New motor, 383. 7qt miloden stroker pan, full windage trey plus 1 qt filter (8qt system) with melling m55hv pump.

I just switched after break in to German made Castrol Synthetic 0w-30. Oil pressure at idle is 30-35 psi fully warm, cruising is 50-55psi. Also am using NAPA gold oil filter, part #1060 (made by wix, recommended by many here)

Anyways, I never saw any cavitation like issues on first break in with the motor, but then again i never really pushed the car super hard. However tonight i got on it 2-3-4 short shifting at about 4500 and watched the pressure just DROP into the lower 30/high 20 psi range right after throttling it up.

Really dont see cavitation being the issue with a full length windage trey.

Cant see the pan being sucked dry (even though HV pump) since A) its an 8qt system, and B) the oil sump area of the pan is VERY deep (8 1/4).

So heres my thinking. I never noticed it with my original filter which was a 1qt ProLine filter, aka PepBoys in house brand.

Could the Napa/wix filter be blocking the flow enough to cause such an issue where the cheapo no filtration special pep boys filter didnt?

Oil only has about 50 miles on it since change. If thats a possibility I'll take it easy and next change try the other filter again.

Other thoughts?

EDIT: Pan picture to get an idea of size/shape.
http://memimage.cardomain.net/member...497_9_full.jpg

 

Where can I get a LT1 pan like that and how much?

 

Its miloden part number 30909
http://www.flatlanderracing.com/oilsssbcothers.html

Or summit/jegs anyone else who sells miloden

 

What are your clearances set at? I had the exact same issues with a very simular engine. GEN 1 385 with 7quart canton system. Mains @ .003, rods @.002. After break in with sae 30 I switched to RP 10-30 and it held perfect pressure until i stabbed the throttle and then it would drop to 20 or so. I even questioned the oil filter and swapped brands twice to no avail. Solution? Valvoline VR 20w50.

 

You may just have to try a different weight as suggested and go from there. The pan you have did you buy everything w/ it in that catalog listed? You know if that pan will clear other style LT's. I've got FLP's but I haven't heard one person run a after market pan w/ them yet, well canton's at least. I need a new pan and the one you have is what I'm interested in. If I have to switch to Kooks to have a decent pan so be it.

Thanks.

 

I bought the motor from a friend who had it built, then changed his mind on the direction of the car. Ill see if he still has the paperwork on bearing clearences.

I know the pan works with PaceSetter LT, and Hooker LT. FLP seems to have fitment issues with everything, but i cant say one way for sure with the pan. Once again, i didnt do the ordering of the parts for the pan since the original builder ordered it. You could shoot him an email or PM. His user name is BES-383

 

block off plate between pump and block fixed my problem

 

The symptons you are talking about are a product of loose mains which will drop the pressure at low Rpm's and under a load. Take it to a higher rpm and try it. The engine may have more than .003 in the mains. The .002 in the rods are OK. The mains should be about .0025 for the street.
Change to a different weight oil(thicker).

 

Thanks for the reply. The motor was originally built as a track only car, 14:1, huge cam etc etc. I was able to put on some huge 76cc AFRs to drop the compression and swapped the cam. Long winded reply, but the bearings may be looser as suggested than what is ideal for the street.

Either way, he sent me all the paperwork and invoices that he had and the bearing clearance wasnt on there, but they had specced straight 40wt for it. Ill go thicker next time and see how that affects it.

Thanks for all the help.

 

I wouldn't run it far until I found out if I could stabilize the pressure.

 

Even just driving around with good pressure? (asked seriously)

I have no intentions of running it hard until i can get the pressure where it should be.

 

I wouldn't,but that's just me.The guage may not be quick enough to let you know.

 

ok, I will take that advice, thanks.

Also, I looked up the fine print on the Wix filter. It has no bypass valve in it, Any problems there?

Also any idea of how many gallons a HV pump can spit out at 7k rpms? The wix filters are rated at less than 2psi pressure drop while filtering 4 g.p.m.

 

I wanna see what the main clearances are..... I think Larry is on the right track with that.

Bret

 

Bret-
Tony Bischoff @ BES did the motor.

As an engine builder do you keep files of the engines you do around? If so ill call them and see what i can find. Like I said before, the guy who had the motor built wasnt supplied the bearing specs so i dont know what else to do other than try out a heavier weight oil and see what happens.