Bearing Clearance

[oldgold]

Your high volume pump isn't the culprit.. A high volume pump pumps the same amount of oil as a standard pump, the difference is it's CAPABLE of pumping more if necessary.The problem more than likely wasn't the clearances you used although a little tight but the failure to get oil to the bearing under running conditions. ie pickup too close to pan, oil drainback inefficient, over heat from insufficient cooling, detonation from too much timing, etc. An engine with tight clearances doesn't like to be overheated.Someone a whole lot smarter than me showed me something that stuck with me. He took a crank and warmed it to 200*. Took the rod and heated it to 200*.....Then measure clearances.....You will quickly see that things don't stay where even the best machinists put the tolerances. A whole bunch of this (not a nice word)(not a nice word)(not a nice word)(not a nice word) you read is hockus pockus to sell parts. I've ran cranks at 10 thousands *of course this isn't recommended* clearance with no ill effects. Looser will always be better than tight as long as you can maintain required pressure to lubricate. Too lose requires HP to move the oil and require oil pumps capable of the task.

i guess i have always thought that it was better to have 65psi at racing speeds than 35-40 and was always worried about oil lite on in the turns 15-20psi.
i wouldnt ever try .010 clearance in a motor but i suppose someone would.i have used blocks that have been messaged in oil returns and some not. both have worked and we dont turn them over 62-6300.we are limited in our division to what we can do to the motors scat or eagle cast cranks same with rods ,no lightened or knife edge cranks and rods have to be cast stock appearing.is it possible to supply oil to a engine with with large clearances on a stock pump.?

[perfconn]

Oldgold,
Your talking pressure not volume.You are correct that 35-40 pounds at racing speeds won't cut it.You are also right that. 010 clearance won't cut it.Trust me I tried it once by accident.A worn out oilpump(too much clearance on the gears) will not have enough volume or pressure for a race engine.

[oldgold]

Oldgold,
Your talking pressure not volume.You are correct that 35-40 pounds at racing speeds won't cut it.You are also right that. 010 clearance won't cut it.Trust me I tried it once by accident.A worn out oilpump(too much clearance on the gears) will not have enough volume or pressure for a race engine.

i have been told by some to use a big block standard pump

[dirtdevil]

Okay - if it is measuring that it is .0016 on the rods, do I need the .001 bearing set or what needs to be dome?

[perfconn]

Yes you need plus. 001 bearings.That should give you. 0026 but you still need to put the new rod bearings in the rods and torque the bolts and check you measurements again.
By the way.never seen a need for the BB Chevy pump even with remote filter and remote cooler.

[dirtdevil]

Yes you need plus. 001 bearings.That should give you. 0026 but you still need to put the new rod bearings in the rods and torque the bolts and check you measurements again.
By the way.never seen a need for the BB Chevy pump even with remote filter and remote cooler.

Thank you Perfconn.

If I understnd correct then I order the same part #, but instead of std I tell them .001 OR 1x. I see that is how it is listed in the catalouge.

[perfconn]

Yes you are right and as an earlier poster stated you can even use a half set of std. and a half set of 1X to get proper clearance. I have even used a half set of coated bearings to come up with proper clearance.

[racer69]

Dont be afraid to mix and match. Thats what you'll have to do to get it right!

Also I have had the best luck with a blueprinted standard volume oil pump and the high pressure spring. I pull the new ones apart and start measuring. And there are some tricks the make them work better. A lot of extra work but it does payoff later on.

[dirtman45]

I'm pretty sure the .001 bearing is for a journal that is worn down and the .001 tightens it up. If you are at less than .002 either "let er buck" or have the crank polished more to give you more clearance.

[let-r-eat]

i guess i have always thought that it was better to have 65psi at racing speeds than 35-40 and was always worried about oil lite on in the turns 15-20psi.i wouldnt ever try .010 clearance in a motor but i suppose someone would.i have used blocks that have been messaged in oil returns and some not. both have worked and we dont turn them over 62-6300.we are limited in our division to what we can do to the motors scat or eagle cast cranks same with rods ,no lightened or knife edge cranks and rods have to be cast stock appearing.is it possible to supply oil to a engine with with large clearances on a stock pump.?

What I was trying to say is was lean on the loose side of things. The stock pump won't supply oil for .010 for sure. Lean on the loose side. Much easier to get hot and grab a bearing at .002 clearance than at .003.

[fast_crew]

I'm pretty sure the .001 bearing is for a journal that is worn down and the .001 tightens it up. If you are at less than .002 either "let er buck" or have the crank polished more to give you more clearance.

You can't polish a crank and remove enough material to gain clearance with out barrel shaping the journal. The "x" suffix bearings will give an extra .001 of clearance or use half the set for .0005 extra.