I was wondering what the perfect bearing clearance is. The motor is a B18C5. The horsepower will be in the 4-450 range and it will be daily driven. Im not sure which rods i am going to select yet but im looking for main and rod clearances. I have the tools to measure down to a micron. The range honda gives is very wide and im having a hard time deciding what is best.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by b18bEKcoupe &raquo;</TD></TR><TR><TD CLASS="quote">I was wondering what the perfect bearing clearance is. The motor is a B18C5. The horsepower will be in the 4-450 range and it will be daily driven. Im not sure which rods i am going to select yet but im looking for main and rod clearances. I have the tools to measure down to a micron. The range honda gives is very wide and im having a hard time deciding what is best.</TD></TR></TABLE>

I'd use factory bearings (check your crank and block stampings to get the right color bearings) and specified clearances.

There's no need to do anything non oem in terms of bearing clearances for that power level.

I put this excel sheet together for occasions such as this. Feel free to use it.

http://ffdet.com/members/jan/JNiemiMBworksheet.xls

 

OT, but what tool would you use to measure the clearance? I used plastigage when I rebuilt my motor to measure the rods cap-to-bearing clearances.

OEM and ACL work, but I believe the most important thing to remember is to keep the clearances equal for all. i.e. the same clearance for all main caps and same clearance for all rod caps.

 

I work in R&D for a major engine manufacturer. I have many ways of measuring it but the most simple would be with an inside and outside micrometer. I might just take it to the inspection room and throw it on a layout table for the hell of it.

 

You can use a snap gauge and regular micrometer, or an inside micrometer. Due to the extra parts of the inside mic, I'd suggest a snap gauge. Thats what most of our internal measurements are done with here, and we get enough resolution with them to use on the mics measuring to the one tenth (.0001").

btw on-topic, review this document for bearing clearances. Its by Jeff Evans, who's known for quite a few powerful hondas. He among most people here like looser clearances, but w/in the tolerances of the manual. Tighter for more power, looser for longevity.

http://forums.evans-tuning.com...build

 

id aim for .015-.017

 

good info.

 

Good information!