high oil pressure

[gor in san diego]

A 1960 283 power pack Chevy Engine was assembled after a complete rebuild and put into my 1964 Chevy C-20 PU with a four speed granny tranny and a 456 rear end running on 750-16 tires. (workin' truck). The no load oil pressure was 30 psi at 600 rpm and 60 psi at 2000 rpm after a 45 minute unloaded run at 2000 rpm, and a 10 mile test drive around town. The original mechanical oil gauge and fitting in the truck was retained. 60 psi is the top peg on this gauge THIS OIL PRESSURE SEEMS TOO HIGH. Updated observations. After putting 60 miles on it half street, half freeway, the oil pressure has reduced. No load: 600rpm idle, 15psi. 2000 rpm, 45psi, 4000rpm 55 psi. 4000rpm on the freeway, 50psi. Because the gauge did not peg at driving speed, I am relieved, but this still seems too high. I used Sta-Lube graphite-moly rebuild compound which seemed a little thick and heavy. This stuff may be slow to wash out of the bearing clearance areas.

Any and all opinions and comments are wanted and welcome. This engine may have some collector value, (1960 three speed corvette) and I do not want to mess it up. Thanks to any and all responders. I just got my license to post, so bear with me as a newbe. I went ahead and included a pretty good write up on the rebuild for anyone interested. Gor in San Diego.

The 1960 engine was described as a "crate engine" that had been installed into a desert vehicle and had sat around for perhaps 30 years or more. The motor had triangle over rectangle heads a Carter WCFB four barrel carburetor and a 10 1/2 inch clutch. Disassembly indicated that it was stock, all casting numbers matched, the carb number was correct, the water pump back cover, timing chain cover and valve covers had the old large head phillips screws. The block was hot tanked, magna-fluxed, and bored 0.030 over by a reputable shop in town. A Northern Auto Parts rebuild kit was used, with the only upgrades being brass block plugs and a high torque RV cam. The local shop installed the cam bearings and block plugs, and mounted the pistons on the rods. The crank was magna-fluxed and ground to 10 - 10 under by the local crank shop. The heads in very good condition were hot tanked, and a conventional valve job was done including knurling of the valve guides. Almost new rockers and push rods were used. Intake manifold was hot tanked, and the Carter Carb rebuilt; the metering rods and all operating linkage were in good condition.

Assembly was done by this author. The crank bearings were not plasti-gauged, because the local crank shop is considered to be very good ? The rings were trial fitted and were exact. All block components were smeared with a thin layer of Sta-Lube graphite-moly compound. Bolts were torqued with a flex handle wrench and held at final torque for several seconds. The assembled short block could be easily turned over at 30 or so foot pounds. The final assembly was installed into the truck. (attempted to post pic, I know, truck engines are grey) 10-30 oil was put in. The engine was timed by running on the starter with the spark plugs removed, and the oil gauge indicated 30 psi on the starter motor. With spark plugs in, the motor started right up, and sounded fine. As previously mentioned, the engine was warmed up for 20 minutes, the carb mixture and idle set, and allow to purr along for 30 or so minutes. Sounded great. Went for the test drive, It wanted to get up and go....but the oil pressure pegged at 60 psi above 2000 rpm.

Truck was parked for the night. Oil level is right at the add a quart line. Driver side valve cover was removed and the rockers were full of cupped oil. The engine was started, and the lifters oiled well and began to leak over the edge of the head. Valve cover was replaced, and the passenger side cover removed. The lifters oiled even better, perhaps because the engine had warmed up a little. They began to spit and flip.....a lot like my old 57 with the 098 Duntov. The oil filter cannot blow out because of the original 1/8 inch walled can contained by a 1/2 bolt is in place.

[pmkrew]

Sounds about normal for a fresh engine with a high volume/ pressure pump.

[T Smith]

Yeah, that's just right. A hot small block with 15lbs at idle is normal and 50 at cruise is great, my fresh 355 has about 45ish. The factory gage is likely not very accurate anyway.

[awbrown]

When you say reduced oil pressure now that it has been run , the first thing I would do is change the oil and filter , Did you change it after running the cam in ?? I normally suggest that my customers change the oil and filter after run in while it is hot that way the metal in the oil from break in doent settle to the bottom of the pan ... We dont normally use HV pumps in any of our rebuilds , we just run the clearances in the middle of spec .... 15 psi at idle will make you feel nervous but it should be ok ..

[gor in san diego]

Hey thanks guys, I am feeling better already. I will keep an eye on the oil pressure and level. This seems like a fun forum. Posted pic is of my old '64 in progress, not restored, but sort of rehabed and is sort of a day driver right now. He's got 68 or 69 wheels and hubcaps. I think, got ,em in a junk yard quite a few years ago. He came with 15 inch split rims....I know, I bought him in 1966. Cheers, gor in san diego.

[gor in san diego]

Originally Posted by awbrown

When you say reduced oil pressure now that it has been run , the first thing I would do is change the oil and filter , Did you change it after running the cam in ?? I normally suggest that my customers change the oil and filter after run in while it is hot that way the metal in the oil from break in doent settle to the bottom of the pan ... We dont normally use HV pumps in any of our rebuilds , we just run the clearances in the middle of spec .... 15 psi at idle will make you feel nervous but it should be ok ..

AW, I am right with you, I ran the engine for 45 minutes at 2000 rpm with no load. I assembled this engine with Sta-Lube graphite-moly rebuild compound. It seemed too heavy. I am an ole shade tree mechanic, but have put a few small blocks together. We always used STP for bearings and perhaps white grease with STP for cams and it always seemed OK. This one has 60 mixed load miles on it. Next operation, I will warm it up and change the oil and filter. I want to get the Sta-Lube stuff out and the break-in metal debris out, if I can. This engine has a low end Melling pump. I will put in low quality 5 -30 oil. Thanks for your professional opinion. gor in san diego

[Captainfab]

I hope you used a good breakin additive to start with. And be sure to use either an oil with sufficient ZDDP or a ZDDP additive with the next few oil changes.

[T Smith]

Originally Posted by Captainfab

I hope you used a good breakin additive to start with. And be sure to use either an oil with sufficient ZDDP or a ZDDP additive with the next few oil changes.

Truth!

[1963c-10]

Great looking truck too

[scottofksu]

Awesome story! Welcome to the forum!

[T Smith]

I wouldn't get out in it after dark!

[LT1 Burb]

My Lt1 on the freeway pegs my oil pressure gauge also and it drops to 20#s at idle so I wouldn't worry to much.

[chevyrestoguy]

You're going to be OK. A lot of the engine kits on the market today come with a high volume/high pressure oil pump, and that's probably the reason why you've got such good pressure. Even the low-end Mellings seem to produce a higher than stock pressure. The pressure is determined by the spring inside the pump, and most pump manufacturers lately seem to put the same spring in everything.

The engine looks great! From what you've posted, you definitely did it right. Nowadays, I'm more freaked out about flattening the cam at break-in than anything else. If you've ran the engine as long as you have and she's not popping, I think your cam survived the ordeal. As was posted by Captain Fab, definitely use a good oil with ZDDP (I like Rotella) or use an additive. It sounds like you want to use a lighter viscosity oil, so I think the additive is your best choice. It's cheap insurance.

I like your truck alot, and the fact that you've owned it since '66 makes it really special. You've probably got some some great stories about that truck!

[Rich 5150 69]

My truck runs at 30 lbs idle and 50 lbs at 2000, and it has about 120,000 on it.

[gor in san diego]

Hey all, Thanks a ton for all the responses. I have my plan of action to change the oil, add some ADDP additive and let er run. Chevyrestoguy, my 64 looked a lot like yours. Took a lot of hammering, wire feed welding, some LMC fender panels, some fiber glass, and some
Bondo. Painted with a lot of dissassemby. Lights are back in now. Thanks again guys...PS my car is a 1995 Police Caprice with a very fast LT1.

[1Bad62Pro/Street]

F.Y.I.
"New" Oils and "Old" Cars Don't Mix
http://joegibbsdriven.com/trainingce...oiloldcar.html

http://joegibbsdriven.com/trainingce...hotrodoil.html

http://www.youtube.com/user/JoeGIbbsDriven/videos

[awbrown]

Originally Posted by gor in san diego

AW, I am right with you, I ran the engine for 45 minutes at 2000 rpm with no load. I assembled this engine with Sta-Lube graphite-moly rebuild compound. It seemed too heavy. I am an ole shade tree mechanic, but have put a few small blocks together. We always used STP for bearings and perhaps white grease with STP for cams and it always seemed OK. This one has 60 mixed load miles on it. Next operation, I will warm it up and change the oil and filter. I want to get the Sta-Lube stuff out and the break-in metal debris out, if I can. This engine has a low end Melling pump. I will put in low quality 5 -30 oil. Thanks for your professional opinion. gor in san diego

actually yours is almost like mine (my 97 7.4 silverado) cold it is past 3/4 (60psi)of the gauge ,hot it is 20 the minute it gets over an idle it goes to 60.. I don't know if anyone has been into the engine before or not , I run 5-40 synthetic.. I have had trucks with little or no oil pressure and ran 15-40 or 20-50.........

[GASoline71]

Originally Posted by gor in san diego

10-30 oil was put in. The engine was timed by running on the starter with the spark plugs removed, and the oil gauge indicated 30 psi on the starter motor. With spark plugs in, the motor started right up, and sounded fine. As previously mentioned, the engine was warmed up for 20 minutes, the carb mixture and idle set, and allow to purr along for 30 or so minutes. Sounded great. Went for the test drive, It wanted to get up and go....but the oil pressure pegged at 60 psi above 2000 rpm.

Any ZDDP in the oil when you did the "timing by starter"?

Gary

[Bigstevex4]

Had a 6.2 corn binder in a ford service truck Manuel gauge quit plugged in a gauge see it had 5lbs at idle 20 at full rpm called ford in spec. As long as it has pressure it has oil. were it needs it.