AFR vs. WP S/R torquer heads
Thread Starter
Instructor
Joined: Feb 2006
Posts: 240
Likes: 0
From: Allentown PA
AFR vs. WP S/R torquer heads
Right now I have a set of S/R Torquer heads from World Products(2.02, 170cc runners w/ 67 cc chamber) ) on my 350. I have a chance to buy a set of new of aluminum Air Flow Research Heads (180 runner w/ 65cc chambers).
I'm trying to determine about how much horsepower difference the AFR's would make with the rest of my existing setup. Here's the rest of the engine setup....approx. comp ratio now is 9.0
bottom end is a stock 1981 350
Comp 270 flat tappet magnum cam(108)
1.6 Comp roller tipped rockers
Edelbrock air gap manifold
670 street avenger carb w/ 1" spacer
Davis distributor(34 degrees) all in @ 2400
Hooker header sidepipes/ Max flo's
Flex Fan
A good friend says they might make as much as a 50 horsepower difference with my setup...I realize it would be better, but really that much better?...Looking for some opinions from you guys, without getting into pricing...just the horsepower to be gained. Thanks guys.
I'm trying to determine about how much horsepower difference the AFR's would make with the rest of my existing setup. Here's the rest of the engine setup....approx. comp ratio now is 9.0
bottom end is a stock 1981 350
Comp 270 flat tappet magnum cam(108)
1.6 Comp roller tipped rockers
Edelbrock air gap manifold
670 street avenger carb w/ 1" spacer
Davis distributor(34 degrees) all in @ 2400
Hooker header sidepipes/ Max flo's
Flex Fan
A good friend says they might make as much as a 50 horsepower difference with my setup...I realize it would be better, but really that much better?...Looking for some opinions from you guys, without getting into pricing...just the horsepower to be gained. Thanks guys.
Safety Car
Joined: Oct 2004
Posts: 3,926
Likes: 739
From: Youngstown Ohio
30 to 50 HP sounds accurate to me also.....I'm not really familiar with S/R Torquers, but I gained 30 HP when I replaced the Trick Flow heads on my 383 with AFRs.......and the Trick Flows were very good heads which were 50 HP over my stock heads.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Not much with that cam.
I'm just guessing but i expect that cam will run out of rpm 'bout 5500rpm and stop breathing before the 185cc runners on those AFR's would make a difference. 350 sb's were designed with 167cc runners flowing at <6,000rpm and that cam is not designed for more rpm than that. AFR's make big flow numbers but at higher lift than u have to use with that cam. You might see some difference on the dyno or in 1/4mi time - or u might not.
If it were mine i would just have the WP torquers pocket ported and vlv bowl cleaned up and put'm back on.
Good luck,
cardo0
If it were mine i would just have the WP torquers pocket ported and vlv bowl cleaned up and put'm back on.
Good luck,
cardo0
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
here is a quote from another post about trick flow heads. AFR flows better than trick flow
They are good heads. I have a pair on my 71. I picked up about 70 rwhp over the set of S/R torquers that they replaced. I'm running a comp 282S (.495/.495, 236/236@.50). Idle is very smooth at 800 rpm and very torquey from 2000 on up. Vacuum is 12" at idle so all vacuum accesories work well. As others have said, you can by with a bit more cam, but you're choice will still run well. However, if I had to do it all over agian, I would probably go with dual pattern cam as it would compliment these heads better. Here's my chassis dyno run.And a nice flat torque curve with a single plane.
Drifting
Joined: Mar 2001
Posts: 1,396
Likes: 6
From: Indiana
I agree that basing a decision on peak lift numbers is very misleading. However, they still flow much better even at lower lift numbers, so a significant power improvement will be there even with a mild cam.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Runner size just does not match cam and cubes.
I just don't see an significant improvement as those 185cc runners of the AFRs will have lower velocity at low and midrange rpm. And the 108 lobe sep angle of his cam will move the power band even lower where higher velocity would be needed for better cylinder filling.
Yes, this is really all just chalkboard talk as only the dyno can prove this. But regardless, IMHO this is a case where bigger is not always better. The correct matching of parts will get the job done for less $$$ and run better too.
Also a couple of extra improvements to the WP heads would vlv springs that can support 1.6 rockers (no need for roller rockers <0.500" lift) and of course 1.6 rocker arms.
Good luck with whatever the Kid chooses,
cardo0
Yes, this is really all just chalkboard talk as only the dyno can prove this.
But regardless, IMHO this is a case where bigger is not always better. The correct matching of parts will get the job done for less $$$ and run better too.Also a couple of extra improvements to the WP heads would vlv springs that can support 1.6 rockers (no need for roller rockers <0.500" lift) and of course 1.6 rocker arms.
Good luck with whatever the Kid chooses,
cardo0
Race Director
Joined: May 2005
Posts: 10,674
Likes: 122
From: Millington Illinois
St. Jude Donor '08-'09
A 180 CC head is not too big for a 350. You have a poster above with a fairly mild street performance engine that picked up 70 RWHP from the exact change you are discussing. 70 RWHP is about 90 Flywheel HP which is a huge difference. This should reflect in a noticable torque and power increase across the board. These are dyno measured results. Better flowing heads will somewhat compensate for a smaller lift and duration cam by allowing better volumetric efficiency (filling of the cylinder) and you will also boost your 9.0 compression a little.
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Thread Starter
Instructor
Joined: Feb 2006
Posts: 240
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From: Allentown PA
Thanks for your input guys...I ran it at the track a few weeks ago...turned a 14.008 @ 100.5 spinning all the way thru first on street tires (700r4 w/ shift kit & 3.55 gears)...I was a little dissapointed not to get into the 13's tho...I really don't wanna go bigger on the cam because I'm very happy with its street manners and enjoy taking 200 mile cruises with it...but, would like to try to get a little quicker when taking it to the track...guessing the AFR 180's might be worth the 50 H.P. then ...and some drag radials will help too...Is it spring yet? Thanks again JL
Team Owner
Joined: Apr 1999
Posts: 21,953
Likes: 1,445
From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Actually there is a formula for increased cfm of the HP potential of a given motor. You can look it up in the net.
I had a hot rodded 79 with 3.55 gears and a gear slamming TH350 and ran 12.70's with 9X27 hoosier slicks. I installed a 3000 stall 700R4 and went slower. The reason being is the increased hp required to run the 700R4. The 700R4 takes more Hp because of the pump............... The 700R4 has bad gear spacing Very low first and a big jump to 1-2 and even worse 2-3. I would have to go 90 mph in second to shift into third
To get back to the 12.70's I had to changed my rear gears to 4.11 and then at the line put it in second at the tree with a 5000 rpm Governor to do an instant auto shift right past the 60 foot mark and an manual shift at 6900 rpm to third.
my final stages of 355 ci I was able to run very consistent 12.38's and won allot of trophy's in NHRA bracket racing. I have old time drag slips from the all Corvette drags at the Sacramento California
IMO the 700R4 sucks way to much HP like Auto tranny. I have an Art Carr racing tranny with a 3800 stall 3 clutch lockup 850 hp handling sitting on the shelf , I took it out when I installed 427 and went with to a 5 speed road racing TKO 5 speed
I had a hot rodded 79 with 3.55 gears and a gear slamming TH350 and ran 12.70's with 9X27 hoosier slicks. I installed a 3000 stall 700R4 and went slower. The reason being is the increased hp required to run the 700R4. The 700R4 takes more Hp because of the pump............... The 700R4 has bad gear spacing Very low first and a big jump to 1-2 and even worse 2-3. I would have to go 90 mph in second to shift into third
To get back to the 12.70's I had to changed my rear gears to 4.11 and then at the line put it in second at the tree with a 5000 rpm Governor to do an instant auto shift right past the 60 foot mark and an manual shift at 6900 rpm to third.
my final stages of 355 ci I was able to run very consistent 12.38's and won allot of trophy's in NHRA bracket racing. I have old time drag slips from the all Corvette drags at the Sacramento California
IMO the 700R4 sucks way to much HP like Auto tranny. I have an Art Carr racing tranny with a 3800 stall 3 clutch lockup 850 hp handling sitting on the shelf , I took it out when I installed 427 and went with to a 5 speed road racing TKO 5 speed
Melting Slicks
Joined: Apr 1999
Posts: 2,010
Likes: 3
From: Moon Twp. PA USA
Thanks for your input guys...I ran it at the track a few weeks ago...turned a 14.008 @ 100.5 spinning all the way thru first on street tires (700r4 w/ shift kit & 3.55 gears)...I was a little dissapointed not to get into the 13's tho...I really don't wanna go bigger on the cam because I'm very happy with its street manners and enjoy taking 200 mile cruises with it...but, would like to try to get a little quicker when taking it to the track...guessing the AFR 180's might be worth the 50 H.P. then ...and some drag radials will help too...Is it spring yet? Thanks again JL
No bite in 1st gear now, but you want 50 more HP. How is this going to help you times? You will have even worse bite problems with more HP.
Get your traction problem fixed, run the track, and see what you have for times. This will be your baseline.
Cruising
Joined: Jun 2006
Posts: 11
Likes: 0
Hi!
According to "desk top dyno" you will get a 41 Hp increase. The result I got was:
Your combo now = 351 Hp @ 5000 RPM, 392 Ft/Ib @ 4000 RPM, torque at 2000 RPM = 350 Ft/Ib.
Swapping to AFR 180 I got: 392 Hp @ 5500, 406 Ft/Ib @ 4500, torque at 2000 RPM = 345 Ft/Ib.
Simulations done with small tube headders and mufflers. You may get more from your combo with your exhaust system. But I gues the difference of 41 Hp will be close to what you can expect.
Good Luck!
According to "desk top dyno" you will get a 41 Hp increase. The result I got was:
Your combo now = 351 Hp @ 5000 RPM, 392 Ft/Ib @ 4000 RPM, torque at 2000 RPM = 350 Ft/Ib.
Swapping to AFR 180 I got: 392 Hp @ 5500, 406 Ft/Ib @ 4500, torque at 2000 RPM = 345 Ft/Ib.
Simulations done with small tube headders and mufflers. You may get more from your combo with your exhaust system. But I gues the difference of 41 Hp will be close to what you can expect.
Good Luck!
