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is there a four cyclinder turbo engine that I can put in my 72 Opel
You might try using a turbo from an early 88, 89 Saab. I have a turbo (extra part) for my 89 Saab SPG. It is a 4 cyl like the Gts, but the problem arises when you try to run the exhaust pipe from it. I always wondered about the same thing you are asking about. Some of the long time members may have the answer to this question. The 1 person who would know is Rallye Bob. I have known him from C&R small cars (70s era). If anyone knows the answer to your question, he would be the one to ask, and listen to. Jarrell
 

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Anything is of course possible but there are no easy alternatives. There were kits available in Europe for converting to an OHC/DOCH engine, but I don't know if they are still available. If you can find an OHC/DOHC kit(or build an oil pan and pickup, motor mounts and move the distributor from the end of the OHC cylinder head) , it could be possible to swap in a Pontiac Sunbird Turbo engine.You would also have to source an 18S OHC bellhousing from Europe(or make an OHC/DOCH to CIH adapter plate between the original GT bellhousing and block) https://consumerguide.com/used/1990-94-pontiac-sunbird/ The exhaust system would also have to be custom made.
All this is way too much work, a souped up 2,2 or 2,4 liter CIH is much cheaper and easier to build.
 

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Easiest turbo install is the Opel C2.0LET or Saab 204 engine(Same block I think)
You will need a mounting kit available from Lenk
You will also need a sump and oil pick up pipe from a 1.8 OHC engine found in the Opel Manta (Hard to find but reproductions are available on ebay)
Suitable header which is available.
The stock 4 speed and the normal 5 speed Getrag240 will not work so you will need an Opel r25/28 box from an Omega and then I think the GT trans tunnel will need to be modified/widened.
There are adapter plates available to use a mazda rx8 box to the Opel engine but I think the gear stick will be in the wrong place and unsure if it can be moved.
There is a Getrag 265 which should be suitable but are difficult to get.
After all that the prop and rear end will struggle to last and options here are the Volvo 240 of possibly BMW e30 rear end install to name just 2 options.
Then, don't leave the brakes as standard or you will have some brown trousers moments and that's if luck is on your side.
There are probably a lot of other options and requirements but this is what I know on the subject due to looking into it for one of my cars.
It is a lot of work but if you are up for it then keep us informed.
 

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It can be difficult to find a C20LET engine in the US(I don't know about the Saab). Why wouldn't the stock 4-speed or a Getrag 240 work (strength would be an issue of course) ? A CIH bellhousing fits with an adapter like this: https://vilderi.kuvat.fi/kuvat/opel ohc/kaaveli 001.jpg/_full.jpg . There is also an OHC/DOCH to T5 bellhousing available in the UK. An R25 has a cable clutch, the R25 R28 has a hydraulic clutch that brings extra adapting work.
https://www.rwdmotorsport.com/vauxhall-2-0xe-engine-to-borg-warner-t5-bellhousing.html
 

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It is such a popular thing to do that I don't recall any Opel turbo GT owners posting here on a regular basis....

That's the thing with these engine swaps or turbo/supercharging an engine the designers thought not one minute of doing when the motor was on the drafting boards in Russelsheim.

Good luck!
 

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Turbo

Listen to, read, what the others have posted ahead of me, they have way more knowledge than me. As what what was posted before me, be ready to spend a lot of money, on a lot of parts, that some are rare, to do what you want to do. You might be better off to go to Gil's site and buy a complete moter and transmission, drive shaft. That is basically drop, in drive off. Do not expect it to be cheap though, you get what you pay for, and Gil will stand behind his parts. This is just My opinion. Others have theirs, Sincerely, Jarrell
 

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boomerang opeler
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You may find it easier to do a large displacment (2.5 , 2.6 or 2.7 Litre ) swop. Power will be up near the top end of what the chassis can handle and so much easier as its the same block. Charles Goin does them, dont know if Gill does them but if you have a search there are a few posts about them.

Dont mistake the early Saab turbos based on the Triumph slant 4 engine with the GM era Saab turbos btw, a way different kettle of fish.
 

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Starter for a C2.0LET is on the other side. The Getrag240 from the 1.8 Manta will fit but won't handle the torque.
How is it possible then that there are several OHC/DOHC engine swaps done with a CIH Getrag and an adapter plate here in Finland ? Perhaps a Getrag 240 is not the strongest choice for a very healthy turbo engine, but there are many cars with one behind a C30NE, C30SE or even a C40SE. An OHC/DOCH to T5 bellhousing and a T5 would seem like the most logical choice in the US considering availability and price.
 

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Opeler
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Standard 4-speed transmission is too weak but Getrag 240 is safe until 177 ft lbs of torque. The most popular swap is Opel C20XE engine which develops max torque of 145 lb⋅ft, so Getrag 240 is good match for that engine.
Turbocharged version of that engine (C20LET) develops 207 lb⋅fts max torque. My 2.5 CIH engine has been dyno-ed at 201 ft lbs, but nobody guns the engine at maximum torque all the time. Still, I wouldn't mind having even stronger transmission. If I would have to do it again, I would opt for Tremec T5.
 

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When I researched this a while back it would have been based partially on my driving style. As such a Getrag 240 would not last. If I was to put a LET into a GT it would be to floor it every now and then. Probably more now than then if truth be told. So for me, to do it right it would have to be an R25 or R25/28 box. I also like the idea of using Opel parts where ever possible when upgrading.
 
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With a C20LET there is not room left in the engine bay.But is "Thor`s Hammer":speechles
Never ever will be a passenger again,NO NO NO!
 

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I think maybe age and self preservation might have kicked in, but to quote a Queen song "who wants to live forever?":D
For sure:yup:
Its hard to tell my feelings when drove with Willi.
To read the poster is one shoe,drove it the other!

342 hp and 453 Nm by 4200 rpm its enough for 302 Km/h and towe a trailer.

Yes Willi have a removable hitch:lmao:
And registrated as 4 seater:haha:
 

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Depending on your timeline, I may have a solution in a year or so. I built a prototype GT turbo kit in 2015, but right after that closed my shop and moved. I’m about 4 months away from having a new shop. At some point I will be making jigs off the prototype kit for production. Perhaps in a year from now, who knows.

Anyway, give some serious thought to your overall budget. Going from 75 hp to 150 hp is no small feat, and certain systems in the car will be overtaxed even at that modest power level. The cooling system, the brakes, the suspension, the stock clutch...all pushed to their limits.

Up the boost a little bit to 200 hp and then the gearbox and rear axle will have a very short life. Without substantial braking, suspension, and tire upgrades the car will be dangerous to drive.
 

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Opeler
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Sorry its not GM, but type SR20 into the search and you can see what it takes to install a modern turbo engine in a GT. If you're good at finding deals and willing to put in the Fab hours yourself it can be done cheaper than an upgraded CIH and Gertrag 5spd.
 
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