Heads and H P or Bogus Testing and Lies

[Guest Anonymous]

I have been thing about upgrading to a set of aftermarket heads.

 

It seems that in all of the recent test in various mags that the AFR flow the best. I have also seen buildups with the 195's on a 350 with 10:1 or less that make as much as 520hp.

 

If this info can be trusted, why would one buy anythig else...

 

Or is this some kind of Dyno juju to reward advertisers?

 

Furthermore, does flow translate to HP and is HP the best measure of an engines ability to accelarate the car.

 

I have read an artical in one of grumppy vetts links which speaks of an engines ability to recover after a change in load as a better measure.

 

I wnat to be as informed as I can prior to buying a set of heads.

[Guest Drewz]

It all depends on what you want out of the car. I went big cam big heads and big vavles since the car is light I do not want a lot of bottom end and I love the sound of a 350 chev being "raped" at 7500rpm. MMMMMMMMMM . I feel all flushed just thinking about it! LOL!!!! AFR's are very good but edelbrock and Dart are right up there. I don't have a big preference since my car is a driver and not a strict comp. car. Z's are very light and unless you want to back half it be careful what power you wish for cause it will bite you as mine has on occasion. I am running 2.0477 valved Darts and love them since the ports are not oversized so mid range is very slick. Ask as many questions as you can since once the money is spent you are pretty much stuck without taking a loss. Good luck on the car and keep us posted!

[grumpyvette]

the AFR 195cc and 210 cc heads along with the DART pro-1 200-230cc and CANFEILD 223cc heads,TRICKFLOW ®and TWISTED WEDGE G-2 series heads can all give you the big hp numbers, some of these heads (out of the box) are slightly better than others, but all of them with minor port work are good heads. talk to a good head porting service and they can advise you on which head best meets your needs.

http://www.ondoperformance.com/

http://www.cfmperformance.com/

 

the hp numbers that your seeing are made by running the engines on a dyno with no accessorys and open exhaust with full length headers, and in most cases when those figgures are over 500hp, the use of solid roller cams, any of the above listed heads can get you those hp numbers.

 

http://www.airflowresearch.com/chev215.html

 

http://www.dartheads.com/

 

http://www.canfieldheads.com/

 

http://www.trickflow.com/product/prhomefeature_index.htm

[DavyZ]

Grumpy, you just blow me away sometimes...

 

Thanks for the information and the links!

 

Davy

[Guest Anonymous]

So buy the AFR? and trust the figures?

[grumpyvette]

here are some flow figures pick the head that flows the best at the lift figures that you intend to use.

 

http://www.topher.net/~bearman/gmheadcomp.html

 

http://purplesagetradingpost.com/sumner/techinfo/heads1.html

 

 

http://www.airflowresearch.com/Articles/A11-P1.htm

 

but remember if the flow numbers are the same the head with the smaller port voluum will have the better throttle response.... and spend more time looking at the .200-.500 lift figures.... as the valve is at that lift twice each time it opens but the valve only gets into the .600-.700 lift once in each cycle makeing it less important!