oil preesure at gauge vs. oil pressure in block?

[scon]

ok guys its been awhile since my last visit here with ?`s,but i have returned..
just got through with new floor and rebuilding motor in my 20` invader......but i have problem....my oil pressure gauge on dash shows 20-25psi at a 600 rpm idle(5.7l sbc)but im not getting any oil to the top end . i have researched this site n found a oil circut diagram and see that the oil pressure switch gets oil before any vitals do...i think thats foolish. .i ran the motor motor in the boat for bout 3 minutes to try n get oil but no luck...have i hurt anything? im guessing i need to pull engine and tear down to find where this blockage is....but ? is since i have readable oil pressure then the problem is not the pump rite? r my marine headgaskets reusable still?..things are getting very discouraging now(if thats how u spell it lol)..ive got alot invested in this boat and all im trying to accomplish is a running engine and new interior before i winterize it

also i have tried different oils and oil filters.and engine was primed before cranking.

 

[bruceb58]

Re: oil preesure at gauge vs. oil pressure in block?

Buy one of the oil priming adapters and run the oil pump with a drill to see if you get oil up to the top end.

 

[Bluestream]

Re: oil preesure at gauge vs. oil pressure in block?

My Merc 3.0 took 5 mins of idling before oil showed up at the rockers arms looking through the oil fill cap. This was after an 8 month winter layup and using SAE 30 motor oil

 

[HT32BSX115]

Re: oil preesure at gauge vs. oil pressure in block?

Howdy,


This used to be a big problem with 50's and 60's Ford Y-block v-8's.

The oil passages in the head that supplied the rockers came from a camshaft bearing.

Blockage was either due to sludge buildup (because they used NON-detergent oil AND didn't change it) OR a camshaft bearing that "moved" and covered the oil hole. I don't think this happens in an SBC though....(unless it's REALLY sludged!)

If you have used a direct reading gage (to verify that you actually DO have oil pressure) and you STILL don't have oil flow to the upper end, you may have to tear the engine down.

The SBC gets oil for each pushrod like below...

by the way, if you don't have the dist in you may not get oil to the top-end......it appears that having the dist out uncovers an oil gallery that will relieve pressure..........you may need to use a priming adapter specifically designed for an sbc to prevent that.....

Here's a good reference for an sbc.

http://www.cartechbooks.com/vstore/...0&CATID=23&Product_ID=3245&DID=6&chapter=7587

 

[6meter]

Re: oil preesure at gauge vs. oil pressure in block?

Did you put in new cam bearings? Did you line the holes up with the block? Are the push rods holes clean?

 

[scon]

Re: oil preesure at gauge vs. oil pressure in block?

pushrods are clear i can see through them.cam bearings installed by machine shop. but had a guy tell me today something about a 10 psi bypass in the oil filter adapter? is this a common problem?

 

[scon]

Re: oil preesure at gauge vs. oil pressure in block?

bruce.....i borrowed a oil primer from a friend today and ran for about 15-20 minutes and still nothing..after reinstalling dist i noticed when i rev the motor from idle to about 2500 it shoots oil of the hole between pushrods on cyl.7 and 8 onlyand its not a little oil it shoots it all over the exhaust ..about a foot .... does that mean or tell anyone anything?

 

[coheej]

Re: oil preesure at gauge vs. oil pressure in block?

bruce.....i borrowed a oil primer from a friend today and ran for about 15-20 minutes and still nothing..after reinstalling dist i noticed when i rev the motor from idle to about 2500 it shoots oil of the hole between pushrods on cyl.7 and 8 onlyand its not a little oil it shoots it all over the exhaust ..about a foot .... does that mean or tell anyone anything?

What hole? Cylinder 7 & 8 are on opposite sides of the motor.

 

[coheej]

Re: oil preesure at gauge vs. oil pressure in block?

Did you put in new cam bearings? Did you line the holes up with the block? Are the push rods holes clean?

Sbc's have grooves behind the bearings. The holes are not lined up.

 

[scon]

Re: oil preesure at gauge vs. oil pressure in block?

the hole between where the pushrods come through the head and yes i know 7 and 8 are on oppisite sides...

 

[Don S]

Re: oil preesure at gauge vs. oil pressure in block?

Can you post some pictures of where the oil is coming out? What year is this engine?

 

[coheej]

Re: oil preesure at gauge vs. oil pressure in block?

the hole between where the pushrods come through the head and yes i know 7 and 8 are on oppisite sides...

There should be no oil squirting from the head between the pushrods.

 

[scon]

Re: oil preesure at gauge vs. oil pressure in block?

don,,cohee....ill have pics up shortly...but it comes out a good foot out that hole bettween pushrods on 7 and 8......more than likely after work ill be pulling engine tonight,ive been lookin for all other options but its comin down to a complete tear down and rebuild i believe..i want a reliable engine i dont want something to doubt next year..ill also be replacing cam with a comp marine, they have one for low idle and better performance.....what should i check after a teardown? cam bearing ? oil passages? bypass on the oil filter adapter? what else?

 

[Aloysius]

Re: oil preesure at gauge vs. oil pressure in block?

The rocker arms are tight enough to make the pushrods seal properly in the lifters, aren't they? They ARE properly seated??

 

[gbeltran]

Re: oil preesure at gauge vs. oil pressure in block?

Didn't your original post say the engine was rebuilt? How was that done?

 

[scon]

Re: oil preesure at gauge vs. oil pressure in block?

ok guys i have found why i had low to no oil pressure.....my lifter valley on this engine is not for a solid roller how ever i tried to make it work..the prime hole in the lifter never could go low enough in the lifter hole to pickup oil or let oil pass by to get to the rest of the lifters and everything else that follows...called comp got a new marine enrgy cam n lifter kit and all is great now.....guess it took leaving it alone for awhile n gettin back on it with a fresh mind..thanx for everyones help...i actually learned alot off this goof up.....thanx again guys