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TKFireman
09-21-2011, 09:20 PM
I have a 401 with about 500 miles on a rebuild that had great oil pressure, at idle it was around 60 cold and 20 hot, then one day I cranked it and nothing. Here's the entire story

Engine - '77 401 complete rebuild, I built the engine. .030" over, crank ground .010"/.010" heads resurfaced, deck blocked, new bearings, rotating assembly balanced, new timing cover, new pump, pump housing cover lapped on glass to be perfectly smooth and flat. I checked the pump gear clearances both on the end and side and everything was in spec according to my Haynes manual.

First I checked the mechanical gauge, wound up replacing the line and gauge, no help.

I pulled the oil pan, oil was clean, no shiny specs, nothing in the pick-up, re-installed the pan, pulled the dizzy and tried to prime with a drill, drill turned noticeably easier than when I built the engine, oil pressure went up to around 12 psi on the drill, during the build, the drill got 40+ psi.

I pulled the oil pump cover and oil pump gears. No noticeable wear in the oil pump housing or on the gears, you can see where the gears rubbed the end-plate, but barely and no marks deep enough to feel or catch a finger nail on.

Where do I go from here, pull the pan again and re-inspect the bearings? I have a 304 that had good oil pressure when it was pulled, I could pull the timing cover from it and try it on the 401, but I don't see the point as the pump still looks new. Any suggestions?

jeepsr4ever
09-22-2011, 09:40 AM
This will sounds basic but the purple wire didnt fall off the sending unit did it?

TKFireman
09-22-2011, 10:02 AM
It has a mechanical oil pressure gauge, new gauge and hose since this started, pump is moving some oil, oil comes out of gauge hose, but not very much.

jeepsr4ever
09-22-2011, 01:36 PM
It is possible the filter collapsed or your oil pressure valve stuck open.

TKFireman
09-22-2011, 02:22 PM
I thought the same thing, when I re-installed the oil pan, I put fresh oil in it and a new filter. The trap door under the filter was closed and moved freely. I removed the bolt and spring from the pressure by-pass, plunger was all the way down and moved freely, re-installed everything, same result.
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1296.jpg
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1292.jpg
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1297.jpg
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1300.jpg
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1288.jpg

390spirit
09-22-2011, 05:10 PM
oil line under the intake, if there is one came loose?

one of the galley plugs come out?

its not skipping right? the reason i ask is in my younger days i kinda over reved my 390 and bent a push rod, which in turn let the lifter pop outta the bore. instantly no oil pressure.

tufcj
09-22-2011, 05:14 PM
One thing I notice is no spacer in the oil pickup. From the factory, the pickup had a plastic spacer about 1/4" thick in the hole in the pickup (where th oil is running out in the last pic). It kept the pickup from being too close to the bottom of the pan. I've seen the pickup actually suck itself tight to the pan, so no oil will flow. I don't think the spacer is available any more, but I've brazed a 1/4" nut to a couple with good results.

I've also seen the oil pump gear that connects to the distributor spin on the shaft. Something to check.

Bob
tufcj

390spirit
09-22-2011, 05:14 PM
i also notice no button on the bottom of your pickup in the last picture, it could be sucking it to the bottom of the pan

390spirit
09-22-2011, 05:16 PM
oh man treed^^^^^^^^LOL

TKFireman
09-22-2011, 07:16 PM
Thanks guys, I'll pull the oil pan back off, re-inspect everything and see about adding spacer to the pick-up. Would the pick-up suck to the pan while priming with a drill, after having great oil pressure for the first 500 miles? Could I mig weld a nut to the bottom of it, or drill a hole and through bolt it to add a spacer?

The engine still runs great if you fire it up, strong, sounds great, just low oil pressure, too low for the gauge to read at idle, goes up to about 20 psi at 2000 rpm. I did not do the valley oil line mod. This is in an '80 CJ7, not trying to turn high rpms, Melling MTA-1 cam, new stock lifters and rockers. I was also wondering if a oil galley plug cam out, but the only way I know to tell is to pull the timing cover and intake manifold off, was hoping to try all other possibilities before I pull those, but I think I may be running out of options.

jeepsr4ever
09-22-2011, 07:54 PM
I cant remember the last time I saw a plastic plug in the bottom of a pickup...maybe the last year was 1974 I cant remember but if you were running fine then it dropped off I wouldnt guess the pickup. I would guess a cam bearing walked out on you, filter stuck, pressure relief stuck, blown out gasket on the timing cover. I would measure from the bottom of the block to the end of the pickup and then from the top lip of the pan to the bottom of the pan. This will tell you if your pickup is not screwed in all the way.

TKFireman
09-23-2011, 09:01 AM
I pulled the oil pan again this morning. From the bottom of the block to the bottom of the pick-up is 7 1/4" From the top of the pan to the bottom of the pan is 7 5/16" Only 1/16" difference. Of course that is with no gasket in there. That could definitely be the culprit. So I went to unscrew the pick-up and found that the headers and the passenger side motor mount are in the way. So now I can either support the engine, remove that motor mount and header, install new pick-up, with spacer, re-install oil pan and hope that fixes it, or I can go ahead and pull the engine and strip it down on a engine stand and check everything, all the way to getting new high pressure cam bearings installed. That's lots of work, but only the cost of new gaskets and cam bearings. This is the first engine I have ever built and would appreciate any suggestions on where to go from here.

jeepsr4ever
09-23-2011, 10:26 AM
Did you lube the threads on the pickup tube before installing it? Can you tighten it 2 more turns?

TKFireman
09-23-2011, 10:43 AM
I used thread sealant on the threads, and if I remember correctly, I screwed it in until it got tight. I may can tighten it, but again, I'll have to remove the pass. motor mount and header to do so.

TKFireman
09-23-2011, 10:45 AM
Is it possible it sucked to the pan and actually bent the tube slightly and lost some clearance? I put modeling clay on it and sat the pan in place to test the fit when I was first assembling it, seems like I had plenty of clearance, however I don't recall the exact amount.

tufcj
09-23-2011, 04:57 PM
I'd just MIG a nut to it. Be very careful not to get any spatter in the engine or pickup. Normal engine vibration could let it drop if it was marginal to begin with.

Bob
tufcj

tufcj
09-25-2011, 06:23 AM
Another thing I thought of is that I've seen the tube on the pickup stress crack at the bends. It will suck air thru the crack. Inspect the tube carefully.

Bob
tufcj

TKFireman
09-25-2011, 08:54 AM
I'll inspect it, try to make sure its sealed to the block,and make a spacer of some sort for it. Think I might order the steel midplate set with thin gaskets too, seems like a good price for extra insurance, what does the oil filter bypass plug do for your engine?

tufcj
09-25-2011, 11:32 AM
The oil filter bypass is just supposed to open if the filter is constricted enough that oil can't pass thru it. Dirty filter, bad media, etc. It does let unfiltered oil back into the engine. That's why they eliminated it sometime in the 80's. Later oil filters adapters don't even have the passage machined.

I use the Bulltear midplate in all my builds. Cheap insurance.

Bob
tufcj

TKFireman
09-25-2011, 12:44 PM
I'll order the midplate, .007 gasket and bypass plug, any other upgrades from Bulltear recommended while I'm at it? I assume I get some plasti-gauge and try the .007 and .085 gaskets to see which has the best clearance? What is the optimum clearance? It says these gaskets go in dry, with no sealant whatsoever, is that right?

jeepsr4ever
09-26-2011, 04:47 AM
Yes assembly must be dry

TKFireman
09-26-2011, 07:33 AM
Thanks. That may have been the original problem. When I assembled the engine I used high tack gasket sealant on it. That may have messed up the clearances and caused excessive wear on the oil filter adapter assembly.

tufcj
09-26-2011, 05:09 PM
Sealer would have made the clearances looser than expected. That shouldn't have caused wear on the filter adapter. The clearance specs for the oil pump are in any TSM that covers a V-8. I can dig mine out and scan the pages if needed.

Bob
tufcj

TKFireman
09-27-2011, 06:15 AM
I'll check my Haynes manual when the parts come in, thanks.

TKFireman
10-04-2011, 03:49 PM
Got my order from Bulltear in today and had some time to tinker on it this afternoon. I installed the oil filter bypass plug, cleaned everything up and installed the oil filter housing using the steel mid plate and the .007 gasket. I thought I had some plastigauge but did not, installed it anyway and it became clear very quickly that the .007 gasket was too thin, tried to turn the pump from the top of the engine, was obviously way too tight. I took it back apart and installed the stock gasket, pump turned freely, must be the size gasket I need.

I also mig welded two 1/4" nuts to the bottom of the pick-up, they have a thickness of about 7/32" so I am guaranteed to have almost 1/4" of clearance between the pick-up and oil pan. I need to pick up some more sealant before I re-install the pan, will hopefully get that done on Thursday and try it out, but honestly I'm not very hopeful that this will fix my problem, but want to try every in-expensive option before I go to expensive options.

TKFireman
10-06-2011, 11:35 AM
Put the oil pan on this morning, oil filter and filled with oil, hooked up the drill to prime the oil, and got 5 psi. I'm going to re-install the .007 thin oil pump gasket and see what happens even though I'm a little concerned about it putting undo stress on the cam and dizzy gears. But at least I'll see if it boosts the oil pressure to a reasonable amount.

TKFireman
10-06-2011, 12:25 PM
I put the .007 gasket in. I got about 8 psi on the drill and I can not turn the pump from the top of the engine with a screwdriver because the clearances are so tight.

So now I have ensured that the gauge is not the problem, ensured that the pick-up is not sucking to the pan, re-did the pump with a steel midplate, thin gasket, oil filter bypass plug, so I'm thinking in has to be inside the engine, I reckon I'll pull the timing cover and check the galley plugs there and under the intake, unless someone has and other suggestions for me.

rollbar
10-07-2011, 10:17 PM
What does this mid-plate look like?

Is it the gasket between the pump & block?

Thanks,
Jim

TKFireman
10-09-2011, 04:49 PM
It looks like this http://www.bulltear.com/catalog/product_info.php?cPath=21_35&products_id=217 It goes between the oil pump cover and the timing cover, lets the gears ride against a piece of steel instead of aluminum for less wear. You use 2 paper gaskets and the steel midplate which is similar to the gaskets, but made of steel

rollbar
10-09-2011, 08:52 PM
Thank you,
Jim

TKFireman
10-11-2011, 09:00 AM
So I disassembled everything, grill, radiator, electric fan, AC compressor, alternator, power steering pump, fuel pump, all hoses, then after remembering the hard way that the water pump has to come off before the harmonic balancer, everything came off this morning, including the timing cover. Both galley plugs behind the timing set are there and sealed, thats not the problem, can't see the upper ones without pulling the intake.

So I think to myself, what to do next. I think "hey, lets pull a valve cover and see if oil is getting to the rockers" then immediately after that "hey dummy, you pulled the timing cover, too late" So I put the timing cover back on with a few bolts and the old gasket, hoping it would seal good enough and it did, 5 psi oil pressure on the drill, no leaks. I pulled the driver side rocker cover and ran the drill for a good 2 minutes straight with around 5 psi oil pressure, never saw a drop come out of any of the push rods to any of the rockers.....not good.....

So I guess I will keep disassembling, I'm thinking intake next, which I'm going to drop some coolant into the oil pan when I pull it, but shouldn't hurt the engine to prime it with a little coolant mixed with the oil will it? I'd like to prime it after pulling the intake and see if I can see anything else.

TKFireman
10-13-2011, 10:06 AM
Pretty sure I found the problem, which I was not expecting because I honestly did not notice a difference in engine sound, I reckon I'm just deaf or something.....Now.....What all do I need to replace/check? Obliviously all new push rods, those are the factory original ones with spacers under the rockers to make up length. Should have gone with new hardened ones when I rebuilt.

Should I buy a tool and measure for new ones, go original length and use shims again, which may be easier. Any company ya'll recommend to order push rods from? What was the probable cause for this? Too much HP/RPMS for 30 year old stockers or something I did wrong during assembly?

http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1301.jpg
http://i785.photobucket.com/albums/yy137/TKFireman/IMG_1302.jpg

tufcj
10-13-2011, 11:30 AM
I had the same thing happen in my CJ when one of the rocker bridge bolts broke.

Why spacers under the rockers? Was a lot milled from the heads or block? They will usually tolerate a .010-.015 total milling without shims. What's the closed pressure on the valve springs? How much lift on the cam?

Could be too heavy of springs. Could be the valve retainer hitting the valve guide. Could be simple metal fatigue. I'd do a leak down test to be sure the valve hasn't hit the piston and bent, check springs and valve guide to retainer clearance. If that all checks out, throw new pushrods in it and run it.

Bob
tufcj

TKFireman
10-13-2011, 12:30 PM
Thanks for the suggestions. Springs are stock replacements that's all I can tell you about them. Spec sheet from machine shop said deck height is 9.190" which is .015" shorter than stock I think. Heads where surfaced by .010" for a total of .025" taken off.

Machinist said to install push rods and tighten to zero lash, or just where the lifter was not pushed down at all and measure the distance between the rocker and head. He said the distance needed to be no more than .030" and no less that .015." My gaps where around .040" for most cylinders so the shims went in, which is what the machinist suggested. Odd thing was cylinders #3 and #5 were right at .030" so I did not use shims on those cylinders, intake or exhaust. Broken push rod was #5 intake.

Cam is a Melling MTA-1, here are the specs
----------------INT----EXH
Cam lift---------.281---.296
Valve Lift-------.450---.474
Lobe Ctr--------105----115
SAE duration----280----289
.050 duration----204----214

SAE Timing
BTC-- ABC-- BBC-- ATC
30 ---- 70 ---74 --- 35

.050 Timing
BTC-- ABC-- BBC-- ATC
-3 --- 27 --- 42 --- -8

tufcj
10-13-2011, 07:43 PM
With that cam, there shouldn't be a retainer to guide problem. Stock compression? Stock style pistons? I had flat top pistons in a 304 that had to have reliefs cut with just a .468" lift cam. You might want to look at the top of that piston with a bore scope.

Bob
tufcj

TKFireman
10-14-2011, 10:57 AM
the pistons are. 030" over stock compression. I don't have a bore scope but I think my neighbor has a leak down tester. I think that would be a good idea. With the intake off it would be obvious if the intake valve is damaged and leaking at all. Thanks for the suggestions.

390spirit
10-14-2011, 01:45 PM
glad you found the problem.



i nailed it with my first post LOL not saying you over reved it but i had the same thing happen to me LOL

Norm

TKFireman
10-14-2011, 03:29 PM
You did hit it on the first post 390spirit. It is possible I over reved it, cam is rated for 1500-4500 rpm. Pretty sure I hit 5000+ a time or two. I got to remeber I have a CJ7 and not a race car sometimes. I ordered new push rods made by comp. hopefully will be able to put it back together, test everything and fire it up next week.

TKFireman
10-17-2011, 10:06 AM
I borrowed a cylinder leak down tester this morning and ran a test on the #5 cylinder, which is where the intake push rod broke. It passed and none of the air coming out of it was coming out of the intake port on the head or the exhaust.

I went ahead and cleaned everything up and re-installed the timing cover, water pump, harmonic balancer and the alternator. I'll leave the AC compressor and power steering pump off just to keep them out of the way while installing the intake. This afternoon I plan to pull the rockers and old push rods, clean up the intake, and maybe open the bolt holes on it just a little, it was a PITA to put on on the stand, gonna be worse in the engine bay. Opening those holes a fuzz won't hurt anything that I can see, or am I wrong?

I'm debating on whether or not to install the intake, which then I could install the grill, radiator and everything else, or wait until the push rods get here and install the intake after putting the valve train together, any opinions on that?

390spirit
10-17-2011, 04:46 PM
i personally would do the intake after the valvetrain, but either way will work

TKFireman
10-19-2011, 04:53 PM
Its all back together and I have oil pressure!!!! However, now I have a weird ticking sound, it sounds like its coming from the front of the engine, not from under a valve cover, but I could be wrong. I'm going to remove the belts and turn everything by hand to see what happens. I'm betting its the pulleys hitting in one spot, we'll see. Thanks again guys for your help finding and fixing the problem.

TKFireman
10-19-2011, 06:15 PM
Took the power steering belt off, noise went away, put it back on, kinda loose, noise was not as loud, looks like I may be in for a new power steering pump before long. I also found that the water temp gauge is reading 250 degrees+ all the time, the engine is obviously not that hot, so I need to look into that too.

I got the timing to 8 DBTDC and idle at 800 rpm and went for a drive, felt good. Filled it up with gas, after the drive it had 28 PSI oil pressure at idle. Around 50 PSI cruising. Looking forward to taking it to work tomorrow, thanks guys.

390spirit
10-20-2011, 04:35 PM
thats awsome, enjoy it!

tufcj
10-20-2011, 05:41 PM
Glad you found it and it was nothing major.

Bob
tufcj

TKFireman
10-21-2011, 07:18 AM
Thanks again guys, a broken push rod seems major to me, but I guess it could have been worse. I still have to try and dial in the tuning, I'll probably be back with another thread for that before long.

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