SOHC to DOHC?

I figure it's possible to convert to DOHC... How hard is it? I have a 98 Saturn SL and we might think about getting a new motor for it so I was wandering how hard it is to convert to a DOHC...? Anyone? Thanks.

not hard, you can swap the whole engine or just the cylinder head, the block is identical. swap the PCM. only real possible problem is the trans, auto or manual?

Manual... But the thing is. I was thinking of replacing my engine for the fact that there were some problems... :-/ But i talked to someone about that... And won't you have to buy a chip or do something to the computer? And does this mean I will have to buy a DOHC tranny too?

well, the MP2(SOHC trans)and MP3(dohc trans) will bolt right up to each other. besides the gear ratios, they are basicly identical. however, the general consent(sp?) is unless you boosted, the MP3 is better.

ether way, the only way to pull a saturn engine with a manual trans, is to pull it with the trans attached. its a very tight fit. there is a how-to posted by Wolfman over at saturnfans.com

you won't be able to reprogram or add a chip to the pcm, just swap it with one from a DOHC, the same one from where you got the motor if you can.

but the good news is the auto trany doesn't like engine swaps, the manual doesn't know the difference

Thanks man... I would be low on money so if I did do it, I wouldn't have money for the tranny and engine for a while. But I'll be suer to keep all that in mind if I do it... Thanks again... And a lot. :)

So, then, sierrap615, your saying the DOHC cylinder head will bolt straight to the SOHC block? PCM should be easy enough, but what about timing adjustment? Surely there is more to it than that. 5-speed tranny, btw.

the saturn uses a DIS, no ignition timing adjust is necessary or possible.

i've never done one my self only relay what other tell me.

well, you also will need to change the timing chain and cover(was that what you were talking about). best to buy a new one, not a junkyard one.

only problem i see is if its a 91-94, you'll need to convert TBI to MPFI (fuel injection type)