924Board.org

endwrench · Joined: 07 Dec 2002 Posts: 1631 Location: Victor, Montana

Just got these back from the machine shop and thought I might post a couple pics. This was a 1977 NA head so the ports are slightly smaller than the late model heads.

As you can see, the valve seats where removed before cutting but the rest is pretty complete. If anyone needs some different angles or measurements please let me know.

Todd
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'79 924NA. Rebuilt 9.5:1, MSDS header, Mega Squirt Injection, MJLJ-EDIS Ignition, 1.6L Whipple Charger and Intercooler, 10lbs Boost, 944 Trans, Custom HD Clutch.
"simsport" said....superchargers are better than turbos its official!....

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

you're a legend!
_________________
1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

Joes924Racer · Posted: Sat Mar 29, 2003 10:38 am Post subject:

Very cool.."wow" its amazing I didnt go into the water jackets!
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

you can see the major porting changes they did for the 931 head. Basically just fill the green area and cut the red area. Then they cut back the sides so the port went from 42mm x 36mm to a very smooth 40mm circle.

_________________
1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

Zuffen · Posted: Sat Mar 29, 2003 2:22 pm Post subject:

Well damn, I quess I don't need to worry about that project.

If I can get a 931 head I'll still cut it up though.
Doesn't seem to be much meat on the runners.
_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

Todd

when you have time would you post a shot looking into the port and one looking in from the valve end.

Thanks for doing this. These pics are going to be a great help to anyone contemplating fixing the ports.
_________________
1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

4porsches · Joined: 07 Feb 2003 Posts: 36

Taking some demensions of the metal between the ports and the water jackets might be very helpful as well while you are at it. Thanks for getting the cross section of the head. Thats something I wanted to see before I even touched my head.

John

Vince Ponz · Joined: 02 Nov 2002 Posts: 3581 Location: Florida

Pictures from inside the valve stem would be nice as well as some from 50 feet away.

Just kidding great pics and very helpful. Now what do I use to fill the spaces. Just ran out of my wifes cheesecake that I normally use.
COMING DEAR.

78porsche924 · Posted: Sun Mar 30, 2003 5:47 am Post subject:

Is that second picture the exhaust port?

jpab924 · Posted: Sun Mar 30, 2003 6:43 am Post subject:

Richard · Joined: 04 Nov 2002 Posts: 617 Location: Pacific N.W.

Thank-you Thank-you Thank-you!!!! Real Progress here. That valve guide sticking down into the port has to go. That is a butt-ugly intake port, the short side radius can be smoothed out and the bowl right behind the seat opened up. No wonder these heads don't breath. Exhaust is better though.

Zuffen · Posted: Sun Mar 30, 2003 9:56 am Post subject:

Richard get that PC paint program out and show us what you are wanting to fix.
_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951

Peter_in_AU · Joined: 29 Jul 2001 Posts: 2743 Location: Sydney, Australia

here's an example of something more current. I think it's from Honda CRX head. Makes for an interesting comparison.

_________________
1979 924 (Gone to a better place)
1974 Lotus 7 S4 "Big Valve" Twin-cam (waiting)
1982 924 (As featured on Wikipedia)

Learn to love your multimeter and may the search be with you

Richard · Joined: 04 Nov 2002 Posts: 617 Location: Pacific N.W.

I got the picture on the desktop, but can't get appleworks paint program to draw. Will try some more.

Zuffen · Posted: Sun Mar 30, 2003 1:28 pm Post subject:

you know the injector could be moved to the intake and the port could be straightened....assuming your not blocking off the coolant path when you weld it up

_________________
Bob Dodd - 924turbo@cox.net
931 1982, 944 1982 euro, 924S 1988SE, 93 968 tip 06 Silver Cayenne S, 06 Black Cayenne S

I have Way too many cars, parts for the 931,944 and 951