but then that idea got changed to 412 cubic inches... lots more fun to drive!

[rowdygt]

I agree to agree....many successful unibody Chevy Vega, Monza, and Ford Pinto V8 conversions. As long as horsepower and torque are kept reasonable. Never saw one "pop out a windshield'. Using aluminum heads and light weight components, i would bet you could get the weight of the small block close enough to the 1.9 that the GT would not know the difference

[namba209]

RowdyGT, I've got a 75 monza with a factory installed 350 in it, and you would not believe the extra bracing the factory did to make the body survive the extra torque it puts out over the stock I-4 engine. Things like extra steel panels in the rear wheel well, braces welded in from the frame to the front sheetmetal and a very longish torque arm from the differential to the tranny, just to name a few. The body weighs about 200-300 lbs more than the stock I-4 body, and that doesn't include the suspension upgrades to handle the extra engine weight. Jeff is probably right, that he could put one in his GT and it will handle the power easily, but he's got a full cage inside his, which as he said, radically stiffens up the body. Plus like he said, suspension and drivetrain have to be modified or built to be able to handle it too. I'll take the word of the general consensus that I'm approaching the limit of what an almost stock GT can handle with my 160 HP V-6 setup.

[opelwasp]

Originally Posted by rowdygt I agree to agree....many successful unibody Chevy Vega, Monza, and Ford Pinto V8 conversions. As long as horsepower and torque are kept reasonable. Never saw one "pop out a windshield'. Using aluminum heads and light weight components, i would bet you could get the weight of the small block close enough to the 1.9 that the GT would not know the difference

Vega's, Pinto's, and the Monza are very different cars than a GT. The GT's extremely curved windshield makes it more prone to pop under high power applications.
And as far as keeping torque and horsepower "reasonable", who wants a 200 HP V-8? If someone puts a V-8 into a GT I don't think reasonable is what they had in mind. Someone drops in a V-8 it will likely be pushing at least 300 HP, WAY beyond the GT's body limits.

[jordan]

Yes, I would say as well if you have a 200hp goal I would just build a hot opel engine. Probably cost less in the long run and save a alot of time hacking the engine bay. Also it makes for a much more interesting car, the original tiny opel engine putting out your power goal, or a big v-8.....big deal.

[rowdygt]

Who wants a 200 HP V8?....Buick/Rover 215 V8's are so popular with MGB owners that it makes this engine hard to get. No popped out windshields on the MGB either. To get a small block Chevy to produce 300 real live no B.S. horsepower on a REAL no B.S. rear wheel dyno takes some work- beyond stock.

[jordan]

You are comparing apples to oranges, most MGB V-8 conversions are done on the convertibles and not the MGB GT because the convertible has a beefed up unibody that allows the car to supports itself and also enough to handle the additional hp and torque that the V-8 puts out (within reason.) Many people think the reason for this is merely because the B-GT isn't as popular, but there is more of a reason.

[jeff denton]

Uh-oh. Time for a quick lesson about one of my personal favorite sports cars, the MGB GT. I've had two of them. I came to love them when I was stationed in Scotland, where a local tavern owner had one called a MGB GT/V8, he also had a Lotus Europa, what a car!
The Olds 215 aka Rover V8 was an option in an MGB GT, it was clearly marked GT V8. Factory stock. I didn't see very many of them, when I did they were a blur blowing by me on the highway between Glasgow and Gourock, a superhighway I traveled often. My MGBs both had the four cylinder, five speed OD, fun yes but no tire fryers...
I haven't followed any MG stuff in many years, when I got back to the States I went more into drag racing, hot rodding, and circle track. Kind of left the four cylinder stuff behind until I decided to enter the Compact Class fray with an Opel GT of all things...
So I don't know what the long term lifespan of the MGB GT V8 was, if there are any around anymore, if they are valued and treasured, or what.
My machinist friend at Hilde Construction years ago in Great Falls used a 215 in his autocross car, an MGB with the windshield and posts removed, when you walk up to the car the whole thing incuding the rollbar came up to just above my belly button! His engine used a homemade billet crank, aluminum rods, was bored and sleeved, displacement was 304. It screamed.
It is my understanding that the latest Rover V8s are the good old 215 basically, with all forty years of improvements and modern tech added.
This would truly be an awesome engine for any little car you want to make a rocket out of. Oh sure, it would be some work to do it and get it right, certainly not a challenge I'd be afraid of, here comes an argument that only a pro could pull it off... There would be some fab work involved. There is no kit in JC Whitney for under twenty dollars. Some structural mods may be needed to the Opel GT unibody, but, hey, let's face it, most of them are rustbuckets now anyway, they need structural help just to hold together with the 1.1 engine, right? I could be wrong, maybe not most of them, but lots of them, certainly any of them that have been "thrown away" or passed on as junk. These are the cars to hack up and play with!
Wanna get really crazy? Use the new Chev LS series engine. All aluminum, all 400 plus horsepower. You can pick up the phone and order one from many distributors. See what Hot Rod Mag did with one recently. Put it in a Solstice. Yes, again, a major fab job, but all the hardware needed was listed in the article by GM part number.

[kwilford]

Originally Posted by jordan You are comparing apples to oranges, most MGB V-8 conversions are done on the convertibles and not the MGB GT because the convertible has a beefed up unibody that allows the car to supports itself and also enough to handle the additional hp and torque that the V-8 puts out (within reason.) Many people think the reason for this is merely because the B-GT isn't as popular, but there is more of a reason.

The MGB-GT V8 conversion is probably more common that the convertible. At least it is here in Calgary, as we have a shop that specializes in Rover V8 MGB conversions,
Home
When they brought their customer cars to our VSCCC show, three of the five conversions were the coupes. Malcolm converts both, but the B-GT is far stiffer than the convertible, so handles the power better.
Also, it is pretty hard to pop the windshield in an MGB due to body twist as the windshield just sits in a frame attached to the body, rather than being part of it.
The biggest problem IMHO with installing ANY V-engine in a GT is the width of the engine bay. As Ron can attest, it requires pretty radical surgery and clever re-structuring of the foot-well to make the darn things fit. And in his case, it was a 60 degree V-6, not the wider 90 degree in the SBC V8

[jordan]

Here is a convertible that was at carlisle a couple years ago that I took a picture of. I am not quite sure of the engine size but the fellow says that it does have a stiffened unibody to help handle the power. http://www.opelgt.com/photos/showpho...0/ppuser/13272

[rowdygt]

Oh i do realize how much work would be involved...and can understand the hell that Ron went through stuffing the V6 in his GT, and that a subframe and roll bar set-up would really enhance the install, but ruined handling and popped out windshields...i'm not buying in to. No disrespect to the GT purist...the GT is a neat little car just the way it was built, but if a fella wants to modify it...why not. Like any conversion, whether it be a Vega, Pinto or MGB ot Opel, if you take it beyond it's limit..you will break it. Someday my GT will recieve a V6 or V8, and the more that this surgery is documented (thanks Namba) the easier it will be for others (me)

[GTJIM]

Originally Posted by rowdygt ruined handling and popped out windshields...i'm not buying in to. . Someday my GT will recieve a V6 or V8, and the more that this surgery is documented (thanks Namba) the easier it will be for others (me)

I have both a Rover 4.4L alloy V8 and a Lexus 4.0L alloy V8 sitting here beside my GTs - Rationality struck home as I was having the body work done and I realised how thin the sheet metal in a GT body is and how light the running gear. They were built as light as possible to 'enhance' performance with their small motors with very little margin of strength.

When carefully examined, the GT body is a technical marvel - other than the doors, hood and light buckets it is welded into ONE piece. The first production car to be TIG welded together.

Mine was parked beside a Ferarri in the body shop and the vast difference in quality of build was self-evident - the Ferarri was a hodge-podge of over-lapping lumps of sheet metal just spot-welded together ...

Good luck with fitting a V8 - just don't ruin another GT. Try finding a finished conversion ... and drive it around some twisties with a 4-cylinder GT for comparison.

[jtb]

I too had a mgb-gt, thought about putting the 3.5 litre (215 to you US folk) into it, but it was too rusty. Wound up building a TR8 (TR7 with the 215 engine in it). I couldn't afford to buy one, so I just did the conversion myself. My block came out of a buick (also available in Olds F85).
They are great engines, there are parts available (after you explain to the parts guy that it is an 8, not a 6), and they can be hotrodded. There was a machine shop in Washington state that specialized in these. There was an article on building them up in Hot Rod magazine in March 1985.

Geez, Jeff, sounds like you've had a similar car history to me... the B-GT, the GT6 and now the Opel GT!

jtb

[jeff denton]

Something may be overlooked in all these engine swap discussions, regarding the chassis integrity and safety and the limited space under the hood. Both issues can be resolved simultaneously.
Once the rollcage evolves from six point to eight point, the original unibody structure is no longer required. Fenderwells are excess baggage. The front fenders and hood become fiberglass. The driver's seat moves back quite a bit. Then so do the pedals, now the firewall is too far forward... There is LOTS of room for a BIG engine. Still has the stock frame and floor, the body is still attached, see the car isn't cut up that bad yet. Weight is an issue if you want to go around corners, that's why I would consider only an aluminum engine!
Perhaps the term "engine swap" makes one envision a simple job. It just isn't going to be that easy with a V8. I shouldn't say that, it is easy. But not quick and simple. It would take me two years to do it, working hard on it every Sunday. It won't happen in a couple weekends!

[blancojp]

I would forget about the Rover/Buick 215, it only has 148HP in stock form and cost quite a few $$$$$$$$ to get up in the high HP range.

You can fit any engine you like as long as you plan the work and do it properly. I have 305HP on my car, it has been running since 1995 with a buick 90 degree V6 engine. I am still running the stock rear end and suspension and have yet to break a windshield on any take off.

If you have the knowledge and the tools required, put whatever you want in the GT. IF you don't, then do a few minor mods to increase HP and call it a day.

[jeff denton]

Quote:
If you have the knowledge and the tools required, put whatever you want in the GT. IF you don't, then do a few minor mods to increase HP and call it a day.

Right, JP.

Well, I wonder why it would be so hard to get 1hp/ci (or maybe a bit more) out of a 215? Costs too much? Are Rover engines and parts hard to get?
What is it about a Buick V6 that makes it easy to get 305 hp? Cheaper maybe?
Hey, how about the aluminum (aftermarket) Buick V6? That would be cool, horsepower and lightweight all at once, and not horribly expensive. I visited a shop down your way a few years ago that specialized in these, even in turbo GN drag race use. Impressive!
I know cheap and easy are key words in our club, I think this thread started without these inhibitive roadblocks, for a change. Something different, anything unusual is kind of a neat approach!
Plan ahead, yes. You hit the nail on the head. Get it? Nail-head, isn't that what they called the big Buicks way back in the sixties?
That's it. I wanna see an aluminum ("Buick") V6 go into a GT. Go for it, Snakes!

[rowdygt]

Snakes, A lively debate on this issue. If you do convert, post and update your progress. Another concern is state emissions and inspection??...could pose a problem.