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I just put a forged 383 stroker in my c5. At first I used a Melling M295 and the oil pressure was great. I drove it for 3 or 4 months with no issues. I got on it really hard last weekend, and the oil pressure fell off. When I crank it cold it goes to like 40. After it warms up it goes to like 15 or lower!! I replaced the oil pressure sensor and put a Moroso racing oil pump in it. The problem is still there!! Any advise is appreciated!!!!!!!!
[QUOTE=HPS MASTER TECH;1595159707]are you talking about the oil pump spacers when using a double roller chain? yes. got pics of them?[/QUOTE. Yes I have the double roller timing chain. I don't have any pics of the spacers. I guess I'll go back in and check the o ring on the oil pickup tube. There are 2 options there. Maybe the larger one will be the remedy.
are you talking about the oil pump spacers when using a double roller chain? yes. got pics of them?[/QUOTE. Yes I have the double roller timing chain. I don't have any pics of the spacers. I guess I'll go back in and check the o ring on the oil pickup tube. There are 2 options there. Maybe the larger one will be the remedy.
you were supposed to put those spacers in with the double chain. the pump won't sit flat against the block allowing pressure to bleed off. and you probably have a hole in your oil pump now.
you were supposed to put those spacers in with the double chain. the pump won't sit flat against the block allowing pressure to bleed off. and you probably have a hole in your oil pump now.
I've had those spacers in place ever since the cam installation two years ago. This engine ran fine until I got on it really hard! Now it's experiencing low pressure. I do all my own work. I put the Moroso oil pump in, and I noticed it has the capability of securing the pickup tube with two bolts. The tube I'm using only has one. Thinking of buying one with two bolts....and using the thicker O-ring. Almost has to be something simple. This engine has like 3 or 4 thousand grandpa miles on it. Got on hard once!! Thanks for input btw
assuming nothing in your engine got worn out. its probably the cam retainer plate seal is worn/ loose, rear cover gasket blew out the oil passage seal or the barbell pushed out some how. did you use locktite on everything?
assuming nothing in your engine got worn out. its probably the cam retainer plate seal is worn/ loose, rear cover gasket blew out the oil passage seal or the barbell pushed out some how. did you use locktite on everything?
I think I'll look into that pickup tube girdle. It looks nice. Or a new tube with dual fastener capability. Definitely will try the larger o-ring there. What do you mean by the barbell? Only thing I can imagine is on the cam retainer plate. Like I said, when I crank it cold oil PSI is like 35....so it's not a total failure. Just need to isolate the root cause. Man, you're such a godsend in your replies, and your concern with helping me. I really appreciate it!
no problem. the barbell is installed in an oil galley in the back of the block under the rear cover. i replaced mine with a better fitting billet one.
the block is upside down in the pic.
did you use loctite on the oil pump and pickup tube bolts?
if the oil pump bolts back out you would still have some pressure. but alot bleeds off.
if that happens the oil pump drive on the crank will eat into the pump case. if you cut your filter open you should find some metal shavings.
Alright, I got the pan off today and there were small chunks of metal in the oil. Also the oil is filled with microscopic flakes, and it only has like 50 miles on fresh oil. I'm going to pull the motor back out ASAP. The thing that perplexes the hell out of me is, how could it build decent pressure, then suddenly fall off? Probably something simple.
As the bearing surfaces wear and create more clearance between the "oil filmed" surfaces, the oil will bleed thru instead of creating the cushion of oil it normally rides on..
This applies to all engines. But modern ones are built with really tight clearances.
SO anytime that changes, you'll see oil pressure changes too.
BTW, that's A LOT of metal !! Id be talking to the builder/machinist or figuring
out what you may have done incorrectly in the run in/ break in or even the wrong oil
07-15-2017, 02:16 PM
Oil pressure!!!!!!
