main bearing clearance

[turbosuzi]

I went to buy the Bently and they are out of stock. I am loking for the mainbearing clearance does anone have the spec? And should I be using the red or green plastigauge?

[turbosuzi]

Iused the red plastigauge and the largest clearance was .004in. with the old bearings. Does that sound reasonable? I will be replacing the bearings any ways.

[Rabbit on Roids]

that seems fine to me.

[turbosuzi]

OK, the engine has new main bearings that plastigauged out at a little over .002in., replaced 2 broken oil jets, new rod bearings, new intermediate shaft bearings, and a new oil pump, 15w40 oil and new filter. After start up it oil pressure went up to 50psi then after about 2min at idle down to 25 psi then after a trip around the block it went down just below 5psi. The pressure will go up to 25psi while on the throttle but drops immediatle after letting off. My quetion is what do I look at next to bring the oil pressure back to where it should be? the only improvement is that the low oil psi light wnot come on now.

[Rabbit on Roids]

are there any other bearings in the bottom end of the motor that you can replace? have you replaced the oil pump yet?

[53 willys]

OK, the engine has new main bearings that plastigauged out at a little over .002in., replaced 2 broken oil jets, new rod bearings, new intermediate shaft bearings, and a new oil pump, 15w40 oil and new filter. After start up it oil pressure went up to 50psi then after about 2min at idle down to 25 psi then after a trip around the block it went down just below 5psi. The pressure will go up to 25psi while on the throttle but drops immediatle after letting off. My quetion is what do I look at next to bring the oil pressure back to where it should be? the only improvement is that the low oil psi light wnot come on now.

are there any other bearings in the bottom end of the motor that you can replace? have you replaced the oil pump yet?

turbosuzi did you say these new readings are at the head or oil filter flange?

[turbosuzi]

oil filter flange.

[turbosuzi]

After searching for a couple of hours I found that oil pump shaft bearing, vac pump seal, and the vac pump/oil pump key way might be the next step in my quest to stop low oil pressure. Why would a bowtie shape in the vac pump gear be related to poor oil pressure?

[Rabbit on Roids]

there is a hole through the center of the oil pump shaft and vac pump shaft. oil pump is supposed to have a nice tight fit in the vac pump drive slot. not a large amount of back and forth play with a bow tie shaped slot. i bet that right there is your culprit. oil pump pumps it right up the shaft, and then instead of oiling the vac pump, it just squirts out the bottom of the drive slot and right back to the oil pan. i bet anything...

[burn_your_money]

I don't recall seeing a hole in the shaft for delivering the oil up to the vacuum pump? I thought that the IM bearing had a groove in it to spray oil at the vac pump?

[turbosuzi]

Does anyone have a part number or name for the vac pump oil seal?
Is the oil pump bearing located whare the shaft goes up through the motor and how would that affect oil pressure?

[Rabbit on Roids]

vacuum pump oil seal wont make a difference in oil pressure. and yes tyler, there is a hole through the oil pump shaft. the one i took out of my TD has the hole, the stock one from my 1.5 had the hole, and a couple other 1.6 pumps ive messed with had the hole. just because the ones ive seen have a hole, doesnt mean they all have them.

[theman53]

It is a long shot but could you try another gauge? Every gauge I have seen always reads different, but maye that one is just a little off. Something is different since your low pressure oil light isn't comming on. Maybe check to  see if the other 2 squirters aren't sticking open or that the new pump bypass spring isn't messed up. These are just guesses, but not out of the question I don't believe.

[Rabbit on Roids]

anything that can go wrong, it will.

maybe not right now, but some time.

[rallydiesel]

Are you sure oil goes through the pump shaft? I never heard this before. The vac pump gear gets lubed by the IM shaft bearing. Good luck finding a vac pump without the bowtie wear pattern unless you buy a new one from the dealer, if they're even available.