[Speedracer_SS01]

can anyone explain how this is done or maybe supply a few pics so I can see what needs to be done to make this happen thanks fellas

 

[CPMotorworks]

File a small chamfer along the upper shell edge from the oil groove to the rear only.

 

[Speedracer_SS01]

Do i file the groove on both sides to the rear or just on one side??

 

[novafornow]

Both sides, from the groove back. Does not take a lot.

 

[ColeBalster]

Do you see any risk in rear main seal leakage when doing this? I run a vacuum pump, so I figure it's probably OK. I am only considering this because we will be running a trans brake this year, and I don't want to burn up the thrust side of the crank.


Cole

 

[duke66]

Why is this needed on a sbc with a converter? If the converter isn't ballooned, there isn't extra pressure on the thrust bearing. In the old days with a 3000lb clutch, I never had problems. Do you properly set the thrust bearing when you lay the crank? Torgue the front four mains and snug the rear, use a large pry bar and move the crank forward and rearward, which evens the thrust faces, pry crank forward and torque rear main.

 

[Straight Shooter]

It's a none issue with an automatic. When I ran heavy clutches we just never started or shut down with pressure on the clutch pedal.

 

[Speedracer_SS01]

I was having chassis issues where i would run out about a truck length and would unload the tires on one small kit. initially I set thrust at .007 and is around .015 now caught it while cleaning my olberg filter im thinking the sudden rpm spike caused the converter to thrust forward and cause the issue but taking any precautions i can to prevent it from happining again

 

[gordrc51]

This is an example of converter loading thrust bearing. In this case the cooling circuit was restricted but the converter does load the crankshaft in any application under heavy load.

 

[Speedracer_SS01]

also i have a 3/16 gap between the flexplate and converter i had about 30 all motor passes and about 20 aborted nitrous passes while we were trying to get the chassis figured out, had rotella 15-40 in it but before the last outing switched to 10-30 vr1 im thinking the thicker oil was giving just enough cushion to keep this from happining

 

[novafornow]

If you have a high stall, trans-brake application, it is FREE insurance.

 

[mach9]

Also a good idea to check for correct converter charge pressure.

 

[OldRusty]

I had an issue where the cooler plugged converter got 215 psi and took my thrust from .005 to .015 in 5 runs. Always good to check converter pressure.

 

[Coloradoracer]

also i have a 3/16 gap between the flexplate and converter i had about 30 all motor passes and about 20 aborted nitrous passes while we were trying to get the chassis figured out, had rotella 15-40 in it but before the last outing switched to 10-30 vr1 im thinking the thicker oil was giving just enough cushion to keep this from happining

Oil flow is what provides the cushion, not weight... There isn't enough difference between those two oils for the engine to see a difference....

 

[Straight Shooter]

Hard to dispute video proof. Thanks. My current car is a pipe rack so I can see right in there. I have never watched it close from underneath like the video but I have watched my balancer up close on the brake and off at 7300 stall or free rev to 9000 and never saw it move perceptibly. The flex plate and balancer are swimming all over in the video. I wonder how much of that is just the flex plate flexing rather than the crank actually moving.

Next time I'm get a chance I will GoPro my balancer going through the motions and will see if it is indeed sliding in and out of the block like the slide on a trombone.

 

[Barry_R]

If you want to pressure feed it you can drill a teeny hole (.020) from the thrust face back to the main oil feel hole.

 

[Blown06]

Hard to dispute video proof. Thanks. My current car is a pipe rack so I can see right in there. I have never watched it close from underneath like the video but I have watched my balancer up close on the brake and off at 7300 stall or free rev to 9000 and never saw it move perceptibly. The flex plate and balancer are swimming all over in the video. I wonder how much of that is just the flex plate flexing rather than the crank actually moving.

Next time I'm get a chance I will GoPro my balancer going through the motions and will see if it is indeed sliding in and out of the block like the slide on a trombone.

I'd be willing to bet that if the crank were moving that much, the motor would be pretty fucked at that point. Maybe it was fucked, hence the reason for the video, but I'm gonna guess that most of that movement was the flex plate. Thats what they are designed to do.

 

[junebugfan]

Has to be the flex plate flexing, or that engine has about .125" thrust clearance.

 

[jimmylauri]

I never considered this on a automatic trans vehicle. Good read..thanks you guys for sharing your knowledge.

 

[desoto30]

ditto, got me thinking