Valvetrain heads???
 

Are they generally noisy? I had the cams cut and sent to the engineer to have the shims on buckets modified and yet they are still noisy? what is the danger of having then so noisy? I was told that is could be the springs is this true... or am I being bull****ted....the engineer assure me that everything was in order after he set the shims twice... costing me moon beans... what too do? any other experiences?
Thanks peepz
San

What year of car is it? they should not be noisy, have the cams been modified to produce more lift?

If the base circle of the cams have been ground,then you might have trouble getting the correct shims to take up the extra clearance.
If it has Hydraulic lifters,then they might have trouble pumping up to take up the clearance.
What Version engine/ MY car do you have/WRX or STi ??

Mick

cams are slightly cut apparantly, but should'nt the cylinder head builder have accomodated for this?
its shim and bucket legacy b4 twin-turbo heads... on a 2.5block and a gt30

If it is shim and bucket type and they are correctly set - it wont be noisy.
Did he fit the valve springs the right way up ? They are progressive springs and the spring has a paint ID mark on one end of the spring - this paint mark should be at the top when fitted.

Mick

I am not sure... the cylinder head builder says he has built over 50 heads and none of them are noisy... only mine???
These are shims over buckets... I also been reading about guys recommending flushing the oil as the galeries are blocked??? After a head recon, is this not cleaned? I spent a sh1t load of cash on this subaru which now sounds like a diesel truck...
So noisy shims over buckets are they ok to run with?
I am currently running the car in less than 4k rpm and .7b boost
What action should I take?
Thanks in advance for your opinions.

The oil gallery's and the oil restrictor jets in the cylinder heads should be thoroughly cleaned prior to final assembly of the valve-train.
This will remove all traces of debris/sealant/machining swarf/grinding paste etc etc and make's sure no oil starvation problems occur on startup/running.
If the valve clearances are excessively big and you have the outer shim setup - you run the risk of flicking a shim out of a bucket at high rpm once the engine is run-in.
Not trying to scare you but a correctly shimmed head will not be noisy.
What did you have done to the cams when you said they had been cut,and what modifications were done to the shim/buckets ??

Mick

The cams shafts have been ground done to a 268 degree... now I am not sure whether the head assembler accommodated for this... he should have though is that not right?
Thkz.
San

Thats one of the problems which comes up when a ground cam is used - the builder has to compensate for the stock removed from the cam and if the valves have been faced and the seats recut,you get an even larger clearance between the bucket and the base of the cam lobe.
You need to find out what the valve clearances were set to by the head builder - Standard Clearance's are Inlets 0.006~0.008" Exhausts 0.008~0.010"
He might have "Bench Set" the clearances but they will alter when the heads are torqued down to the block and the cam belt is fitted.
If the measured clearance exceeds the largest Subaru shim size,then he is going to have some shims made to bring the clearances back down to what they should be.
It might be worth getting a second opinion from one of the Scooby specialists near to you who can actually hear the engine running.

Mick