questions about a C4

hardtimes · 09-03-2014, 12:37 PM

I am pulling the C4 out of my bracket car this winter to be freshen up and was just wondering if I had it rollerized how much ET could I expect to pick up.

Bill Harris · 09-03-2014, 01:54 PM

It probably isn't worth much of anything in terms of ET for a bracket car. Dial what you expect it to run and cut a good light. For a stocker/super stocker who is trying to get the last couple of thousandths for a heads up it might be a justifiable expense, but would be pretty low on the list of cost/benefit expenditures.

Rollerizing a C4 involves installing torrington roller bearings in place of the lead/babbett thrust washers and that involves some significant machining of several components. It isn't cheap or easy unless you have your own machine shop and expertise. The primary benefit is increased durability as opposed to reduced friction. You would likely see a greater ET performance improvement by investing in a straight cut gearset which is both more mechanically efficient and essentially eliminates all the thrust loading in the transmission.

If you are not having durability issues, spend your money on something else. However, it is always a good idea to replace the last thrust washer in the assembly (usually called #9) with a roller bearing as it takes the highest thrust loading and has the highest failure rate, especially if the assembly end play is set on the loose side. That bearing is between the back of the case and the roller clutch (sprag) inner race. Broader has a drop-in kit for this bearing, no machining is needed.

Good luck!

09-03-2014, 12:37 PM	#1
hardtimes Junior Member Join Date: Sep 2012 Posts: 32 Likes: 0 Liked 0 Times in 0 Posts	questions about a C4 I am pulling the C4 out of my bracket car this winter to be freshen up and was just wondering if I had it rollerized how much ET could I expect to pick up.

09-03-2014, 01:54 PM	#2
Bill Harris Member Join Date: Mar 2002 Location: Ooltewah, TN Posts: 420 Likes: 13 Liked 26 Times in 13 Posts	Re: questions about a C4 It probably isn't worth much of anything in terms of ET for a bracket car. Dial what you expect it to run and cut a good light. For a stocker/super stocker who is trying to get the last couple of thousandths for a heads up it might be a justifiable expense, but would be pretty low on the list of cost/benefit expenditures. Rollerizing a C4 involves installing torrington roller bearings in place of the lead/babbett thrust washers and that involves some significant machining of several components. It isn't cheap or easy unless you have your own machine shop and expertise. The primary benefit is increased durability as opposed to reduced friction. You would likely see a greater ET performance improvement by investing in a straight cut gearset which is both more mechanically efficient and essentially eliminates all the thrust loading in the transmission. If you are not having durability issues, spend your money on something else. However, it is always a good idea to replace the last thrust washer in the assembly (usually called #9) with a roller bearing as it takes the highest thrust loading and has the highest failure rate, especially if the assembly end play is set on the loose side. That bearing is between the back of the case and the roller clutch (sprag) inner race. Broader has a drop-in kit for this bearing, no machining is needed. Good luck! __________________ Bill Harris ex 2172 STK ex 2272 S/S