How's my port!

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18teener

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I thought I would make a start on porting my heads loosely following the sticky guide.
This is my first port (on a 318) so any comments/feedback would be welcome.
One question regarding the exhaust port. Can I remove the hump on the roof completely or do I risk water?

318 porting.jpg

No more photos at the moment, that's all I've got.
 
Looks like you followed 318willrun videos! That looks pretty good, smoothing the rough edges and areas will definitely make a difference. 65'
 
Thanks guys, appreciate the feedback.
I didn't go too mad. The short turn is untouched apart from blending in the ridge in the bowl and the pushrod hump is likewise untouched.
 
I’m of a porter so with a grain of salt from what I remember reading, the bump in the roof of the exhaust port can take a minor grinding, at most because there is water behind it. Proceed with caution! I also have read there is a most minimal gain there.

The bowl porting your showing, should have a percentage of bowl ground away relative to the valve size. I forget what the percentage is. I do believe there is information in Justin’s thread on that and for surly else where but I’m not sure where to send you on that.
 
Thanks rumblefish. I can't seem to find a definitive statement on the exhaust port bump so I will be cautious. Plan is to smooth it out and call it good.
The bowl shown is opened up to 89% of valve size give or take a tad.
 
I did my first exhaust port. I cut the bump down as far as I dare, it's just a very slight rise now.
Bowl is opened up and all edges blended in. The black area in the photo is a divot in the casting.
After not finding water (hurray!) I completed all the ports.
318 exhaust port.jpg
 
They are 675's.
What would you like pics of? They are not the prettiest examples of porting, I don't claim to be any good at this!
Probably be tomorrow now.
 
18teener said:
They are 675's.
What would you like pics of? They are not the prettiest examples of porting, I don't claim to be any good at this!
Probably be tomorrow now.
Click to expand...
Thx for the reply, honestly I'm going to attempt my first port job. So no judgment here, just trying to learn. I'd like to see the bowl and area around the valve stem. It looks like you opened up the diameter under the valve just shy of the ID seat diameter. 65'
 
OK. It will be tomorrow now, it's 5 in the evening here, I'm finished for the day (retired so time is mine to do as I please:icon_fU:)
 
18teener said:
Here's a quick photo I took this morning. As I said I don't claim to be good at this.
View attachment 1715706303
Click to expand...


You can’t get good at it if you don’t do it. There is no other way to learn it. It’s always best to start with a head (or two) that are junk so you can learn how to get the shape you want.

I don’t use stones for porting very often. I use carbide burrs. You need to be able to control cutter speed.

There are plenty of threads on here about porting that are worth reading. There is no substitute for time behind the grinder.

You are doing fine BTW. It just takes time.
 
Thanks YR.
I've done a few heads over the years but the gap in-between is usually a long time. The last set were a pair of d0ve Ford heads for a 460 about 15 years back!
I used burrs on the 318 heads, as you say practice is key. I have an air die grinder so speed control is easy. Getting used to long burrs is not so easy!
 
When was grinding a part, I noticed the metal would start to turn shades of anything but silver (blue/brown/black) when it was getting very thin. that's a good indicator that your getting very thin there and to stop and move on. Dont take that as the end all thickness indicator, but it may help someone.
 
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