i have a fresh built olds 455 .030 over forged pistons c heads arp everything the problem im having is when i first start the car oil pressure is around 60 after its warm opperating temp 180 oil pressure is around 40 when u drive the car around 3000 or so rpms the oil pressure drops u let off the gas and it goes back up i have a morroso 8 qt deep pan melling hv pump correct pick up for the pan and pump the guy who built it says it has 2,000 clearence what ever that is it is a street build lot of street driving is what it was intended 4 but also wanted fun to drive comp 305h cam kit so everything matches 373 gears 28 inch tall tire so please any info would help gonna send back 2 the machine shop over wenter just want it fun 2 drive and reliable

 

Oil pressure should not drop as the rpms go up, what is it dropping to? I would look at the oil pickup. The 60 and 40 psi is normal depending on the viscosity of oil used.

 

it was broke in using brad pen 30w the whole time we were breaking the cam in it was around 40 psi then we draind the oil and put 20w50 in it when u are at a stop light it will be around 40 or so as soon as u take off normal it goes up slightly and the starts to drop around 20-15 let off the gas it climbs back up

 

and also thanks 4 the reply need all the help i can get trying not to go chevy i have alot to learn

 

if some 1 has time to call me please can explain everything my name is kyle 810-336-5487 much appreciated

 

What oil filter are you using, 20-50 for a new build is very thick. You may want to cut your current oil filter open and check for particulate. Another thought, is your oil pressure gauge working properly?

 

Dont do anything until you try a good direct pressure gage. you didnt say if you had a sending unit model or a live gage. But, in any case, try a good live gage before doing anything else. If you still have that movement. Do as above and get that oil filter cut in half and look for trouble!!

 

sorry guys i have the dakota digital dash i thought maybe it was off so i hooked up a set of auto meter gauges thats where i got my readings the guy who built the motor said it ha 2,000 clearance dont know if that makes a difference i drove it like that for to days it hasent started knocking yet its been parked ever since

 

im using a stp filter

 

Take your oil filter off and cut it open and look for metal particles in there. Did you or the builder assemble the engine? Who installed the oil pump and pan?

 

God knows im not one to talk about Olds oiling systems, but I did make a (A) in my hydraulics class in aviation school, Too much pressure? sounds like kicking open pressure relief valve and not seating back till pressure drops, just 2 cents worth,

 

Good point!.
Also I think 20w50 is too heavy for your engine, 10w30 if it's cold where you are or 15w40 if it's hot should be fine.

Roger.

 

I agree, I had exactly the same problem with my build 3 years ago. Revving the engine above 2500, pressure would drop suddenly(about 10 psi to 45-50), then recover when taking foot off accelerator. After checking pan to pickup clearance and everything else I could think of, I took the oil pump apart(was a new hv melling) and found the pressure bypass valve was hanging up intermittently. Honed the bypass, shimmed it 1/8" and all is good now for 3 years using 20w-50.
Hope this helps
Greg

 

Another thought was maybe the oil is not draining from the heads properly, but I wondered about the pressure relief valve also. But 20-15 psi is pretty low for thick oil and higher RPMs.

 

thank u all for the input im in michigan so i have down time over the winter going to take it out. i thought it was crazy how it was dropping it would idle at a stop light around 30-35 lbs or so i take off goes up slightly then drops until you let of the gas. also is 2,000 clearance to much for a street car. should i buy a new oil pump all together the car will rarely see 5500 rpm only drive it on nice days so whil its out what r some reccomendations on what i should do

 

it dosent have restrictos any where either dont no if i should buy them i called mondello just 2 see what they said the guy on the phone said i need a new crank my clearance were to far gone they had new crank and bearings already clearenced ready to go for $1054 im just learning and dont want to get screwed lol and despertly trying to keep my olds
olds powerd

 

I dont know what the 2000 clearance is referring to. I would not buy a new crank yet. My crank has been turned down twice and put back in with oversized bearings. Maybe a return to the engine builder would be my next move.

 

First off, oil not draining back to the pan wouldn't show up until a sustained rpm run(until it pumped the oil up to the heads,like a boat)....not right off the throttle.
Second, don't do business with Mondello(if it's Mondello performance products, with Lynn) $1054 for a crank kit is just ridiculous.

Cut the filter open and look for "glitter".

I don't know what your referring to with the 2,000 clearance....does that mean .002, if so that is TOO TIGHT on the mains.

I'm in the school of Bill Trovato(BTR Performance) with loose clearances(.0035-.0040) and I've had good luck with them.

Greg

 

im sorry yea what ever .002 clearance anthe bottom end when u assemble it i think it has to do with the bearings crank and rods

 

so what should i do first once the motors and also out of the blue never over heated i have antifreez in 1 cylender number five dont no why there just basic felpros that come in the kit

 

He must be reference to the crank @ 2000 clearance on rods and mains, and that's way to tight for cyl wall clearance, pistons would gauld and seize, BBC run 0.0020 on mains and 0.0015 on rod bearings.

 

coolant in a hole? no steam? or stinky sweet smell while runnin? spill any on motor? mixing?

 

no coolent in the oil was trying to start 1 day it was hard 2 start once it fierd up white smoke came out then went away didnt think nothing about no white smoke while drivng just once it sets 4 a while everything in the heads r new except the castings there c heads they were checked for cracks b4 assembley magnafluxed i think its called so was the block arp head bolts and rod bolts n crank .010 under on mains and rods arp main studs melling hv oil pump correct pickup to go with morrosso 8qt deep sump pan 305h comp cams kit all springs roller rockers ect. match

 

first 3 days struggled to get over 180 degreez crusing woodward here in michigan miles of stop and go never broke 180 then 1 day the white smoke came out when i startwed it is when it wanted to run 190-200 so shut it off and flat bed home it also has a aluminum 4 core radiator with duel 16 inch electric fans and a 185 thermostat

 

190 - 200 isnt realy hot,

 

whow, whow....mixing on first day?? unless you use a power adder and dead blow copper head gaskets to seal, should not have an issue, I cant remember if olds has blind head bolt holes or go straight in to water jacket. you replaced head bolts with ARP? are they right length? think all head gaskets same, some one correct me if wrong. you might want to drop back and punt on that motor and check it all out again, jus my 2 cents.

 

You didn't mention on the OP that you were leaking coolant into a cyl. That engine has to come out and be gone through THOROUGHLY by a competent OLDSMOBILE engine builder, not a Chebby mass production assembler. They are different animals, and need different tolerances. Get yourself a copy of Bill Trovato's book, building performance Oldsmobile engines as a good GUIDELINE. Maybe even give him a call on the phone: 585-303-7560

He's in Rochester, New York, so it's not that far away for shipping

 

no the coolent in the cylenders was a few days latter after driving it the oil pressure allways did that weird stuff so i should find a new block maybe

 

Your getting coolant in the cylinders when it sits a few days?

 

yea u start it it puffs out some white smoke then goes away dont smoke while driving and no antifreez in the oil either no matter how long it sits just in cylender 4 heads and block were magnafluxed b4 assemblie

 

If your getting coolant in a cylinder you need to talk to your builder and go from there if he assembled the engine. If not, then you need to pull the heads and see whats going on.

 

I would not drive it with coolant in the cylinder.

 

Well what ever he doe's, needs to do it quick,,,, coolant will etch or rot that cylinder.

 

k thanks so much guys gonna drain antifreez 2 day and get it out the cyclender