Engine oil pressure issues

#21
I'm really thinking some of your clearances have got to be out of whack, or like what mikestang said. You have to keep in mind, with turning the pump fast with your prime tool is the same as revving the engine. What is the first sign of a worn out engine? Low oil pressure at idle because of internal parts worn out and clearances being out of spec. I.E. your main bearing should have a tolerance of .005 - .007, (strictly an example) and after 200k miles that bearing has worn out to about .025, so a lot more oil will seep by. You also have to take in consideration that your dizzy is not spinning very fast at all at idle, 1/2 engine rpm. So when my car is idling, my oil pump is only turning about 300-400 rpm. Just picking my own brain a little. I hope you can find the problem!
 
#22
Okay I just put agob of vasolin in the end of the dis and is touching the oil pump shank. For :poo:s and giggles I pulled the great of the dis put it in and turned it with the drill and it builds pressure same as with tool.i just don't see how when it's running it gets ZERO pressure but manually priming gets over 45psi. I guess I'll be pulling the motor and swapping the crank kit out with a new one free of charge. Anyone who builds motors want to make some cash and help me install it lol? I live in ga
 
#23
It makes absolutely no sense that your getting pressure with the drill but 0 when running. Usually a drill will read a little lower.

Since your able to get steady oil up top with the drill I am doubting a oil galley plug came out. One thing that has me stumped is with the dist out you get pressure....dist in no pressure.

Are you sure the shaft is going in the dist and actually turning?

Basic clearances

Mains .0018-.0028"
Rods .002-.0025"
Thrust .005-.008"
Rod side clearance .015-.021"
Oil pan pickup to oil pan .375"

What end clearance did you have on the camm

Sent from my XT907 using Tapatalk 2
 
  • Like
Reactions: ratio411
#24
Have you ever looked inside a socket that is rounding out?
You can't really tell with the eyes that it is rounding, unless it is really bad or was rounded with an impact.

It makes no sense that you can get pressure with a manual prime, but nothing with it running.
It still comes down to the distributor drive.
 
#25
Rick 91GT said:
It makes absolutely no sense that your getting pressure with the drill but 0 when running. Usually a drill will read a little lower.

Since your able to get steady oil up top with the drill I am doubting a oil galley plug came out. One thing that has me stumped is with the dist out you get pressure....dist in no pressure.

Are you sure the shaft is going in the dist and actually turning?

Basic clearances

Mains .0018-.0028"
Rods .002-.0025"
Thrust .005-.008"
Rod side clearance .015-.021"
Oil pan pickup to oil pan .375"

What end clearance did you have on the camm

Sent from my XT907 using Tapatalk 2
Click to expand...

Rick, the OP said he slapped the motor together without even using plastigauge, so who knows what the bearing clearances are.. As many have pointed out, it could be a dozen or more things either individually or combined which are the problem.

Could the distributor gear pin be broken and not turning the shaft to engage the oil pump so that the dizzy gear is just spinning?
 
#26
Okay pulled the motor apart. Number 3 main is down to the copper and chewed in the sides. The rest or the mains all have groves but not down to the copper as well as the rods. The number 1 main part of the crank actually had grooves in the crank it self. I don't think the rest do. Idk if there some how got trash in the motor for the bearings to look like that or if it got like that from the number 3 main bearing being chewed up or cause it ran low oil pressure for a long period of time....grrr. Oh well they're replacing my crank kit for free. Can you describe how to set thrust? It's a little confusing to me reading it from the alkdara. Seems you just pry the crank forward after setting the rest of the main bearings then torque number 3 to spec and check end play. Right?
 
#28
Oh yeah the most important thing I for got now you mentioned it lol the number 2 and 6 rod cap was switch in the wrong spot. I guess that's what happens when your blind putting a motor together in the dark with a drop light Lol. The crank would have to be turned but oreillyautoparts is going to swap my crank kit out for a new one free. But yes all the main caps were facing the right direction with the arrow pointed to the front of the motor
 
#30
mr2gq said:
Okay pulled the motor apart. Number 3 main is down to the copper and chewed in the sides. The rest or the mains all have groves but not down to the copper as well as the rods. The number 1 main part of the crank actually had grooves in the crank it self. I don't think the rest do. Idk if there some how got trash in the motor for the bearings to look like that or if it got like that from the number 3 main bearing being chewed up or cause it ran low oil pressure for a long period of time....grrr. Oh well they're replacing my crank kit for free. Can you describe how to set thrust? It's a little confusing to me reading it from the alkdara. Seems you just pry the crank forward after setting the rest of the main bearings then torque number 3 to spec and check end play. Right?
Click to expand...

Well, all this could be explained by repeatedly running the engine without oil pressure.
These things are likely caused by no oil pressure, and not the cause of no oil pressure.

However, when I read over and over, things like you didn't check clearances, used an old oil pump, and now that you have put rod caps on wrong... I have to assume that this is what happened:
You made a series of errors installing parts, these caused your initial low oil pressure, and in a downward spiral of running the engine with low oil pressure, trying to figure it out, you caused a snowball affect of damage that ended in no oil pressure at all, and severe damage.

The only theory I have for higher oil pressure with the manual operation is the fact that the bearings were not spinning, allowing more oil to reach the gauge. When the engine was running, with such severe damage, it allowed the pressure to bleed off quicker, not reaching the gauge.
 
#31
Before you put this thing back together, get with someone who has done this before. That is great that Orielly's is replacing it for free, but don't go back at it again until you are 100% clear on what you are looking for. We all make mistakes, this is how we learn. So no harm there. At a minimum, you need to be pastic gauging all your tolerances. Tourqe specs and setting the thrust bearing are also important. My 331 was the first motor I have ever built alone. I read, read, read, asked questions, asked questions, etc... You get the point. I borrowed some good dial indicators and bore gauges from my fathernlaw and measuered everything I could. Two years later, and about 8000 miles, still going strong (knock on wood!). You can do it, just research it out before hand.

Where are you in GA?

Joe
 
#32
Ahhh oh well. It's a learning experience for me anyway lol it's all good. I'll buy plastigage this time and check clearances. Explain to me how to correctly set the thrust. Tried finding a YouTube vide for a 302 but couldnt find one
 
#33
mr2gq said:
Ahhh oh well. It's a learning experience for me anyway lol it's all good. I'll buy plastigage this time and check clearances. Explain to me how to correctly set the thrust. Tried finding a YouTube vide for a 302 but couldnt find one
Click to expand...
Hopefully I am doing it right... :)
Here's what I do:

Install the crank with it's bearings and caps correctly oriented, lubed, and torqued.
No rods or anything else yet.
Spin the crank over several times, making sure everything is smooth and free.
Both directions. (The last engine I did, you could spin the crank with your fingers on a counterweight, and when you stopped pushing it, gravity would keep spinning it slightly until the counterweights were in their down-most postition. Smoothest I have ever had.)
Then use a pry stick between a main cap and crank weight to push the crank back and forth gently a time or two, making sure it is smooth motion.
Then push it back one last time.
Set up a dial gauge, mounted to the block, gauge pin on the crank, ready to be pushed forward.
Then when it is all zero'd out, push the crank forward from the main cap again, and see how far it goes.
Repeat a few times to make sure you are right.

I do this after final assembly. Any plastigauge on the mains would be done first.
This can be done with feeler gauges between the thrust bearing and crank, checking each side as you push the crank back and forth... I have never done it that way though, so don't know the procedure. Probably just push forward, measure, push back measure... Not sure though.
 
#35
mr2gq said:
I'll use the Plastigage. I read somewhere that with everything fully assembled (crank rods) it should take no more than 10 foot pounds of tq to spin it and if it does something is wrong.
Click to expand...
I have never used plastigauge myself, but I was told by a guy that builds engines for a living (used to, he retired), that if you are going to use that product, you must make sure it is "fresh" (however you do that?), or it doesn't mean a thing. He claimed that after the stuff is on the shelf, waiting to be sold, it goes through changes, and won't give correct readings. He says that even handling the stuff and getting it any kind of dirty also makes it useless.

I don't know if it's true or not... Just throwing that out.


Edit:
Just thought of something funny...
My first engine I ever built (in high school), I had to push with all my might to get the crank to spin! Needless to say, I had bearing issues relatively quick... but the engine did run for a long time. I even tried to blow it up in the driveway after I had the replacement engine ready, and I gave up trying before it gave up running.
 
#36
I did mine similar to ratio411. If I remember correctly, I put all the main caps on and loosely tightened all of them with a ratchet, only torquing the number 3 main to spec. I then went through the prying method used, then torqued the remaining caps and checked the end play.

I don't remember where I came up with this method, but it was somewhere during all my research and question asking.

Good luck with it!

Joe
 
#37
mr2gq said:
I'll use the Plastigage. I read somewhere that with everything fully assembled (crank rods) it should take no more than 10 foot pounds of tq to spin it and if it does something is wrong.
Click to expand...

I went with the 20lb rule, agian, this is what I came up with during all my research, reading and question asking. Mine spun over just at that too. I had two main bearings that were on the extreme tight side of the tolerances allowed. I was told by an old timer that I could use something like a scotch bright pad to remove some bearing material. I decided to not touch them, they were after all within spec, just a little tighter than the others.

A good point to all this: I bought everything as a stroker kit. Crank, rods, pistons, rings and all the bearings. None of the bearings fit exactly the same, they do have tolerances. Luckily, they were all within tolerances, but I believe it could be very possible to buy a crank, or rods, and bearings and not have them fit out of the box like they "should". A lot of people get away with throwing it together blind. I know two different people who both built 347's without any measuring. One held together for about 5 years and 100's of track passes and thousands of street miles before it wore out the crank snout. The other one has been together for about 4 years with no problems, only enthusiastic street driving.

Joe
 
#39
Yeah that's pretty much why I just threw the crank kit in. My friend just the his striker kit in and had no issues. My neighbor has thrown a few crank replacement kits in with no issues. So I focus what the hell lol of course they didn't get 2 rod caps mixed
 
#40
Another thing. I'm not sure what the stock rods are like, but my Scat rods have a bevelled edge. The bevelled edge faces the crank counter weights and the straight edges rode against the neighboring rods straight edge. Just be sure everything is back in its proper place.

Joe
 
You must log in or register to reply here.

Similar threads

T
Oil burning on my recently buil 302
Replies
3
Views
97
Fox 5.0 Mustang Tech
Noobz347
Noobz347
limp
Engine Gas in my oil
Replies
35
Views
1K
Fox 5.0 Mustang Tech
Mindseye007
Mindseye007
P
Weird Voltage & Oil Pressure Gauges
Replies
0
Views
29
SN95 V6 Mustang Tech
PNN
P
B
Engine Strange Noise
Replies
8
Views
325
Fox 5.0 Mustang Tech
keel
keel
M
01 mustang 3.8 fuel pressure issue
Replies
0
Views
41
1996 - 2004 SN95 Mustang -General/Talk-
Mhaley2006
M
Top Bottom
Back
Forums
Menu