No pressure fed tensioners on high revving engines?

[TargaFlorio]

Hi guys,

I was talking to an engine builder and he mentioned that he does not install oil fed tensioners on high revving engines. In his experience, the hydraulics failed and ruined a couple of engines.

This would be for an early aluminium-case S-spec engine for my '68.

I have the oil-fed Carrera tensioners on my current engine (original '68 T / magnesium case) installed.

Is it common practice NOT to install the pressure fed tensioners on high revving engines?

Thanks,
n.

[kenikh]

I dumped my pressure fed tensioners for this (and the look of originality) reason. I am now using 930 tensioners with collars. I have a box full if you need a set. They are rebuildable, so they last forever.

[Neil '67 911S]

What did you use for a tool to install the 930 tensioners? A solid steel clamp (sold by Pelican and others) is supposed to be used to keep the piston retracted during installation. However, that clamp must be for something else because it doesn't fit the 930 tensioner. Someone suggested using a hose clamp but I would hope that someone has come up with something a bit more appropriate by now!

Thanks!

[ajwans]

I have heard the exact same thing. I guy I know who talks to some
very knowledgable people asked "why didn't they use pressure fed
tensioners on the 935", the answer was they are not reliable over
8k rpm.

Now this is all second hand but all the same I'm going 930 tensioners
on my 67S rebuild.

Another consideration is the early chain housings have a different
bolt pattern from the pressure fed covers so the entire housing needs
changing out.

Henry Schmidt at Supertec is making late style wide idler arms by
manufacturing a wide bushing, the early narrow idler arms have also
been identified as part of the problem. This is a much cheaper option
than buying the later wide arms.

andy