Opening up the small end?

[Marty]

On quite a few ford engines the pin hole is 20.638mm on the con rod. I know people have opened these up to 21mm to use XE pistons but would it be safe to go as far as 22mm? I have a con-rod here and it looks like it has enougth meat on it. 1.362mm isn't exactly loads

What would the best way to go about doing this? I was thining of an adjustable reaming tool? then hone afterwards for final fit.

Opinions?

[capri v8 driver]

what rod's  and pistons are you using? what engine?

0.4 mm and 1.362 mm is quet a differance. why do you want to use a 22 mm? 1.362mm maybe doesn't look like exactly alote, the loads on the con rod are very heavy. drilling out the pin hole leaves you whit a weaker rod. most stock rod's are not designed to do this.

the best way to drill the rod's is do it on a machine, a decent machine shop would be able to do it. depending if you want a pressed fit or a floating pin, the tolerance's need to be spot on. to lose or to tight will give problems very fast. doing it by hand whit a adjustable reaming tool will never be 100% straight compaired to the rod. so thats not such a good idea.

also keep in mind that if you do use other pistons, you need to rebalance the whole rotary assemble.

greetz paul.

capri v8 driver.

[Marty]

There is alot of choice for 22mm pin size pistons

[Taps]

Dont you ever stop      

[Marty]

No  never

[Mikey J]

This is precision engineering work.  You need a jig to clamp the rod to which can then be clamped onto a milling bed. This will get the bores drilled correctly.  Then find an engineering firm with a honing tool.  This will centre on the bore and hone to the final size.

Mike.