401 swap into my CJ7

There are a lot of things that could be happening here but I would start with the pickup tube and screen especially if any silicone has been used on the motor . To remove mine in the vehicle I had to heat the pickup tube and bend it a to get it to screw out. Next, replace oil,remove distributor and try to prime motor with a drill instead of starting it. If that doesn't do it I would look at replacing front cover and oil pump assembly.
 
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if after that it sill has no psi pull the oil pump gear cover and take a look. looking at side gear clearance and the gear cover/plate looking for grooves chipped teeth etc. thatll let you know if you need the front cover
 
That sounds like a good idea, thanks Bertie. I will look for a replacement oil pan gasket, get some more oil and see what I can find. The way that it went from sugar to s**t so quick, I'm thinking it has to be something clogged somewhere, the engine didn't make any weird noises, just low pressure. The oil pump and timing cover were new when engine was rebuilt around 500 miles ago. I really hope they are not the problem. That timing cover is not cheap and I really don't want to have to take the front end apart again.
 
Thanks CJ5walt, I'll see what I can find tomorrow.
 
I went ahead and removed the oil pan this morning. Oil pick-up screen is clean and so is the inside of the pan. I still haven't been able to remove the plunger from the oil pressure relief. I tried to blow the plunger out with air pressure but never got it to move. I remember moving that plunger when I was rebuilding the engine, the only way I got it to move was pushing up on it with the end of a screwdriver through one of the galleys on the oil pump cover. If that plunger is there to relieve excess pressure, then it being stuck all the way down would not cause me to not have any pressure would it?
 
I cleaned the pan, block and pick-up, then re-installed pan. Issue doesn't appear to be inside the pan. I put everything back together, pulled the dizzy, filled with 10w-40 and primed with a drill while the wife watched the gauge, it went to 12 psi, but then I kinda expected it as all I really did was take it apart, clean it and put it back together. It went to around 60 PSI on the drill when I primed the engine for the first time after the rebuild.
I ordered a new oil pump gasket today, will probably pull the oil pump cover tomorrow and see what it looks like, thats the only other thing I know to do.
 
Sorry to hear it's being such a PITA. I know there are others but H&F Performance in Wilson built my 401 it holds about 40 psi @ hot idle. If all else fails they may check your front cover and pump gears for wear. Doug has an awesome reputation on the older big AMC motors. 252 243 2050 Good Luck! p.s. words of wisdom: when priming with a drill don't make contact with camshaft dist. gear
 
Thanks for the tips BERTIE RENEGADE, I hope it doesn't come to me hauling it to a mechanic, but its getting closer to that every day. I'm using an old dizzy to prime it with the drill, with the cam drive gear removed.

I pulled the oil pump apart today. I didn't find anything that looks like it would make it loose oil pressure. There was some slight wear on the cover plate, but I think that it is normal the way the gears ride on it. The inside of the housing looks perfect, just the way it did when I put it together. The gears look new. The oil pressure relief was all the way down and moved freely. Is not a gauge problem because when primed with a drill, the pump spins noticeably easier, so its either the pump not pumping to full capacity, or something in the oil path is not allowing it to build pressure. I'm stumped, any ideas?
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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.
 
BERTIE RENEGADE said:
I heated a length of the pickup tube with it in the jeep and bent it carefully to allow enough clearance to unscrew it.(Mine was clogged)
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How did you get it back in, with the perfect bend in it to have the right clearance between it and the pan?
 
I know the scoring on the oil adapter where the gears ride doesent look like much, but with my 360 I had similar scoring (at least from what the pic shows) on mine and I had a low oil psi when hot, 5 psi or less. I installed a mid plate, oil bypass block off, and the thinnest gasket i could and it took my psi up to 20 psi hot.

You can find the parts hear:
http://www.bulltear.com/catalog/index.php?cPath=21_35&osCsid=f15057b305cd9767ab8901d15f5ed4c3

And check out the forum there, they have a section devoted to oiling systems
 
TKFireman said:
How did you get it back in, with the perfect bend in it to have the right clearance between it and the pan?
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I first screwed it back in and then bent it back as close as I could to original and placed pan in position until I couldn't feel the tube hitting the pan and bent it about another inch away from the bottom of the pan. As cj5walt mentioned it doesn't take much scaring on aluminum pump assembly to lose pressure, according to the picture I would say yours is very questionable, but it's strange that it went bad so quick. I know this get's expensive doing it by POE but from my research the bulltears price on the cover and assembly is a pretty good deal and replaces all oil pump components.
 
I've looked at bulltear's steel midplate and thin gasket set, its not very expensive, wouldn't hurt to go ahead and put it in there, the steel shouldn't scar like the aluminum. The oil bypass block-off covers the little trap door under the oil filter, which allows oil to bypass the filter in case the filter becomes clogged correct? Could that be a place to loose pressure, or just bypass the filter?

I started a thread in Bulltear's oiling forum a few days ago too, looking for all the help I can get.
 
TKFireman said:
The oil bypass block-off covers the little trap door under the oil filter, which allows oil to bypass the filter in case the filter becomes clogged correct? Could that be a place to loose pressure, or just bypass the filter?
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Yes you can loose psi at the bypass, either by the tube clogging or the spring going weak. Its really common for carbon to build up and cause the bypass to become "sticky" allowing the plunger to hang open at times.

The bypass block off plate is easy to install. Remove the bypass plunger and spring. Then use a deep 6 point socket and remove the peice the oil filter threads on to. Clean oil filter adapter in parts washer or with brake-clean, dry with compressed air. Trail fit block off plate (just for good measure, I have used many of their parts with no issues at all) and re assemble
 
Thanks CJ5walt. I ordered their steel midplate with standard gaskets, a .007" gasket and the bypass plug. I was surprised to read on their web site that the gaskets go in dry, did you use any sealant? I'll get some plati-gauge and assemble the pump with the different thickness gaskets and see which one has the best clearance.
 
I bought the engine for $400, no front accessories, no flywheel. I saw several 360's in the $75 to $250 range depending on condition while I was looking, but the 401 didn't cost anymore to rebuild than a 360 would and is just cool.
 
yea I got a 78 cj5 and just put a 360 v8 in it but I was thinking about trying to find a 401 to rebuild and put in it so thats why I asked
 
82cj5 said:
yea I got a 78 cj5 and just put a 360 v8 in it but I was thinking about trying to find a 401 to rebuild and put in it so thats why I asked
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ive got a mild 30 in my cj5 and i think a 401 would be a little (lot) more fun than it needs to be.....not enough wheel base


any who.... any luck on the engine yet??
 
the 401 is definitely fun and plenty of power, little scary on occasion. I'm still waiting on a delivery from Bulltear to keep working on mine.
 
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 said:
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.
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hopefully it will work out for you, the midplate and thingasket made a 20 psi diffrenece on mine
 
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