Porting Pro-Comp heads

I know the pro-comp subject has been utterly beaten BUT...
I recently purchased a set from tri-state heads.

[2.05x1.60 valve size 60cc/210cc runners]

Tri-state did a fine job with the troubled areas and made recommendation on the correct valve train to keep the proper geometry.

My question is on the valve guides and how to handle that area when blending the guide to the chambers. These guides go at least 1/4" beyond the chamber. Can I shorten them to blend them in?
How long should the guide be to keep the valve stable?

Hello sir

There are other areas that deserve more attention and have payoffs. If you dont have a flow bench to validate chopping down the length of the guide - dont mess with it.

there are things such as opening up the pushrod pinch and fixing that diverging wall that will help out.

Also the chamber on those chinese heads is awful - remember the chamber is kinda a extension of the port/valve job.

Jim

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On 2007-03-06 07:07, TALONS wrote:
Hello sir

Also the chamber on those chinese heads is awful - remember the chamber is kinda a extension of the port/valve job.

Jim
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These heads were flowed after cleaning up the casting flaws with a 612 lift cam - At 7000 rpm they flowed a little over 300cfm.

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On 2007-03-06 07:07, TALONS wrote:

there are things such as opening up the pushrod pinch and fixing that diverging wall that will help out.

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If you want to see really bad pushrod pinch check out the 190 versions!!

The pushrod holes are considerably larger than the 210 units and there is no way to open them up to where they need to be without breaking through. [img]/forums/images/smiles/icon_frown.gif[/img]

Maxed out I could only get 1.95 sq in of cross section.[img]/forums/images/smiles/icon_bicker.gif[/img]

Do you have a pic of the chambers to show how the ridge around the valve seat was blended into the rest of the chamber?

Hello gents

re: pushrod pinch
you pretty much have to decide that you need to blast through and repair with sleeves.

Order some 5/8 thinwall brass tubing from a hobby store to make your sleeves

You drill/ream out the pushrod holes - then port and let it break into the pushrod holes.

after you are done - your clean the pushrod holes/sleeves with denatured alchohol and then jb weld the sleeves in place.

re: chamber contour
I dont have any pictures
your chambers will be about 67cc's when done - so count on surfacing the heads( even with flat faced valves ) - look at the chambers that make power - AFR and the like. You valve seat configuration will also effect what the chamber looks like

Here is some pictures of my Pro Comp combustion chambers. I don´t have good pictures yet, from ready combustion chambers, finished them today. Mine were supposed to be 190cc ones. Measured one intake and one exhaust: 184cc/71cc. After blending valveseats and de-shrouding valves the chambers ended up to 66cc. I don´t have flow bench, so I didn´t touch the runners. Just slightly blended the guides.

I´ll post more pictures in few days.

http://kuvablogi.com/blog/3570/1/
[addsig]

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On 2007-03-06 08:22, rj45lanman wrote:

These heads were flowed after cleaning up the casting flaws with a 612 lift cam - At 7000 rpm they flowed a little over 300cfm.
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I'd be interested to know what flow bench measures rpm along with the cfm. [img]/forums/images/smiles/icon_wink.gif[/img]

At what lift did it flow 300 cfm?
[addsig]

Mosse, thanks for the pics. These are windsor heads right? A bunch of guys on another forum are chipping in for a set of cleveland heads to see how they go. The clevo heads have a similar ridge around the valve seat and it really hurts the low lift flow numbers. Are you going to get a 3 angle cut on the seats and back cut the intake valves to make the most of your chamber blend?

The link that is provided above shows a very close match to what I have for the bowls and guides.

As for the lift of the cam that was measured at 300cfm; it was .600