[DylanZ]

Ive got a couple of questions for the engine gurus:

I've started taking the exhaust liners out of my P79, and found that I'm doing a better job of mangling the things than removing them. Is this a fable that they come out and I'm now screwed, or am I using the wrong approach?? (hammer, pry bar, vise grips, punch + large dose of brutality) Also, for porting, there is a "stairstep" in the port at the base of the valve guide, and a bit of an abrupt 90 degree corner in the port at the valve opening bottom edge. I assume these are the things that I want rid of, anything more? Enlarge?? It'l be a daily driver, and I'm not looking for all out race job.

Secondly, the parts store that I got the valve seals from did'nt have the whole set, they had to get one from one warehouse, another two from another place, and so on. Anyways, I took a look at them today, and half of them were these short little orange-brown things, and the other half were taller and black like the ones I pulled out. Are these both for my car?? the orange ones look way wimpier compared to the black ones. Anybody used the orange ones??

Any insight would be much appreciated.

Dylan

 

[yo2001]

DylanZ wrote:
>
> Ive got a couple of questions for the engine gurus:
>
> I've started taking the exhaust liners out of my P79, and
> found that I'm doing a better job of mangling the things than
> removing them. Is this a fable that they come out and I'm
> now screwed, or am I using the wrong approach?? (hammer, pry
> bar, vise grips, punch + large dose of brutality)

Yap, that's what I had too do. I used large flathead and hammer. I slit the top and bottom. once I got it split just pull it out one side at a time

> Also, for
> porting, there is a "stairstep" in the port at the base of
> the valve guide, and a bit of an abrupt 90 degree corner in
> the port at the valve opening bottom edge. I assume these
> are the things that I want rid of, anything more? Enlarge??
> It'l be a daily driver, and I'm not looking for all out race
> job.

yap you work the bottom pocket of for better flow. I would enlarge the ports to match and polish out the chamber.

>
> Secondly, the parts store that I got the valve seals from
> did'nt have the whole set, they had to get one from one
> warehouse, another two from another place, and so on.
> Anyways, I took a look at them today, and half of them were
> these short little orange-brown things, and the other half
> were taller and black like the ones I pulled out. Are these
> both for my car?? the orange ones look way wimpier compared
> to the black ones. Anybody used the orange ones??

I think I had orange one with my cam kit because they were shorter. My orange ones were from Chevy. Black ones are stock replacement

>
> Any insight would be much appreciated.
>
> Dylan

 

[ENNO]

Actually there is an article somewhere where someone has flowtested the heads and states that the P79 outflows all others for power up to 230HP. I amusing a MAxima head with valves changed, unshrouding them, and slight port smothing but definitively with the liners!
Enno