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GM Rocket block oiling problem

General engine tech -- Drag Racing to Circle Track

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Warp Speed
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Re: GM Rocket block oiling problem

Post by Warp Speed » Thu Aug 01, 2019 2:06 pm

exhaustgases wrote:
Thu Aug 01, 2019 1:27 pm
Warp Speed wrote:
Thu Aug 01, 2019 10:03 am
That is a bunch of bearing clearance!
Yeah for 0W-20 it would be.
It is for straight 50w!

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Re: GM Rocket block oiling problem

Post by BOOT » Thu Aug 01, 2019 2:16 pm

Are the lifters going too high and just into the roller area causing a huge leak?
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Re: GM Rocket block oiling problem

Post by treyrags » Thu Aug 01, 2019 4:15 pm

I would drain the oil and check for aeration after a short blast.

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Re: GM Rocket block oiling problem

Post by amc fan » Thu Aug 01, 2019 5:09 pm

What is the GPM of the Titan oil pump ? You might need an Accusump. That is a lot of Main and rod clearance. I think the flow of a standard SBC pump is 7 GPM at 3000 rpm.How high are you turning the engine? I am wondering how much flow at 6,7,8000 rpm?

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Re: GM Rocket block oiling problem

Post by swampbuggy » Thu Aug 01, 2019 6:32 pm

Rewguy, are those Lunati roller lifters the ones you are using ( i assume so) ? Are those identical to the lifters used in the past ? Mark H.

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Re: GM Rocket block oiling problem

Post by rustbucket79 » Thu Aug 01, 2019 9:05 pm

rewguy wrote:
Wed Jul 31, 2019 5:14 pm
p.s. When the engine first fired it would not oil the rockers.......I added small grooves to the pushrod feed hole to help. About .020 deep, and .025 across. PLENTY of oil then. But I have a very hard time believing that the grooves are the issue with running the pan dry this quickly.
Have you tried priming the engine? I did the same thing more or less using a Dremel tool to groove, once assembled I primed it. Nice, lots of oil (had same issues, would not oil up top until running for a minute with the first set of non grooved lifters, actually burnt up a rocker tip and valve over the season) but after a few seconds you could hear the pump suck air. #-o The is with a Dart Little M and fortunately I had installed .090" restrictors in the front (was wide open in the rear) so I plugged the back lifter gallery oil feeds and ran it. It's not brilliant, 7 quarts in a 6 quart pan and the oil pressure gauge fluctuates between 42 and 50 for the last half of the track. I'll finish off the season then look at the bearings in the off season. I plan on restricting it further for next year, trial and error on the engine stand by plugging the front and adjusting the rear orifices as required.

Using Lunati ultra pro which I believe is made by Morel. The bodies I believe are about .001" bigger than Comp and that is what I attribute to the "no oil" issue (at least in my case) I plan to hone another .0005" into the bores as part of a major refresh down the road with new, non grooved, lifters. I had no oil pressure issues before I put in these oiling grooves.

Does your block not have provisions to restrict the lifter gallery feeds?

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Re: GM Rocket block oiling problem

Post by steve316 » Thu Aug 01, 2019 10:03 pm

Drop the pan 1 to 2 inches in the front spin the pump with a drill and watch where the oil is going.

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Re: GM Rocket block oiling problem

Post by Charliesauto » Thu Aug 01, 2019 11:06 pm

rewguy wrote:
Wed Jul 31, 2019 5:21 pm
20190731_155754.jpg20190731_155628.jpg
Lifter to bore clearance is .0019
That looks like a Morel lifter with two edge orifice holes. With .0019 lifter to bore clearance, you should have had plenty of oil to the top without modifying the lifters. We run that style lifter with .0013-.0014" clearance and no modifications and get plenty of oil thru the pushrod.

Those grooves you added are massive and it appears you have two per hole. If you ever do another set, have someone surface grind them or mill with a carbide endmill. One .002" deep flat per hole adds a lot of oil and consider doing just one hole per lifter.

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Re: GM Rocket block oiling problem

Post by levisnteeshirt » Thu Aug 01, 2019 11:39 pm

I would make a drain hose from the back of the valve covers to the pan

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Re: GM Rocket block oiling problem

Post by tjus » Fri Aug 02, 2019 8:04 am

i had same issue with Valvoline VR-1 20W-50 in my hyd roller BBC changed to mobil1 5w-50 and no issues.

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Re: GM Rocket block oiling problem

Post by rewguy » Fri Aug 02, 2019 10:54 am

tenxal wrote:
Thu Aug 01, 2019 8:19 am
Have you tried it w/o the vacuum pump?
I have not tried it without the vacuum pump as my valve covers don't have breather enough provision for adequate breathing

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Re: GM Rocket block oiling problem

Post by rewguy » Fri Aug 02, 2019 10:55 am

Charliesauto wrote:
Thu Aug 01, 2019 11:06 pm
rewguy wrote:
Wed Jul 31, 2019 5:21 pm
20190731_155754.jpg20190731_155628.jpg
Lifter to bore clearance is .0019
That looks like a Morel lifter with two edge orifice holes. With .0019 lifter to bore clearance, you should have had plenty of oil to the top without modifying the lifters. We run that style lifter with .0013-.0014" clearance and no modifications and get plenty of oil thru the pushrod.

Those grooves you added are massive and it appears you have two per hole. If you ever do another set, have someone surface grind them or mill with a carbide endmill. One .002" deep flat per hole adds a lot of oil and consider doing just one hole per lifter.
I agree completely......

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Re: GM Rocket block oiling problem

Post by rewguy » Fri Aug 02, 2019 10:56 am

swampbuggy wrote:
Thu Aug 01, 2019 6:32 pm
Rewguy, are those Lunati roller lifters the ones you are using ( i assume so) ? Are those identical to the lifters used in the past ? Mark H.
It is the first build for us on this. So they are the only lifters we've tried in it.

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Re: GM Rocket block oiling problem

Post by rewguy » Fri Aug 02, 2019 10:57 am

steve316 wrote:
Thu Aug 01, 2019 10:03 pm
Drop the pan 1 to 2 inches in the front spin the pump with a drill and watch where the oil is going.
I believe we will try this soon. I plan on restricting the oil to the top first as long as I can figure a way to do so.

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Re: GM Rocket block oiling problem

Post by rewguy » Fri Aug 02, 2019 11:02 am

Warp Speed wrote:
Thu Aug 01, 2019 2:06 pm
exhaustgases wrote:
Thu Aug 01, 2019 1:27 pm
Warp Speed wrote:
Thu Aug 01, 2019 10:03 am
That is a bunch of bearing clearance!
Yeah for 0W-20 it would be.
It is for straight 50w!
I don't know how familiar you are w maxracesoftware......Larry Meaux......But a few years ago he talked about the oil clearance He and his buddy Chris used in their engines......and this is very similar. Even Darin Morgan made a statement along the lines of.....It had been twenty years since he ran less than .003-.0035 on rods OR mains in ANY engine period. This especially is a run "almost right off the trailer", very little warm up time, sportsman style crank.........(no winberg or kellogg) etc. The cheaper cranks tend to move a bit more than the big dollar stuff..... And we've run similar clearances for years and bearings always look new after a year of thrashing.

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