Vac pump destruction / mystery

[ss3011]

What is the main bearing diameter, what brand oil and weight ?

[joespanova]

Originally Posted by ss3011

What is the main bearing diameter, what brand oil and weight ?

Why would you ask me what the main journal dia. is? 2.450 / 2.449..........the clearances are .0025 /.003.
The current oil is Brad Penn. Break in oil ( 30 weight ) ...........this inspection is only after 5 trips down the track.
BTW.......this is a 350 inch engine.......

[Ed Wright]

Because journal diameter tells you how much oil clearance is needed. .0025"/.003" is fine. How about your rod journal dia & clearance?
I ran a vacuum pump on mine before I made an SS legal car of it. I used the same pump and clearances then as now. I have seen no difference in bearings. I doubt it's the pump.
How much oil pressure?

[joespanova]

Originally Posted by Ed Wright

Because journal diameter tells you how much oil clearance is needed. .0025"/.003" is fine. How about your rod journal dia & clearance?
I ran a vacuum pump on mine before I made an SS legal car of it. I used the same pump and clearances then as now. I have seen no difference in bearings. I doubt it's the pump.
How much oil pressure?

60 PLUS......
Did you lose any power worth noting WITHOUT the pump?
At this point I have little choice but to run it without the pump. The bearings looked as though there was trash in the engine , as bad as I've seen............but , it may well have been bearing decomposition getting in the oil?
I cant take any pics now since my wife has the camera and she's out of town.....

[Ed Wright]

On my old chassis dyno, taking the belt on & off the pump was a consistent ten hp at the tires. Probably worth 12 to 15 hp on an engine dyno. I can not imagine the vacuum pump causing a bearing problem. I also plug the bypass in the oil filter mount, so all oil goes through the filter. Keeps crap out of the bearings better. 60 psi has always been enough in mine. Ran 45 for years with zero issues. I'm no professional engine builder, so more knowledgeable pros here may have more info.

[CFMCNC]

WE use Brad Penn break in oil on our dyno a lot, but of all the break in oils we get the BP out of the engine before it goes in the car ,WE use vacuum pumps on most of race engine we build with no failures related to the vac pumps.Bill C.

[MAURICE BLENDHEIM]

Your 60lbs. oil pressure. Are you taking your oil pressure reading from the rear or the front of the block? MB.

[RJ Sledge]

Although my application was a Stocker, low to mid ten Ford small block, I had the same problem after about 5 or 6 passes. I had set my oil pickup clearance too short and it was starving my bearings. Set it to .400 and I never had any more problems. You can get it too close.
Sometimes its the little things you can take for granted.

Hope you figure it out.

An Accumulator can also help.

RJ

[joespanova]

Originally Posted by RJ Sledge

Although my application was a Stocker, low to mid ten Ford small block, I had the same problem after about 5 or 6 passes. I had set my oil pickup clearance too short and it was starving my bearings. Set it to .400 and I never had any more problems. You can get it too close.
Sometimes its the little things you can take for granted.

Hope you figure it out.

An Accumulator can also help.

RJ

Thanks.......great point. Mine may be a little too close too @ .250ish. or less even
The only way to fix is to take a 2x4 and wack the pan bottom a little.