Head Porting...What is the True Value??

Ok, I know that I have brought this up once before a long time ago, but I feel that it is a subject that I must revisit. I have been talking to a friend of mine, one that I feel knows his shiit. We were talking about head porting and he had suggested that people make the mistake when they port heads by just making the ports bigger. He suggested that the best way to port heads is to do it in such a way that the speeds up the cylinder fills with air (Velocity). My friend also suggests that large duration cams, and enlarging valve sizes are pointless for real useable street power...

I happen to agree with the cam size choice aspect. If you don't choose a cam that is made for where you spend most of your time in real time riding, then what good is it?? You just threw your money out the window.

I am very curious to what the opinions are about valve sizes and actual port enlarging. Do those actually make a difference???

Anytime you do the heads , talk to the head man and he needs to know everything about the build so he can match the valves, valve springs, the porting he does , and he needs to know which style pistons yer using, and what compression ratio yer lookin for.
You can call and talk with Bean at Big Boyz or Scott with Hillside or with Wolfgang Grasser with Mutant Motors.
But they will probaly talk over yer head. Cause I tend for forgit even what I know.
If you ever deceide to do a build leave it to the head men and buy a package build
You got to match the parts so you don't git Pinging too.
Bottom line talk to the head man.
All three I showed you are good head men.

It's all math JB....Here's a link that give you a good idea and understanding...not over your head:roflmao:
Big Boyz Street Heads - Big Boyz Head Porting

Thanks Lucifer.....

I think all guys can use good head man.......

Well...you can use a man if you want:gah::roflmao:

:rant::rant: that is sick...:roflmao::roflmao:

At least none of us have stuck our tongue out.....:roflmao::roflmao:


Anyways, how about the head porting?

Yeah,if it's done right...you can hog out the ports and turn your heads into an expensive set of paper weights...you want to keep velocity high and you can ram more air in with high velocity smaller ports and valves than large ports and valves with low velocity....

the answer to your question is yes it very much so worth spending money on head work not just port work. the art of porting heads in the proper manner is a lost art . good cylinder head man is worth his weight in gold ,. now then about porting the fact is its all about knowing crosssection size. no two heads are the same they are casted in sand and there is allways core shift . math comes in to play one must find out what the cross section is before material is going to be taken out and were to remove it . fact is smaller ports make for better air speed than larger ports !!! most of the time on any head we want to get air and fuel over the top of the intake valve as mush as possible . for that to happen we must add metal to the floor of the intake port thus making the intake port smaller. and then port it to size that will flow to a good and fast speed so its back and forth to the flow bench removeing material a little at a time to the point that the port starts to back up in flow. and this is done many times and some times its back to the welding and start over . all of this is done at diffrent lifts as well some times different valves back cut standard tulip style many diffrent valves ! make the head flow at diffrent speeds . on the exhaust side it would help some what to have a bigger valve but you will loose bottom end torque at low rpm if they are to large. so i would stick for the street with a small exhaust valve and focus on the short turn of the exhaust port not hog the port to much both pockets should be laid down and blended . and all sharp edges around should be laid down that will help keep detonation at bay . to finish up on the heads all free drops on the valves should be as close as possible . spring installed heights should all be equal pockets should be machined for spring locaters to keep them at them steady and not move around at high rpm . lay down a nice five angle valve job . it will act as a venturi around the intake valve and aid in flow . why not match the exhaust! valve stem tips should all be within one thousands of each other motor will make more power and run equal spring pressures across the board and run real smooth and the valve opening will be equal all the time . my friends this is to be done for both heads and they need to match ! dont forget to have the heads cc as well . bigger valve dont mean **** for the street air speed is what you want . a good 88 with a good set of heads will run with a well built 95 with stock heads . do your home work!!!! before you hand over your heads to just any porter . bigger aint allways better!!!!!

I am taking in a lot here . I can assure you that when the work gets done, it will get done right because I am not afraid to admit that I do not know a whole lot about this stuff, but I am not afraid to ask so I can learn.

hey can you ask some thing simple i suck at typing:roflmao: i dont know if i answerd the question correctly this is what works for me when i was taught on automotive and it can be applied to any cylinder head we use . hope it what you needed for info im sure i left something out see ya jb .

explained it pretty good IMO....

I wonder if CB understood that?????:roflmao:

thanks lucifer . im far from a know it all but it makes you feel good when you can explain something to some one else and they can get a grip of what your trying to get across. you know ? and share the knowledge that someone took the time to teach me . to many guys get taken advantage of in this industry because they took someone elses advise . and if you can share what you know and it saves them a headache good enough for me! a stupid question in my opinion is one you dont ask!!!!!

he will chime in soon ! :rant::rant::rant::rant:::roflmao:

HEHEHEHE!!! That Funny!!!!!!:roflmao::roflmao: