I need help. I just remanufactured my 302 and kept the original cam and lifters (they were still in great shape), but I can't seem to build pressure in the lifters. Oil pressure is great and engine runs uneasy (I think due to the lifter issue)

They are in the spots where they came out and the push rods and rockers are as well.

I don't want to run the engine for fear of damaging anything. Any ideas out there.

 

The oil for the lifters should come up from the main bearing journals to the cam passage ways. It's been a while since I have been in a 302. It's possible that the cam bearing holes aren't lined up in the cam bearings. The rebuilder would have to be a dips**t to do that. You might want to use a drill on your oil pump until you get this fixed. If the lifters don't have oil then I bet the cam doesn't either.

 

I can't imagine the rebuilder did that with the cam bearings, he is a pretty reputable builder in the area. I think what I might do is pull off the valve covers and rocker arms and see if I might be able to bleed out the lifters that way.

Maybe they are clogged and can't get oil into them. I did notice that there was a notch of some sort in the side of the lifter itself. I'm wondering if that notch needs to be lined up in a particular position in the block (they can only go in two directions since they are roller cam lifters).

What do you think? Any other advice.

 

How do you know that no oil is getting to the lifters? Is there no oil on the rocker arms? None.

 

I'm almost positive I am getting oil to the lifters. I haven't taken the valve covers off yet, but there is oil that is leaking from the valve covers onto the exhaust manifolds (I need to put some sealer on the covers) when the engine runs. I'm just more concerned that maybe the lifters are not letting oil inside to pump them up.

 

Mine does similar with new lifters, I bought the crane energizer package, and I think the lifters are weak, reason for the low price I guess. For yours though, in a new motor it is not a good idea to run either an old cam or lifters. You can try two things, pull the lifters, and pump them up in a pan of oil by hand to bleed all the air out, or buy new lifters and pump them up. From experience do not buy the low price ones, better off with higher quality. Another option to is to run it a little and see if they will bleed themselves, weak lifters will just cause it to run bad. I did the same as you as to new motor, and Itried reusing stock cam, eventually number 4 exhaust lobe was ground off, and lifter sunk, pain in the but to clean out the motor and install new cam.

 

Jeffbran, you got me thinking you had no oil to the lifters. You actually just have a bad running engine. Of all the things possible without popping a valve cover, how did you get on the "no oil to the lifter idea"?

 

Never pump up lifters out of the engine. What you get is maxed out lifters, and flat cam lobes when it starts and runs up against a brick wall.

The only way to pump up lifters is to spin the oil pump with a drill and an adapter shaft. That way, the lifters pump up to match the cam position.

 

I was always told they had to be bled before install, it was probably good that these I have now wouldn't pump up.

 

New cam and lifter is a couple hundred.... Cheap insurance You get all the lifter back in the same holes they came outta?

 

The way I understand a hydraulic lifter to work is:

While off the lobe, the lifter fills through the lifter oil valley and pressurizes the lifter and pumps it up. Some oil goes up the pushrod.

While traveling up the lobe the lifter starts to compress because the oil fill passageway is restricted. At the top of the lobe the lifter is fully compressed. This compression process cushions the open valve travel.

Past the lobe, the lifter on it's path down, the oil passageway in the lifter opens and starts to refill the lifter and this cushions the closing of the valve.

Repeat as needed.

I think it's best not to pre-fill the lifters with oil.

 

Well, it's standard practice to prime a new engine before startup. When you do that, the lifters are gonna pump up. But, they won't pump up past where the cam will allow them to.

Then, it's really no different than when you cut the engine off. The lifters will be in various states of pump up/bleed off depending on where they stopped on the cam.

The problem with a brand new cam is that it hasn't yet been broken in. Anything wrong with the lifter, and you're gonna wipe out a lobe.

I know that most authoritative books on engine rebuilding say never to soak lifters or pump them up outside the engine before assembly.

 

according to the book i have(HP Books-How to Rebuild Small Block ford Engines) it say to prime the lifter first-, fill from the hole on the side till oil comes out the top of the lifter, this also was in the instructions with the comp lifters i installed , as well fill the push rods with oil before bolting the rockers on. I just installed a 351 w, did all that and pumped up oil pressure before starting engine, makes a rattling noise and sort of a tapping noise as well, and its coming from the rocker area, cam, lifters, rockers and push rods, all new, its a little confusing to me with the instructions they give for adjusting the rockers, i can turn the rocker bolts down by hand and then tighten between 1/4 -1 turn to set torque at 20 ft lbs, which is ok, but they talk about the lifters possibly needing a min or two to bleed down, but i get the same result no matter how i do it, y do you need to set to tdc if you get the same results if you don't. do i perhaps have the wrong length rods? i would expect to at least a little pressure on the bolts before i get them all the way in using only my fingers. right?
i also coated the bottom of the lifters with a approved grease and the cam lobes as well.

 

I have never primed a hydraulic lifer. I may just be lazy, but they usually prime themselves during the time I spend turning the engine over findind Ignition timeing. I dont prime anything, just use moly assembly lube.

 

superhooperduty something is wrong. If you set TDC and then tighten down the rocker arms cylinder #1 will have both valves closed but most of the others will be in various states of valve open. There is no way you should be able to tighten the rockers with fingers.

Priming the lifter. Hmmm. I think priming the lifters would be a good idea if you aren't going to prime the engine before starting. The lifters should drain down after you tighten the rockers. I feel that if you are going to rebuild the engine then priming with the oil pump is a must.

When rebuildng I always do a leak test. You hang the engine with the pan off and run the oil pump. You can watch all the bearings and see if any are letting too much oil pass. If a bearing passes too much oil then remove the bearing cap and lap sand .001" off the cap faces and put it back on and try again. Some people really hate this idea but if it's the last rebuild before the scrap yard and you don't have the bucks to turn the crank it will do the job.