The Stovebolt Site Forums The Shop Area Engine Shop cams and lifters

Hey guys',
I have a 51, 235 car engine with hydralic lifters. Question is does a cam go flat if you turn the lifters around? That is, filler hole in the front to the rear. Oil comes into the passage from the rear cam bearing. Heck, does it make any difference which direction the lifter fills from? My oil pressure only runs about 5-7psi hot.

the lifter rotates when running so position in the bore when installed doesnot matter...using used lifters or not keeping used lifters removed on the lobe they were removed from will cause problems of wear to cam...doc

Thx doc41. I thought they rotated but had read an article where someone had noisy lifters. He said he turned them around and the noise went away. I any case, I just replaced my lifters with new ones.

You can probably get away with new lifters. but check the old ones close. Pay attention to what hole they came from. Look at the bottom wear surface, if its flat with no sharp edge the cam should be all right, if they do have a sharp edge and a concave or dish, the cam is most likely bad.

Why do you think the lifters are bad?
Are they noisy?

A few tips to unstick a lifter, add about 1 quart ATF to the oil, it has lots of cleaner in it, #2 loosen the rocker nut while the engine is running and let it clatter a bit, this tends to clean them out, adjust it back down 1 turn after it quits clattering.

Joe

Gec52,is this the same engine that was breaking rockers ? We never heard anymore about it.

You dont possibly have a solid cam with hydraulic lifters ?You will have a abnormal vacuum readings and rough running conditions. Normally if one has a micrometer he can measure the lobe tapper.You should have around .002 difference measuring front to back.The taper along with the convex shape of the lifter is what makes it turn.If you havent pulled the cam yet I would steer in this direction.As bowtietim asked if this is the one breaking rockers maybe this is the case ?

Bowtie is correct. This is the engine that kept breaking intake rocker arms. Six total. That is why I changed lifters. I've changed everthing else. Tomorrow I'll take it out to see if that finally fixed it. I don't think the cam is a solid. It runs like a swiss watch when nothing is broke. Vacuum is a steady 19 at a low idle and stays steady with an increase of rpm. Joe are you absolutely sure about adjusting the rockers 1 full turn after the clatter stops? Some folks say that is my problem. That I am adjusting them too tight by going 1 turn. Some say 1/2 . I really don't know anymore. The Chevy manual calls for 1 1/2. Right now I have then at 1/2. It is really hard to tell when the clatter stops because the clatter is so loud and no amount of adjusting stops it. You can hear it clattering 1/2 a block away. Anyway, I'm going to run it 20-30 miles tomorrow and see what happens with the rockers at 1/2. If all goes well I'll adj tighter. I'll keep you all posted.

Glenn,

+I too had a problem with a terrible clatter from hydraulic lifters on start up in a 235 engine. My solution was to replace the lifters with solid ones and adjust them to solid specks. No more clatter, just sounds like an engine with solid lifters. The cam is hydraulic. I ran another engine this way for over 100k miles with no problem but may have been lucky. Wouldn't want to cause you guys any engine damage but this worked for me.

Thx Ed. My valve train never quiets down. As for this last go around, I adjusted the rockers to only 1/2 turn after zero lash. I then drove the truck for 40 miles and it ran well other than the deafening clatter. I then read justed it 1/4 turn more for a total of 3/4. I drovre it ten miles and #5 intake broke. It has always been the intakes. This is the 8th one I think. I then drove it home and replace it and turned all of them back to 1/2 a turn from zero lash. We'll see what happens tomorrow. But after putting a hose to my ear and the water pump I've found out most of my clatter (noise) is from the new water pump. I took the belt off and ran it and she really quieted down.
Glenn,

The newest forum here at the Bolt is the Hauling Board. There you will find information on fellow Bolters either looking for or offering transport to various parts of the country. It's a great resource for someone like yourself. Give it a try.

ps..some have welcomed you but I see from your registration number that you've been with us for quite a while.

My daily driver late 235 with hydraulic lifters got a head rebuild 3 years ago. I replaced all the lifters and adjusted them only 1/8 turn (or less) after they stop clicking, because of prolonged high rpm freeway driving. Otherwise I would adjust them to 1/4-1/2 turn max.

I like to adjust them hot while running at low idle with a few seconds of higher rpm after adjusting and recheck. If done right each pushrod rotates freely - too tight and it stops spinning.

Here is a good link with detailed explaination ... valve adjustment procedure