Switching Engines Question

78P930 · 78P930's Garage

I have a 78 Euro engine and tranny that I want to put in a 1986 chassis...any ideas on how difficult or easy this will be?
Thanks,
Pat

78P930 · 78P930's Garage

Well you have come to the right place with your question, this board can provide you with a wealth of information. Anyway, I don't think that you will have any problem with fitment, it should just plug right in. Just make sure that you hold on tight to that 13mm wrench when you're tightening the power cable to the starter so it doesn't slip and hit you on the head.
Pat

full quack · 10:12 PM

Well the '78 was the first year for the 3.3 engine with intercooler(same as an '86), trannies are all the same in the 930's (until '89 with the 5spd.).
For shear bolt in issues, it matters not if it is a Euro version or a stateside version.
So a '78 engine & trans into a '86 chassis...all should be good.
Mark

78P930 · 78P930's Garage

Thanks Mark, Actually, I was more concerned about the electrics, even though I didn't state that in my original question for some reason. The only thing that doesn't work is the tach, I need to switch it out to see if it is a bad or a communication issue.

On another note, the darn thing just quit last night when I was backing it out of the driveway, restarted for a second or two then wouldn't catch at all. Almost like it ran out of gas, but I know I have 3/4 of a tank. Will go and check it out today some time.

full quack · 01-01-2011, 05:33 PM

Well a bad CDI box will exibit symtoms just like you are describing. Mine did that as well, but without the decency of being in my driveway, I was 15 miles from home!
Turn your ignition key all the way to the ON position, but not to the start position, go back to the engine compartment and listen for the whine/humm of the CDI box. If you can not hear that high pitch whine, either your CDI box is dead or the electrical connection has failed somewhere.
The CDI box is located just behind the drivers side fuse/relay panel area on the drivers side of the engine compartment (pot metal housing with small heat cooling fins).
A bad CDI box could also explain the non-functioning tach as well, but check with others with that possibility as I'm not 100% clear on that.
A 1986 930 should be running a 6 pin connector for the CDI box, is that the same for your 1978 as well? Or did your 1978 have a 3 pin connector?
Just throwing out ideas here, and seeing what might stick to the wall???
Mark

voitureltd · 06:14 PM

[QUOTE=full quack;5757373] trannies are all the same in the 930's (until '89 with the 5spd.).

Pre 1978 930 has a shorter trans axle. 78 thru 88 are dimensionally the same. 1978 and onwards the bell housing was lengthened to make room for that dreaded "rubber clutch" which moved the motor rearwards by over 2 inches ( didn't need that ), and prompted the recommended rear tire pressure to be raised 4psi to 43psi.

78P930 · 78P930's Garage

Mark, Both are 6 pin. It "whines" w/ the key on and seems to run fine now, can it give problems intermittently? I guess next time it doesn't start I'll check it again.

Tony, Does that mean that the chassis was changes to accommodate the longer bell housing..., so a 78 and later engine won't just bolt up to a 75-77 chassis?
Thanks,
Pat

full quack · 01-03-2011, 12:56 PM

Yes they can, mine was intermittent for 2 hours or so, before leaving me stranded for good. However, once it started to fail, it would only run for short periods of time before crapping out again, then of course finally nothing.....
Mark

voitureltd · 01-03-2011, 04:27 PM

Tony, Does that mean that the chassis was changes to accommodate the longer bell housing..., so a 78 and later engine won't just bolt up to a 75-77 chassis?
Thanks,
Pat[/QUOTE]

The motor will bolt up, just the transaxle is shorter on pre 1978 turbo cars. So yes the chassis mounting location on a 1975-1977 is different, due to the transaxle being shorter, not the motor.

JakobM · 01-04-2011, 09:24 AM

Does any one know how much shorter a 1975-77 930 transaxle is compaired to a 1978-88 ??

This information would be very valuable considering a G50 short bellhousing/axle conversion. Such conversion will fit 1978 but will they fit a 1975-77 ???

How many inch is the difference in lenght between 1977 vs. 1978 transaxle??

Thanks
Jakob