sbc cylinder head flow

mr305 · 08-13-2008, 12:35 PM

what are some of the common flow numbers for a typical set of super stock sbc heads? just a good refrence point to see where i am compared to where i need to be. any help is appriciated!! thanks
aaron disinger

astikhossw · 08-13-2008, 02:15 PM

Well if no one will fess up you can kind of get a basic idea by there hp numbers i saw one small block super stocker engine in california that was making over 600 hp on the dyno.

Daran Summerton · 08-13-2008, 02:50 PM

CFM x 2 = HP

300 on some double humps I guess is alright

mr305 · 08-13-2008, 05:20 PM

Thanks guys, im in the process of putting together my super stocker and i really dont have the $$ to go out and drop $5500 on a set of heads and beings that we are in the business i have a flow bench and a serdi and a grinder lol so im not looking to set the world on fire just be fast enough right now to get under the index. im gonna run the combination of a 85 305 camaro in a 89 pontiac firebird. just was curious on what kinda flow numbers i should roughly achieve. thanks again guys for all the input!
aaron disinger

Mike Pearson · 08-15-2008, 09:29 AM

I dont think anyone is going to tell you what your there flow numbers are. Its a comparison of what you had to what changes you have made to the ports. Flow them stock then flow them once you have done some port work. If you are working in the right area of the port the flow numbers should be better. If you have one of the small flow benches it will not show you everything. I think most of the head guys flow them at 25 inches of vaccum. That 305 head has a large intake runner so you can get some really good flow numbers on the bench but with the small cu. in. there will not be any velocity. One of my friends ran a 305 for years and his heads were no where near the cc limit. He ran 1.00 under with those heads. Be very careful porting the 305 heads as they are very proned to cracking and water leaks.

mr305 · 08-15-2008, 12:22 PM

Thanks mike, appriciate all the help i can get. lol

Mike Pearson · 08-15-2008, 02:02 PM

MR305,

Check your private messages

Mike

Aaron Keown · 08-16-2008, 12:31 AM

Around 300 cfm for most 1.94 heads.Just remember that a flow bench can easily lead you in the wrong direction when porting heads.Hope this helps you out a little bit.

mr305 · 08-17-2008, 03:26 PM

Your exactly right Aaron I'll remember that thanks!!!!

08-13-2008, 12:35 PM	#1
mr305 Member Join Date: May 2007 Location: Monticello Posts: 160 Likes: 0 Liked 2 Times in 1 Post	sbc cylinder head flow what are some of the common flow numbers for a typical set of super stock sbc heads? just a good refrence point to see where i am compared to where i need to be. any help is appriciated!! thanks aaron disinger

08-13-2008, 02:15 PM	#2
astikhossw Member Join Date: Jul 2008 Location: moreno valley Ca Posts: 266 Likes: 2 Liked 20 Times in 9 Posts	Re: sbc cylinder head flow Well if no one will fess up you can kind of get a basic idea by there hp numbers i saw one small block super stocker engine in california that was making over 600 hp on the dyno.

08-13-2008, 02:50 PM	#3
Daran Summerton Senior Member Join Date: Jun 2003 Location: Las Vegas nv Posts: 601 Likes: 18 Liked 66 Times in 37 Posts	Re: sbc cylinder head flow CFM x 2 = HP 300 on some double humps I guess is alright

08-13-2008, 05:20 PM	#4
mr305 Member Join Date: May 2007 Location: Monticello Posts: 160 Likes: 0 Liked 2 Times in 1 Post	Re: sbc cylinder head flow Thanks guys, im in the process of putting together my super stocker and i really dont have the $$ to go out and drop $5500 on a set of heads and beings that we are in the business i have a flow bench and a serdi and a grinder lol so im not looking to set the world on fire just be fast enough right now to get under the index. im gonna run the combination of a 85 305 camaro in a 89 pontiac firebird. just was curious on what kinda flow numbers i should roughly achieve. thanks again guys for all the input! aaron disinger

08-15-2008, 09:29 AM	#5
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,441 Likes: 611 Liked 1,909 Times in 573 Posts	Re: sbc cylinder head flow I dont think anyone is going to tell you what your there flow numbers are. Its a comparison of what you had to what changes you have made to the ports. Flow them stock then flow them once you have done some port work. If you are working in the right area of the port the flow numbers should be better. If you have one of the small flow benches it will not show you everything. I think most of the head guys flow them at 25 inches of vaccum. That 305 head has a large intake runner so you can get some really good flow numbers on the bench but with the small cu. in. there will not be any velocity. One of my friends ran a 305 for years and his heads were no where near the cc limit. He ran 1.00 under with those heads. Be very careful porting the 305 heads as they are very proned to cracking and water leaks. __________________ Mike Pearson 2485 SS

08-15-2008, 12:22 PM	#6
mr305 Member Join Date: May 2007 Location: Monticello Posts: 160 Likes: 0 Liked 2 Times in 1 Post	Re: sbc cylinder head flow Thanks mike, appriciate all the help i can get. lol

08-15-2008, 02:02 PM	#7
Mike Pearson VIP Member Join Date: Mar 2007 Posts: 2,441 Likes: 611 Liked 1,909 Times in 573 Posts	Re: sbc cylinder head flow MR305, Check your private messages Mike __________________ Mike Pearson 2485 SS

08-16-2008, 12:31 AM	#8
Aaron Keown Junior Member Join Date: Mar 2004 Location: 1710 Dutch Lane,Jeffersonville,IN Posts: 63 Likes: 0 Liked 0 Times in 0 Posts	Re: sbc cylinder head flow Around 300 cfm for most 1.94 heads.Just remember that a flow bench can easily lead you in the wrong direction when porting heads.Hope this helps you out a little bit.

08-17-2008, 03:26 PM	#9
mr305 Member Join Date: May 2007 Location: Monticello Posts: 160 Likes: 0 Liked 2 Times in 1 Post	Re: sbc cylinder head flow Your exactly right Aaron I'll remember that thanks!!!!