I think I know the answer but even after all the research I did to find a smooth idle - low end torque 454 camshaft....I have to ask.

Is a Comp HE 256 camshaft noisy ...?

I have adjusted the hydraulic lifters (rockers) "a million" times and it's not as quiet as the old GM stock camshaft. I wish I had known! I will swap it out when I figure what camshaft to go with.

Thanks for any knowledge on this!

 

What do you mean by noisy, is it ticking or something else ?

 

Constant "machine" noise....you can hear all 16.

Light ticking sound....not just one ..... all of em.

Just not as quiet as the stock engine was.

All stock specs except the mild Comp cam.

 

Make sure the pushrods are not hitting the heads and you could try adjusting while running, cutout the top of an old valve cover, works like a charm

 

Sorry to instigate paranoia but hope you didn't do this! http://forums.corvetteforum.com/c3-t...p-problem.html

 

The original High Energy cams were usually pretty quiet. The newer Xtreme's get a little noisy sometimes.

Who's lifters? Some out there are... how shall we say it.....not quite machined as well as they could be?

What oil? Sometimes heavier oil will quieten things a little.

Rockers and pushrods in good shape? None hitting valve covers? What rockers..stockers?

Springs?


JIM

 

That cam should be pretty quiet. My first thought was valve slap, but if that happens it's usally with a cam with steep ramps.

Can you better describe the noise? Like a sewing machine? Or more of a rattle? Ticking? Knocking? Thumping?

 

YES...sewing machine.....that's it!

Totally rebuilt original LS4 454 ....1974. crank, pistons....everything > Cam, rebuilt heads, new springs and rhoads lifters.

I did the 6 / 1 method for adjusting. Haven't tried it running yet because of the oil MESS. I suppose I could cut up an old cheap set of covers to use for that.

 

rhoads lifters are noisy.....

 

You said it already. Rhoads lifters are going to be noisy no matter what you do. That's what they do. They bleed off and produce valve lash. That's what reduces duration and makes cam act smaller. I had a set years ago and adjusted them every way in the world and they always sounded bad. A solid lifter cam is quieter.

Put some regular lifters in it and you'll be fine.

JIM

 

I have a small block (383) with an XE268, Comp match lifters and Scorpion Roller Rockers and it's noisy! Loud sewing machine I would agree ...almost a cross between solids and stock hyd. All my old school hot rodders and the machine shop race engine guru who helped build say it's normal for this setup. I have almost 4k on this motor and it romps so I'm not worried about anymore .... actually have gotten used to it...

 

The local machine shop guy recommends Johnson 817 Hydraulic lifters.
I think I will get a set and see if it quietens down a bit. It runs great but has the sewing machine sound. More noticeable with the hood closed....comes from underside.

Thanks y'all!

 

I like the sound of solids and, similarly, those of Rhodes lifters!

 

If you get genuine Johnson lifters they'll be good. Just watch for imitations.

Rhoads don't sound as sweet a a solid too me. They are a little quieter when they first fire up cold because oil is thicker. After it warms up they get noisier.

I figure the one thing a hyd cam can do better than a solid is be quiet. Why add a product that makes it noisy again? If you are OK with a little noise, might as well put a solid in it and have the ability to rev as high as you want.

JIM

 

I fought a valve train problem for almost 2 years.... it indeed sounded like a sewing machine....was breaking springs and loosing HP above 3Krpm..... thought it was just a spring problem... changed out to the beehive springs... definite improvement, but still not what it should have been... the engine still sounded like a sewing machine... i had gone to H-roller lifters by CompCams at the beginning of this build so i thought it was a normal sound for them... while i was changing springs i noticed that some of the old RR's were a not 100% smooth on there travel, so i decided to change them out as well to the comp cams pro mag 1.52 RR's.... While putting the new RR's in i was going by Gkull's guidance and adjusting them to all .045" backlash... set them all up perfect, put it all back together started the engine and was running fine... for about 2 min.... i did not set a single lock screw in the RR's... AAAHHGGGG!!! but this was actually a blessing ... so i went in to set back lash again to all lifters and found that 3 of the H-roller lifters were not keeping a pump!!!! so did another tare down, pulled the H-roller lifters, called CompCams they warranted them and sent me a new set... WOW... WOW ...WOW.... reves like a Banshie all the way to 6500+ and never losses power... just keeps going....

AND NO SWEING MACHINE SOUND for the first time in this build..... look at the lifters for this sound, i would say ether bad, or not adjusted properly...

my .02.... p

 

Nothing to do with how you adjusted them the problem is the Comp Cams Hydraulic Roller Lifters assembly grease went rock hard and I mean rock hard in them and played havoc with your setup. My advise would be do not assume because you soak them in mineral spirts etc... that they are going to work as they should and as I did. I was lucky in that I spotted the problem while trying to find correct pushrod length. I have mine moving smoothly now, but it was a lot of work ie. heating soaking in gas etc... to get the plungers and the roller tips too work the way they are suppose to. I think it would be wise to check for this especially if using old Comp Cams stock lifters or any lifter for that matter. I,m sure glad I did not have to go through pauldanas' ordeal, but could have easily happened had I not noticed it when I did.

Here is my initial post on the problem with my lifters plungers not returning to the top position.

http://forums.corvetteforum.com/c3-t...-problems.html

ikwhite

 

I was concerned with my cam when I got the engine running.

I have Pro Magnum lifters and they are to be set at 0 lash almost no preload.


Got the following back from comp cams

Subject: RE: COMP Cams Product/Technical Support

The Pro Magnum lifters do tend to be noisy because of the placement of the plunger.

If they are the Pro Magnum Lifters it is .002-.004" after zero lash. This is barely anything, a little more after zero lash. We do not recommend adjusting them running. It would be best to warm up the motor, do one side, then warm up the motor again and do the other side.