|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289506
08/22/12 09:22 AM
08/22/12 09:22 AM
|
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
Dragula
I Live Here
|
I Live Here
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
|
Quote:
I asked this question in my "Horsepower Post" but didn't get any feedback at all.  I had my Edelbrock RPM's cnc-ported..and milled .060,by Jeff at Modern,last Fall. Still have to finish re-assembly of the 440 they're going on. With approx. 35 cfm more flow on the intake..and a bump-up of compression,from 10:1 to 11:1...what can I expect to see in horsepower gains? Thanks!  Randy B 
If your combo can take advantage of the extra flow, that can be worth 50-70hp, and the extra compression should net you around 40hp, maybe slightly more...I would say overall, you going to gain just under 100hp...What is the total cfm on the heads now?
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289508
08/22/12 09:51 AM
08/22/12 09:51 AM
|
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
gregsdart
master
|
master
Joined: Jan 2003
Posts: 9,996
Frostbitefalls MN (Rocky&Bullw...
|
I bet the reason you didn't get feedback was the real answer is "it depends" There are so many variables that it is impossible to give a ball park figure without someone having the virtually identical combo.
First off, how much NET valve lift do you have? Take away lash, and another .020 for flex, and you may be close to what flow the motor can access. Don't forget that the valves are not at peak lift very long, so the numbers that mean the most are below the peak. Compression increase is fairly consistant I believe, but other areas may not be.
My WAG would be based on a very well matched exhaust ,intake, carb and cam setup that is making close to max hp for the flow you had before, which should fall in the range of 2 hp per cfm. Now take a look at the AVERAGE flow increase from say .100 to max net valve lift and see what you have. You might see 2 hp per cfm gain, maybe not.
Case in point. If you had installed those heads on my old 535 cube stroker, going from the iron ported 906 s that were on it to the new ported heads would show some very serious gains in deed. The motor is choked to death by the heads. Do the same trade on a 383 with a stock cam, and you might not see any improvement.
I increased the flow on my 440-1 heads by an average of 5 percent. But I got ZERO gains. Part of the problem may be that there is a spot right in the mid lift area where the gains go down to very little. The other is the cam may not be the right grind for what I now have, or other components don't match and restrict the increase in Hp. I may not be running the motor up high enough either. Lots to think about.
8..603 156 mph best, 2905 lbs 549, indy 572-13, alky
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: tboomer]
#1289509
08/22/12 10:05 AM
08/22/12 10:05 AM
|
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
Dragula
I Live Here
|
I Live Here
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
|
Quote:
Interesting question,Randy! If I get back to racing next year,I will replace my MP aluminum heads that flow 299 cfm with Edelbrock Victors that go around 350 cfm...
Our unported OOTB EZ-1 heads are in the 350-370cfm range, and they really let the big block we have fly! Trapping almost 135mph on pump gas is just awesome. Can't image what it would run with them fully ported.
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289513
08/22/12 12:22 PM
08/22/12 12:22 PM
|
Joined: Jan 2003
Posts: 17,844
S.E. Michigan
ZIPPY
I Live Here
|
I Live Here
Joined: Jan 2003
Posts: 17,844
S.E. Michigan
|
I would hope to see 70 to 80 HP better than it was, and I think it should have about 500 at the wheels at that point when it's done.
Edit, to be more detailed about it....
60 to 70 from the head work
9 to 13 from the CR increase
And though it is an oversimplification, I am talking about adding that to the 425-ballpark number that was observed earlier, which should put it pretty close to 500rwhp at the end I would think. Maybe more.
Rich H.
Esse Quam Videri
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: ZIPPY]
#1289514
08/22/12 12:35 PM
08/22/12 12:35 PM
|
Joined: Jan 2003
Posts: 9,875
Weddington, N.C.
Streetwize
master
|
master
Joined: Jan 2003
Posts: 9,875
Weddington, N.C.
|
General rule of thumb an old NASCAR Guru (who probably forgot more than I'll ever know) for normally aspirated conditions is around 4-4.1 cfm per hp per cylinder is your OPTIMUM full-race potential, so you're looking at roughly another 68hp or so of Maximum potential. The one point bump in CR is "generally" ~3-4%, but....your CR bump may only help in that it keeps the pumping pressures adequate to use the extra airflow....so it's sorta complicated. If you have the ability to get the extra air in and out.
And then who is to say either your old combo was optimized or your new one will be?
I generally shoot for 80% of optimum as a realistic guestimate for a Mopar Wedge motor bracket car....so I would wager with what I know of your BB wedge to look for around 50-55 hp max.
Hemi's and some of the better Canted Valve combos (Like a Yates Ford) generally get closer to the optimum for the same % increase...but that's just from my xperience.
Another trick and to me the most accurate measurement for this type of thing is to look more at the AVERAGE CFM increase that occurs between 1/3 and 2/3 of your valve lift....if you look at your flow as a Window you realize that your valve spends much more total duration time between 1/3 and 2/3 open that it does at the peak (where everybody seems to fixate on peak flow.)
Last edited by Streetwize; 08/22/12 12:42 PM.
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289515
08/22/12 02:05 PM
08/22/12 02:05 PM
|
Joined: May 2003
Posts: 2,117
Cleveland Ohio
10secGTX
top fuel
|
top fuel
Joined: May 2003
Posts: 2,117
Cleveland Ohio
|
Quote:
I asked this question in my "Horsepower Post" but didn't get any feedback at all. I had my Edelbrock RPM's cnc-ported..and milled .060,by Jeff at Modern,last Fall. Still have to finish re-assembly of the 440 they're going on. With approx. 35 cfm more flow on the intake..and a bump-up of compression,from 10:1 to 11:1...what can I expect to see in horsepower gains? Thanks! Randy B
Randy ...No feed back ? I see 54 responses that all make some sense ......until you get the GTX to hook and go low 1.5 60' or high 1.4 you could make an extra 300 hp and if you don't get it to hook your wasting time. Getter Done then have fun working it out ..instead of worrying what it will do on paper
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289516
08/22/12 02:32 PM
08/22/12 02:32 PM
|
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
Dodgem
master
|
master
Joined: Mar 2008
Posts: 5,746
Ontario, Canada
|
I would say you'll pick up .3 minimum and .5 to .6 on the high end! as said above looks like at 120 on 11.19 your 60 foot was not optimized or you had a 40 MPH tail wind??  so there is probably another .1 to .2 in optimizing your 60 foot!
Last edited by Dodgem; 08/22/12 02:37 PM.
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Dragula]
#1289517
08/22/12 02:44 PM
08/22/12 02:44 PM
|
Joined: Dec 2009
Posts: 83
Southern IL.
jafr
member
|
member
Joined: Dec 2009
Posts: 83
Southern IL.
|
Quote:
Quote:
Interesting question,Randy! If I get back to racing next year,I will replace my MP aluminum heads that flow 299 cfm with Edelbrock Victors that go around 350 cfm...
Our unported OOTB EZ-1 heads are in the 350-370cfm range, and they really let the big block we have fly! Trapping almost 135mph on pump gas is just awesome. Can't image what it would run with them fully ported.
I'm in the market for new heads, where can I find a set of unported EZ heads that flow 350-370?
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: jafr]
#1289518
08/22/12 03:18 PM
08/22/12 03:18 PM
|
Joined: Jan 2003
Posts: 6,350
Aurora, Oh.
max_maniac
master
|
master
Joined: Jan 2003
Posts: 6,350
Aurora, Oh.
|
Quote:
Quote:
Quote:
Interesting question,Randy! If I get back to racing next year,I will replace my MP aluminum heads that flow 299 cfm with Edelbrock Victors that go around 350 cfm...
Our unported OOTB EZ-1 heads are in the 350-370cfm range, and they really let the big block we have fly! Trapping almost 135mph on pump gas is just awesome. Can't image what it would run with them fully ported.
I'm in the market for new heads, where can I find a set of unported EZ heads that flow 350-370?
Hmmmm --- better check with someone about those numbers for unported heads first 
Russ
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: max_maniac]
#1289521
08/22/12 04:24 PM
08/22/12 04:24 PM
|
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
Dragula
I Live Here
|
I Live Here
Joined: May 2004
Posts: 12,387
Taxes & Virus's R-US, NY
|
Quote:
Quote:
Quote:
Quote:
Interesting question,Randy! If I get back to racing next year,I will replace my MP aluminum heads that flow 299 cfm with Edelbrock Victors that go around 350 cfm...
Our unported OOTB EZ-1 heads are in the 350-370cfm range, and they really let the big block we have fly! Trapping almost 135mph on pump gas is just awesome. Can't image what it would run with them fully ported.
I'm in the market for new heads, where can I find a set of unported EZ heads that flow 350-370?
Hmmmm --- better check with someone about those numbers for unported heads first
Russ
Can't find the flow numbers on line for the un-ported heads...Got a link? Got numbers from a flow bench? I was just going off a flyer from Indy..
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Dragula]
#1289522
08/22/12 04:46 PM
08/22/12 04:46 PM
|
Joined: Jan 2003
Posts: 9,875
Weddington, N.C.
Streetwize
master
|
master
Joined: Jan 2003
Posts: 9,875
Weddington, N.C.
|
Last set of -1's I saw out of the box were ~310-315-ish but they can reach 335-340 without a ton of work. Well Ported the ones I've had were close to 360 by .650-.700 and ~380 by.800. I'm sure there are sets approaching (or just over) 400 in Max wedge PLUS form. Interestingly, OOTB the Cast Iron -1's always seemed to flow a little better than the Aluminums; As-cast I suspect they might be slightly thinner (less meat) around the guides I suppose but I've never had them side by side It's been about 7 years or more since I've run them and I'm sure the state of the art CNC programs today are even better.
Last edited by Streetwize; 08/22/12 04:47 PM.
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Labratt]
#1289523
08/22/12 04:55 PM
08/22/12 04:55 PM
|
Joined: Jun 2005
Posts: 793
Utah
topbrent
super stock
|
super stock
Joined: Jun 2005
Posts: 793
Utah
|
Quote:
labratt: I asked this question in my "Horsepower Post" but didn't get any feedback at all. I had my Edelbrock RPM's cnc-ported..and milled .060,by Jeff at Modern,last Fall. Still have to finish re-assembly of the 440 they're going on. With approx. 35 cfm more flow on the intake..and a bump-up of compression,from 10:1 to 11:1...what can I expect to see in horsepower gains? Thanks! Randy B
may 2010: https://board.moparts.org/ubbthreads/show...rue#Post5999014
For comparison purposes, ie same head, same CI, smaller cam but similar combo:
Quote:
topbrent: In the Fall 2007 Engine Masters Magazine, Steve Dulcich dyno'ed a simple 448" motor back to back with stock RPM heads vs Modern Cylinder Head CNC RPM heads.
At 6000-rpm peak, he gained 46 HP with the swap. From 529hp to 574hp
Dulcich's combo:
- Speed-Pro-2355 pistons, 10.2 compression
- Comp MM Flat tappet cam, 243°/247° @.050, .586/.597 lift, 110°LSA, 106° installed
- Comp 1.6 Roller rockers
- Victor intake
- RS1000 Demon carb
- TTI 2-2_1/8 headers.
1 point in compression is generally thought to increase power about 3-4%.
|
|
|
Re: HORSEPOWER GAINS FROM HEAD WORK???
[Re: Dragula]
#1289524
08/22/12 05:13 PM
08/22/12 05:13 PM
|
Joined: Feb 2003
Posts: 1,646
Ontario,Canada
firefighter3931
top fuel
|
top fuel
Joined: Feb 2003
Posts: 1,646
Ontario,Canada
|
Quote:
Can't find the flow numbers on line for the un-ported heads...Got a link? Got numbers from a flow bench? I was just going off a flyer from Indy..
Here are some ottb EZ-1 flow numbers from Dwayne's bench :
440EZ-1(MW opening, CNC bowls)
lift-----I/E
.100--65.4/55.1
.200-140.9/102.7
.300-209.7/138.1
.400-265.9/178.2
.450-290.0/193.0
.500-308.1/202.7
.550-324.2/211.9
.600-333.1/218.4
.650-340.3/223.7
.700-343.9/227.6
Here's the link by Dwayne from several years ago on the EZ heads :
https://board.moparts.org/ubbthreads/show...&PHPSESSID=
Ron
|
|
|
|
|
