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Discussion Starter · #1 ·
I ran accross a video with a guy running comparisons between the 270 phaser and the 6.4 cam. The 6.4 actually outperformed the 270 phaser in his test results. So I' really curious to see dyno results between the two. If you are interrested in posting your dyno results I would sincerly appriciate it. I think quite a few other memebers may be curious as well.

Looking at the cam specs it does seem like they would perform very closely. The 6.4 has more duration while the 270 has more lift. I haven't been able to track down the LSA on the 6.4 cam so I don't know how the power bands compare but I would think being able to use more of the VVT on the 6.4 would actually provide a longer power band. I do believe you have 34 degrees on the 6.4 while limited to 14 degrees on the 270.

  • 6.4L = .577 intake .537 exhaust, Duration is 286/288
  • 270 = .615 intake .609 exhaust, Duration 270/283 LSA 115
 

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These two cams are not really that close in specs. Total duration by different manufacturers are done at different lift specs, that why the best way to compare cams is by the duration at 0.050 lift, The 6.4 manual cam is 215 int. 221 exh. duration, lsa 121, icl 108 and the Comp 270 is 222 int. and 230 exh. duration, lsa 115, icl 119 which will kill low end torque and enhance high rpm horsepower on the Comp cam. Now lift is another point of contention, the factory rockers are supposed to be 1.65 ratio ( I read somewhere that the factory tolerances can run between 1.62 and 1.68 but don't quote me on that ) , Comp specs there lift on a 1.7 ratio. Cam lift is 0.362 int. and 0.358 exh. by Comps cam specs, at 1.7 this is 0.615 int. and 0.609 exh. at 1.65 rocker ratio the lift would be 0.597 int. and 0.591 exh. I check the lift on the 6.4 cam I have with a dial caliper and my rounded off numbers for cam lift are 0.350 int. and 0.325 exh which at a 1.65 ratio put the lift at 0.5775 int. 0.53625 exh. very close to the factories 0.577 and 0.537 spec. The 6.4 cam with its VVT's advanced cam timing and wider timing curve would have a wider power band than the Comp 270 with its retarded cam timing and narrower timing curve. Peek horsepower would go to the Comp 270, more usable daily driving power goes to the 6.4 cam in my opinion,(but remember I am not an expert).
 

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Discussion Starter · #3 ·
These two cams are not really that close in specs. Total duration by different manufacturers are done at different lift specs, that why the best way to compare cams is by the duration at 0.050 lift, The 6.4 manual cam is 215 int. 221 exh. duration, lsa 121, icl 108 and the Comp 270 is 222 int. and 230 exh. duration, lsa 115, icl 119 which will kill low end torque and enhance high rpm horsepower on the Comp cam. Now lift is another point of contention, the factory rockers are supposed to be 1.65 ratio ( I read somewhere that the factory tolerances can run between 1.62 and 1.68 but don't quote me on that ) , Comp specs there lift on a 1.7 ratio. Cam lift is 0.362 int. and 0.358 exh. by Comps cam specs, at 1.7 this is 0.615 int. and 0.609 exh. at 1.65 rocker ratio the lift would be 0.597 int. and 0.591 exh. I check the lift on the 6.4 cam I have with a dial caliper and my rounded off numbers for cam lift are 0.350 int. and 0.325 exh which at a 1.65 ratio put the lift at 0.5775 int. 0.53625 exh. very close to the factories 0.577 and 0.537 spec. The 6.4 cam with its VVT's advanced cam timing and wider timing curve would have a wider power band than the Comp 270 with its retarded cam timing and narrower timing curve. Peek horsepower would go to the Comp 270, more usable daily driving power goes to the 6.4 cam in my opinion,(but remember I am not an expert).
Thank you for the specs on the 6.4 cam. I was struggling to find that, that was the main reason I just generically threw the specs out there. I wasn't sure if the specs I found on the 6.4 were at 0.050.

I was also under the impresson that the comp specs were based on the engines rocker arm specs. Are you sure they are using 1.7? That would be bad advertising and I can't find that listed anywhere. Not trying to argue, I would just really like to make sure that is coming from a solid source.

I agree with you on being able to use the fuller range of the VVT on the 6.4. I do however think that some of the VVT is geared toward emmisions and gas milage not so much performance so there is some of that applies to emissons over HP/TQ so the gap may not be that broad, but it's still a factor. As you can see in the attached dyno the phaser 274 in the 6.4 was dialed in to create power accross the curve when you would think power would be lost down low based on the specs of the 274.
 

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Wow that's a pretty impressive dyno sheet for a 274 cam, from what I heard and researched about the 270 and 274 cams it should have lost torque and horsepower below 4000 and picked it up over 4000. Do you know who did the tuning on it , because whoever it is they have it dial in. If you go on Comp Cams web site you can get the full specs on all 3 of there VVT hemi cams and if you look at there cam lobe lifts, the only way you can come up with there valve lift specs is to multiply them by 1.7. The one thing I will say is because I have a 5.7 that's what I did my research on not the 6.4. The 6.4 with more cubes and little longer stroke will mellow out those two cams. I put a 6.4 m6 cam in my 2012 5.7 classic back at the beginning of 2014 and the cam ran great. But 2 years ago I wanted more power and bought a Comp 270 after looking at the full specs on it and talking to the tuner I ended up putting in a custom ground cam from Moe's over the this winter, with very close to the specs of the 6.4 cam @ .050(214/ 224) with more lift and cut on a 112 lsa and and installed at 106 icl. This cam met more of the criterias of what I was looking for, it is civile enough to go for a nice ride with my girl in the country on a sunny day, but pull twice as hard as the 6.4 cam from 2000 till 6500 and has that chompy idle we all like in a performance cam.
 

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Discussion Starter · #5 ·
Wow that's a pretty impressive dyno sheet for a 274 cam, from what I heard and researched about the 270 and 274 cams it should have lost torque and horsepower below 4000 and picked it up over 4000. Do you know who did the tuning on it , because whoever it is they have it dial in. If you go on Comp Cams web site you can get the full specs on all 3 of there VVT hemi cams and if you look at there cam lobe lifts, the only way you can come up with there valve lift specs is to multiply them by 1.7. The one thing I will say is because I have a 5.7 that's what I did my research on not the 6.4. The 6.4 with more cubes and little longer stroke will mellow out those two cams. I put a 6.4 m6 cam in my 2012 5.7 classic back at the beginning of 2014 and the cam ran great. But 2 years ago I wanted more power and bought a Comp 270 after looking at the full specs on it and talking to the tuner I ended up putting in a custom ground cam from Moe's over the this winter, with very close to the specs of the 6.4 cam @ .050(214/ 224) with more lift and cut on a 112 lsa and and installed at 106 icl. This cam met more of the criterias of what I was looking for, it is civile enough to go for a nice ride with my girl in the country on a sunny day, but pull twice as hard as the 6.4 cam from 2000 till 6500 and has that chompy idle we all like in a performance cam.
Sounds like a nice cam, it pays to do your homework. I think with VVT, EFI and running the car through the ECM instead of using all mechanical mechanisms to tune the cars it has changed what you can get away with in regards to the CAM. I went with the 274 in my 5.7 expecting to loose low end and was very nervous I would lose drivability. But it literally drives great in all scenarios. The trick is getting a good tune. It is a hard cam to dial in but once it's set you can't go wrong IMO. I really like it. Also the grind isn't bad for a super charger. I talked with my tuner and he said it's good to go. He has tuned many 274's with an SC on top. So shopping for an SC now, just need to get past the 6-7k price tag.
 
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