Camshaft / shim gaps, noisy?

[kev edwards]

Probably a bit of "end float"

Not end float it's to rhythmic, quiet as a mouse on idle as soon as revs applied it's very audible

[DogsbolloxofZ1B]

Listening to that audio clip are you sure you haven't jumped a link on the cam chain at some point? Sounds like one or more of your valves are double seating, by that I mean you may have a slightly bent valve head by a gnats which is aligning itself into the seat. I'd whip that head off and take a serious look.

Mike

[zpower]

I'd whip that head off and take a serious look.

Mike

+1

Every suggestion has been covered.

Enough guess work it's time to strip it in my opinion.

[warren3200gt]

I've had two different engine builders listen to it today and both immediately said worn buckets/tappets or what ever you want to call them. So 4 x new buckets on their way to me. I'll do the front four first with the new ones and have a listen then I'll do the four back ones if it still sounds iffy. Its nearly winter so no great rush now.

Thanks for your help guys and I'll keep you posted next week after another play.

[ADRIAN H]

Fingers crossed, it aint too much grief.

[warren3200gt]

Well, new exhaust cam buckets x 4 and all sounds as it should! Thankfully all resolved. Baffles me that the steel buckets would wear before the ally head but I ain't complaining.
Big thanks to Kev again for all the help and support.

[kev edwards]

More than welcome Warren, it's always a pleasure when it comes right and you can listen to that big Zed motor doing it's stuff.

[wilsonsjw11]

Warren,
That sounds like a good result.
What is the mileage on this engine
Regards
Steve

[andyb1962]

Well done guys,
Nice work this is what this club is all about

[warren3200gt]

Warren,
That sounds like a good result.
What is the mileage on this engine
Regards
Steve

no idea re mileage Seve, clock shows mid 20, s (yeah right) but since rebore and loads of new internal bits, about 500 miles max. One of the engine builders that I mentioned earlier was the guy that did all the work. The way he jumped at the exhaust buckets immediately makes me think he knew more than he was letting on. I imagine the dealer didnt want to throw a few more hundred quid off his bottom line at it.
Still, all history now.

[warren3200gt]

Looks like I may have been speaking to soon. After running for a short while it sounds like the rattle is returning. The solution last time was new valve buckets as the old ones had been seriously hot and had scorched. So now I'm thinking it may be a blocked oil way to 3 and 4 exhaust cam bearing. This could have been due to the engine builder not cleaning them properly when he did all the work.Is there any way to check without stripping the entire top end assuming I have decent pressure from the pump? If I blow compressed air into the oil pressure check plug with the cams out it should escape at the cam bearings right? Or is there an easier and/or better way? Or is the only way stripping the top end right down?
alternatively, if I blow compressed air down the cam bearing oil way on 1 and 2 exhaust cam bearing oil way it should escape from 3 and 4 bearing oil way?

[wilsonsjw11]

Warren,
I think it maybe time to take the advice of some of the more knowledgeable guys on here and take the head off for closer investigation.
Regards
Steve

[zed1015]

So now I'm thinking it may be a blocked oil way to 3 and 4 exhaust cam bearing. This could have been due to the engine builder not cleaning them properly when he did all the work.Is there any way to check without stripping the entire top end assuming I have decent pressure from the pump? If I blow compressed air into the oil pressure check plug with the cams out it should escape at the cam bearings right? Or is there an easier and/or better way? Or is the only way stripping the top end right down?
alternatively, if I blow compressed air down the cam bearing oil way on 1 and 2 exhaust cam bearing oil way it should escape from 3 and 4 bearing oil way?

The only way to check for oil getting to the cam is to run the engine with the cam cover off and you should see oil emerging from around the cam journals.
Blowing air into the main oil gallery probably won't reveal anything as this feeds other parts of the engine too ( crank,clutch etc ) so air pressure may be lost into other areas and the crankcase before it gets chance to reach the head.
The same goes for pressurising 1 and 2 as they aren't linked to 3 and 4 in the head but at the main gallery.

[warren3200gt]

Steve, I think your probably right. Just trying to workout what could get them that hot. Can only be lack of lubrication or gases bypassing the exhaust valves. As all 4 exhaust buckets I took out had been VERY hot I suspect lack of lubrication to the front cam. I think the oil pump is ok as the inlet buckets are fine.
So before I take the head off I wanted to check the oil paths are ok. Is it possible to force oil backwards through the pump with the engine not running? If you can't then I should be able to determine where the blockage is by syringing oil in at various points and seeing where it comes out.
edited to add the previous was posted while I was typing the above.

[zed1015]

The only practical way to check for oil circulation is with the engine running and syringing would be a waste of time .
The oil feed for the cams splits in the head so if you are getting oil to the inlets the only place for a blockage is the cross drilling to the exhaust.
This means only taking the head off to check but blockages in both cross drillings to the exhaust is extremely unlikely and exhaust gasses getting up the guides even less so.
The exhaust buckets showing signs of excess heat is not unusual for obvious reasons and if there were no lubrication they would have seized in their bores and the cam shells would be wrecked also as they all share the same oil feed.