6.1 HEMi head/cams on a 5.7 HEMi
07-13-2005, 12:13 PM
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6.1 HEMi head/cams on a 5.7 HEMi
There is a guy over on HTC that did the conversion, said he has gained about.3 in the 1/4 mile with the conversion vs. the stock heads/cam. He also claims to have not thrown any codes, etc. and the truck is running a 100% strong. I assume these runs he did were real recent and the heat may have hurt his runs vs a good track condition. Anyone did the conversion or looking into it care to chim in on it?? 
07-13-2005, 12:58 PM
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Seems to me that would kind of an expensive mod to only pick up .3 seconds but on the other hand, if .1 equals 10 hp which I've been told it does, then .3 would be 30 hp and that's a respectable gain.
Jim
Jim
07-13-2005, 11:46 PM
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for the work he had to do and only and .3 in the quarter? that's not really respectible since he could have ported his stockers and ran an aftermarket cam and pic up quite a bit more for the same amount of money.
07-15-2005, 10:44 PM
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Hey Rob, I think it was closer to 0.6 seconds gain.
Lots of interest in this, seems the 6.1L heads use a 73cc chamber volume vs an 85cc for the 5.7L. The increase is static compression is a big reason for the 1/4 improvement IMHO, although I am a little concerned that the CR is creeping toward the 11:1 range ( stock 5.7L CR is 9.6:1 ). The 6.1L has a larger bore size that helps lower the CR with the smaller head volume plus the piston to deck height is altered.
Patriot is introducing some stage I heads for the 5.7L. KRC just installed some with the smaller ( 260 ) Comp Cam stick. Including a TC, underdrive pulleys, and some other minor mods they think it will compare with some F/I systems for HP gains.
Lots of interest in this, seems the 6.1L heads use a 73cc chamber volume vs an 85cc for the 5.7L. The increase is static compression is a big reason for the 1/4 improvement IMHO, although I am a little concerned that the CR is creeping toward the 11:1 range ( stock 5.7L CR is 9.6:1 ). The 6.1L has a larger bore size that helps lower the CR with the smaller head volume plus the piston to deck height is altered.
Patriot is introducing some stage I heads for the 5.7L. KRC just installed some with the smaller ( 260 ) Comp Cam stick. Including a TC, underdrive pulleys, and some other minor mods they think it will compare with some F/I systems for HP gains.
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07-16-2005, 01:17 AM
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http://hemitruckclub.infopop.cc/eve/...5870037433/p/5
ok I went to the track today first run about 20 min after the 45 mile drive truck hot track hot.
r/t .166
60' 2,177
330 6,061
1/8 9.271
1000' 12.097
mph 76.60
1/4 14.524
mph 92.83
before the 6.1 heads and cam
r/t -.056
60' 2.271
330' 6.396
1/8 9.794
1000' 12.692
mph 72.78
1/4 15.158
mph 90.91
r/t .166
60' 2,177
330 6,061
1/8 9.271
1000' 12.097
mph 76.60
1/4 14.524
mph 92.83
before the 6.1 heads and cam
r/t -.056
60' 2.271
330' 6.396
1/8 9.794
1000' 12.692
mph 72.78
1/4 15.158
mph 90.91
07-16-2005, 01:36 PM
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I keep hering conflicting reports about the comp cams and krc cam's. Some guys have got them working, with a couple codes being thrown but otherwise driveable as a daily driver, where as others have idealling problems and stalling issues anytime they let off the gas.
The heads and cam off the 6.1L seem to be a good way to go, 3/4 of a second drop off those two mods isn't too bad at all. There still is the 6.1L intake. The guy doing the heads and cam didn't go for it because it was a pricey item, and there were some differences in fuel system. Some minor modifcations would be required to make it work on a 5.7.
The heads and cam off the 6.1L seem to be a good way to go, 3/4 of a second drop off those two mods isn't too bad at all. There still is the 6.1L intake. The guy doing the heads and cam didn't go for it because it was a pricey item, and there were some differences in fuel system. Some minor modifcations would be required to make it work on a 5.7.