1980 Saab 900 engine replacement

[mark55master]

I need to replace the engine in my 1980 900 Turbo. Are there later model year engines that would work without too much modification?

Will my transaxle (which is in great shape) fit some of the later model engines, or should I be looking for a good engine/trans assembly?

Thanks in advance for your help. --mark

[peva]

Any later C900 turbo engine will fit up to '93 with very little modification. Later engine will be 16v too.The gearbox should fit also. The only thing to bear in mind is later engines are more powerful have an APC boost ECU and require some form of inter-cooling and also have electronic fuel injection and will require a fuel ECU. All of these things are easy to overcome depending on your requirements. You could just fit a later engine with lowered boost and mechanical injection and leave things how they are.

[Grif900]

Your 1980 transaxle will fit any 900 engine. And I have seen with my own eyeballs , a 16v engine run with an early Bosch C.I system.

[s900t8v]

who put k jet on a 16v? That is sheer awesomeness hahahah

[euromobile900]

For practicality's sake, I'd stick with an 8-valve 900 engine. Your transmission will fit anything, but I'd recommend an 8-valve engine from after 1980, because these will be the much more robust "H-engine", which has a belt-driven water pump instead of the very archaic water pump driven off the jackshaft. Also, these will not require any weird conversion of the fuel system. Of these, just make sure you get a turbo engine. To convert from the "B-engine" that your car has, you may have to slightly alter the routing of some coolant hoses, but I don't think you'll have to do much. It's definitely worth this upgrade. The B-engine is notorious for water pump and jackshaft failures and very hard to get parts for. I would not put one in a car unless it was one of the early (pre-1975) Saab 99 engines, which came with a much more durable forged drive gear with coarser teeth.

There are 3 possible compression ratios available for the 8-valve H-engine. Non-turbo engines have high compression, and these shouldn't be used with a turbo ever. You will melt a piston unless you are VERY careful and only use premium fuel. APC turbo engines, built after 1983, have slightly higher compression than non-APC turbo engines, built 1981-1983. As Peva says, the APC turbo engines will require either the installation of an APC box and harness (not bad, will give you more power without much if any decrease in economy) or making sure the boost is low enough not to cause knock. Intercooler is optional on all, but again boost must be adjusted with this in mind.