F-BIRD'88

These ports look pretty good. Just need to cleanup and file straight the roof and wall a little (brown line) and tighten up some of the new corner radii. ( yellow arrow)

I use a 5/16" rat tail file with the end cut off, in an electric drill to file the roof and walls and corner radii. It leaves the right texture on the surface and really helps ya see high and low spots. Air and fuel does not like to change directions, or take a bumpy hilly ride as it rushes thru the port into the bowl so nice straight port walls and corner radii make all the difference. I use the same 5/16" rat tail file to elongate the pushrod slots in the head for 1.6:1 rockers.
its real easy to hog out a choppy port that will have lots of turbulance. The file helps ya straighten it all out again.

Sonix

iTrader: (1)

by tighten up the radius, you mean make it smaller? grind it back more?

should you still use sanding rolls after the file? then cross buffs? (oh no, those are just for the exhaust side right?)


would that be a single/double or bastard cut file?

Thx

Doom86

finnaly i got my "money maker" 6" carbide cutter. I looked all over town and everyone could "order it" for me, for $35+. So i ordered it for myself for 15$ from www.carbidebur.com/ .. (it was at my house in 2 days time too)


1 head is completely rough cut and only needs surfaced with 40 and 80 grit rolls. The combustion chamber hasent been touched but it looks like a 10 minute job.

Sonix, about the "finnishing"; what it says in my SA porting kit, for intakes, is to first go over with 40 grit rolls, then finish with 80 grit rolls, and to not just jump straight to the 80 grits, for a finished surface. Exhaust are to be cleaned with above said for intakes, and 120 grit flap wheels, then cross buffs.

About that hole in the intake bowl, what kind of brazing rod should we use to braze it up?? my uncle wasnt sure if there was a certain rod he should use for this; we dont want to have to take these heads off again..

i'll try to get some more pictures tonight for you all.

Thanks again for all of your help everyone

rustybluebird

jb weld

Sonix

iTrader: (1)

ah, so your not using any grinding rocks eh? ok...

carbidebur.com, gotta remember that one, that's a good deal.

does filling in that void actually help? does anyone have any feedback on that?

Doom86

I used one of the grinding stones in the SA porting kit just because it was there and i wanted to see how it worked. If your doing any serious removal of metal use a carbide, those rocks are great for smoothing out sloopy cutting though, so not completely useless. If you were doing a very basic porting job they would be ok, which is what i think the kit was intended for.

Doing a search you'll find some information on filling in that viod (dont think anyones going to reply on this one) under the rocker studs; someone claimed +13 cfm here on TGO, but ya never know what thats worth, ya know?

JB weld huh, rustybluebird? If thats the case couldnt i just JB weld up those viods too? Anyone object??

Sonix

iTrader: (1)

nope, JB weld or an epoxy putty, are both rated at high enough temp to be fine on the intake port. just sand it after to make it smooth again.

F-BIRD'88

A general purpose brazing rod should work. Use brazing flux also.

The trick to brazing case iron is to preheat the head uniformly to like 400*F . A pizza oven or a big gas barbeque would work nicely to preheat the head. will take about 1 to 2 hours to heat it up. Then use a oxeygen/aceteline brazing torch to braze the hole. Then put the head back in the oven or barbeque an shut the thing off.
Close the lid and let the whole thing cool all the way down to room temp all by itself (overnight) Do not remove or disturb it until it is stone cold.

If you don;t preheat the head the brass will not likely flow and the head may crack on ya.

Brazing cast iron is a bit of an art search the web for info and
techniques. because its not a structural repair or a crack you should be fine thou.

After all done the heads deck surface may need a cleanup cut to straighten it. this is a routine job for a qualified machine shop.