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Having developed a knock in the right head of my father's 2.5 GTV6, we decided to pull the valve covers and take a look. What we found was a badly worn valve lobe and tappet. So, at the recommendation of so many, we replaced the cams with those from the 164s. We pulled the heads, did the head gaskets, and through in the new cams. The engine is now back together, and the knock on the right side is gone.

However, we now have a knock occuring in the left side. We've had the cam in and out, checked the clearences, and it all seems good by the numbers.

One more thing, if you apply pressure to the cam cap nut on the face of the cog, the knock goes away completely. Now, we're stumped. Any help would be greatly appreciated, Thankyou

Hi:

Does this happen when the engine is cold or hot or both?
I have a knock that happens when the engine is cold and disappears as the engine warms up. I think its due to lack of lubrication on the #4 cylinder intake valve as the oil bath in the head seems to empty out for some reason (noticed when the valve covers are removed). Anyway, it’s been like that for years and does not seem to cause any wear on the cam or lifter.

Cheers,

When first started (cold engine) you can't hear it, but by placing your thumb on the cam cog nut, you can feel it. As it warms up over the course of a couple of minutes, you begin to hear it.

The original knock we had, which we got rid of, was caused by a worn lobe and tappet which, as you say, was loud on startup, and would then slowly go away. Look for pitting on the face of a tappet.

Thanks for the feedback

Does anyone have any information on modifications that need to be made to install the 164S cams. The knock we have now only started since having installed the new cams. Thanks

If going for a aftermarket programmable ECU, would adjustable cam sprockets be necessary? I haven't seen/read anyone using them and if there are some available, where can I get them? Thanks for any info
Brian

Brian,

Why do you need one? For the TS or V6? In either case, no you don't need one.

Yeah, I just re-read my post and figured it's probably only relevant for the quad cam engines.
Zamani,
Did you have any problems with idle using the C&B cams and did the autronic allow you to achieve a relatively smooth idle?

The quad cam motors already have adjustable cam pulleys from the factory

So you dont really need them - But I went with Lightweight Alloy pulleys for my 3.7 race motor

But only to look cooler than everybody else!!! Sad I know. I can tell them it's worth 1/2 a second a lap

Was a development between myself and Div at Glenwood

A couple of things that can and have caused knocking in engines have been broken rockers ,valve seats coming loose,bearing cap studs stripped during tightening,and my favourite-worn small end bushes.

ANDREW.B

Where did you get the adjustable cam gears??

Anybody else have them for a 3.0l dual cam???