Hey all, I have a stock standard crankshaft with rods and mains standard running Skat rods.
The stock range listed is from .0004-.0033
and Im getting .0015 ish slightly bigger but not at .002 on the plastigage. Im using a high volume oil pump 7qt pan. Engine has slight cam engine wouldn't see over 5500 rpm. I see everyone going .0025 on rods this is not crazy modified. Whats your thoughts on the clearance? Good to go bigger clearance?

 

That is tight. A proper measurement would be best. The probably needs a polish to be safe, check your mains while you are at it.

 

mains are good .002 .0025 #5 the crank was polished. Are You are saying plastigage is not reliable form of measurement?

 

You can’t use a regular P bearing on these cranks anyway. Buy an HXN.

 

not following you, this is a. Original olds N crankshaft?
I used clevite CLE-MS804H on mains ,could not get them on rods so I went with Speed-Pro Competition Series Rod Bearings 87040CH

 

Sorry. Thought you were using a Scat crank as well.
If you want extra clearance you can use clevite X series bearings.

 

no worries cutlassefi. I didnt state it was oem crank.
This is funny, I had a new set from the 80's FM 2340-AP
and with these I get .002 clearance. So i guess is the question do I need more clearance than the .0015 with the sealpower 8-7040ch bearings, or the fm 2340-ap @ .002 which are a stock replacement bearing really dont want to put these in and I Can't find X bearings in stock anywhere.
X standard bearings do you know where I can grab a set?

Whats the gap number I should be going for? Street with slight mods and rpm max shift will be 5500. Ill be running castrol classic 20w-50 and again. Its a hv oil pump.

 

Use the Federal Mogul 108M for the mains.
Clevite CB 542HXN or HX for the rods.

 

I can't find any do you know where i can get a set of the rod bearings

 

It is very much interpretation on the reading. Those mains are pretty tight as well for a big block Olds. You might get away with it but maybe not as well. With those clearances, consider VR1 10W30. I still occasionally peg my 100 psi gauge cold with 10W30. I was running just 1 quart of 20W50 VR1, it actually went over a 100 psi. I had .002 to .0025 rods and .0025 to .0028" on a 330 crank in a 350. Also check out video Lake Speed did on that Classic Castrol. He thought it had less wear than regular Castrol. It did till he checked the larger particles, it wasn't good.

 

I am not worried about the main clearances ran that for years on my drag car. The rods are my concern being
under. 002 I measured them with a mic and pretty close to the plastigage reading both stated short of .002.
also Castrol used on drag car street car every tear down was perfect. I believe if you have a machine shop that line hones and gets everything dead on ***** accurate solves alot of problems people have with the engines

 

Ha!! I just found out the old FM 2340-AP bearings are a tri metal not a stock replacement. I got
002 on 1 rod going to check the others if good these will work fine. Thanks everyone who gave thier input!

 

probably, I’ll check.

 

appreciate it!!

 

Yeah, if it all worked, why change. You will have incredible oil pressure with 20W50 hot. There have been a couple others who ran what you are planning without fail. It must come down precise machine work and assembly that makes the difference.

 

I live in SW florida I need the 20w-50

 

my pressure never went that high. 55-65 psi the normal not a high pressure pump nor changed the spring. You must have an issuse with your pump or have hv and high pressure pump. A hv pump with a tighter clearance will have more pressure but it still gets regulator through the spring.
Plus I live in SW florida I need the 20w-50 weather here doesn't get cold lol

 

Yes, HV oil pump with the purple spring and Canton pan. I also have SB Molnar rods with the 330 crank. I live in South East Saskatchewan. Our Summer is similar to your Winter for temps, maybe a bit warmer at times. Above freezing today but over a foot of snow on the ground. Plus sand, salt and slick roads. My Cutlass gets parked nearly half the year up here. Sounds like you will have nice build and I bet your oil pressure at idle in your hot Summers will be great.