Bent cylinder fins

[soonerbillz]

Has anyone straightened bent fins successfully?
The jugs I bought have a couple that are bent up..
I am afraid of breaking them by trying to straighten them.

[Striker1423]

Has anyone straightened bent fins successfully?
The jugs I bought have a couple that are bent up..
I am afraid of breaking them by trying to straighten them.

I read on a forum a few years ago. A guy used wood shims and gently applied heat and let them sit, then added more as he went. Supposedly worked without breaking them.

[Jspooner]

Has anyone straightened bent fins successfully?
The jugs I bought have a couple that are bent up..
I am afraid of breaking them by trying to straighten them.

I've done it many times. Use heat otherwise you WILL break them. Keep in mind that they've already been bent once in the cold state and it is cast so it will break if you bend it cold. Gently apply heat on the bend, I use a needle nose pliers to straighten with. Don't pry. Once you get the right amount of heat in it you will feel it start to move. It is aluminum so the heat dissipates fast, you need more heat than you think but it's real easy to get too much in one spot and melt it. If you have a junk head or cylinder I'd practice on that first.

[RD7]

I endorse what Jspooner has said. I use a heatgun it is slower to get to temp but there is no risk of melting the fins.

[soonerbillz]

Thanks all for the tips.  I will give it a go as noted.. lots of heat 

[1976RD400C]

Yes, the trick is to put tension on it as you are starting to heat and when it gets to the right temperature you will feel it start to give and pull heat away. Works for bent levers too.