Dyno results from TSP 2.5 LS6 Heads with 233/239 112+2
#41
Any idea what the flow numbers are on the 2.5 heads?
#42
Here is what TSP posted in the following thread
PRC 2.5 LS6 Heads
Int. Exh.
.200 147 114
.300 209 152
.400 258 191
.500 294 207
.600 316 226
PRC 2.5 LS6 Heads
Int. Exh.
.200 147 114
.300 209 152
.400 258 191
.500 294 207
.600 316 226
#43
Here is what TSP posted in the following thread
PRC 2.5 LS6 Heads
Int. Exh.
.200 147 114
.300 209 152
.400 258 191
.500 294 207
.600 316 226
PRC 2.5 LS6 Heads
Int. Exh.
.200 147 114
.300 209 152
.400 258 191
.500 294 207
.600 316 226
Thanks are they still a 220cc runner?
To the OP, do you think you would have been better off with the 2.5 5.3l heads?
#44
I ran the PRC 2.5 LS6's on my 383. I was seriously deficient on tq. The hp was all right but I had just about every other bolt on there is. I ended up making 490/445rw. I ran 10.8's@130 on motor with 478/435rw. The PRC flow numbers are slightly inflated and the runner is huge. I flow all the heads I get on the same bench and it is pretty accurate. Here is what I came up with.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
#45
I ran the PRC 2.5 LS6's on my 383. I was seriously deficient on tq. The hp was all right but I had just about every other bolt on there is. I ended up making 490/445rw. I ran 10.8's@130 on motor with 478/435rw. The PRC flow numbers are slightly inflated and the runner is huge. I flow all the heads I get on the same bench and it is pretty accurate. Here is what I came up with.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
This h/c could definitely use more compression. I believe that any milling on the heads with this cam would require flycutting. I had Patrick G spec me a new cam (224/230 113+2 XFI lobes) that I was going to install. It would have bumped my SCR to 11.1 and DCR to ~8.5. I learned all about making an efficient setup after I bought this h/c setup
I have been following your 416 build because that is the same setup I am considering. However, I am looking at the TFS 225 heads with a smaller cam (236/240). The only reason why I have not purchased a new shortblock/longlbock is I am unsure on the h/c I want to use.
Last edited by potac; 06-22-2008 at 02:11 AM.
#46
You should check with TSP on the runner size but I believe they are ~235cc.
#47
This h/c could definitely use more compression. I believe that any milling on the heads with this cam would require flycutting. I had Patrick G spec me a new cam (224/230 113+2 LSK lobes) that I was going to install. It would have bumped my SCR to 11.1 and DCR to ~8.5. I learned all about making an efficient setup after I bought this h/c setup
I have been following your 416 build because that is the same setup I am considering. However, I am looking at the TFS 225 heads with a smaller cam (236/240). The only reason why I have not purchased a new shortblock/longlbock is I am unsure on the h/c I want to use.
I have been following your 416 build because that is the same setup I am considering. However, I am looking at the TFS 225 heads with a smaller cam (236/240). The only reason why I have not purchased a new shortblock/longlbock is I am unsure on the h/c I want to use.
I wouldn't go with any other head than the TFS 235's on your 416 build. I can PM you my flow numbers on those. They were 38-47cfm better than the PRC's and the intake runner on my head is an actual 233cc's. I cc'd the PRC's personaly and they were 240cc's. I also just had Pat G spec me a cam for the 416. I am going to try to order it on Monday and have it in in a couple of weeks. I want to do a 3.90 bad but at 7,000 you are only able to go 140 in 4th. I am expecting the car on motor to trap 137 and high 140's on bottle. So the 3.90's may be out for me.
#48
Yes, I think the smaller heads would have worked better. Or using a better cam that optimizes your DCR and milling these heads achieve a higher SCR. The car was so lazy down low, driving it around town was kind of boring. I lost around 25rwtq under 3500 rpms compared to when I was stock with LG Pro headers. The RPM 3.90 gears were probably the best mod I did to the car and made the car fun to drive.
You should check with TSP on the runner size but I believe they are ~235cc.
You should check with TSP on the runner size but I believe they are ~235cc.
#49
Pray - You do not have to give out your cam specs from Patrick G but did you go smaller or bigger than your current size? I am wondering if the 236/240 114+2 cam is too small with TFS 235 heads.
#50
I ran the PRC 2.5 LS6's on my 383. I was seriously deficient on tq. The hp was all right but I had just about every other bolt on there is. I ended up making 490/445rw. I ran 10.8's@130 on motor with 478/435rw. The PRC flow numbers are slightly inflated and the runner is huge. I flow all the heads I get on the same bench and it is pretty accurate. Here is what I came up with.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
PRC 2.5 LS6's
Intake runner 240cc.
..........Int......Exh
.100----73-----66
.200---135----116
.300---194----154
.400---247----186
.500---283----205
.600---304----213
.650---306----214
Potac. Just as a reference. When I only had a 224/228 cam and headers and BFG DR's, stock every thing else, I ran 11.36@123.5. So there is more in your combo as it sits. I would have the heads milled if you can get away with it with out fly cutting. Just keep an eye on your DCR. I have run up to 8.9DCR on pump gas with no problems.
#51
LS1C5Vette - Using Piano Prodigy's calculator, I come up with 10.93 SCR and 8.29 DCR. This is with a 0.054" thick gasket and 62cc. If you use a 0.040" gasket, the SCR is 11.33 and the DCR is 8.58.
Pray - You do not have to give out your cam specs from Patrick G but did you go smaller or bigger than your current size? I am wondering if the 236/240 114+2 cam is too small with TFS 235 heads.
Pray - You do not have to give out your cam specs from Patrick G but did you go smaller or bigger than your current size? I am wondering if the 236/240 114+2 cam is too small with TFS 235 heads.
#52
They must have just revamped the program. The heads I have are not even a year old. They are 799 castings as well, not 243's. I hope they did redesign the head. I like TSP alot and for a budget head I think the 2.5's are great as they were. But they still fall well behind other heads with smaller runners.