As of now I am in the middle of an S5 TII engine build. I have the short block town apart and the irons bridgeported from an EZTRAC vertical mill. Which turned out great BTW. I was contemplating on resurfacing the irons to be like new. My question is can they be surface ground or do they have to be put on a rotary table and lapped. Are there any other alternatives to lapping such as surface grinding?

 

Anybody?

 

They are ground at both Yawpower and Arizona Rotary Rockets.. there's lots of pics on arizonarotaryrockets.com

 

Some grinders can get the finish right. Some can't. I've found out the hard way that some operators of good machines provide poor results. Grinding is a viable method. I just wouldn't trust my only good set of irons to a new shop that doesn't specialize in such work.

 

Right now I have a several test irons they can use. I talked to one of many machinests from the shop that disagrees with everybody else. He claims that if the irons will be ground it would change the grain pattern of the iron and wear the side seals out unbelievably quick.........The other machinests seem up to it. I will give them several test irons and find out.

 

FWIW I had a set of brand new factory irons measured for surface finish and they measured at about 12-15 RA. The guy I had doing mine could get 8 RA (50% finer finish) with a grinder. That guy moved on and the new guy fubared a set of irons on the same machine. Just thought I'd pass that on and give you some numbers to shoot for.

 

Great I will pass that on!