M30B34 vs M30B35

[rsporsche]

both are good motors for a coupe. yes, the motronic 1.3 injection is better than the injection on the b34 ... that's why SFDon uses it. compression isn't the only thing that creates HP - true, but what i have found is that it creates an engine that winds up faster. the other thing to consider is where an engine makes its HP. look at the s14 and s38 engines - beautiful engines that make their power at the top end ... and they like to live high in the revs. look at HP and torque curves to see what kind of engine is right for the type of driving you will do. my last 2002 was a real radical engine - made all of its power and torque up high - it rev'd to 7500 rpm but had no low end torque ... not a civilized engine for street driving.

 

[jeme9]

Thanks, I am planning to use my horn type inlets for more period look (originally from 1977 3.osi with L jet) hence I plan to use an aftermarket ecu (Wolf etc.) to match all the differences rather than fixed 1 or 1.3 Motronic.
I recognise there are some losses in using the older inlet.
Your comment on better Motronic 1.3 raises a good point, I am planning on using the injectors from the B35 / 1.3 in the L jet inlet manifold. I have not checked this yet, does this work ?

 

[rsporsche]

the engine that SFDon is doing for me will use 1.3 and the original type intake (the same one that you are using). that is the only inlet that Don uses as it looks period correct. so you don't necessarily have to go to an aftermarket ecu. you might want to start a conversation with Don on this subject ... my understanding is that he will be in Oz in the coming months.

 

[Layne]

Maybe I should be building engine with B34 block with B35 head and B35 pistons ? Am I understanding correctly?
PS my B35 engine had compression 190 - 200 psi.

That would be ideal if you're not allowed to use the adapter brackets, and if you only want to use parts you have on hand.

As I said before, I wouldn't personally move pistons from one block to another and just expect them to work without honing the block and using new rings, but other people seem to do it all the time. Make sure neither engine has been bored oversize, obviously.