clevite rod bearing

[Weekend Racer]

The connecting rod bearing #CB 663-H are no more available. They replace by CB-663-HN. This bearing is 2 gram lighter , and more narrow .

Is there an issue with the crank balance ?
Do this bearing change oil pressure?

Thank!

[Alan Roehrich]

Yes, you need to rebalance.

No, there is no loss in oil pressure.

[Weekend Racer]

Thank! Mr.Roehrich , for your info!
Do you known where to find a new set of CB-663-H. ?

[Alan Roehrich]

Originally Posted by Weekend Racer

Thank! Mr.Roehrich , for your info!
Do you known where to find a new set of CB-663-H. ?

You probably won't. Those bearings were probably all sold out with new cranks in rotating assemblies. They have not made those bearings in at least 3-5 years.

I use King race bearings in almost all of my stuff, coated by H.M. Elliott, so I don't keep up with the Clevite stuff much anymore.

[Weekend Racer]

I will look to use my old one.

Thank you!

[pmrphil]

I do have a limited supply if needed. Holler if you want.

[carl hinkson]

Originally Posted by Weekend Racer

The connecting rod bearing #CB 663-H are no more available. They replace by CB-663-HN. This bearing is 2 gram lighter , and more narrow .

Is there an issue with the crank balance ?
Do this bearing change oil pressure?

Thank!

Being 2 grams which on my balance card would put you 4 grams over balance is not going to hurt a thing.

If you have the crank rebalanced onece its done and the bobo weights are removed have the machinist put the bob weights back on and see how close it is!!!

Like guys guess the oil weight how do they really know what to add for the weight of the oil ???

[rustbucket79]

Originally Posted by Weekend Racer

The connecting rod bearing #CB 663-H are no more available. They replace by CB-663-HN. This bearing is 2 gram lighter , and more narrow .

Is there an issue with the crank balance ?
Do this bearing change oil pressure?

Thank!

FM makes race bearings that maintain the width with the large chamfer. 8-7100CH.

[Reed Granrt]

Originally Posted by carl hinkson

Being 2 grams which on my balance card would put you 4 grams over balance is not going to hurt a thing.

If you have the crank rebalanced onece its done and the bobo weights are removed have the machinist put the bob weights back on and see how close it is!!!

Like guys guess the oil weight how do they really know what to add for the weight of the oil ???

Carl is correct. Crankshaft balancing is governed by the world wide standard of ISO1940 and if you plug in all the figures and do calculations based on a 1700 gram bob eight and 8000 rpm, the residual unbalance of -4 grams is under balanced (remember you are removing 2 grams per rod). The residual unbalance change is minuscule. The weight change is only .002 %. And as Carl said, remove the bob weight and re install and get your big surprise. You will be appalled at how many shops that do not re calibrate their machines on a timely basis. Many dont even center the bob weights on the rod journal except by visual and the same in placing the bobweight perpendicular to the rod throw. And get real surprised when you tell them you want to over balance the crank since you are going to drag race it. And even more so when the "machinist" over balances a circle track motor because it works on a drag car.
Do not worry about re balancing unless that is what you want to do
reed

[JRyan]

I whole-heartedly agree with Carl & Reed that the two grams makes virtually no differnece. In fact, knats-*** balancing is highly overrated. For instance, you're in a circle track car turning left, do you balance the right side lighter than the left due to oil being thrown onto the right bank? Do you balance the rear lighter than the front due to loading the rear on acceleration? What about when you hit the brakes. In a
Formula 1 dry-sump world, pan efficiency might correct some of those issues, but in our world, we can only guess. Does your balance guy use one, two, or three percent overbalance? Does he really know what's correct 'cause the bearings might look good in all three cases?

Grumpy Jenkins used to put 70 gram heavier wrist pins in the race engines and put them on the dyno. When it came time to go racing, he put the light ones back in. If 70 grams per rod end weight didn't cause problems for the Grump, four grams per journal certainly won't. Don't worry about it.

Jerry