Oil starvation issues SBC HELP?

[joespanova]

Originally Posted by pmrphil

OK, new block and pump. Same pan? Oil clearances strike me as a bit loose for aluminum rods. Is the oil getting too hot? Does the pressure gradually go down or does it just drop at a certain point or RPM? The pump should be more than sufficient.

Same pan. No those oil clearances are spot on. Oil getting too hot? Doubtful. Pressure goes down as a result of bearing surface going away.
I made 2 runs today and the engine's coming out.
The vac pump issues has been mentioned by several others on Speed Talk. That's something I didn't give any thought to as my understanding is that high vac starts showing issues with wrist pins........I never see that.
I did change to a larger pulley and vac is about 5-6" at idle and I believe 10-12 throught the lights...............but I can't confirm that. I've never noticed it being too high but then I dont look at the vac gage during a run either.

[joespanova]

Is an accumulator a solution.

[Ed Wright]

Originally Posted by joespanova

Same pan. No those oil clearances are spot on. Oil getting too hot? Doubtful. Pressure goes down as a result of bearing surface going away.
I made 2 runs today and the engine's coming out.
The vac pump issues has been mentioned by several others on Speed Talk. That's something I didn't give any thought to as my understanding is that high vac starts showing issues with wrist pins........I never see that.
I did change to a larger pulley and vac is about 5-6" at idle and I believe 10-12 throught the lights...............but I can't confirm that. I've never noticed it being too high but then I dont look at the vac gage during a run either.

I don't think those bearing clearances "are spot on", but on the loose side. I don't ever run one that lose. One thousandth per inch journal diameter. That is all you need. That is not enough RPM to be a problem. What are you doing that you need aluminum rods? You understand that your already a little loose rod bearing clearances are getting looser as it warms up, right?
How much end play in your oil pump? I never run more than .001" end play on my pump impellers. If I open up a new pump and find more than that (often do) I lap the end of the pump housing until I get it there. Done that for years with zero issues.
What weight oil are you using?

[ss3011]

Is the plug installed in the block, under the rear main cap , that sends oil to the filter ? If missing it will bypass the filter, and may cause contaminated oil to ruin the bearings . Don't know if the Dart blocks are machined like a production Chevy block, but when I bought a couple of factory blocks that plug was missing .

[Greenlight]

Just curious, how much oil are you running and what oil pan (part number and manufacturer) are you using?

I'm leaning toward aeration.

[joespanova]

The pan is an older Moroso Ultimate 2..........steel pan . they stopped producing them in the early to mid ninties?
The oil is a 30 weight Brad Penn breakin oil as of right now.
Maybe a vac pump issue..........
The oil clearances are what the rod manufacturer ( GRP ) suggests.......who am I to argue? I could certainly look at that though........why aluminum? Because that was better suited to what I'm doing IMO.
6 quarts plus filter total as of now. Have run 5 plus filter..........same result.
I think a wet sump is a PITA right now.

[rod butcher]

It may be your hurting the motor after the finish line? I run a 3qt. accusump on my bracket stuff after a few rod failures. Never had a problem since.

[carl hinkson]

Originally Posted by joespanova

The pan is an older Moroso Ultimate 2..........steel pan . they stopped producing them in the early to mid ninties?
The oil is a 30 weight Brad Penn breakin oil as of right now.
Maybe a vac pump issue..........
The oil clearances are what the rod manufacturer ( GRP ) suggests.......who am I to argue? I could certainly look at that though........why aluminum? Because that was better suited to what I'm doing IMO.
6 quarts plus filter total as of now. Have run 5 plus filter..........same result.
I think a wet sump is a PITA right now.

Maybe there is a reason they stopped making the pan !!! What are they using for a windage tray?

Aluminum rods have a very short cycle life compared to a good steel rod. There is a lot of mass swinging around there which does not help windage issues.

Sounds like a windage issue!! How much vacuum are you pulling. If your using cam bearing with 3 holes there is a serious bleed off issues along with you don't have a clue what your lifter bore clearance is which could be bleeding off to much oil and dumping it on the crank.

Go to dry sump problem solved!!

[joespanova]

Originally Posted by carl hinkson

Maybe there is a reason they stopped making the pan !!! What are they using for a windage tray?

Aluminum rods have a very short cycle life compared to a good steel rod. There is a lot of mass swinging around there which does not help windage issues.

Sounds like a windage issue!! How much vacuum are you pulling. If your using cam bearing with 3 holes there is a serious bleed off issues along with you don't have a clue what your lifter bore clearance is which could be bleeding off to much oil and dumping it on the crank.

Go to dry sump problem solved!!

Carl...a boatload of Super Stock racers have the wet sump figured out.
Send me the money for a dry sump setup , I'll install it and put "thanks CNC blocks" on the quarter panel.

[Ed Wright]

I agree with Mr Hinkson (big surprise) I have plugged the filter bypass in my oil filter mount since the 1970s. I use only the NAPA 1061 filter as well.

Anytime your aluminum Rod is black at the rod bearing, that is what killed the rod. Bearing or oiling.
I don't understand you using them. They will not make you run one bit faster. Manley, or Carrilo steel rods will handle anything you are doing. Don't have to replace them nearly as often either. Run aluminum rods too long and they just break bask me how I know. LOL Back in the '60s & '70s we all ran them in our Modified Eliminator cars. Ran a set of BRCs too long, kicked one out in the final round of a div 4 points race. Broke right in the middle of the beam. Good steel rods would not have done that.
Still has to be built correctly.