TheSamba.com :: View topic - New engine

Mon Jun 10, 2013 12:33 pm

Someone here has had this happen I am sure, but since the late 60's, I've never run across this problem.

Long story short - I changed the engine case to a universal type III looking case due to some interior damage (water) inside my old case. I also wanted to de-cam the engine a little so I went from an Engle 110 to a Schneider 275F - a step down, but still above stock on my 1641. Every moving part in the engine is new - .010/.010 crank, straightened and re-bushed rods, all properly fitting bearings (case line bored to .080 and .080 on thrust), new lifters, valves, guides, new DOPR springs and plungers, oil pump, plus I flattened the inside of a thicker cast iron pump cover on a surface grinder, etc. The whole case was vat cleaned for a couple of hours and compressed air sent through all galleys.

I assembled the engine and no (ZERO! nada, zilch) oil pressure on start-up. I run an electric oil gage and the idiot light. I removed them and installed (temporarily) a VDO mechanical oil pressure gage. Still no oil pressure. I removed all gages from this hole and no oil comes out on start-up! Flat cam/proper pump. Blew air back through the sending unit hole to eliminate any air bubble. Pulled the pump to ensure the inlet/outlet holes are OK. I even overfilled it by a quart of oil to "force" something to happen. Nothing.

What are your favorite ways to prime the oiling system? Total run time on 4 ~ 5 start ups is still under 2 minutes, so I don't think the damage is permanent yet.

Mon Jun 10, 2013 12:58 pm

Pack the oil pump with petrolium jelly

Mon Jun 10, 2013 1:32 pm

drs1023 wrote:
What are your favorite ways to prime the oiling system? Total run time on 4 ~ 5 start ups is still under 2 minutes, so I don't think the damage is permanent yet.

First of all, what in the world were you doing starting the engine before you knew you had oil pressure? First crank it with the starter to make the oil light go out a couple of times to pump up the oil system, THEN put gas in it.

Did you check and set the depth of drive shaft on the driven oil pump gear? It needs to be deep enough in the camshaft slot so that it fully engages, but doesn't bottom out.

Did you check to make sure the oil inlet AND outlet holes on the pump line up with the corresponding holes in the case, and that they're at the same depth?

The oil pickup is correctly bolted to the bottom of the case? You might remove the oil sump screen and look up to make sure the pickup didn't get blocked or shoved upwards out of the oil.

Craig Steffen

Mon Jun 10, 2013 2:31 pm

Some guys do not realize it but the pump drive shaft is pressed in. I lost a Sqbk engine after a few thousand miles because the shaft backed out of the gear. Usually the face of the shaft is not flush with the gear mine was. No clue it was no overheating, I guess seeing I was using what ever part I had it may have had a million miles on it.

Mon Jun 10, 2013 2:47 pm

Quote: Pack the oil pump with petrolium jelly
Have done it before on a Buick 340. Haven't gotten that far yet.
Quote: Did you check and set the depth of drive shaft on the driven oil pump gear? It needs to be deep enough in the camshaft slot so that it fully engages, but doesn't bottom out.
Measured with a digital caliper. All OK. Cover to Gear "slop" is 0.002. Quote: Did you check to make sure the oil inlet AND outlet holes on the pump line up with the corresponding holes in the case, and that they're at the same depth?
Yes, paint marker on center of case holes and pump holes match identically.
Quote: The oil pickup is correctly bolted to the bottom of the case?
Yes, I removed it to get the case level for drilling and tapping case savers. Re-installed correctly.
Quote: You might remove the oil sump screen and look up to make sure the pickup didn't get blocked or shoved upwards out of the oil.
I knew a guy many years ago who didn't run with that screen. He installed the full flow oil filter pump and cover instead. That's my next step, also, is to remove the oil screen and snake the opening in the pickup to the rear of the case. This, too was vat cleaned, but this is an old case and I didn't check the pickup tube after it was vat cleaned. Is there a pressure primer I can attach to the oil sending unit hole?

Mon Jun 10, 2013 3:12 pm

drs1023 wrote: Quote: Pack the oil pump with petrolium jelly
Have done it before on a Buick 340. Haven't gotten that far yet.

. Is there a pressure primer I can attach to the oil sending unit hole?

Instead of blowing AIR into the oil pressure sender hole, what I've always done is just take an oil can with a pump and flex-tube on it, and pump oil into that hole, a few pumps, then turn the engine backwards a bit, pump some more, turn the engine backwards, then pump some more... That's always worked for me to get enough oil in the works for the pump to work right away.

You might also have a look at the pressure relief valves that they aren't sticking at all.

Mon Jun 10, 2013 3:26 pm

i had that happen to me happened to be that the case was plugged at the rear it had been a case made for aixilarry oil cooler/filter

Mon Jun 10, 2013 3:57 pm

Quote: Instead of blowing AIR into the oil pressure sender hole, what I've always done is just take an oil can with a pump and flex-tube on it, and pump oil into that hole, a few pumps, then turn the engine backwards a bit, pump some more, turn the engine backwards, then pump some more... That's always worked for me to get enough oil in the works for the pump to work right away.

You might also have a look at the pressure relief valves that they aren't sticking at all.

I understand, but it seems that the oil sent down the gage hole slowly would simply seep back into the sump beside the cam gear.

I stated before that the pump was new (30 mm), but I am going to order another new one (26 mm on a real mechanic's recommendation) in addition to trying the various things you guys have noted. I believe the first order will be to snake the pickup tube, pull the coil wire, and turn it over to try to get the light to go off.

There is one thing I didn't mention. The old Type I case (circa 1971) oil dipstick tube is 1.475" above the case, and the universal case is 1.175" sticking out of the case. When I used the same dipstick from the old case, it was showing full before the full ~2.75 quarts went in - the stick was going in .300" farther than it was in the old case. I re-marked the stick to reflect the difference. BTW, my dipstick is from the original 1200 engine from '63.

I really appreciate your help on this one. Lots of good questions and comments.

Mon Jun 10, 2013 4:35 pm

Make sure that your cam gear and oil pump drive are of a compatible design.....

Dave

Mon Jun 10, 2013 5:18 pm

drs1023 wrote:
Quote: Did you check and set the depth of drive shaft on the driven oil pump gear? It needs to be deep enough in the camshaft slot so that it fully engages, but doesn't bottom out.
Measured with a digital caliper. All OK. Cover to Gear "slop" is 0.002.

(My understanding is that the desired difference between the pump body top and the gear top is ZERO; the (very very thin) gasket provides the thickness for the gear to turn. And the cover should be smooth and shiny enough to use as a mirror. But none of that will cause NO oil pressure.)

No, what I meant was you need to check the SHAFT of the oil pump gear to make sure that it engages fully in the slot in the camshaft. That is, with the pump body installed in the engine, insert the gear with the shaft so that it engages. Then slide the gear out, turn it 1/4 of a turn, then push it back in. It should hit the camshaft gear and stick out about 1/4 of an inch.

Here's a blog post I made in April of 2009 when I did this. As delivered, the oil pump gear shaft just BARELY engaged the camshaft slot, I had to extend it quite a bit.
http://craigsteffen.net/blog/2009/04/2009_04_12_00_26_00_A.php

Craig Steffen

Mon Jun 10, 2013 8:09 pm

Bentley's calls for a maximum of. 004" between the gear and the top of the housing. I am at about. 0015" (.002" feeler gage scrapes). The oil pump drive gear engages about 5/16" - roughly what your 1/4" mentioned. I measured it because this is not a stock pump, so I don't trust that the tolerances are too tight. I have never been sure why the drive shaft doesn't enter more. I know there must be allowances for the thrust of the helical gears on the cam, but it seems the shaft should enter more. I re-used the pump cover only after I put it on a surface grinder in the machine shop and flattened it to a mirror finish.
All good advice-thanks

Mon Jun 10, 2013 9:05 pm

drs1023 wrote: Bentley's calls for a maximum of. 004" between the gear and the top of the housing.
Interesting. I thought someone told me that the correct clearance was zero. But I just looked up the official answer in the "Without Guesswork" book, and the only thing it says is, as you said, that .004 inches is the wear limit. There is no "new installation" number, oddly.

Quote: I am at about. 0015" (.002" feeler gage scrapes).
I think if the .002 scrapes, you're at .002.

Like I said, I ground the pump body until it was dead level (with a straightedge) with the gears. I'm not sure where I read that was the way to do it.

Quote: The oil pump drive gear engages about 5/16" - roughly what your 1/4" mentioned. I measured it because this is not a stock pump, so I don't trust that the tolerances are too tight.
It's not really a matter of tolerance. Different years have different outer wall thicknesses, so several different things could be different.

Quote: I have never been sure why the drive shaft doesn't enter more. I know there must be allowances for the thrust of the helical gears on the cam, but it seems the shaft should enter more.
The slot in the camshaft isn't much deeper than that. If the tang goes much deeper then it will bottom out and the camshaft can push the gear against the cover plate.

Quote: I re-used the pump cover only after I put it on a surface grinder in the machine shop and flattened it to a mirror finish.
I had pretty deep gouges in mine. I did it with sandpaper by hand. It took me most of a Monday Night Football double-header, and my shoulders were SORE.