The V8 Owners Forum -

H, am in need of some advice please - the engine seems down on power compared to other 3.5s and has started tapping from one side sometimes so its about time to start buying bits.
Its from a 1972 P6, I'm not looking for massive power gains so my plan is new standard cam, new followers, new shafts & rockers if they're worn (probably will be), a bigger oil pump kit and might as well fit the SDI heads I've got in the shed at the same time (and maybe smooth out any lumps behind the valve seat inserts first).
It doesn't burn oil so I'm going to leave the pistons & rings alone.
So far so good, but what chain & gears to go for? I only want to do this once and don't mind paying out for a Cloyes roller or similar if it'll maintain the timing better than a cheaper set, what do you think?

This sort of thing http://www.v8tuner.co.uk/product.php?id=98 should be fine for your set-up - really you just need to avoid the standard nylon toothed sprocket

Consider going for the 3.9 cam. Apparently it does wonders for torque.

Pocket rocket wrote:This sort of thing http://www.v8tuner.co.uk/product.php?id=98 should be fine for your set-up - really you just need to avoid the standard nylon toothed sprocket

Just curious - is there anything wrong with the nylon toothed sprocket on a standard engine?

unstable load wrote:Consider going for the 3.9 cam. Apparently it does wonders for torque.

Thats the one I was going to get, I might as well since it gives a bit more torque lower down.
From what I've been told, the 3.9 cam has the same lobe shape and timing as the 3.5 except that its all shifted about 2 degrees - I don't know if this is true though?

Pocket rocket wrote:This sort of thing http://www.v8tuner.co.uk/product.php?id=98 should be fine for your set-up - really you just need to avoid the standard nylon toothed sprocket

I agree, plastic teeth don't sound like a good idea unless you're the accountant!
So whats the advantage of a roller chain? Does it wear less? If so, maybe its what I should be looking at because I'm hoping not to have to strip the engine again for many many years?

I'd say the cog as used would cost more to make than an all steel one. The nylon is for noise reasons. They have a pretty long life on a standard engine - much longer than the cam.

Well, I've decided to go for a Cloyes Street Roller chain set, its around twice the price of the Clevite one but hopefully it'll last longer before it wears enough to start affecting the timing - I'm planning on keeping this engine for a lot of years.

My experience of Rv8s going back over 40 years says they wear out a standard cam before a standard chain set.

DaveEFI wrote:My experience of Rv8s going back over 40 years says they wear out a standard cam before a standard chain set.

Ah... Thanks for that info, in that case I might as well go for the Clevite set, no point spending unneccesarily!

ratwing wrote:

DaveEFI wrote:My experience of Rv8s going back over 40 years says they wear out a standard cam before a standard chain set.

Ah... Thanks for that info, in that case I might as well go for the Clevite set, no point spending unneccesarily!

It could be there are other benefits in using an aftermarket setup - like being able to adjust the valve timing. And maybe with a non standard cam where loads may be higher, or where you're increasing the maximum RPM.

In my experience standard nylon teeth timing wheels can eventually crack - I have seen this 1st hand, but this is usually only on high mileage pretty worn out engines

mr-scott wrote:In my experience standard nylon teeth timing wheels can eventually crack - I have seen this 1st hand, but this is usually only on high mileage pretty worn out engines

Yes - as I said they last as well or better than the cam.