427ls7 vs 440tfs dyno graph
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From: San Francisco, CA
427ls7 vs 440tfs dyno graph Hopefully this helps someone out there building a similar motor.... and save some $ at the same time.
This isn't an apples to apples comparison... but it does show how good the TFS heads are in comparison to LS7 heads which cost more then them in the end. I did mine in 2008 and the heads were hard to come by.... I was into them for around $4K. I used an older grind QM600 cam and that maybe left some power on the table....
My old motor in the RX-7
427ci (4.125" bore/4" stroke) 11.25:1 compression
LS7 heads with stock size valves (Ti intake, s/s exh), dual springs
WCCH old CnC program from 2008 (exhaust clean up only)
LS7 intake mildly cleaned up, ZR1 injectors, 90mm cable TB
QM600 243/256" .650" lift cam
Straight shot style intake (no major bends)
1 7/8" long tube headers with standard stamped 3" collectors, dual 3" into single 3.5" and Magnaflow muffler
520rwhp/472rwtq peak (e85/91 e30 blend with added timing over 91 tune)
* 91 octane tune was 10rwhp peak less and 2rwtq peak less... but from 5Krpm-7K it carried the power longer before falling off
My buddies motor
440ci (resleeved 5.3) with 4.1" crank, 11.5:1 compression
TFS 235cc heads touched up by Vengeance Racing, ported FAST90, 90TB
244/248 .623" lift cam, 1 7/8" long tubes, similar exhaust.
550rwhp/513rwtq
(on e30 91/e85 blend) it made 563rwhp
I know the cubes on the 440 helped a bit.... but the TFS heads are definitely better. The 440 slapped around my motor thru the entire powerband.
Both motors at 6K didn't make any more HP and just stayed around that peak. I'm guessing intake manifold restrictions. The 427 didn't seem to fall off as fast above 6K.... but it was really behind from the start. Same dyno... different day.
This isn't an apples to apples comparison... but it does show how good the TFS heads are in comparison to LS7 heads which cost more then them in the end. I did mine in 2008 and the heads were hard to come by.... I was into them for around $4K. I used an older grind QM600 cam and that maybe left some power on the table....
My old motor in the RX-7
427ci (4.125" bore/4" stroke) 11.25:1 compression
LS7 heads with stock size valves (Ti intake, s/s exh), dual springs
WCCH old CnC program from 2008 (exhaust clean up only)
LS7 intake mildly cleaned up, ZR1 injectors, 90mm cable TB
QM600 243/256" .650" lift cam
Straight shot style intake (no major bends)
1 7/8" long tube headers with standard stamped 3" collectors, dual 3" into single 3.5" and Magnaflow muffler
520rwhp/472rwtq peak (e85/91 e30 blend with added timing over 91 tune)
* 91 octane tune was 10rwhp peak less and 2rwtq peak less... but from 5Krpm-7K it carried the power longer before falling off
My buddies motor
440ci (resleeved 5.3) with 4.1" crank, 11.5:1 compression
TFS 235cc heads touched up by Vengeance Racing, ported FAST90, 90TB
244/248 .623" lift cam, 1 7/8" long tubes, similar exhaust.
550rwhp/513rwtq
(on e30 91/e85 blend) it made 563rwhp
I know the cubes on the 440 helped a bit.... but the TFS heads are definitely better. The 440 slapped around my motor thru the entire powerband.
Both motors at 6K didn't make any more HP and just stayed around that peak. I'm guessing intake manifold restrictions. The 427 didn't seem to fall off as fast above 6K.... but it was really behind from the start. Same dyno... different day.
Last edited by gnx7; Aug 29, 2014 at 04:23 PM.
I guess the question I have is if the WCCH heads would have made more on the 440ci. I agree that TFS heads are pretty damn bad, but a good CNC ported set of LS7 heads I think would be better. Obviously, you have to have the right cam for the heads, right supporting valve train, etc.
Not really the best comparison.
I'll say, not a fan of LS7 heads on a pump gas motor. Our more powerfull 427's run Cathedrials. They drive better and make more power across the curve.
I'll say, not a fan of LS7 heads on a pump gas motor. Our more powerfull 427's run Cathedrials. They drive better and make more power across the curve.
Thread Starter
Joined: Nov 2002
Posts: 3,656
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From: San Francisco, CA
My buddy had a mid 230's cam with .600" lift in a 427 with the same CnC ported LS7 heads and LS7 intake and his motor never really made great power.... it made around 500rwhp/480rwtq also..... Not until he sold it and went to this 440ci/TFS setup was it quick.
With a big Vengeance Racing cam on 91 octane the 440ci setup made 585-595rwhp.
247/255 .656/663 115LSA cam specs. 140mph all motor in a 3000lbs car (with driver, T56, 3.73 gears). Did 196mph at the TX Mile all motor.
With a big Vengeance Racing cam on 91 octane the 440ci setup made 585-595rwhp.
247/255 .656/663 115LSA cam specs. 140mph all motor in a 3000lbs car (with driver, T56, 3.73 gears). Did 196mph at the TX Mile all motor.
Thread Starter
Joined: Nov 2002
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From: San Francisco, CA
Blackonblacksls-
Once you send in the LS7 heads to have the guides redone, upgraded s/s exhaust valves, valve job, dual springs, mill the heads.... you are above the price of a TFS head that is better out of the box and produces better overall power.
Also your heads I'm guessing were seriously milled for high compression and you were running an $800 FAST that also needs billet rails and the taller style injectors which adds to cost.
I would love to see a current CnC program on an LS7 casting vs. a TFS235/245 head with some touch up work on the same cubes, same compression, similar sized cams, same dyno, same style trans. I know the LS7 heads can make killer peak power when fully ported... but in the meat of the powerband they seem low.
Once you send in the LS7 heads to have the guides redone, upgraded s/s exhaust valves, valve job, dual springs, mill the heads.... you are above the price of a TFS head that is better out of the box and produces better overall power.
Also your heads I'm guessing were seriously milled for high compression and you were running an $800 FAST that also needs billet rails and the taller style injectors which adds to cost.
I would love to see a current CnC program on an LS7 casting vs. a TFS235/245 head with some touch up work on the same cubes, same compression, similar sized cams, same dyno, same style trans. I know the LS7 heads can make killer peak power when fully ported... but in the meat of the powerband they seem low.
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gnx7, I understand why you posted but this is a really bad comparison. You can achieve 520rwhp/472rwtq on a LS7 with a cam, bolt-ons and no head work these days. Another 20-30 rwhp can be achieved with more overlap before touching the heads. It's true that LS7 based motors have a later torque peak then the cathedral motors but a lot of that torque curve can be beefed up with proper valve timing.
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gnx7, I understand why you posted but this is a really bad comparison. You can achieve 520rwhp/472rwtq on a LS7 with a cam, bolt-ons and no head work these days. Another 20-30 rwhp can be achieved with more overlap before touching the heads. It's true that LS7 based motors have a later torque peak then the cathedral motors but a lot of that torque curve can be beefed up with proper valve timing.
I disagree. I have experience with ported stock casting cathedral heads, ETP and Trick Flow heads. Both aftermarket castings are very nice and made great power. I have also have experience with stock ported LS3, LS7, WCCH and Mast square port heads. You really need to pay attention to valve timing for square port heads to get the right torque curve. However, when you do they will out perform the cathedral heads through the curve.
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I disagree. I have experience with ported stock casting cathedral heads, ETP and Trick Flow heads. Both aftermarket castings are very nice and made great power. I have also have experience with stock ported LS3, LS7, WCCH and Mast square port heads. You really need to pay attention to valve timing for square port heads to get the right torque curve. However, when you do they will out perform the cathedral heads through the curve.
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here is one detailed test i remember in super chevy... pretty interesting results... just shows that cat heads make better power down low than squares, which is better for a street car and even peak power was within 1-2hp... so with that in mind i'd much rather have the heads that make tq sooner rather than later
http://www.superchevy.com/how-to/ght...-head-to-head/ page 1
http://www.superchevy.com/how-to/ght...discharge.html page 2
http://www.superchevy.com/how-to/ght...-head-to-head/ page 1
http://www.superchevy.com/how-to/ght...discharge.html page 2
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this is from the article note how its stated that the cat heads make better tq down low which again is waaaay better for a street car
Conclusion
The results of the head-to-head shootout indicate that (despite the flow differences) the cathedral-port heads were the equal of the rectangular-port LS3 heads. It is interesting to note that the cathedral-port heads offered better low-speed power and produced peak torque lower than the LS3 heads (irrespective of cam choice). This might be attributed to the difference in port volume, though these Mast LS3 heads featured intake port volumes of 256 cc compared to 245 cc for the cathedral-port heads. What the LS3 heads really needed was a cam that could take full advantage of the head flow (372 cfm) offered at .700-inch lift. The use of our .624-lift cam negated some of the additional flow offered by the LS3 heads, though 360 cfm at .600 lift was still a sizable jump over the 335 cfm offered by the cathedral-port heads.
Conclusion
The results of the head-to-head shootout indicate that (despite the flow differences) the cathedral-port heads were the equal of the rectangular-port LS3 heads. It is interesting to note that the cathedral-port heads offered better low-speed power and produced peak torque lower than the LS3 heads (irrespective of cam choice). This might be attributed to the difference in port volume, though these Mast LS3 heads featured intake port volumes of 256 cc compared to 245 cc for the cathedral-port heads. What the LS3 heads really needed was a cam that could take full advantage of the head flow (372 cfm) offered at .700-inch lift. The use of our .624-lift cam negated some of the additional flow offered by the LS3 heads, though 360 cfm at .600 lift was still a sizable jump over the 335 cfm offered by the cathedral-port heads.
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and the ls3 heads tested here are much better than stock ls7 heads
ls7s don't flow 360cfm at .600 like the ls3s tested do, they don't even at .650
and also note that the flow numbers on the ls3 heads below are on a 4.00 bore and not on a 4.125 like the ls7s are... if you put the ls3s tested here on a 4.125 bore they will flow more than 360 at .600 and will out perform the ls7s at every lift value as well, but still can't deliver as much low end power as the cat heads, so again cat heads seem much much better for a street car
LS7 heads 4.125 bore plate
intake exhaust
.200 161 114
.300 227 171
.400 291 193
.500 330 203
.600 351 209
.650 353 204
mast ls3 heads from test
Flow Data w/4.000" Bore Plate
Lift Intake Exhaust
0.100 74 61
0.200 146 119
0.300 222 188
0.400 282 219
0.500 330 236
0.600 360 251
0.700 372 260
ls7s don't flow 360cfm at .600 like the ls3s tested do, they don't even at .650
and also note that the flow numbers on the ls3 heads below are on a 4.00 bore and not on a 4.125 like the ls7s are... if you put the ls3s tested here on a 4.125 bore they will flow more than 360 at .600 and will out perform the ls7s at every lift value as well, but still can't deliver as much low end power as the cat heads, so again cat heads seem much much better for a street car
LS7 heads 4.125 bore plate
intake exhaust
.200 161 114
.300 227 171
.400 291 193
.500 330 203
.600 351 209
.650 353 204
mast ls3 heads from test
Flow Data w/4.000" Bore Plate
Lift Intake Exhaust
0.100 74 61
0.200 146 119
0.300 222 188
0.400 282 219
0.500 330 236
0.600 360 251
0.700 372 260
Something to notice in that test also is that the Mast heads have the smallest intake runner of any square ports I have seen. Most ported LS3/7 heads come in around the 270-285cc runner range. That would have killed even more low end tq and hp. I think the power difference up top between the two though is in the intake manifold. It doesn't matter how much the head flows when a FAST 102 can't take advantage of it. So now you are not gaining anything up top but you are crutching the tq output of the LS3 motor by running one. If the test was run with say a Holley High Ram maybe the results would have been different. Although, the Holley would have lost even more tq down low on the LS3 motor and it won't fit under the hoods of the cars most of us are looking to modify.
Like stated above, cam timing also has a huge role in the tq output of the LS3 motor. You really don't need much intake duration to make great power with them. Look at most of Ticks cams and others of the same caliber, they don't go over 235* intake duration. There are some cam only LS3's making into the 475/440rw range with under 230* intake duration.
On a big motor I still think I would lean towards the LS7 combo with today's porting programs from AI or FRH if you want the max results. I know Chris is cranking out stock ported LS7 combos in the 650rw range. I just did one with AI ported LS7 heads and BER stock ported LS7 intake and TB that did 611/574rw on a MD.
Like stated above, cam timing also has a huge role in the tq output of the LS3 motor. You really don't need much intake duration to make great power with them. Look at most of Ticks cams and others of the same caliber, they don't go over 235* intake duration. There are some cam only LS3's making into the 475/440rw range with under 230* intake duration.
On a big motor I still think I would lean towards the LS7 combo with today's porting programs from AI or FRH if you want the max results. I know Chris is cranking out stock ported LS7 combos in the 650rw range. I just did one with AI ported LS7 heads and BER stock ported LS7 intake and TB that did 611/574rw on a MD.
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Something to notice in that test also is that the Mast heads have the smallest intake runner of any square ports I have seen. Most ported LS3/7 heads come in around the 270-285cc runner range. That would have killed even more low end tq and hp. I think the power difference up top between the two though is in the intake manifold. It doesn't matter how much the head flows when a FAST 102 can't take advantage of it. So now you are not gaining anything up top but you are crutching the tq output of the LS3 motor by running one. If the test was run with say a Holley High Ram maybe the results would have been different. Although, the Holley would have lost even more tq down low on the LS3 motor and it won't fit under the hoods of the cars most of us are looking to modify.
Like stated above, cam timing also has a huge role in the tq output of the LS3 motor. You really don't need much intake duration to make great power with them. Look at most of Ticks cams and others of the same caliber, they don't go over 235* intake duration. There are some cam only LS3's making into the 475/440rw range with under 230* intake duration.
On a big motor I still think I would lean towards the LS7 combo with today's porting programs from AI or FRH if you want the max results. I know Chris is cranking out stock ported LS7 combos in the 650rw range. I just did one with AI ported LS7 heads and BER stock ported LS7 intake and TB that did 611/574rw on a MD.
Like stated above, cam timing also has a huge role in the tq output of the LS3 motor. You really don't need much intake duration to make great power with them. Look at most of Ticks cams and others of the same caliber, they don't go over 235* intake duration. There are some cam only LS3's making into the 475/440rw range with under 230* intake duration.
On a big motor I still think I would lean towards the LS7 combo with today's porting programs from AI or FRH if you want the max results. I know Chris is cranking out stock ported LS7 combos in the 650rw range. I just did one with AI ported LS7 heads and BER stock ported LS7 intake and TB that did 611/574rw on a MD.
yeh i agree with the intake manifold restriction... i run into the same thing with my setup... i hit peak power at 5700 and it just goes completely flat till 6500... my intake system just can't supply enough air at that rpm to continue making power even though my heads should be able to make power much higher than that and with my cam specs power should peak at 6400 instead of 5700
PRC 247 Head Flow Data:
No Exhaust Pipe
LIFT INTAKE FLOW EXHAUST FLOW
.100" 66 CFM 57 CFM
.200" 147 CFM 117 CFM
.300" 228 CFM 170 CFM
.400" 282 CFM 206 CFM
.500" 321 CFM 227 CFM
.600" 343 CFM 235 CFM
.650" 355 CFM 241 CFM
.700" 360 CFM 245 CFM
Same scenario when I built my 416 in 06' or 7'. No FAST 102's. No sewer pipe intakes. No 100mm TB's. With cut out's, a 4" intake and ported FAST 102/100 I am sure it would have cracked the 600rw barrier.
Although I think part of your issue is your headers, compression ratio and exhaust duration. Your lobe separation could be hurting some also.
Although I think part of your issue is your headers, compression ratio and exhaust duration. Your lobe separation could be hurting some also.
this is from the article note how its stated that the cat heads make better tq down low which again is waaaay better for a street car
Conclusion
The results of the head-to-head shootout indicate that (despite the flow differences) the cathedral-port heads were the equal of the rectangular-port LS3 heads. It is interesting to note that the cathedral-port heads offered better low-speed power and produced peak torque lower than the LS3 heads (irrespective of cam choice). This might be attributed to the difference in port volume, though these Mast LS3 heads featured intake port volumes of 256 cc compared to 245 cc for the cathedral-port heads. What the LS3 heads really needed was a cam that could take full advantage of the head flow (372 cfm) offered at .700-inch lift. The use of our .624-lift cam negated some of the additional flow offered by the LS3 heads, though 360 cfm at .600 lift was still a sizable jump over the 335 cfm offered by the cathedral-port heads.
Conclusion
The results of the head-to-head shootout indicate that (despite the flow differences) the cathedral-port heads were the equal of the rectangular-port LS3 heads. It is interesting to note that the cathedral-port heads offered better low-speed power and produced peak torque lower than the LS3 heads (irrespective of cam choice). This might be attributed to the difference in port volume, though these Mast LS3 heads featured intake port volumes of 256 cc compared to 245 cc for the cathedral-port heads. What the LS3 heads really needed was a cam that could take full advantage of the head flow (372 cfm) offered at .700-inch lift. The use of our .624-lift cam negated some of the additional flow offered by the LS3 heads, though 360 cfm at .600 lift was still a sizable jump over the 335 cfm offered by the cathedral-port heads.
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We suspected that the rectangular-port heads were not optimized with the cathedral-port cam, but we were still surprised to see such a small difference in power given the extra airflow offered by the LS3 heads.
The final test run was to combine the rectangular-port cam with the Mast LS3 heads.
they used cams for both cat and rectangle heads... not the same one for all tests