just dropped heads off.......

[low 84]

..........at kendrick machine shop in san antonio. they have done several sets of darts before. they said they usualy flow 255 cfm out of the box and they should flow close to 290 cfm when they are done with them you usualy figure 2 hp per increase of one intake cfm. so do the math..............

[Tom]

o yeah, my kinda talk How much is all this port work running you? Also, whats the change in port volume?

[TIMSPEED]

Originally posted by low 84
they said they usualy flow 255 cfm out of the box and they should flow close to 290 cfm when they are done with them

****! 255cfm out of the BOX?!?! What size is that intake runner? 200cc?

[low 84]

the prices on their port work are very reasonable. most of the heavy work is done around the intake valve and every thing should be polished smooth. and they are getting flowed before and after so hopefully that will back up their claims. beyond that i really can't say much because i'm far from an expert on porting.

i'm also having them milled to 59cc chambers to up the compression about 1/2 a point to help with the bigger cam i'll be running.

tim, yes they are 200 cc intake runners. dart actualy claims they flow 262 out of the box, which i think might be a little optimistic

[Tom]

255 out of the box isen't amazing, buts its very good. Some of those 18* heads will flow above 300cfm out of the box, but it will cost you

and every thing should be polished smooth

I think you should check again on this. Porting the intakes = good. Polishing the intakes = bad. Only polish the exaust ports smooth. With polished intake ports, the fuel tends to be "thrown" and stick the the walls and not in the mixture like they are supposed to.

[TIMSPEED]

Originally posted by low 84
tim, yes they are 200 cc intake runners. dart actualy claims they flow 262 out of the box, which i think might be a little optimistic

WOW! 200cc heads that flow 250cfm out of the box! VERY nice! These are the Dart Pro I Iron heads?

[76HighSierra]

Originally posted by Tom
255 out of the box isen't amazing, buts its very good. Some of those 18* heads will flow above 300cfm out of the box, but it will cost you



I think you should check again on this. Porting the intakes = good. Polishing the intakes = bad. Only polish the exaust ports smooth. With polished intake ports, the fuel tends to be "thrown" and stick the the walls and not in the mixture like they are supposed to.

Ditto on this. A relatively rough intake runner promotes proper fuel atomization. This leads to improved driveability and more power. Any head shop who will polish an intake runner, is a head shop that wouldn't get my business.

[low 84]

Originally posted by Tom
255 out of the box isen't amazing, buts its very good. Some of those 18* heads will flow above 300cfm out of the box, but it will cost you



I think you should check again on this. Porting the intakes = good. Polishing the intakes = bad. Only polish the exaust ports smooth. With polished intake ports, the fuel tends to be "thrown" and stick the the walls and not in the mixture like they are supposed to.

in my opinion 250+ cfm out of the box on a 23 deg iron head that costs less than 800 bucks complete is pretty dang good. as far as polishing the intake runner, i'm not sure exactly what they are doing to the runners. they do a ton of these heads and they are doing whats best for them, i'm not gonna stick my head in the door and try to tell them what to do, they are the professionals.