Re: exhaust cross over (heat riser) fill
 

Sorry to bring up an old thread but I was wondering how much zinc you needed to do this procedure?

This is what I found on McMaster-Carr's website:

http://www.mcmaster.com/#zinc-alloys/=outleo

Great info guys! Thank you

Re: exhaust cross over (heat riser) fill
 

I usaully buy the 4 1/2 lbs. bar 9069K2. depending on what type of heads you are working sbc can do 2-3 sets.
Have also filled intakes that are cracked in heat cross over area,just fill it up does'nt matter then.
Mike Taylor 3601

Re: exhaust cross over (heat riser) fill
 

Interesting... I used the exact same Zinc material/part # from McMaster (9069K2) and when I pulled the heads after about 50 passes, I found the material melted back pretty bad in the port area.

Granted, I know it says it melts at 792°F, but I saw others using it with success, and figured there would be enough heat transfer into the head casting to keep it from melting...

Was going to use Aluminum next time (melting point ~1,220°F)....

No one else has melted the Zinc ???

Re: exhaust cross over (heat riser) fill
 

Thank you for the information

Re: exhaust cross over (heat riser) fill
 

I have'nt had any problems that I know of with it melting out of head,I will tearing into one that was done about 200 passes ago will let you know how it looks.

I wonder how consistent melting point is? I have noticed some of the bars seem to melt easier,but I could just be less patient that day.
Mike Taylor 3601