Welding cylinder heads, distortion?

2443TT Fahrvergnugen

962 posts · joined Dec 2002 · 3 Jul 2007, 7:32 pm

#600064

Hi all,

I've got a question for those out there that have welded cylinder heads.

My question is about distortion of the head and will I expect any.

The heads are CB competition eliminators. I have had the middle 3 of the lower 5 cooling fins milled off the heads and am having water jackets welded on them. I figure because the welding will be being done to whats left of the cooling fins which is an inch or so from the solid material around the combusion chambers this should prevent any distortion of the combustion chamber.

Thoughts anyone?

2443TT Fahrvergnugen

962 posts · joined Dec 2002 · 3 Jul 2007, 7:56 pm

#600071

One other thing is what kind of rods should I be using? I am told for cast alloy I need to use a high silicon content rod. CE heads are aparently made from cast 356 alloy so will this affect the rod choice?

Cheers,
Ian

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 3 Jul 2007, 10:05 pm

#600132

I am thinking you are right about the minimal distortion,
but be prepared to do a little bit of flycutting or squaring up just in case.

Give CB a call and have a chat with Pat.
He has welded those castings quite extensively
and will know which rod to use, and if distortion is at all a worry.

That's my thoughts.

westi wrote:That's mad Alan.

2443TT Fahrvergnugen

962 posts · joined Dec 2002 · 3 Jul 2007, 10:23 pm

#600145

Thanks Dave, will do.

vw54 Administrator Always Waiting 4 Friday

16,723 posts · joined Aug 2002 · 4 Jul 2007, 6:35 am

#600186

when welding an alloys its best to pre heat the whole item evenly before you weld

prepare the area first grind or vee out and clean the area to be welded

heat the head in a oven evenly to about 150C and allow a decent soak peroid say min 1 hour for a head allows the heavy section to be heated evenly and penetrated

remove an do welding as quick as you can cover with a heat blanket to minimise heat loss

after welding complete put back in the hot oven and allow to stabilise once again for 1 hour or so then switch off the oven and allow to slow cool dont remove before its cold

we used this method at Qantas for welding aircraft parts very minimual distoration if any at all

You could also tak weld the jackets into position before heating the heads up would make the job easier and a tak weld wont effect the distoration

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