Wrist pin Bushing

If you really wanted to drill your rods, find some one or a shop that has an edm drill. I've seen them go through the off center side of a hardend steel ball with an electrode as thick as some 5lb test fishing line.
 
Joesixpack said:
I'm having a real hard time seeing the factory pins flexing.
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I've seen a motor that had Carrillos, stock pins and stock Pistons do that. Same hp engine but with tool steel pins and the tear down of it did not have those issues.


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What oil do you run? What do the main and rod bearings look like? I had a braided line pull out of a fitting going to the external oil filter on the truck just as I was letting the clutch out this summer and made a 290 foot pass before it siezed the motor and turbo tight but the wrist pins and bushings looked perfect yet even after that with a factory wrist pin.
 
50wt oil Rods and mains look great, almost new, other than a little trash in them. This engine has seen almost 6k every time it leaves the line. Made 50+ Passes this year. Would that drilling process hurt the rod, Could you get is straight? The rods are h beam and not much meat in the middle to wonder around.

What about running both styles of cooling jets?
 
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I don't like to disagree with anyone else's findings, but I have a hard time believing that the wrist pin is flexing. There's 100 other engines at the same power level that are still using factory pins. Most of the time a tool steel pin is used to reduce some rotating weight. It would be a fairly cheap solution if it fixes it though. And yes, an EDM drill could do that, no problem. The one we have at work will burn a hole .015"-.250" in diameter and straight within ~.003 over 9". It also doesn't get hotter than the water it is supplied with, usually 80* or so.
 
Looks more like some sort of oiling issue to me. Is there a problem with the crank bearings where the cooling nozzles get their feed?
 
No problems with the cooling jets and the mains look good. If I have the rods drilled what size hole?
 
Pony_Kegger said:
No problems with the cooling jets and the mains look good. If I have the rods drilled what size hole?
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Are you thinking of drilling extra holes in the rod/bushing?

A recap for us?

Stock rods and the billet rods have had the same results?
Same sets of pistons in both builds?(or replaced the pistons each time?)

Anything else unique on the bottom end(fancy girdle?) What 50w oil?
 
I was thinking of trying to pressure feed the pin. Edm a feed hole from the big end to the small end. Also adding the j-jets with the original main jets.

Stock rods and billets did have the same results.
New pistons and pins both times.
Was in the same block both times.
No fancy girdle, just the factory plate on the bottom, that I made to work with the main studs.
Used the main web cooling nozzles both times.

Oil was brad peen 50wt
50+ passes both times
All engine bearings looked good.
 
I would use the j-jets, definetly better direction to the pin. Can't use both as you loose to much pressure and sacrifice the rod/mains.

Did you ever measure the small ends to see if they are egged out?
 
Ok I will switch to the j jets. I did take one bushing out that looks the worst and had some heat damage and it was still round. .0002 out of round, That is about the limit of my measurement capibilities. Also the pins are still round where they were not scored up to badly.
 
In my untrained eyes it looks like a lot of heat damage. I'd assume oil temp and coolant temps are in check. I think that's been asked already?
 
joefarmer said:
In my untrained eyes it looks like a lot of heat damage. I'd assume oil temp and coolant temps are in check. I think that's been asked already?
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We pull the engine cold and don't see oil temps over 150 Egts are 1700-1750 from start to finish
Just shipped rods back to corrillo. Getting checked out and new bushings. Not going to drill them for pressure feed as was told it will only work on 1 of the strokes and not worth it in there eyes. They also suggested switching to j-jets.
 
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Pony_Kegger said:
Not going to drill them for pressure feed as was told it will only work on 1 of the strokes and not worth it in there eyes.
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Groove the rod bearing, full time oil supply to the wristpins.

I'd use both oilers, and use a big oil pump.
 
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Cummins doesn't groove the rod bearing on C/L or X. While it may be ideal to, I doubt it hinders any advantage a drilled rod would give.

And with the already narrow bearing, I wouldn't want any less load surface area. Give up one problem for another.
 
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9724VF350 said:
Groove the rod bearing, full time oil supply to the wristpins.

I'd use both oilers, and use a big oil pump.
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You have pressure on the wrist pin on 3 of the 4 strokes sealing the hole in the rod.

Would a bigger oil pump be needed, It is on the relief valve now anything over 1500rpm right now. Even at 150 degree oil temp it is still on the relief at 2500. 75-80 psi
 
Pony_Kegger said:
You have pressure on the wrist pin on 3 of the 4 strokes sealing the hole in the rod.



Would a bigger oil pump be needed, It is on the relief valve now anything over 1500rpm right now. Even at 150 degree oil temp it is still on the relief at 2500. 75-80 psi
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Increase relief valve pressure?


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Pony_Kegger said:
You have pressure on the wrist pin on 3 of the 4 strokes sealing the hole in the rod.

Would a bigger oil pump be needed, It is on the relief valve now anything over 1500rpm right now. Even at 150 degree oil temp it is still on the relief at 2500. 75-80 psi
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Having pressurized fresh oil available at any available moment to squeak it's way in and replace the "worn out" oil is a big improvement.

I'd be tempted to try the sock oil pump, just to avoid relieving more oil than necessary. It's not like the pumps are hard to change if the stock one is not enough.
 
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