Head porting

[ZROSSA]

Howdy,

have any of you guys ported your own heads before? I know of the basics, deburing, smoothing the short side of the port and so forth but how do you get big power out of these things? I have a few vizard books and so forth that are helpfull but not specific. Is there any info on the www. I have done a lot of searching and not really come up with to much on the chevy. I guess I am looking for the secret recipe for power. Any Ideas?

 

Cheers

 

Douglas

[pparaska]

If you have Vizard's book on How to Modify Small Block Chevy Heads (or something close to that) you will be well on your way to understanding how to do it.

[Guest Anonymous]

I have ported my last set of heads. Major recontouring of a head is hours of work. Simple match porting of manifolds heads, and exhaust is reasonably easy to do with some proficiency, but if you are looking for serious HP increases, nothing short of ten to twenty cc increases in intake volume will make any bankable differences. You have to remove a tremendous amount of material to effect a ten CC change much less a 20. In hind site, I would have much rather bought a larger intake volume heads right out of the box. Of course now a days the selection of heads, volumes, chamber shapes, valves and spring sizes is huge. Ten years ago this simply wasn't so.

If you can afford it, buy the performance level you are looking for, but if you are simply looking for the satisfaction of saying "you did it", go for it. It takes a very steady hand and a great deal of patience. Let us know how it turns out.

[ZROSSA]

Thanks,

I havent even turned the bugger over and probable wont intill after the new year. Its in my shed waiting for my house to be built and under all my worldly posessions. I dont even know what heads i actually have yet. I looked at what it would cost to import a jtr kit and bought a whole car with a locally certified 350 chevy in it for very little more. Vizzard is unfortunately buried somwhere under the worldly goods. I dont know if you have to go through a certification process with the local transport authorities in the USA but in aussie and here its a big and expensive process. It makes buying a car that has already been through it far better value. I guess i thought that you could get a stock chevy head and put big valves and a good port job on it and it and the puppy would put out 500 odd horse. When i read vizzard i was looking for 4 cylinder power and he didnt have much to offer there. In saying that, i have ordered a few more books, but you will have to but up with me untill they arive.

I would love inputt on what heads do the stuff. i would really like 480 to 500 hp.

 

Cheers,

 

Douglas

[Mike C]

Chevy High Performance magazine has test results from over 30 different small block heads on their web site. Hands down, the AFR 190/195 are the best flowing head under 200cc intake volume and outflow most heads with 220cc intake volume. The difference in the 195 is they have a higher intake port that matches up with intakes such as the VIctor Jr. They are expensive at $1295 here in the US. Trick Flow has a decent street head from Summit for $895. Obviously shipping is an issue. The GM heads can be made to flow well, but they have dated combustion chambers and unless you have 64cc heads, you lose 20 hp right off the bat. The David Vizard book (How to build and modify SBC cylinder heads) is an excellent source with specifics on porting. Time and money make the aftermarket heads look like a good deal. Good luck with your project!