vimzzz

Hi.

I have a freshly built engine with a Dart SHP 31161111 block.
All parts are brand new this winter.

The setup uses a flat tappet cam with hydraulic lifters and roller rockers.
My issue is that I cannot build / maintain pressure to my hydraulic lifters.

I built the engine, primed it and then started it. I got pressure to most lifters except for a few. So I went inside for a while, and when I came back a few hours later, those last lifters had built up pressure while standing still.

So now I went our for a ride, and about 5 minutes into my ride, I started loosing pressure in a few of my lifters again as they started making noise. So I went back to the garage and took off the passenger side valve cover. I could push back on 4 of the pushrods with no resistanse.

I started the engine again without the valve cover on, and saw that no oil where coming up through the pushrods and on to the rocker arms. When I then revved up the engine to about 2500 rpm, oil started flowing up to the head through the front oil drain hole of the cylinder head. Meaning that the gallery must have been so flowed with oil that it came up there instead.

My oil pressure is about 25psi on idle, and 50psi from 1500rpm and up.

Also, I have another question about the block. On the front of the block in the gallery, there are two holes which are not normally there on SBC. What are these for. They seem to be blocked by two 1/8 inch bolts.

Any tips however, on where the christ my oil is going instead of to my lifters would be much appreciated.

L Holmes

Before you install the cylinder heads, make sure to plug only the outer portion of the top driver-side oil hole on the fire deck. Do not drive a plug deep into this hole or all of the engine's upper-end oiling will be blocked. Any chance you have this plug set too deep?

claysmoker

Dart SHP doesn't have that plug.

SH-60B

That block has priority main oiling. Those are the oil galley plugs for the main bearings and cam also I think. One of those plugs covers a restrictor that feeds the top end, that's probably why so little oil is getting upstairs.

rklessdriver

The (2) 1/8th inch holes on each side of the camshaft tunnel are for the camshaft thrust retaining plate when using an 87 and newer small nose hyd roller cam.
Will

vimzzz

Are we talking about the same holes? I mean those that are located inside the gallery, you can see one of them on this picture, the other hole is angled right behind it. (to the left).

centuryoldracer

Probably a dumb question but you didn't forget the plugs in the front of the block under the top timing gear.
Also I have seen dart blocks so core shifted that they leaked internally, coolant on one, and oil on another ironically in the lifter bores.

SH-60B

[QUOTE=vimzzz;1592152563]Are we talking about the same holes? I mean those that are located inside the gallery, you can see one of them on this picture, the other hole is angled right behind it. (to the left).


I see now. Those are drilled as part of the oil galley circuit, they should be plugged like that.

claysmoker

I think the plugs you're referring to are 1/8 NPT plugs which go into to front top of the cam tunnel. They must be plugged or they will be a geyser in the lifter galley when the oil pressure is up.

Did you assemble the engine? If not, ask the assembler if he put those in.

rklessdriver

OK. That is in the lifter valley and those should be plugged/blocked off. That is where Dart drilled the intersect galley for the cam and main oil galleys.

As said if not blocked off the oil will come up from the main galley and spill into the lifter valley instead of completing the circuit to the cam and lifters, then on to the top end.
Will

fishslayer143

I remember that happening many many years ago on a 427.. Turned out it was an incorrect camshaft that had no oiling journal at the rear to match the cam bearing used.. almost no oil could reach the rocker

vimzzz

Thanks. Yes, they are blocked off. Checked both of them, and both had a bolt inside them. The one was quite a bit down in the hole though, Id say about .7 inches. Is there any way that this is so far down that it restricts the flow to the lifter galleys?

I thought that the oil came up the back, went through the lifter galleys in a forward directions to the front of the block?

Also, on a side note. I pulled the oil pan today, and switched the oil pump, as I had installed a HV oil pump, and replaced it with a regular according to Darts recommandations for this block. Before I did this, and after I had good oil pressure on idle (800rpm), about 40-50psi. But when the engine gets warm, it drops to about 10-20 psi on idle, and goes up to 50 psi before 2000rpm is reached. Is this normal (the low pressure on idle?)

vimzzz

And then another question. Those three holes in the front, and rear of the block, right above the cam.

I understand that these on regular block can be filled with oil restrictors to the top end. And Ive also read that you shouldnt restrict the oil here on Dart SHP-blocks because they have main oil priority system. So I filled all these three holes in the front, and in the back with just flat bolts measuring maybe .15 inches. Not even going all the way in, just enough to seal the holes. Can this cause oil not preasurising my lifters?

vimzzz

Okay, so finally I found the fault. The two holes in the front of the lifter gallery (on the top of the cam front bearing, only found on Dart blocks) was missing their block off bolts.

Oil were squirting out of them like a volcano when I removed the intake manifold and started priming the motor.

Going to plug them when I buy to 1/8" NPT plugs tomorrow, and I guess all should be fine then.

Thanks for all the tips.

centuryoldracer

Hopefully it didn't hurt the cam lobes.