tk's944

I have a set of 16v pistons and rods if your interested. I also have alot of other 16v parts.

StyleLab

hey Arash, the tensioner mounting point broke on my S2.

FRporscheman

Hey Nick, yikes, AFAIK the S2 head mount design is the same as the 968, and was improved from the S. I guess it's still not bulletproof. Anyway thanks for letting me know!

StyleLab

the tensioner mounts the same way on both s and s2 heads, it is only supported by one cylinder. On the 968 it is improved and supported by both cylinders on either side thus reducing failure

FRporscheman

OooOOOooOOh, I had it all mixed up, I thought the S2 was also supported by 2 cylinders. Thanks for the info.

<inside-voice> whew! </inside-voice>

pjburges

Hey all, bringing this thread back from the dead...

I have a weak lifter on my 16V S motor that I just had apart and the head milled flat/ rebuilt. I was thinking of replacing the lifters with solid ones.... I used to have an old DOHC Jaguar where you just pulled the valve cover, used a feeler gauge and slipped shims into this little cage to take up the lash. I can see how that would be hard with an 8V, but the procedure would be really simple for a 16V.

Does anyone offer 16V solid lifters similar in design to what we'd have seen on the DOHC Jag? This is really a high-rev kind of motor. Im also considering making ITB's - bypassing all the electronic fuel stuff and using Webers. Keeping the knock control and electronic ignition timing of course!

Thoughts?

The engine is in a very lightweight car, low ratio LSD gearbox, stripped of all emissions controls including PCV and the cat....

Raceboy

Why don't you use standalone engine management instead of Webers? Cost of buying is pretty much the same and both need to be tuned but end result is much better on EMS.

Oh, if anyone has an S2 exhaust cam for sale, i'd be very interested!

Olli Snellman

Old thread, but solid lifters might interest also others.
R/D Valvespring in California fabricates them. Same company who deliver lifters for example for Lindsey Racing solid cam kits. R/D offers lifters for 928 and 968 models, so you should be able find lifters for your needs.

GoKart

Old thread, I know.

Anyone have more info on this tensioner mount failure? Is it common? Is it a mileage issue? Can it be resolved preventatively??

Thanks!

Arominus

Its easy, change the cam pads. They get damaged due to this not being done. This was covered in your other thread. For reference, my S is up to around 180, 000 miles now, and its on the original head. The pads have been changed though. Its due for another set soon.

thomasmryan

Chain pad wear is proportional to the number of dry starts after periods of non-use.

Pads and a new chain are cheap. Sprockets will wear when running a chain that has stretched.

Some say replace at 60k but definitely before 100k

V2Rocket

He was asking about the actual aluminum boss in the head that the chain tensioner bolts to.

They are known to sometimes shear off sending the tensioner flying and killing the cams...though I imagine that is usually caused by the plastic pads rubbing through.

Arominus

That is the failure mode, I'm sure some have broken on their own, but its an exceedingly rare failure vs neglected cam pads causing rhe tensioner to get ripped out. Pads will knock out any of the 16v heads that way. I'd be focused on rod bearings and replacing the pads/chain, getting the head properly reinforced is an expensive adventure for a street driven car. I would reinforce for a race motor though.

PorscheChampion

Has anyone ever repaired or had one of these 16v heads repaired that suffered the tensioner mount break? Can a normal machine shop do it?

Scott at Team Harco

I did not have the repair done, but it obviously can be. Based on what I observed from the head that came with my car, it looks as though they must have machined some holes and then pinned the pieces together. There is also a lot of evidence of JB Weld. They also built up the plug hole with a ring that was then machined down. Maybe the ring and the pins work together. I don't have any plans to dig into it much deeper.

Sorry for the less than detailed photo. It is clear from the orange RTV, where the fix was made. I needed to add extra sealant to reduce the flow of oil into that plug hole.

The new head that will go on the engine is behind the old one. I may be willing to let the old head go - but not until I have the engine completely rebuilt and have satisfactorily completed enough time/miles to consider the job a success.