350 Buck Truck Project engine revival

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#2 intake lifter preload

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#2 exh preload

this quick method May not be 100% accurate it is within specs

while I had # 4 int lifter out I cranked and cranked and saw no oil flow out of lifter bore

to recap the noisiest collapsed lifters 4 int and 2 exh were replaced with primed lifters. On startup lite clacking went away, normal exh sounds 5 mins the collapsed lifters. Repeat performance with 4 int and 2 exh replaced with originals hand primed. Must be something wrong in 2468 lifter gallery.

304 coming back out
 
Also at the end of day yesterday changed filter to napa gold and 15w40 diesel oil. Oil pressure was roughly same with breakin oil on shop gauge . Dropped to 19 lbs hot was 50 cold at high idle. Hot high idle 45. Shop gauge installed in stock sending unit hole
 
Zero change with new oil/filter after a 20 minute runtime. 1357 no issues from get go. Funny that was bank with flat cam lobes when I got truck . Originally no problems with 2468. And heads were reinstalled in original locations.
 
The oil supply to the lifters comes by way of the last cam bearing. It migrates around the block cover. If the cam bearing protrudes too far aft, or the proper gasket wasn't used under the plate, then there could be a diminished volume of oil to the lifter galleys. Not sure how one would be affected more than another though.
You are sure the even side (passenger) is providing less oil than the drivers side?

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I can't remember how the front of the lifter galley gets plugged. Is it the timing cover? I don't remember any pipe plugs. Am I on drugs? Diminished oil volume could mean an internal bleed in that particular galley.
 
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I've been in frequent communication with steve on this problem.

I have carefully examined the oil system diagram in the IH truck service manual. Each bank of cam tappets are supplied with oil from a gallery that comes from the rear cam bearing area. Pressurized oil that leaks from the rear side of the cam journal fills the cavity area created by the rear cover plate for the cam. Oil then flows forward, through a hole in the block on either side of the cam bearing saddle area, to the left and right tappet galleries. The manual notes that the oil supplied to the tappets is intermittent, and at a reduced pressure. There is a plug for each gallery at the front of the block.

I'm pretty sure I would have noticed a missing plug at the front of the block when the short block was on the engine stand. A leak from the cam rear cover plate should be very noticeable down the back of the block. There is a slim chance that the front plug is not fully sealing (seeping through the threads).

My line of thinking now shifts to a possible clogged oil gallery for the right tappet bank.
 
Here are the supply/lifter gallery specifics and pictures. Picture of the front is pretty clear.. A small leak from the threads won't cause a problem in pressure.

The rear cam journal has an annular groove in it that is fed by the cross drilled hole that also feeds the rear main through a hole in the rear cam bearing at the 6:00 position.
The rear cam journal is cross drilled 3/16 diameter all the was across. It intersects the annular groove. The cross drilled hole also intersects 1 3/8 hole drilled perpendicular to and centered on the rear face of the cam. The 3/8 hole supplys oil to the chamber behind the cam that feeds the lifter galleries.

The lifter galleries are about 1/2" in diameter so no way those get blocked. The other passages are shared by both lg's but are smaller. The cam rotation cam cause oil flow to favor one lg if flow is limited.
 

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Good explanation Robert. I can't access my pics right now and was going by memory. I agree oil "seeping" past a pipe plug is not what we are talking about. A missing plug is more likely causing such a loss. I once forgot the big welch plug under the timing cover (main oil galley). Priming it only produced 5 psi. Glad I didn't start it!
Could anything else be missing or blocking that galley?
 
Robert kenney said:
...a small leak from the threads won't cause a problem in pressure...

The rear cam journal has an annular groove in it... ...the rear cam journal is cross drilled 3/16 diameter all the was across...

The lifter galleries are about 1/2" in diameter so no way those get blocked...
Click to expand...

That's why I said *slim chance* on the plug leakage: not probable.

I wouldn't say *no way* for a tappet oil gallery to get plugged. Maybe not very likely, but could be possible.

Interesting thought on the oil passage drilling and groove in the camshaft. I don't recall inspecting the camshaft before it was installed.

From what steve has described so far, it seems like the right side lifters are not receiving enough oil pressure.
 
I have some good pix of the rear journal for referance.

Thinking now about it the symptomes steve told me, I wonder if the right side plug is missing. Kinda hidden under the dizzy hole.

Seems to quiet down upon initial cold start but after the oil gets hot the lifters go flat. Btw I left it out on my 152 when I built it 6 years ago.:icon_gonk: so the thought doesn't suprise me. :icon_rolleyes:
 
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Roger that! I will pull the dizzy and break out the dental mirror in the next short while. Now where is that 1/4 drive sidewinder?
 
rusty Scout said:
roger that! I will pull the dizzy and break out the dental mirror in the next short while. Now where is that 1/4 drive sidewinder?
Click to expand...

Man----- steve if it is missing and if you can get it in you are a master contortionist, I must have spent 4 hours screwing around and finally gave up and pulled the front cover. I could see it and get a tool close but just couldn't do it. :idea:

but if it can be done you will find a way.

Crude lifter gallery oil flow diagram.

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Pictures are worth a thousand words.
You could possibly pull the timing cover and rotate it enough to get a view of the plug locations without actually pulling the balancer off. When I figured out I had left out that main galley welch plug, I yarded out the radiator, water pump and eventually the balancer too because I boogered up the timing cover gasket too bad to re-use it. But I didn't have to pull the motor.
 
Well steve, I don't know whether to cheer or say sorry man.

At least you have the answer. :icon_wink:

1/4" npt plug. Needs to be flush internal wrenching like the square drive stockers to leave room for the distributer drive gear. I buy allen drive plugs by the box so I don't run out.
 
That pic is only worth about two or three words...

Its doubtful you hurt anything. The break-in was just a little louder than it should have been. And if it makes you feel any better, you might remember this:
http://www.forums.IHPartsAmerica.com/gas-engine-tech/3894-if-you-need-laugh.html[/url]

Glad you found it.
 
How about a sticky titled: "top 10 bonehead mistakes on your first IH engine rebuild" which includes the hidden right front lifter oil gallery plug. Sounds like others have been here before.

My first hidden clue was the nice new 1/4" npt oil gallery plug with sealer that was installed in the stock oil sender unit hole when I first got my engine back. I was wondering about that?

On the bright side this gives me the chance to move the ebay $180 unobtainium perfect shroud up a little to account for the new engine mounts. I never got a chance to mention this but I had to switch back to the 17" fan with aluminum blades that made mayben's skin crawl because on initial fire up that restored 18" factory IH fan was grinding on the shroud. Just kissing it actually. That May be another top 10 oversight. "new engine mounts almost destroyed rare '74-'75 pickall perfect fan shroud"

today was good and bad. Good that I don't have to pull the 304. Bad: doc stewart was bringing the engine stand back from his storage so I could use it again. When he got to the rendezvous point the stand was missing. It mysteriously jumped out of the back of his service truck and broke a castor on a country road. Luckily no other casualties. He went back 30 mins later and there it was in a heap on the right hand shoulder on a dangerous curve.
 
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rusty Scout said:
how about a sticky titled: "top 10 bonehead mistakes on your first IH engine rebuild" which includes the hidden right front lifter oil gallery plug. Sounds like others have been here before.

My first hidden clue was the nice new 1/4" npt oil gallery plug with sealer that was installed in the stock oil sender unit hole when I first got my engine back. I was wondering about that?
Click to expand...

Not sure why they would have done you that favor...did you save it? It will probably fit this hole and still clear the timing gear.
That lifter plug was a real sucker to tech. Being at the end of a long galley, it held system pressure so all indications were pointing somewhere else. And since the first 4 or 5 lifters on that side were quiet all the time, it turned into a real tail chase.
Glad it worked out!
 
What probably happened was he had a certain number that he pulled out and replaced the same amount but just not in right locations. Yeah same size and style 1/4"npt allen head stainless. Also that lifter galley or gallery is a low pressure intermittent feed so if the plug is not there you still get pressure and mysterious conditions. Racer Tom mandera has been here done that too. He answered a desperate plea for help and came up with that a few days ago but I had no idea that you could be able to see it with a mirror until Robert kenney posted those excellent pics.
 
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