Lifter noise

[47chevy9]

Just replaced hydraulic lifters in my 235 due to excessive noise. Motor runs strong but the noise came back after about hundred miles. Noise occurs randomly, very frustrating. Love my 47 truck and really want to keep my six any suggestions..
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[Speedbumpauto]

Without more info, it's hard to give much direction. IMO, you're heading down a slippery slope putting new lifters on an old cam. The problem could easily be related to low oil pressure. Do you know what your running pressure is? Did you try adjusting the old lifters when the noise started? How were the new lifters adjusted? Have you tried a viscosity improver to thicken the oil just to see if there's a difference? Lastly, how was your first lifter diagnosis arrived at? No offense intended but a leaky exhaust manifold can sound so much like a lifter it has fooled me and I'm pretty good at this stuff. The reason I ask is leaky manifolds major symptom is it comes and goes depending on engine load and other conditions.

[OrrieG]

My 235 started having one lifter that would pump up at speed. Engine started going south before I got around to fixing it, turned out the cam lobe matching is was flattening out too. Do not know if was related, but passing it on. Might try asking over at stovebolts.com they are more stock orientated.

[47chevy9]

Originally Posted by Speedbumpauto

Without more info, it's hard to give much direction. IMO, you're heading down a slippery slope putting new lifters on an old cam. The problem could easily be related to low oil pressure. Do you know what your running pressure is? Did you try adjusting the old lifters when the noise started? How were the new lifters adjusted? Have you tried a viscosity improver to thicken the oil just to see if there's a difference? Lastly, how was your first lifter diagnosis arrived at? No offense intended but a leaky exhaust manifold can sound so much like a lifter it has fooled me and I'm pretty good at this stuff. The reason I ask is leaky manifolds major symptom is it comes and goes depending on engine load and other conditions.

It was definately lifter noise. Running oil pressure seems ok. I didn't adjust the lifters but we identified two with excessive wear but replaced entire set. I like an will try the viscosity improver I will also re-
check adjustment on new lifters. Patrick's web site says replacement hydraulics lifters are poor quality they suggest going to solid lifter/cam, prefer to fix what I have now. Per casting numbers my 235 was built in 55 for power glide. Im told it has better oil pressure than pre 53. Not sure though. Thanks for the help....
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[dwcsr]

Originally Posted by 47chevy9

Just replaced hydraulic lifters in my 235 due to excessive noise. Motor runs strong but the noise came back after about hundred miles. Noise occurs randomly, very frustrating. Love my 47 truck and really want to keep my six any suggestions..
Posted via Mobile Device

This was a major issue with 235's. Oiling system was not very good and alway push as much air as it did oil. A few things to try are pinching the top rocker connector tube closed. Make sure you have a block thats drilled for hydraulics. 58 and later and some 55 up Powerglide engines were drilled from the factory.

If your trying to put hydraulics in a sold lifter engine it wouldn't work very well and you end up with what you describe.

Make sure you have minimum 35 - 40 psi when running at 1000 or better. There are more complicated fixes that require machining lifter bores and lifters. Make sure your pickup screen is not clogged or to high in the pan.