AznDrgn

Has anyone ever considered using two cam gears on 16V motor? I've seen a few honda's that have been able to fine tune their intake and exhaust cams and get an extra 5 RWHP out of their motors. This wouldn't be a huge gain but might be worth it if you've done some other stuff. I guess you would need to take a spare intake cam and have it reground to the spec of the exhaust cam or maybe a custom spec and then you would need to find some small adjustable cam gears to replace the single large cam gear. Obviously you would need to do some math and figure out the size of the two cam gears and then how much you could adjust before you would cause problems. Was just sitting around looking at an S2 head and cams last night and the light popped on so I thought I'd see what you guys thought.

J Chen

Hi Azn,
I thought you were coming to Taiwan. I've a 16V head which
I'm planning to fit onto the 951. It's really not that difficult.
What you can do is to use the stock intake cam, get a machine
shop to machine an extension just like the exhaust cam & weld
it on. If you don't feel comfortable with it, you can look for another
exhaust cam & use it on the intake side. According to to my measurements,
The lobes of both cams are identical. Regarding the cam pulley, all
that's needed to get a set made or source from other engines & mod
it to fit on the 16V head. Keep in mind that you must also get the crank
pulley for that engine as well & mod it to fit the crank of the 944 engine.
Remenber that the cams turns a half crank speed.

AznDrgn

J, I'm leaving to go over wednesday morning. I don't actually have a 16V car right now so I won't be doing this, I just thought I'd toss the idea out in case someone is bored and felt like taking on a project. When are you planning on fitting a 16V head to your 951? I've been waiting to see an executing of forced induction on a 16V car but have yet to see it. The 16V's flow so much better and theoretically should make a lot more power but everyone seems to want to stick to the more familiar 8V stuff. I understand that the way the 944S is setup makes it scream in the upper RPMs so hopefully in the near future I will get one and be able to add a SC to give it a little more in the lower RPMs.

Where in Dan Shuay are you? Maybe while I'm there I can stop by and check out your car. I'd tell you where I'm going to be but I really have no clue what the street name is or the general area.

Danno

You'll need to hood-bump to clear the extra cam-gear. It's been done. I got pictures somewhere...

pete944

What would be the advantage? Eliminating the chain and tensioner? It seem like an awful lot or work for a very small gain.

hacker-pschorr

Pete, there you go being all rational again. Next thing your going to start preaching is putting a turbo on an N/A is a waste when you can just buy a 951.

J Chen

Not if it's on a 951. Besides would'nt it be cool that
you're among the only few whose got this conversion ?

Fishey

Call Powerhaus they did it for someone that owns a racecar.

bader$

Some one was also working on adjustable sprockets on the cams. Phil Threshie @ 928developments was telling me about it some time ago. This would alow for separate cam timing adjustments.

Duke

Are the head CC volume the same on both heads?

bader$

If you are refering to the 16v head and the 951 head I do not think so. The intake and Exhaust ports are much larger on a 16v head.

Steve PH

Do you mean something along the lines of a fully adjustable vernier pulley setup ? Like these ?



This sort of thing comes into its own when trying to time cam shafts with revised profiles, but it would seem like over kill on standard cams considering the amount of work involved. Mind you it would mean making both cams, belt driven and getting rid of the timing chain leaving you with only one potential cause of valves hitting the pistons.

Z-man

If you're only getting a 5hp increase, I don't think it's worth it. Just disconnect the balance shaft belts - that's worth about 5hp as well. So you're motor will have harsh vibrations at low rpm's...

-Z.

bader$

From what I have read and been told there is not much left to get out of the 16v engine without sacrificing low end power. Unless you go to forced induction. I have played with cam timing on my S just a little and anything you gain on one end suffers on the other.

sharky47

I just like the idea of getting rid of the chain/tensioner BS. You think the Porsche engineers could have thought up something a little more robust than piggybacking one cam off the other and giving us two weak points.