71 opel gt 5 speed.Could it original?

[Dale .D]

I'm looking at an 71 opel gt on Sat . Original owner. says it has a 5 speed .Did they put 5 speeds in new?

[spdkilz02]

nope.

[baronbors]

1st plus
2nd plus
3rd plus
4th plus
reverse equal an original 5 speed.

[GTJIM]

No 5-speeds in GTs originally but many have had the later (1979-85) Opel Manta Getrag 5-speed trans fitted by the owner afterwards.
The original 4-speed has a cast iron case but the later 5-speed has an alloy case so they are easy to tell apart.

[daveegt]

I am in the process of making a 5 speed adapter for my GT. I have one from an S 10. I want to use a Manta 4 speed bellhousing and trans.(that I have) as a pattern, does any one know if they are the same as a GT ????

[guyopel]

The Gt trans. and eng. tilt to the pass. side .HTH

[daveegt]

Are the bolt patterns for the bellhousing & trans. the same, are they interchangable?? All I need them for is pattern for the adapter.
Dave

[heimue]

Dave,

the bolt patterns of all 1.9 to 2.4 L CIH engines are identical, no matter where they were put into.

Dieter

[namba209]

Yep, as Dieter says, all blocks are the same and the various trannies/bellhousings will bolt up to the block. The tilt on the GT is done with the engine and tranny mounts. I double checked my Opel interchange listing to be sure. BTW it's available on this site in the left hand tool box. HTH.

[daveegt]

Thanks guys, I'm still learning about the GT and this web site. You are a great help.

[namba209]

One thing about the S-10 T-5 tranny, if that's what you're using. I've got a 92 in Willit? with an 88 bellhousing, so I could use the mechanical throw-out arm, vice the hydraulic setup. The gear ratio in mine is more of a stump puller ratio, especially in low gear, and the 5th gear ratio is not as tall as it is in the Camaro/Firebird models. IDK how it will work with a 1.9L engine though, my V-6 will tach up quickly in low gear, requiring a shift to 2nd ASAP. To accelerate in 5th from freeway speeds, quickly, a down shift to 4th is needed if you're in a hurry to accelerate. But from about 75 MPH, it will move out fairly good. At 70 MPH in 5th, the engine is only running between 2200 and 2500 RPM, which is pretty far down the torque curve for a 1.9L. HTH.

[daveegt]

I am looking at adapting the 5 speed to the Opel bellhousing, using the Opel flywheel, clutch, and bearing. It all looks possible sitting on the floor with preliminary fitting, isn't this the way that Mantapart's adapter was designed???

[kwilford]

Originally Posted by daveegt I am in the process of making a 5 speed adapter for my GT. I have one from an S 10. I want to use a Manta 4 speed bellhousing and trans.(that I have) as a pattern, does any one know if they are the same as a GT ????

I posted this back in Sept 2006.
http://www.opelgt.com/forums/6a-engi...ed-engine.html
In that post, I compared my '71 GT bell-housing to my '75 Ascona SportWagon bell-housing, and they are QUITE different. The clutch release arm lies in a different plane on the GT engine. I originally thought it was related to the design-lean in the GT's engine, but the angle is opposite of what I would have thought given the lean (passenger side lower in the GT). Perhaps it is related to the body structure? Or perhaps it is a difference between years rather than models? Anyone know?
The GT bell-housing is the blue one in the photo
HTH

[Manta Rallier]

Originally Posted by daveegt I am looking at adapting the 5 speed to the Opel bellhousing, using the Opel flywheel, clutch, and bearing. It all looks possible sitting on the floor with preliminary fitting, isn't this the way that Mantapart's adapter was designed???

Hey Dave,

I saw your PM, and all this is probably doable per everything I have designed so far. The only question I have on your use of the stock clutch is if the clutch splines would fall into the right place on the trannie's input shaft splines. It probably will be OK (from some quick cogitating, but that is not always reliable!). I assume you have checked the splines on clutch and T5 input shaft and they are the same?

For you the big thing to check is to locate the pilot of the input shaft the right distance into the bellhousing so as to penetrate into the pilot bearing by the right amount, and then determine the adapter plate thickness from that. We ended up designing a 1" thick adapter but we are using the Ford Mustang T5 and so the input shaft length might be different on the S10 T5, and thus cause you to use a different thickness of adpater.....just looked up some data and the Mustang V8 (pre '94) input shaft length and some S10 input shaft lengths are < 1 mm different in length, so a 1" adapter thickness is a good place to start.

BTW, our adapter design will be different as we are using the Ford bolt-up pattern which is different from the standard Chevy 4 bolt-up pattern. I cannot recall if the S10 pattern was the standard GM or the standard Ford; the standard GM is approximately a symmetrical trapezoid in shape.

Regards,
Mark B.