KB Alum. BBC Oil Pressure issue

Fresh KB Alum. BBC. Titan pump. I primed engine with a drill before installing supercharger and had 120 lbs. Nice......
Now I start it for the first time and it only has 40 lbs.
So I pull the pan and check the bearings...OK.....check the pump relief and it wasn't stuck..at least then. Bench tested the pump pressure and it was right on.(135 lbs.)
So I put it back together and with the plugs out and spinning it with the starter it gets 30lbs. Start it and still the same. Takes a couple seconds to build and then stops at 40 lbs. I tried reving it once and it just stayed at 40 lbs.
When I had the pan off I didn't notice any bearing material anywhere.
It is not leaking on the ground !!!!!
I'm running a 3 qt accumulator and that gauge matches the gauge coming off the back of the engine.

Any ideas on what/where to look next??????
thanks
Steve

 

Oil pickup restricted or too close to the pan ?? Air getting in on suction side ??

 

What kind of oil filter do you have?

 

oil pressure

had a friend had a problem like your problem
turned out he assumed without looking at bearing size that he got what he ask for
but got std brgs for a .010 crank
just a thought
d jackson

 

System one....remote.
I checked the pump mounting, to make sure it wasn't hitting the cap stud and not seating...but after thinking about it.... it wouldn't prime well and then not have pressure when running if it wasn't seated.
The question is.."what is diffferent when the engine is running vs not when I drive the pump with a primer drive"? I'm back to thinking about the relief in the pump. Could the extra RPM when the engine is running drive the relief open and have it stick open? I have a oil heater in the pan and didn't use it for this quick/short start. I will heat the oil tomorrow and try it again just to see if I see what changes/happens.
The pump worked fine all last year in the old engine same pan. Merlin iron block. I have another pump...I may just install it and see what happens.
It is strange that the pressure is a steady 40 lbs. even with RPM increase. If there was a galley plug missing or a bearing clearance problem....I would think the pressure would fluctuate.
Steve

 

oil pressure problem

Were you priming wet sump behind blower or dry sump without belt.
If wet sump oil pump drive might be at incorrect height for oil galley grove in block.have primered my motor with great pressure but put in rear drive at wrong height hardly any pressure when running.got it lined up right no problem.That was my issue.
Good luck

 

do you have any loops or lines that come out of the pan that has a small swag in them if so it will trap air and it will not prime and if it does it takes forever..remember rite out of pan to pump point (A) to point (B).Dave

 

We had a System 1 on our car. A fellow racer hot tipped us into using a much finer than stock filter. After the second fire up / low oil pressure deal we replaced filter with the standard one and the oil pressure returned to normal. sorry I don't remember the micron numbers on either filter.

 

Thanks for the ideas....the filter is the same one I've been using for 3 years. The lines are teflon inside w/SS braid outside and they are fine.
BUT I think Horweenracing may have hit something. THAT is the one thing that was different in the two symtoms. Now the wet sump drive is the same one I used in the Merlin block, so could the groove be in a different location in the KB? I will remove the supercharger and try the primer to see if all is OK. If it is then I will measure both blocks to see if I find a difference.
Thanks again for the ideas................this is fustrating!
Steve

 

If it/s a raised cam block the oiling at the dist----oil pump drive is a different height and will let the oil go around the drive.

 

I've been going over events leading up to this problem. First rule of troubleshooting is...if it worked before, and you touched it, and now it doesn't, you better fine out out what YOU did wrong!
This new engine has .080 thk head gaskets....the old engine had .043. When I went to install the drive it wouldn't seat all the way at the intake surface. So I just thought there is a slight difference with the parts combo and I cut a little off the hex shaft to get the drive to seat (if I remember right it was only about an 1/8"). Now I think it has the drive body too low by just enough to let oil leak bye. That is the first thing on my TODO list when I get home from work today. Remove the supercharger and try my primer tool if it has full oil pressure...I know to get the drive in the right location.
I will let you all know..............
thanks again for the feedback. It REALLY helps to get the mind working.
Steve

 

oil pressure

What filter screen do you have in the can? What oil grade? If you run heavy oil, use the nitro filter. Have seen this cause the same thing. Good Luck, just one more thing to check. If you used teflon tape in any fitting, on the oil line, Check the back of the gauge. It likes to through the line + get stuck in the gauge. Never use tape. Use liquid. All this comes from experience it happening to me. Look @ the simple thing also. Don.

 

FOUND IT.......The oil pump drive wasn't into the engine enough by .210". I removed the supercharger and primed it with my cut-up/modified stock GM dist. and immediately had 120 lbs. So I knew I was in the right spot. I used a piece of 1/8" welding rod with a short 90 on the end to probe/locate the casting bottom, the bottom of the oil passage, the top of the oil passage and the top of the casting. I used a fender washer on the intake and marked the rod at all the spots. Then used the rod to see where I was and where I needed to be. Refitted the adjustable ring on the drive and made another hex rod for the drive to make sure it is seated in the pump and into the drive.
Both blocks are "tall" deck. The only difference is I'm now using a .080 head gasket vs .043 before. I'm not sure how it grew to a .210 difference in height taller.
Thanks for all the responses...and to Horweenracing you win the prize????whatever that is !!!!
Steve

 

My KB Olds has a +.250 raised cam, sounds the same as yours maybe. Went through the same drill, had to use a longer drive to make it work. Glad you found it now and not halfway down the 1st pass.

 

I checked the Merlin block in the oil passage area, just above the gear on the cam and compared it to the KB. The Merlin has alot more surface below and above the oil passage hole than the KB. So in the KB block the drive has to be almost perfectly aligned to seal the bottom of the passage. I had to drop my drive down that 210. to put the lower boss at the correct position to seal.
If this was easy....anybody could do it !!!! LMAO