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Folks, I am working on finishing up the top-end for my new Dart SHP 400, with a roller cam, roller hydraulic lifters and roller rockers. I cleaned & then soaked the lifters in oil overnight and set the lash OK.
I bought the special priming tool with the collar and have been drilling for an hour, turning the crank by 30 degrees increments every minute. I measured a pressure of 75 psi at full speed.
The lifters at piston #8 won't pump up though. I can still easily push them down when they're on the base circle. No oil comes up to their rockers. What gives? Should I ignore this situation and go on & put the intake manifold on, etc...?
Hard to tell in the photo,
by the way. That's not a C3 is it?
but your priming tool does not appear to have a collar.
There are two kinds of primers. The better ones have a collar that would normally fit tight in the Intakes dist hole.
Without that collar, I believe the oil pressure is by-passing the lifter-oil-galley. It may show up on your gauge as 75 lbs, but may not be feeding the galley.
I would not install the Intake just yet until you figure this out.
However, I would install the Intake WITHOUT gaskets, just lay it on the heads / block, couple bolts.
Then try the primer tool again. Or buy a different type specific for the hole in the Intake.
Getting adequate oil pressure from that port in the block does not guarantee pressure at the lift bores.
I have not been using the top collar because the intake manifold is not installed.
I believe the lifters at #8 are the last ones to get oiled. I also read that it's when they're on the base circle that they are subject to the pressure - so I'll concentrate on that position.
Dry fitting the intake and drilling again with that top collar installed sounds like a reasonable experiment. There's a huge play between that collar and the intake's hole. The collar diameter is about 3/16" smaller than the intake's hole:
I could put tape around the collar, so it just fits in the intake and is centered.
Not an expert on oil passages down inside the distributor hole.
But perhaps the way you have the tools collar shoved down in there its blocking an oil passage.
The distributor itself does not have a full collar like the primer tool, but rather a "stepped" collar.
I think you should "dry" fit the Intake and try the primer tool again, in the way it was intended.
Note if oil starts flowing better.
Nothing to lose, everything to gain.
Last edited by HeadsU.P.; Jul 21, 2025 at 04:35 PM.
...But perhaps the way you have the tools collar shoved down in there its blocking an oil passage...
Agree. May be lifting the tool a little bit while I drill will help.
Originally Posted by Rebelyell
OP
I know you wrote you cleaned the lifters, BUT
did you disaasemble the lifters (remove plunger-spring-valve etc) as you cleaned them ?
Absolutely not. I rolled them in mineral spirit and dried them. Then soaked them in oil overnight. Never read about opening them up for cleaning before install.
Originally Posted by Rebelyell
Have you attempted to swap lifters from cyl# 8 with lifters from another cylinder ? And then attempt prime ?
It has been on my mind, but I consider this one of the last resort options because I put blue loctite on the three spider retainer bolts and would rather not have to take them out.
Originally Posted by Rebelyell
as an aside: a peek thru one of the dart block's ovoid oil drainback holes reveals a roller camshaft which appears cast ?
If you want to help keep that engine "nice and clean" while you finalize it I would suggest you get a spare old set of valve covers and cut out the center section. This allows the oil to stay inside the system while you are working on the engine or pre-lubbing it. I did this last time and my engine stayed nice and clean despite the mess I was working with. I have the modified valve covers on a shelf for the next time I need them.
I think some part #s and technical #s are in order. Cam # and specs, lifter #, cam bearings 1 hole or 3...are you using the 400 sbc specific oil pump drive shaft (smaller diameter), any oil restrictors installed, were lifter bores measured/checked/honed, etc? What prep was done to the block? Some of these may not be the issue, but still need to be correct. Do a web search, "Dart shp 400 sbc oil flow diagram"....read the Dart papers, and then issues posted on various forums...it could be lifter choice compared to cam lift, could be trash in the oil passage...if it's not pressure loss, it has to be blockage...just my $0.02s worth. Good luck, I would absolutely figure this out before going any further👍
Edit: Dart SHP oiling: Mains, Cam, then lifters.
FWIW, I have a similar looking oil priming tool. It was cheap on Amazon figured I'd give it a try. I tried it out when I was changing the intake manifold gaskets and had the same exact problem. I noticed all the oil coming out around the tool and figured if I ever really needed to this I'd need a better tool. Never thought of trying with intake on.
The top collar for the intake is just for alignment and does little to build pressure. If you are reading 75# of pressure, the pump is working fine. Take out #8 lifters and prime again to see if oil is flowing in the lifter galley. Report back after.
Last edited by 1Hotrodz; Jul 22, 2025 at 09:56 AM.
Reason: Syntax
OP RBrid
Absolutely not. I rolled them in mineral spirit and dried them. Then soaked them in oil overnight. Never read about opening them up for cleaning before install.
Most folk do not disassemble new lifters and check-clean them; most folk have no issues. Some do. Lifter is a close-tolerance, machined assembly that May have some unintended fine schmutz trapped inside it. No matter where I source from, I disassemble, inspect and clean lifters' internals. Same for oil pumps.
**ADD**
little-discussed fact about factory-type roller lifter oil flow:
NOT that this has anything to do with #8 cyl, BUT,
It's a fact the Vortec L30 & L31 roller sbc motors have a pair of OE "air bleeds" at forward ends of Both lifter oil galleries.
Those Two OUTBOARD expansion cups located behind the upper timing sprocket have an approx 0.025" centered hole.
This scheme is to help during startup and to aide oil flow and to prevent trapped air from inhibiting oil flow thru entire length of the two lifter oil galleries. It helps to speed full oil flow and to lessen any roller lifter "startup rattle". Those holes aide purging of air from galleries. Those cups (with holes) have their own discrete GM P/N. I can well-imagine a similar scheme might only improve-accelerate hydraulic lifter oil-purge in SHP block as well ?
Last edited by Rebelyell; Jul 22, 2025 at 01:29 PM.
The top collar for the intake is just for alignment and does little to build pressure. If you are reading 75# of pressure, the pump is working fine. Take out #8 lifters and prime again to see if oil is flowing in the lifter galley. Report back after.
Hold the phone.
I did some more research on primer tools.
I do not know how to post a link but a web site called xenforo? claimed that the cheaper and simpler primer tools will not flow adequate to both lifter gallies.
It said the better tools have dual collars. One top side and one down in the block.
It seems the top collar is more than just for alignment. It holds back oil pressure too. Or should say builds pressure for the gallies.
The article went on to say you will never get oil at the rockers with just a cheap primer shaft.
Will get some oil with one collar primer.
But will get a full oiling to all rockers with dual collar tool.
Keep in mind the distributor flange has an oil gasket or should have. The dist hole in the Intake will indeed leak when the dist is loose.
As mentioned earlier, a 70+ lbs of oil at the rear china wall oil port is NOT an indicator that the gallies are getting equal amount.
mistaken; xenforo has failed you
suggest you grab an old GM dist and stand over an sbc lifter valley and re-educate yourself as to how the two fit together.
While you're at it, witness how loose the fit between distributor and its hole thru intake manifold is.
Thanks all! Agree with Rebelyell - there's no way the upper collar does anything more than keeping the tool somewhat aligned.
Just quick notes on what I had time to do tonight: decided to remove the spider retainer. Removed one #8 lifter and placed my finger in its place. Could feel the oil pressure coming out of the supply hole while I was drilling with the other hand. Did the same with the other #8 lifter: same result. So I could feel oil pressure with my finger in both lifter holes. Yay!
With all lifters back in place, drilled some more and could see a little oil coming out of the #8 tops. Less than for the other lifters though.
Swapped lifters from #8 and #6. Drilled again: exact same results. Conclusions of the evening: oil passages provide oil to all lifters. Visibly less at #8. No lifter problems detected at the moment.
OP RBrid
seems your issue is with Only Both #8 lifters (passenger side cylinder bank) ?
If Yes, and as a test, suggest swap Both #8 lifters with a pair from Driver side bank of cylinders. Prime again and note if any change or if same.
*I Do note: the primary oil supply gallery of this SHP is different from GM sbc blocks. It is located both Outboard of (and Adjacent to) the driver side lifter oil gallery; while the GM sbc block's primary gallery is located Between pass & driver side lifter galleries. Dunno if or how this difference might (or might not) affect this issue at #8 ?
mistaken; xenforo has failed you
suggest you grab an old GM dist and stand over an sbc lifter valley and re-educate yourself as to how the two fit together.
While you're at it, witness how loose the fit between distributor and its hole thru intake manifold is.
One would think that a person like you with superior intelligence would have enough pride in their responses to show where they live and what C3 they own.
As far as anyone knows, you read everything, report it but have no hands-on experience. I assume you have a Vette?
Its fine to disagree with other posters. That's how forums work and make things interesting. We all disagree on some subjects.
But when you tell someone to educate themselves, to some that is an insult.
You have been on the forum for a month and have the attitude that most informational comments by others is beneath you.
Not a very good way to start off and develop friends, trust and credibility.
RBrid, sorry my thoughts were of no help.
Good luck, I am out of here.
In the Dart SHP SBC engine, the oiling system feeds the lifters from the front of the block to the back. This means that the rear lifters—those at cylinders #7 & #8—are the last in line to receive oil during priming. This is the opposite from an OEM SBC where #1 & #2 lifters are fed last.
Anyways, I only had time to:
- swap the #8 lifters with ones from the driver side.
- orient the 16 lifters so that their little oil feeding hole is pointing to the front of the engine, where the pressured oil comes from (I don't know if this makes a difference or not).
- reinstall the spider retainer with blue loctite.
- order the ARP 130-8802 Oil Pump Priming Shaft.
I will re-install the pushrods / rocker arms again and set the lash. Then, once the new tool has arrived, we'll see how things go.
My Thoughts. Grab a used or really cheap distributor and remove the gear and pieces leaving only the body ann shaft. Most priming tools do not seal the passages in the block.
Trouble with engine oil priming
