Either the heads are ported or they're not. Why would one pay to have heads ported not to the fullest extent possible?
I could see it described as a street porting job vs a race port, ok maybe I can see that.
The stages of porting I have no idea, your idea of street porting to full race porting makes more sense.
I have seen those sewer pipes very big and a very high floor on the intake port. These are what made the Boss 302 such a legend.Yes. A really neat head to look at is a 351 Cleveland. Giant ports. A 440 head is tiny in comparison. You really have to look at one to believe it. Many go to the 2V (barrel) heads to get back low & mid range, or add torque plates. Basically restriction to the flow.
Which cc head did you use the 75cc?Ok, Edelbrock Performer RPM aluminum heads. Talked to Vic Edelbrock Jr. and told me that all of their Performer RPM series will shift at 6500 all day. I shift mine at 6 grand with zero valve float. It's all about the total combination. Cheers
Which cc head did you use the 75cc?
For the little its worth... I never did this work, but do understand some of the concepts behind it. Can't speak to "stages of porting" but even if there is a guide, I would expect most claims to be BS, like a "hemi440".
The original port design forms a funnel and helps create turbulence at low speeds causing air and fuel to mix and burn efficiently. Porting is the idea of opening this funnel to add more flow, which helps top end, but may hurt lower rpm performance. If there is a standard out there, I would guess it would relate to how much more flow you created... which would require a flow bench to measure.
I do know that most novices turn their first attempts into boat anchors by ruining the funnel effect. Port matching is making sure the opening of the head doesn't have metal in the way of the opening of the intake and cause the air flow turbulence at the wrong place. this would be the mildest and wisest for mild street use.
I might not have answered anything, but if I helped it make more sense... Dave and others here have likely done more radical work than I ever want to.
the better you get it to breathe at top rpms the worse it will do at low rpms...good rule of thumb...cruisers are low rpms...only racing I want to do is maybe help my buddy pit the historics... and that's because all you do is look at cars.
The stage (X) terms are for the FNF crowd that have no idea how to articulate what's been done to the engine.
It's all in the particular application you are looking for. There are allot of heads out there that will give you more peak horsepower than Performer RPMs but peak horsepower doesn't always mean everything on a street build . Power bellow the curve is just as important. In a heavy c-body you need to retain a little bit of low end torque. Performer RPMs will give you that. If you want a good mild street build I would go with Performer RPMs .Anyone ever used promaxx performance heads? I ve read a lot of reviews on all different forums ford, chevy, mopar etc and seem to be a lot of great reviews with some builders saying they out perform performer rpm heads at a fraction of the cost. any input is appreciated TIA.
Same head same casting and specs. Lots of info on them on moparts. $1075 for a pair ready to run. Ive read my eyes out on these till 2:30 this am then back at it at 7 am and for the price and what im slapping together i think they re perfect. I have not read 1 bad thing about them.