Stampede4ever

I have a set of 799 heads, that I want clean up the bowl areas, remove the rocker arm hump, just a mild touch up, I will practice on my 317 heads first. My question for now is, on the intake side, where the port meets the valve seat, closest to the spark plug. There is a slight under cut, is it best grind of the seat to blend it?

Thanks.

omc8

iTrader: (7)

Are you going stock vavles or oversized ?

RonSSNova

iTrader: (3)

Core shift. If you see enough heads, it varies.
I work the portion of the seat that overhangs just to remove the step. The bottom third. I try not to alter the Venturi that is machined into the seat insert too much.
Wouldnt it be nice to have a flow bench?

Ron

Stampede4ever

Now I'm having second thoughts about even doing it!!
Found a set of carbide burrs on ebay for a decent price, and now looking for a set of cheap ls heads to practice on, then practice on the 317's, then my 799 heads.LOL.
Yes, it would be nice to have a flow bench to check, would like to get close to 300cfm at 0.600" for my LQ4 build.

OMC8, Columbus uh, I work in Columbus, and live 30 miles south.

Stampede.

RonSSNova

iTrader: (3)

Just do it.
I find that an oval shaped bit works well.
Mine is old and dull so I bought some new ones from Amazon.
I use an old Makita electric die grinder on a speed controller so I can go slow.

omc8

iTrader: (7)

Which heads have the overhang that your talking about , the 799s

KCS

iTrader: (20)

I normally open the throat to about 90% of the valve diameter, so with a 2" valve, I end up with a 1.8" diameter throat. That's usually enough to get rid of any steps or undercuts from the original machining.



I do like to use this guy for measuring the dimensions in the port. It's about $50 online and works way better than using snap gauges and a caliper.

RonSSNova

iTrader: (3)

Very nice. I’ve never seen digital dividers.
I use std dividers and a ruler.
I’ll have to get a set of those