Crankwalk?

[biglady112]

We run looser oil clearances than anyone here ever would.

 

[prove_it]

What kind of clearances and why?

 

[donniekak]

Larger bearing clearance supports more power up to a point. The .0008"-.002" called for in the manual is to tight for a race engine. It's one of the reasons acl sells bearings with .001" extra clearance.

 

[prove_it]

At what power levels do you consider it a "race" engine? When I used the ACL bearings with the extra .001", my clearances came out to a perfect .002" on all mains and rods. I'm only hitting 400 crank, so I know it's fine, but at what point do you consider it necessary to go bigger?

At .002" with and BSE, I had to port the OFH due to seeing around 120psi at redline. Now it's a good 90psi max.

Other thing I've been thinking about is the use of revised lifters and how much more oil the flow. Does this drop oil pressure?


Sorry for Hi-jacking, I just love chatting about this stuff. Plus it is related....

 

[biglady112]

Oil flow increases(to the rockers), pressure drops(everywhere) with the revised lifters. Depending on the cars needs, we run .0025-.003" on the mains and .0025-.0035" on the rod bearings. We accomplish this by machining the crank.

 

[prove_it]

What's your thought on the newish debate that using small port lifters is better as they allow more oil to be kept in the oil pan, since less oil it being dumped into the head?

 

[biglady112]

I am not afraid to run either lifter. If a lifter is causing you to have oiling issues you have bigger problems. I run 8.5qts of oil in my engine, so I don't really have those issues. Homemade oil pan and large oil cooler. I have large lifters in my current engine.

 

[prove_it]

That's one thing been working on figuring out. I burned a couple bearings from starvation after some long high rpm driving. Theory is that oil wasn't returning fast enough to the pan. I want to pull the head and clean up the drains. Been finding info on ways to get oil back to the pan faster.

 

[biglady112]

We run more rpms longer than anyone around. We never have any issues. A baffled pan and a whole lot of oil has cured any issues. If your machine work is right, that is most of the battle. A road course car could have more issues. If you keep the pan full and the oil cool, I don't see how it could fail.

 

[BENE38A]

If your worried about excess oil dumping in the head wouldn't the kiggly hla regulator be more effective?

 

[prove_it]

That's one option. Just be reading back and forth arguements about using the 1mm hole lifters for race engines to limit the amount of oil that's dumped in the head.

 

[biglady112]

Most of our cars run the stock regulator withthout any issue.

 

[Coltsfan]

I think the lifter debate is interesting, and wonder if they hurt oil pressure much at idle speed. You would think some testing must have gone into developing the revised lifters.
Anyways, I've been driving 631 for a couple days now and a funny thing happened on the first drive. It was about 89 degrees out at the time, and I drove it into the city to buy parts at a local chain for another vehicle. It was about a 15-20 minute drive, almost all thruway. I had forgotten to set the base ignition timing, and the pusher fan was not functioning, so I was forced to pump the refrigerant back into the system with a compressor.

On the way there cruising at 65 the A/C was reasonably cool for such a hot and humid day. When I got off the thruway and stopped at a light, the dreaded oil lamp started flickering. At this point I thought, splendid! I looked at the temp gauge and it was at 3/4 at least.

Oh, my customer just pulled up. more later...

 

[Coltsfan]

That was with synthetic 10W30. I let the engine cool for a half hour or so, drove it back with he A/C off, fixed the fan, set the timing, and installed a mechanical pressure gauge. Since then, the temp has stayed in the center, and the oil pressure has never dropped below 12psi while idling hot. Not sure if 10W40 would be a better match, or maybe 15W40, or maybe it's okay how it is.

 

[tektic]

I had the large port lifters last build, this time i now have double revised lifters with a slightly smaller than the huge ones. I currently have my oil cooler ports pluged, but otherwise its the exact same oil and setup. 10w-30 Joe gibbs hotrod oil. My pressure at idle now is about 23psi before it was around 11.

Now that I think about it I smoothed out the oil ports on the block and pump housing. I'm using a new Hyundai oil pump and gears too.

The idle pressure is much higher now than it was.

 

[Coltsfan]

I put in Rotella 15W40 and now I have massive oil pressure. Works for me.

 

[iceman69510]

10W30 is a bit light for summer turbo use.

 

[Coltsfan]

Note to self: Installed new BPR6ES plugs and Sealed power main and rod bearings at 117900 miles.
On the subject of notes, I need to put one on my dash to remind me not to push the clutch when I start my car.