Glad I have myself a pair

Consider potential energy and Kinetic. My theory is that if a good engine may convert 15-20% potential energy into kinetic then this should be the difference in port sizing.
ie. 2.02" In. and 1.6" Ex. the difference would be about 20%. So the volume of fluid induced is then aimed at and 20% less volume exiting the cylinder after heat conversion. obviously if you altered this formula you would be estimating a more efficent cycle.

So I have left std. valve 1.92" and 1.54" and gave a mild port to match a mild cam.

Those short headers look great! I am in Sydney area so happy to take my car around to check fitment if the guy is not sure. Just looking at them I suspect they would not fit a Customline/ Mainline engine bay but you never know....

Good luck with the mods CK.

Cheers, Woody.

I Think you can do a bit more in the exhaust side of the head. Here is a pic of a G head sectioned to show the exhaust port. Notice that the black sharpie line on the long radius side of the head runs from the edge of the guide to the center of the ex port flange. You can remove all this. You can also widen the port a bit to get it more round in appearance. The drilled hole shows a lot of material. I found that the biggest improvement was from putting in larger ex valves, I used 1.6" scrub valves that were 0.200" longer but now you can get exact fit valves from John M. The marks on the ex valve and bowl show where to grind a little undercut but removing too much causes loss of compression.

This pic shows the kind of shape I wanted at the exhaust flange. The top manifold in the pic has already been done the bottom one is marked for grinding. I matched gaskets but these days for manifolds like this I would just use HT silicone.



I developed these ideas and some others using a home made flow bench in the early 1990's



Finally if you are going to have fun porting don't forget your special Y Block Goggles



Doug T

The Highlands, Louisville, Ky.

Here are some pics from my ported heads to CK. Intakes are not so much ported but some bowl work and cleaning. Exhausts are quite big. Valve sizes are stock '59.

http://s188.photobucket.com/user/Reilukaista/library/Runners?sort=3&page=1


Hyvinkää, FI

regrind.just had a visit to shadbolt cams in vancouver bc canada. they did a cam for me (used a 57merc profile)barry the owner tels me the older cams are far better material than the new ones.he also refaces lifters,he claims hardness is not a isue and is selective on how far and what style he refaces. frt should be reasonable for cam and lifters.flights ar dailey van to aust.
sorry i do not have his phone # as i am in az for 1 month. Ihave delt with barry for years,when i worked we used him alot.i have never had a failure with his products,just tell him what you want and take his advice.tell him cliff sent you.if you have time i have lifter cores no cams at present cliff

And the exhausts.