Geneqco

Well, the time has come for me to seriously consider a 16v head (for my 951).

I have already done a bit of research on this but all I really have are some pretty vague figures. What’s really appealing about the 16v to me is the more efficient chamber design. From what I understand, because of this, you don’t need to run as much timing advance (all else being equal) so there is less opportunity for knock – ie, you can run higher boost and/or use a higher CR to start with. The stronger 3.0l block would also help here.

As for flow and costs… I’m pretty clear on the 8v… around 180 cfm stock and around 250 cfm for Stage 3 and I know the costs. I also have an idea of what 16v heads go for but don’t know their stock flow rate or the cost of working on them or solid lifter conversion costs etc. I’ve heard that they can flow well over 300 cfm with work but I’m not sure what’s involved to get them to that point. I’ve also heard that a stock 16v will flow much like a heavily worked 8v but not sure whether that’s true.

The only other thing I’ve heard about the 16v is that there may be some reliability issues with the chain guides and tensioners and that the variocam system in the 968 setup can also be the source of problems and catastrophic failures which sounds a bit scary.

Any info available on the 16v setups to help me fill in some gaps would be greatly appreciated.

dillon410021

951 don't have 16 valve heads
just the 944S and 944S2

Geneqco

Thanks, I'm looking at this as an upgrade option using a head from an S2 or 968.

JakeS2

There is one dude with blown 3.0l engine on the forum. 16V head is error-prone to failure on the cam chain tensioner so 16V models are very strict on the maintenance.

dillon410021

Yes, I have to replace the chain in my head before it goes. 68K with stock chain on my 1987 944S

Toolmaster

www.944enhancement.com

Chris W (he's on Rennlist) does this. Chances are he can help you in the quest.