CheZeppelinCorps
May 10th, 08, 12:31 PM
Hi everyone. I went out to work on the chevelle today and noticed that after the engine warms up a bit I start getting a clatter in the valvetrain from both sides, but it only starts after the engine has been warmed up for a couple of minutes. Its a new engine I built myself, doesnt have any miles on it. It runs great, sounds smooth, great oil pressure. It has rhoads lifters which ive been told are noisy but I dont think that they are supposed to be this noisy. I also have pro comp 1.7 roller rockers, and a hydrallic comp cams XE 274 552 int 555 ex. Any suggestions would be great thanks.
Kevin R
May 10th, 08, 12:37 PM
Its just a noisy cam. I had the XE 274 in my 396 and had the same noise.
SWHEATON
May 10th, 08, 2:50 PM
Rhoads lifters are ALWAYS NOISEY BY DESIGN after the motor/oil warms up .
That's becasue they have faster bleed rates to lower the cam duration/lift a little at idle & lower engine speed,then as rpm increase the higher oil pressure overcomes the faster bleed rate and then the full duration/lift is restoerd fr full perfornamce.
These fast bleed/variable duration lifters are designed to be used in motors with lrg cams so they bleed down a little at idle & lower engine speeds when oil pressure is lower (esp when hot) to effectively lower duration a few deg to smooth out the motor some & increase the int vacuum a little too.
If your running lighter oil like 10w-30 in the new motor you could try some 15w-40 chevron delo or even Valvoline VR1 or NSL 20w-50 if the motor has clearances to handle the thcker 20w-50 oil and sometimes that will quiet the fast beeld lifters down a little bit but dont expect miriclas,they are noisy lifters even with heavier oil.
But as already stated an aggresive cam lobe profile can aslo add to your noisey valvetrain making it even worse.
Scott
John D
May 10th, 08, 5:41 PM
Rhoads lifters are ALWAYS NOISEY BY DESIGN after the motor/oil warms up .
2nd that! I've been running Rhoads in my 383 for 15 years now... and yes, after it's warm it sounds like a mech. flat tappet cam is in the thing. I don't know how many times I've 2nd guessed myself on valve adjustment with these things! If you've followed the correct adjustment procedure just leave 'em alone... they clack.
CheZeppelinCorps
May 11th, 08, 3:55 AM
Thanks for the replies. I took the chevelle for its first cruise tonight and it ran great. Drove it around for a couple of hours with no problems!
Hi-po SS 454
May 11th, 08, 1:46 PM
I noticed the same noise after installing Comp pro magnum roller rockers, its like a solid lifter type noise.
Readjusted lifters many times to be sure. Still there, and many WOT miles have passed.
gibbons
May 13th, 08, 12:38 PM
Yup, Rhodes lifters are noisey. I think they sound cool. And they work. I have a 248/238 cam in my car. When I have to do emissions testing, I go from the 20w50 oil to 10w30 to bleed faster, which reduces the cam overlap. It passes! There's no way with the 20w50.