Thread: Rebuilt V8 - Very Rattly ValveTrain!

Did you pump the lifters full of oil before fitting them?. Pat

I cannot really help but I recently started up for the first time a V8 that I rebuilt. If the engine is basically standard with just the usual skimming of heads and block standard rockers etc are all OK and will self adjust - should not need shims etc. Highly modified engines with high compression etc might be different but not in standard engines. Mine has had the block skimmed twice and the heads once and has standard lifters and no shims.

My engine fired up- first go and was not noisy at all including the time before it finally got oil pressure - was a worrying wait,

The obvious thing to look for is a sticking lifter.

When the engine was rebuilt - how was the deck to piston top difference - my rebuilt Haflinger engine was clacking away because the pistons where touching the heads.

What is the timing like - if too far advanced it can be pinging and it can really sound rattling - I had to run my engine with a lot of advance and it did rattle a bit on start but ran fine.

Lastly - if the exhaust manifold is loose anywhere, or is not sealing the noise can mimick all the above.

Good luck with it

garry

Originally Posted by PAT303

Did you pump the lifters full of oil before fitting them?. Pat

Yes, thanks.

Originally Posted by garrycol

I cannot really help but I recently started up for the first time a V8 that I rebuilt. If the engine is basically standard with just the usual skimming of heads and block standard rockers etc are all OK and will self adjust - should not need shims etc. Highly modified engines with high compression etc might be different but not in standard engines. Mine has had the block skimmed twice and the heads once and has standard lifters and no shims.

My engine fired up- first go and was not noisy at all including the time before it finally got oil pressure - was a worrying wait,

The obvious thing to look for is a sticking lifter.

When the engine was rebuilt - how was the deck to piston top difference - my rebuilt Haflinger engine was clacking away because the pistons where touching the heads.

What is the timing like - if too far advanced it can be pinging and it can really sound rattling - I had to run my engine with a lot of advance and it did rattle a bit on start but ran fine.

Lastly - if the exhaust manifold is loose anywhere, or is not sealing the noise can mimick all the above.

Good luck with it

garry

Thank you Garry,

Sounds like 1/2 dozen or so lifters are making a noise, if not more. The sound is terrible. Sounds like an solid lifter motor that's never had a tappet adjustment. Wish i had some way of recording the sound of it. Sound does not get softer or louder with revs (oil pressure). Deck to piston top clearance is fine. Fiddled with timing with no difference made. Manifold gaskets are good.

Edward

I've heard that kind of noise when the timing chain had slipped to 2 teeth out. You can eyeball the rockers on either cyl. 1 or cyl. 6 at TDC on the overlap stroke. Inlet and exhaust valve movement should be very similar either side of TDC, Gives you a reasonable idea before you pull off the front cover.

Which head gaskets are you using ?

Which heads are you using ?

Which pedestals are you using ? ( have you compared heights if you have sets of ? )

Did you check the prelod before you filled the lifters ?

Was there any problem with the initial start and cam run in ?

New lifters on a used cam are ok , used lifters on a new cam are not the done thing .

The cost of fitting a new cam dictates you don`t use old or used lifters .

Used lifters if still in shape/spec can be used on a used cam .

Run the engine with the covers off , carefully feel the rocker arm and locate the noisy ones you will feel it .

Alternately with it running use a feeler gauge on top of the valve stem between it and the arm , use a thin one first even though you say the clearance between piston and valve is ok . If it get worse it`s not ok . If it space that`s making the noise when you use a thicker feeler gauge the noise will stop . If the case your pedestals may be too tall but there will be a cause .

Back when rocker arms had a screw adjustment along with the hydraulic lifter self adjustment this was how the adjustment was done with a running engine by using a feeler gauge and putting socket and bar on the rocking arm .

Not that it`s anything to do with your problem but it was a bit of an art and it reminds me of days gone by .

Whatever you find and whatever you do you have to be aware of the valve geometry , if you don`t get it right it will still run fine just not for as long because parts like stem and guides etc will wear more .



.

Originally Posted by bee utey

I've heard that kind of noise when the timing chain had slipped to 2 teeth out. You can eyeball the rockers on either cyl. 1 or cyl. 6 at TDC on the overlap stroke. Inlet and exhaust valve movement should be very similar either side of TDC, Gives you a reasonable idea before you pull off the front cover.

Thanks Bee utey. The rocker arms seem to be in the same orientation.

Edward

Originally Posted by PLR

Which head gaskets are you using ?

Which heads are you using ?

Which pedestals are you using ? ( have you compared heights if you have sets of ? )

Did you check the prelod before you filled the lifters ?

Was there any problem with the initial start and cam run in ?

New lifters on a used cam are ok , used lifters on a new cam are not the done thing .

The cost of fitting a new cam dictates you don`t use old or used lifters .

Used lifters if still in shape/spec can be used on a used cam .

Run the engine with the covers off , carefully feel the rocker arm and locate the noisy ones you will feel it .

Alternately with it running use a feeler gauge on top of the valve stem between it and the arm , use a thin one first even though you say the clearance between piston and valve is ok . If it get worse it`s not ok . If it space that`s making the noise when you use a thicker feeler gauge the noise will stop . If the case your pedestals may be too tall but there will be a cause .

Back when rocker arms had a screw adjustment along with the hydraulic lifter self adjustment this was how the adjustment was done with a running engine by using a feeler gauge and putting socket and bar on the rocking arm .

Not that it`s anything to do with your problem but it was a bit of and art to do and it reminds me of days gone by .

Whatever you find and whatever you do you have to be aware of the valve geometry , if you don`t get it right it will still run fine just not for as long because parts like stem and guides etc will wear more .

.

Permaseal composite head gaskets. Same as i have used for years without troubles.
Rebuilt heads from a 3.9 L Rover. Pretty much stock - only a mild skim (although the combustion chambers seem a bit smaller than the old 3.5 L heads. i believe this was done from factory to compensate for the composite gaskets used on these motors?)
All pedestals seem to measure the same. I had these same pedestals on my 3.5 L motor for 40,000 km.
Preload was done with dry lifters.
No issues with initial start, except the rattle did not go away after 6 min, so we stopped and removed the 25 thou spacers. We started and immediately went to 1500 - 2000 and continued for another 15min. (To be a bit more precise, the initial really loud lifter pumping type rattle did partially go away after a few seconds, but not the lesser noisy rattle that has persisted until now).
We have used second hand pushrods from another motor that looked good. Tomorrow we are going to swap in the old ones and see what happens.
To me it sounds like there is space between either the pushrods and the rockers, or the rockers and the valve stems. The sound is too tinny to be a lifter, which has a more chunky sound. Very hard to tell the difference though.
I will try the other ricks you mentioned.
Thanks again,

Edward