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Discussion Starter #21
The oil pickup I copied off the moroso pickup. It's a 1.25" slotted tube design. Maybe I should have done a box and mesh design?


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Do you also have a graph from the data logger with vacuum recorded?

what are your bearing clearances?

What oil type / weight are you running?

what are your water / oil temps?

we ran our external wet sump 440 ci SBF’s over 9000 rpms with external wet sump pump and 20+ in hg vacuum and less than 70 psi.

I ran my personal 400 ci SBF over 9000 rpms, 20+ in hg and 50 psi with a 3 quart accumulator , 8 quart pan and only 8 quarts total 0W-5 oil.
 

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Is it possible that your oil pan is holding a lot of oil in top section and not returning to lower section fast enough
Have you had engine on dyno to see if it still drops pressure ? That would help eliminate if it’s g force related
Mine fluctuated on the dyno, took one quart out and all was good
 

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I’m agreeing with all who question why there is so much oil in the pan? That’s crazy. You are beating the hell out of the oil and oil with bubbles compresses and you lose pressure.


I’d start by pulling THREE quarts out and making a pull. You may be able to pull even more.
 

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Would it not be the height of the oil in the pan, not the volume that would cause aeration?. A pan with a very wide, long sump could hold more oil, but still be at the original height as a stock pan. If you can find the original oil level below the block bottom using a dip stick for that engine, then that depth down on an increased volume pan can be measured by filling up to that level. Any oil above that level could increase aeration? Below that would lessen aeration?
 

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Discussion Starter #26
When I built the oil pan I filled it with water so the level filled the sump section up to the removable tray and marked the dipstick. Then when fitted to the car filled to that mark, filled the filter and added an extra quart. Warmed it up and checked the dipstick and it was on the mark.
When at the track I noticed the oil pressure was fluctuating at the big end. I added 1 quart and it did the same thing.
As mark said the volume of oil shouldn't matter just the oil level.
From everyone's advice I think I need to try removing oil and see what it does.
Would this have hurt the bearings again?
I have only done a couple of full passes.

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Discussion Starter #29
Running 5w30 oil. Yes did inspect the filter and it wasn't perfect which is why I'm concerned on running it again.

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Gday Shane.
When I was having rod bearing issues with the clevo I would only see a tiny amount of bearing material, probably not even a dozen bits of tiny pieces.
I would then pull it and crank would be fine at that point.
You shouldn’t be seeing bearing metal
Cheers
 

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Looking at your drive shaft speed and rpm I think you might have something else going on also
Are you tagging limiter at the top of first and second ?
You have rpm fluctuation that is showing up in drive shaft speed also
 

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Discussion Starter #32
Looking at your drive shaft speed and rpm I think you might have something else going on also
Are you tagging limiter at the top of first and second ?
You have rpm fluctuation that is showing up in drive shaft speed also
Yes i tagged the limiter in first and top. I'm not sure why the driveshaft has that fluctuation crossing the line??

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If you are on limiter drive shaft will show a fluctuation so can oil pressure
If you really need to spin it that high I would up the limiter , I hate seeing engines hit limiters up that high unless its from a safety etc
What rpm did it make peak on engine dyno ?
How fast is the car ?
 

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Discussion Starter #34
I don't want to turn it past 8500rpm. The limiter was on 8600rpm. Converter slip is causing it to tag the limiter on the big end. Made peak power at 8100rpm.

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I don't want to turn it past 8500rpm. The limiter was on 8600rpm. Converter slip is causing it to tag the limiter on the big end. Made peak power at 8100rpm.

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Rev limiter will start roughly 200rpm lower than you set it, its starts with a soft cut then hits a hard cut at the set rpm
So u would have started tagging limiter around 8400
Limiters kill engines at that rpm faster than over revving will
 

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When I read through everything, the biggest flag I saw was... "Engine oil pressure was perfect on the engine dyno." I would start looking at everything the engine sees that is different from when it ran in the dyno cell.
 

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When I read through everything, the biggest flag I saw was... "Engine oil pressure was perfect on the engine dyno." I would start looking at everything the engine sees that is different from when it ran in the dyno cell.
Exactly, g force and length of the pull, length of the pull brings in other issues with how the oiling system is set up
Cheers
 

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This data log if after the oil pan upgrades. It's better but still not right.


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I’m still wondering if that bolt in baffle plate needs some holes or louvered slots and a scrapper to help wrapped up oil off crank get back to recovery section near pick up
Or is the 11q of oil getting wrapped around crank from start line gforce
 

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It's worthwhile to see if it has oil restrictors. Each of the cam bearings get a straight shot of oil through a big ole' gallery... and the cam bearings have an outer groove and three exit holes. It can be a major bleed if they aren't restricted. It's easy to do, as the galleries are right under the main bearings. For the top end/lifter galleries, it's not super easy to restrict, but can be done. Also, look out for loose lifter bores, as they will bleed a lot of oil.

One tip... On a stock block, the main bearing feed passage and the cam bearing feed passage are very close together. Dart spread them out by quite a bit! This strengthens things, but can cause an issue with the slots in the bearings. The center main/thrust has a significantly shorter slot that almost blocks off the bearing feed! I had to elongate the slot on the center main in order to feel comfortable. Before elongating, the biggest drill bit I could slid in the passage was a #47 (0.078") Below is the Dart main on my block. The other picture is a stock block.



 
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