Rod Bolts - Bearings

[85_600]

Is it really necessary to use new rod bolts when pulling/replacing a rod/piston? Are these like the headbolts - they get stretched?

Also, the bearings. What chance do I have of them not failing, on one rod, if I reuse just the one set on the rod/piston I pull? As far as I know I don't have a bearing problem, just the high probability of a cracked piston.

Thanks,
Paul

[GLHS0658]

It is not necessary to replace rod bolts. The only time you would replace rod bolts would be for rod reconditioning. If you spun a bearing or the big end (rod bearing end) is discolored from heat (no lubrication), recondition or replace rod.

Look at the bearings for wear. See if it is worn unevenly, excessive scratches and/or excessive wear. You can use plasti-gage to check your clearance.

Though, for the cost of bearings, I would replace them.
Also use new rings and use a ball hone to put a new cross hatch pattern to help the rings seat.

A lot of miles? while you're there...replace the oil pump.

Mike

[85_600]

It is not necessary to replace rod bolts. The only time you would replace rod bolts would be for rod reconditioning. If you spun a bearing or the big end (rod bearing end) is discolored from heat (no lubrication), recondition or replace rod.

Look at the bearings for wear. See if it is worn unevenly, excessive scratches and/or excessive wear. You can use plasti-gage to check your clearance.

Though, for the cost of bearings, I would replace them.
Also use new rings and use a ball hone to put a new cross hatch pattern to help the rings seat.

A lot of miles? while you're there...replace the oil pump.

Mike

The mileage on my 600 is only 46k. What's going on with it is, 87 octane and now a 90 psi on cylinder #2. The others are 150, 120 and 125. I'm hoping that the 120 and 125 are just stuck rings. I don't have any other issues other than the stumble at idle/part throttle. Once it hits boost it runs great.

One thing that's been bothering me: Would a cracked piston give me low vac readings all the time? I only had really low readings when I would get a real bad stumble when at idle either in gear stopped or more so, in Park. the 600 is normally running between 19 - 22 inches (can't remember off hand) but I do know that when the real bad stumble appears, which isn't all the time, I go down to about 10 inches. Once this bad stumble clears up, something like 2-3 minutes, the vac goes back up to the normal reading.

I know Lee's Daytona has the same exact problem. His brother ran his Daytona on 87 octane and pounded on it. Now he has a cylinder with a 90 psi reading and a stumble at idle/part throttle too. I'm waiting paitently for his rebuild since he will be doing it before I will, to see what's going on inside the block.

[MiniMopar]

If the engine isn't idling well for whatever reason, the ECU needs to opent he AIS valve more to keep the idle up. That alone will cause the idle vacuum to drop. Low compression can also effect vacuum, depending what the actual cause is. For instance, a leaky intake valve will have a much larger impact than a slight ring issue.

Could also be a blown HG.

[The S is Silent]

Rod bearings cost $25. If you have the engine out, replace them. I just did it in my charger. The bearings I pulled out had very little wear, but I replaced them anyways because the last thing I wanted to do was open up the oil pan after I get the car started because of a stupid rod knock.

If you decide to replace the oil pump, make sure to replace the pickup tube, or clean it out VERY well.