I'm clueless

[John Pasinski]

I've posted several times about the problem I'm having w/ my 402 engine. I've received a lot of great suggestions. But everything so far has been fruitless. Before I scrap this engine (and maybe sell the truck); I'm gonna try once more. I overhauled the engine. New rings, crank, new crank bearings, RV cam, lifters, timing chain & gear, new oil pump, I think that's it. I am unable to get the #1 exhaust lifter to pump any oil whatsoever to the rocker. It will go up the push rod, but not into the rocker. I put an oil guage in line and ran the pump w/ a drill. The guage showed 40#. I removed the plug at the front of the engine, and ran a rod straight through the lifter bore oil gallery to the rear of the engine to make doubly sure there was no blockage. All other rockers are receiving oil just fine. Yes, I have checked the push rod & rocker, both are clean as a whistle. I even swapped the exhaust w/ the intake lifter to R/O a defective lifter. When I swapped them, that exhaust lifter pumped fine in the intake bore. The intake lifter, then was NOT pumping in the exhaust bore! That proves the lifter is good. I do not "feel" excessive slop in the exhaust bore, so I don't think it's a worn lifter bore. Although I don't have the bore specs to really check that. Would the valve spring (maybe it's too weak?) have anything to do w/ the lifter's effectiveness in pumping oil? I have no more straws to grasp, no more ideas. Is it possible there was some kind of TSB (service bulletin) on this problem 37 years ago? As of this posting, I have not been able to locate any engine builders here in Orlando. This engine is the the textbook definition of insanity. "DOING THE SAME THING REPEATEDLY; WHILE EXPECTING DIFFERENT RESULTS". I appologize for the lengthy question; but this truck's life depends on a solution.

[68gmsee]

Yeah, I remember your dilemma.. I hope you get it resolved. It would be a shame to do all of that work and not find a solution.

The weak valve spring idea could be the next thing to check. It would be simple enough to swap out. Acompressor and adapter to pressurize the cylinder and you could do it real quick.

If that doesn't do it, only thing that I can think of is to go back and recheck the main bearing clearance and rent or borrow a bore gauge to check the lifter bore to make sure it's cylindrical. Lack of resistance will cause weak oil stream on the rockers.

[John Pasinski]

Thank you......Your suggestion is very logical. To my detriment, I am too analytical instead of just goin for it. When you're analytical, you tend to overlook the simple solutions. Although in my case, I don't think there is a simple solution. I'm trying to find an engine rebuilder here. I may pull the engine & have a professional look at it if I can find a good shop.

[Boog]

It sounds like you have only tried to preoil it before starting so far. Correct? Have you posted your situation down in the engine forum? You may get some help there as more engine builders might hang there.

[highperf4x4]

Actually I am assuming that you have this engine running. Otherwise you wouldn't know what the lifter would actually do.

You have a blockage in that lifter bore. Valve spring won't make any difference whatsoever. Before you built the engine, when you had the block vatted, did you blow it out good after it came out of the acid?

There is a possibility that while you have the lifter out you can try to back flush the oil passage with something like carb cleaner. Using one of those red straws, you aim it into the oil hole inside the lifter bore and blow it backflush it.

And just out of curiosity, when you say you swapped the 2 lifters........... do you mean with each other? Or with a new lifter. I'm assuming the camshaft break-in period has already been done therefore, each lifter has been properly "mated" to it's came lobe. In this case, you do not want to "swap" any lifters and run the engine again. You could however, swap the pushrods and rockers and see what happens.

[mr48chev]

If you are pre=oiling it have you tried turning the crank to a different spot in the rotation? it may be that the lifter is in a spot where the oil passage is partially blocked by the side of the lifter and not letting it oil at the moment.

Have you pulled the lifter and primed the engine to see if you have oil flow to that lifter? If there is a steady flow of oil with the lifter out there shouldn't be a problem with the engine running.

If it is running and not oiling I would go along with Highperf4X4 and think that you have a blocked oil passage to that lifter. I'd have to go out and check my block in the garage but there may be an angle or corner where crud can collect in that particular passage and it is at the end of the run on that side so that is where crud might have accumulated in the past.

[jeffspower]

If you have taken the front galley plug out and found nothing, then there is no "hole" to plug. The lifter bore "windows" the oil passage. There is no individual hole or passage.

I agree to pull the lifter and run the pump with a drill. If you get flow, no problem there.

Same goes for moving the crank. See what it does.

Are you using a priming shaft without a collar? That would explain your findings.

I'm assuming you haven't ran the engine yet. I think we all would like clarity on this.

[John Pasinski]

Originally Posted by highperf4x4

Actually I am assuming that you have this engine running. Otherwise you wouldn't know what the lifter would actually do.

You have a blockage in that lifter bore. Valve spring won't make any difference whatsoever. Before you built the engine, when you had the block vatted, did you blow it out good after it came out of the acid?

There is a possibility that while you have the lifter out you can try to back flush the oil passage with something like carb cleaner. Using one of those red straws, you aim it into the oil hole inside the lifter bore and blow it backflush it.

And just out of curiosity, when you say you swapped the 2 lifters........... do you mean with each other? Or with a new lifter. I'm assuming the camshaft break-in period has already been done therefore, each lifter has been properly "mated" to it's came lobe. In this case, you do not want to "swap" any lifters and run the engine again. You could however, swap the pushrods and rockers and see what happens.

Yes....I have the engine running. There's no blockage in the lifter oil gallery. I Removed the plug to the right of the cam gear and ran a 1/4" rod from the front of the engine clear through to the rear of the engine block. There were no restrictions in either the oil gallery, or the lifter bores . Yes...vatted the block. It was cooked twice for 2 hours each time. Then blew out every passage, & bolt hole using compressed air. When I say I swapped the lifters, what I did at that time was remove the plugs and intake, then swapped the lifters while cranking the engine with my remote starter. There was no load on the cam at that time. The lifter that wasn't pumping, then pumped in the swapped bore! I switched them back, and since there was nothing else I knew of to do, I reassembled the intake etc. That's when I did the cam "break in". That was last night. I let the engine run for 15 minutes @ 1200. ALL rockers were getting oil EXCEPT that pesky #1 exhaust. I wanna scream!

[jeffspower]

Original rockers, stock replacement or?

I have seen a few OE style rockers that wouldn't oil. It was because the oil hole/ pushrod pocket fittment/ alignment wouldn't allow it. The oil hole didn't "see" the pushrod hole as the rocker went thru its travel.

[highperf4x4]

John, you might need to look at getting someone to help you with your build and look at a new cam and lifter kit before you toast the rest of the motor. First off, you don't spin a new cam until you're ready to fire the motor. You will only scrub off the assembly/break-in grease/lube and interfere with the proper "spinning" motion required to mate the lifters to the lobes. All lifters spin while the engine is running. If they don't, the lifter and lobe will eat each other to death. That black coating you saw on your cam was to get this spinning motion started as quickly as possible. Secondly, You have to start the motor quickly without a bunch of cranking or you will need to pull the cam again and relube it. Thirdly, you MUST bring the engine up to 2500 rpm immediatey and then vary between 2500-3500 rpm for 25-30 minutes. If you don't, then you will fail to get the "spinning" motion from the lifters. The reason you need to vary the rpm's is because the cam gets it's lubrication from the crankshaft. The crank simply "throws" oil on the cam. By varying the rpms, you will throw oil on different areas of the camshaft. This is necessary to pull the "heat" out of the camshaft during break-in.

I see this as a far more important issue than one non-oiling lifter. However, running a rod through the block isn't going to tell you if it's plugged or not.

You can pull your lifters out and look at the bottom of them They should be scuffed in a circle on the bottom. If any of them are scuffed in a straight line then you are looking at a new set of cam and lifters without a doubt.

[highperf4x4]

Originally Posted by jeffspower

Original rockers, stock replacement or?

I have seen a few OE style rockers that wouldn't oil. It was because the oil hole/ pushrod pocket fittment/ alignment wouldn't allow it. The oil hole didn't "see" the pushrod hole as the rocker went thru its travel.

That's why I asked him if he switched the pushrods and rockers. I would think this test would tell us more.

[jeffspower]

Originally Posted by highperf4x4

That's why I asked him if he switched the pushrods and rockers. I would think this test would tell us more.

[John Pasinski]

Along with trying to locate a professional to continue with my problem, I will try your suggestions as to switching rods & rockers. Thanks all....

[Richard H.]

About the 5th post down gives you a diagram from here...
http://www.chevytalk.org/fusionbb/sh...hp?tid/192284/
I think the only thing you could hurt is your rocker up top if you let it run for a while and keeping an eye on it. It really could be an air block.

[highperf4x4]

Let me ask you this John, have you taken the lifter out completely and then spun the motor and oil pump to see how much oil is being provided to that lifter bore with nothing in it? If it really is tossing out a bunch of oil then you have 3 items to deal with, a lifter, a pushrod, or a rocker arm. You could simply replace all 3 of them.

[John Pasinski]

Thank you so much Richard for the link. Even if I can't solve my problem, at least I've learned a lot more, and have gained a more knowledge on how these function. Thanks again.

[68gmsee]

I think everyone is overlooking the fact that if you have lack of restriction, you have lack of oil pressure. That's why I mention main bearing. If there's too much clearance anywhere in the passage to the lifter and up to the rocker you will not get the oil pressure needed.

If I remember correctly, you said you could see the oil come halfways the pushrod but not all the way out the top. Mating surfaces of the lifter and rod may also be a problem.

And weak valve spring could cause the push rod to lift off the lifter at high revs and cause low oil pressure.

[highperf4x4]

Lack of restriction from main bearings wouldn't cause a lack of oil on only 1 lifter. Likewise, a weak valve spring would only affect the lifter at high rpm's.

[John Pasinski]

Originally Posted by highperf4x4

Let me ask you this John, have you taken the lifter out completely and then spun the motor and oil pump to see how much oil is being provided to that lifter bore with nothing in it? If it really is tossing out a bunch of oil then you have 3 items to deal with, a lifter, a pushrod, or a rocker arm. You could simply replace all 3 of them.

Yes, when I R/R cam, I first dropped in the replacement lifters. Next, using a priming tool, I spun the pump. This verified ALL lifters were receiving oil as I was able to see them "charge up". Next, I removed the #1 exhaust lifter from it's bore, and then again, spun the pump w/ the priming tool. There was a nice flow of oil poring into the lifter bore. I next reinstalled that lifter, dropped in all push rods, and once more ran the primer for about 3-4 minutes. ALL pushrods filled and spilled into their rockers EXCEPT for that #1 exhaust. It filled, but was unable to spill into it's rocker. Today, I'm going to phone a Hi-Perf. shop I found online about 40 miles from me. I'm hoping they'll direct me to professional help (take that any way you want). Maybe they'll be willing to look at it themselves. If they will, I may just drive it there. I don't think I'll hurt that rocker too much. What do you think?

[highperf4x4]

Yeah there's a good chance that the pushrod will go through the rocker arm if it's not getting enough oil and you run it 40 miles. Assuming your using stock-style stamped steel rockers. If it makes it there, I would definitely replace them both afterward.

[highperf4x4]

Originally Posted by John Pasinski

I'm hoping they'll direct me to professional help (take that any way you want).

I'm not sure what you mean by "take that any way you want" but it sounds like a good idea.

I'm not trying to bash on you but it sounds like you've been misled on alot of things. Like pre charging your lifters before you've adjusted the valves or pushrods "spilling" into the rockers instead of shooting over them like they should when you have the proper oil pressure. But I'm going to stop tossing out advice on things you didn't ask for help with. You came in here about a non oiling lifter and best of luck on getting that figured out. Having built performance engines for over 20 years and seeing so many mistakes made that cause engine failure causes me to cringe and I can't help sometimes but offer my insight to others to avoid these pitfalls.

Anyway, I think I've helped ya all I can and hopefully someone else can solve your problem.