iron barrel

[red ghost]

What's the safest size an iron 125 barrel will go?

[bristolmod]

I recon 150 with no problems.

175 is pushing it but may be OK

Chris

[J1MS]

What's the safest size an iron 125 barrel will go?

between the fins the 125's diameter is about 5mm thinner than a 150's and when a 125s bored out to a 175 they have been known to fold like a squeeze box when tightened up onto there studs! Its like a sort of crumple zone after being bored

[corrado]

You'll get overheating problems going to 175 and the seizures that go with it. You'll pick up a 150 cheaper than the cost of boring the 125 to 150 anyway. I'm sure there'll be plenty of freebies knocking about for P&P money.

[shocky]

i was told years ago that 60mm was the biggest to go to so about 165cc mahle used to do a nice piston for these i have one somewere it has dykes rings and is very light

[adriang]

I certainly wouldn't be doing that here in QLD Frank. We were discussing if we'd ever run an iron barrel with the alloy options out there now.

If you fancied boring out a 150 barrel, both Cainy and I have a couple kicking around.

[red ghost]

Yeah, I was just curious as Paul had one on ebay

[jonny snatchsniffer]

ive done a 125 barrel out to 62mm it was a s3 1962 model, i first ported the 125 as it was then got it bored out to 62mm using a thin ringed asso piston and ported it some more i think it was about 155/160 inlet and around 170 exhaust the obligitory 30mm and a pm pipe, ran very well, i never had any problems with it at all but maybe i was lucky.