Low Oil Pressure Cause

[gmakra]

Well gents this is my first post here. And I am just finishing a stroker build while testing the engine prior to installation the engine would fire up with good oil pressure and then drop of to about 5 PSI. The machinist and I figured that it could be the oil pump maybe the oil filter (Melling standard)so he tore it apart and it looked fine but he put a second one in and the same result. Oil pressure started out good then dropped off quickly shut it down and started to tear it down. The culprit was the cam retention spring being weak, at start up the cam would rest properly in the block but as the engine reved up it would walk forward and cause the oil pressure to drop.

After a week of head scratching, goggling and creative use of pronouns and adjectives in combination's that have probably never been used. We figured it out and I figured that I would post it here so that if any body runs into the same issue.

[dwg86]

Thanks for the info.

[SilverXJ]

That is definitely an interesting problem. I wouldn't have thought about that.

[Exos]

I quickly added a cam retention spring to my list of parts after reading you post. Thanks.

[seanyb505]

How many miles were on your engine before you stroked it? Im looking into anything causing low oil pressure, mine drops to around 10 at warm idle and 0 at hot idle.

[dwg86]

I have thought about removing the spring and installing a longer hardened pin(could use a 1/4 inch grade 8 bolt, cut off head and threads). Install with .000 to .003 clearance.

[gmakra]

Sean the answer to the question is kind of long, but I will give you a thumbnail of how I arrived here. A couple years ago I had a really nice YJ that got stolen. After that incident I looked around for another project Jeep and found an 85 CJ with a good frame and good body. The rest was trashed I drove it home and the shifter came off in my hand. So I started to try to repair things. I live in Calfornia so I did the Howell kit and converted to a full MSD ignition (CARB Approved). It ran ok but the motor was tired. And there was a 100 feet of useless wiring mostly soild wire that ran in loops. And just so many more sins.

I figured I would build from the ground up. I looked around for a crate motor and Golen has a ton of hype so I ordered the stroker from him. It was 500 more so I figured why not. The idea of a stoker defiantly had a "high gee whiz factor". Boy did I get my self into some uncharted territory for myself with the stroker. At the same time I ordered a NP435 and a 4-1 kit from Novak. And front and rear Currie 9 inch axles along with a RE 4 springs.

Well the motor arrived and putting the old 4.2 manifold turned into a real hassle. While it is possible that you can put a 4.2 manifold onto a 4.0 head it is a pretty cheesy operation with about a 1/4 inch of real estate to mate the surfaces. I ran the Howell kit and and it never ran right. 6 chips later from Howell I decided to start burning my own chips. A few times I was able to tune around some of the problems and it ran great for about 15 mins and revert back to the same old BS.I spent hours and hours looking for vacuum leaks and they just were not there.

The main problems were no low end power High idle and I had to run the engine up to 1500-1700 just to pull away from a stop sign. @2200 RPM there was really bad lifter chatter. And my AFR was all over the place.

I talked to Chad Golen and he admitted that quite a few guys had problems with the stroker and the Howell TBI.

I figured it was a manifold leak and I looked at both the Offenhouser and Clifford. This time I was not about to just accept any thing, I wanted to talk to someone and hold their feet to the fire if it didn't work. Larry at Clifford told his manifold would work. I drove out there and talked to him in person. He was really helpful and told me the cam was all wrong and he had a cam that would work with the TBI. He said the head would need to be machined to accept the new valve springs.

I asked him to refer me to a machinist, and he did I met the guy Bob Goodwin and was impressed he is about 75 years old builds Cam Am cars and act like a 18 year old around engines. I gave him my head and he machined it but he said he didnt like the look of the intake runners nor how the combustion chambers looked on cylinder 4,5 & 6. He said put the cam in and give it a try but he didnt think it would work.And call him if it didnt.

Well I put in the cam and it ran very poorly. I checked everything 3 times and it just wouldn't work. He suggest we do an autopsy so I pulled the engine and had him go thru it. After only 5000 miles on it it had burned out cam bearings two and three. Pistons five and six were incorrectly bored. The block was never zero decked nor surfaced. And the real kicker was that there were bad grooves in the crank but the journals were stock. He asked me what the oil pressure was and I told him it was fine and his reply was that the high volume oil pump masked the problems. He said never use a high volume oil pump with a Jeep engine to much stress on the cam gear and you run a chance of starving the engine for oil.

So I had him go through the whole engine. He ground the crank, surfaced the head, bored the block (now at 60 over) zero decked the block. installed a true double roller timing chain (the old one was some discount auto parts chain) degreed the cam. He suggested to put roller rockers in he said that he could put in Hartland's but he really liked the Yellow Teras. So It got a set of Yellow Teras. He also ported the head a bit. We also talked about the Joe Shubeck lifters he said he would check into it. A few days later he called me and said it was way to much liter for the street and save my money.

He would not let the engine out of his shop till it ran and was broken in and thats how the oil pressure issue came up. Good pressure at start up and it would drop to about 5 PSI. He tore down the block looking for the culprit. His words were I just dont understand it there are only two allen plugs in the oiling system and the back one was not puking on the floor. And the front one is in place! So he looked at the cam retention spring and it looked very weak to him. Made a couple calls and verified the problem and ordered a new one from Jeep.

Other than the oiling problem he said that while it ran it was terrific fired right up and ran like a striped ape. I pick it up on Thursday.

As far a Golen I did everything to their specs break in and all that. In the end the engine was never put together correctly and shipping the engine back and forth to Boston and fighting with Golen I figured was futile. So I spent 4 grand for a block,crank,head and rods but I learned.

But after trashing Golen I cant say enough good things about Novak, Advance Adapters, Howell, Currie and Moates I am pretty sure Clifford and Bob Goodwin will be in this category.

[gmakra]

DWG Just my thoughts, the clearances sound kinda tight to me. I also would be concerned about boring through your timing chain cover. The springs do work in Jeeps and it probably a 5 dollar part.

[John]

I set them to .000 clearance and have ran that way for many years with never a problem.
John

[dwg86]

DWG Just my thoughts, the clearances sound kinda tight to me. I also would be concerned about boring through your timing chain cover. The springs do work in Jeeps and it probably a 5 dollar part.

The spring and pin would have more of a chance boring through the timing chain cover than just a pin without a spring. The spring is always pushing the pin against the cover.

[dwg86]

I set them to .000 clearance and have ran that way for many years with never a problem.
John

John, so you have eliminated the spring before? if so what do you use?

[1bolt]

How many miles were on your engine before you stroked it? Im looking into anything causing low oil pressure, mine drops to around 10 at warm idle and 0 at hot idle.

Hey Sean your gauge is wrong, at about 10-13 actual PSI the lifters would start to bleed down and make a terrible racket.

I have seen "low" hot oil pressure after long runs, It's not bothered me in over 60,000 miles, it used to bug me but the sender often would read much too high so I changed it and the new one worked better for a while, then got worse, I cleaned the contacts where it plugs into the sender and boom it went back to very normal for a long time... then it got funky again, then I discovered the plug was just loose enough (a little flex after 230,000 actual miles on the chassis) to start getting bad ground and read overly high.... During all this the original alt died and the battery was replaced. At some point I took duck tape (Duck tape will save your life!) cleaned the plug with electrical contact cleaner and sealed that puppy up... No more overly high readings from poor ground... And somewhere along the way the low readings after long drives went away... My theory is the voltage to the sender would get high has the weak battery and/or old worn out alt ran down the road charging for an extended period... shutting it down for a few minutes (like when fueling up) would return everything to normal. I'm not an electrical dude so my theory is probably BS but I suppose it's safe to say, that a poor ground and something FUNKY in the electrical system along with those senders not being very accurate was the main cause of my "oil pressure" problem, and not the actual oil pressure.

If the psi really gets below 10 you'll know it.

[gmakra]

Well I installed the new stroker this weekend. It fired up right away timing was 8 and initial RPM was 600. I will have to massage the chip a little bit (Howell TBI) but WOW this this runs great and has power at all RPMs.

The engine has Clifford pistons with chrome rings, Clifford EFI cam and Standard Lifters, Clifford intake and headers. It has a 4 weight crank, stock rods, the head had the intake and exhaust runners cleaned up, it has the Chevy valves Yellow Tera rollers and a double row timing chain from Australia (dont know the brand name) a Melling standard oil pump.

The block was 0 decked and the head was shaved 20 to make sure it was flat.

Other than that the engine has an MSD Pro Billet dissy a 6A MSD box.

I have a few things to tidy up but its on the road and it runs great.

[dwg86]

AWSOME! What is your oil pressure now?

[gmakra]

Hot idle is around 25-30, 60 at start up and 40ish running.