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Have been trying to find videos of this cam in a ls1 on YouTube with no success.
has anyone out there got any videos of this cam in a 5.7.
not 4.8 5.3 6.0 or 6.2. Only want to here it in a ls1 5.7.
Bonus point if your engine has 11 to 1 or higher static compression ratio.
comp cams 227/235 on a 113lsa with ground in +4
Not exactly what your seeking but I believe the Lingenfelter Performance Engineering GT12 cam is basically the same cam other than being on a 115 LSA. 227/235 duration @ .050 lift - .614/.621 lift with 1.7 rocker 115 CL Great Muscle Car Sound.
Not exactly what your seeking but I believe the Lingenfelter Performance Engineering GT12 cam is basically the same cam other than being on a 115 LSA. 227/235 duration @ .050 lift - .614/.621 lift with 1.7 rocker 115 CL Great Muscle Car Sound.
Not exactly what your seeking but I believe the Lingenfelter Performance Engineering GT12 cam is basically the same cam other than being on a 115 LSA. 227/235 duration @ .050 lift - .614/.621 lift with 1.7 rocker 115 CL Great Muscle Car Sound.
just looked at the timing events for the GT12 cam.
it's way different to the comp cams 227 235 113 cam.
Have a look at the differences just on overlap
The gt12 cam has about 4 degrees compared to the 54 degrees on the comp cam.
Compression in video was with stock LS1 heads per info in comments by poster. ~10.2 to 1
Yes of course there's differences. Apologies if post wasn't of help or interest.
With the same advance they'd be within sevwral of degrees of each other's valve events. The wider LSA LPE cam will be less rowdy with 1 degree of overlap vs the Comp with 5.
Compression in video was with stock LS1 heads per info in comments by poster. ~10.2 to 1
Yes of course there's differences. Apologies if post wasn't of help or interest.
With the same advance they'd be within sevwral of degrees of each other's valve events. The wider LSA LPE cam will be less rowdy with 1 degree of overlap vs the Comp with 5.
Something like...
it was good to here a similar cam in a 5.7.
The valve timing is very different to each other.
The gt12 cam inlet opens at 2.5 degrees btdc and exhaust closes 1.5 ATDC gives 4 degrees of overlap.
the comp cam opens 28 BTDC closes 26 ATDC gives 54 degrees of over lap with a tighter LSA over the gt12 cam. Yes it will be a lot more roudy that the gt12 cam.
it was good to here a similar cam in a 5.7.
The valve timing is very different to each other.
The gt12 cam inlet opens at 2.5 degrees btdc and exhaust closes 1.5 ATDC gives 4 degrees of overlap.
the comp cam opens 28 BTDC closes 26 ATDC gives 54 degrees of over lap with a tighter LSA over the gt12 cam. Yes it will be a lot more roudy that the gt12 cam.
not sure how you're calculating overlap but based on any overlap calculator you can find online where you input the intake/exhaust duration and lobe separation angle it shows the LPE cam as 1 degree of overlap, and the comp cam has 5 degrees of overlap..don't know how you got 54 degrees of overlap unless you're using advertised duration numbers.
not sure how you're calculating overlap but based on any overlap calculator you can find online where you input the intake/exhaust duration and lobe separation angle it shows the LPE cam as 1 degree of overlap, and the comp cam has 5 degrees of overlap..don't know how you got 54 degrees of overlap unless you're using advertised duration numbers.
I agree!!! 54° overlap?? Holy 2,500rpm idle, Batman!!!
not sure how you're calculating overlap but based on any overlap calculator you can find online where you input the intake/exhaust duration and lobe separation angle it shows the LPE cam as 1 degree of overlap, and the comp cam has 5 degrees of overlap..don't know how you got 54 degrees of overlap unless you're using advertised duration numbers.
From inlet and exhaust open and close events.
Inlet opens 28 BTDC AND exhaust closes 26 ATDC gives 54 degrees between the open of inlet to close of exhaust valve total 54 degrees.
Cams can have anywhere upto 80 plus degrees between these events. That's what makes it scaveng more or less and changes idle quality. As more degrees before TDC the inlet opens the more revesion into the inlet track and more the exhaust exiting helps pull the inlet charge into the cylinder due to scavenging effect.
From inlet and exhaust open and close events.
Inlet opens 28 BTDC AND exhaust closes 26 ATDC gives 54 degrees between the open of inlet to close of exhaust valve total 54 degrees.
Cams can have anywhere upto 80 plus degrees between these events. That's what makes it scaveng more or less and changes idle quality. As more degrees before TDC the inlet opens the more revesion into the inlet track and more the exhaust exiting helps pull the inlet charge into the cylinder due to scavenging effect.
further more here is 2 different online calculators that both show it as 55 degrees as they ask for the total degrees NOT THE @50 values.
not sure how you're calculating overlap but based on any overlap calculator you can find online where you input the intake/exhaust duration and lobe separation angle it shows the LPE cam as 1 degree of overlap, and the comp cam has 5 degrees of overlap..don't know how you got 54 degrees of overlap unless you're using advertised duration numbers.
take a look at the 2 photos I have put up of online cam calculators above. Both show 55 degees of overlap and if i was to use a 109 LSA it would increase the overlap to 63 degrees of overlap.
you have entered the @50 values not the actual total advertised duration as they require on the calculators
not sure how you're calculating overlap but based on any overlap calculator you can find online where you input the intake/exhaust duration and lobe separation angle it shows the LPE cam as 1 degree of overlap, and the comp cam has 5 degrees of overlap..don't know how you got 54 degrees of overlap unless you're using advertised duration numbers.
by using the online calculators the LPE GT12 cam with 253 and 263 degrees of duration it has 28 degrees of overlap as the cam card they show the valve events are @60 lift.
just did a search online to find out the total duration for inlet and exhaust.
In my opinion, using @.050 events to calculate overlap isn't good practice. It doesn't give you an accurate representation of how a certain cam will behave in a certain engine. Especially due to varying lobe intensities. The whole reason the industry went to @.050 measurements was to have some kind of uniformity so customers could compare cams more easily, with some companies calculating advertised duration @.004, some @.006, and possibly another lift point, I can't recall. The reasoning was, you don't typically get any appreciable flow through a valve until around .050, so eliminating advertised numbers helped make cam selection less confusing. However, this "lack of flow" idea is really only valid on an intake valve that is being fed by atmospheric pressure. The pressures in a combustion chamber, even towards the end of the exhaust stroke, are going to be significant. It doesn't take hardly any intake valve lift to allow exhaust to flow back into the intake at low engine speeds. You need to know the overlap calculated by "advertised" valve events to be able to make an educated decision about cam choice. And if anyone doubts that the valves can flow at lifts as low as .002, attach a precision valve opening tool to an intake valve and open it to .002 and roll the engine over, see if it will build compression. It won't. That air is going past the valve.
I use the Summit Calculator as do most people and it actually states: '
Notes:1.) For accuracy in comparisons, always use figures measured @ .050 in. lift.
The Texas Speed calculator you show is also at @ .050 in. lift I think you will find.
54 degrees of overlap would be undriveable I think. I've experienced an LS1 cam with 12 degrees overlap and that thumped way too hard for a regular street car in my opinion. Others would disagree. I'm not even sure what one would hope to achieve by so much overlap.
I like low down to mid range power, without too much overlap. I stick between -5 and -8 degrees overlap. However, the IVC seems to have had the most affect on low down performance for me.
I think what people try to achieve with the low LSA you mentioned is with big duration cams, bring the IVC down to help low to mid range. That has the result of also running a lot of overlap. Some love that, for me, it's not ideal on the street. It's also less important if you're running a big stall, if I'm not mistaken. I've only owned manual LS myself.
I use the Summit Calculator as do most people and it actually states: '
Notes:1.) For accuracy in comparisons, always use figures measured @ .050 in. lift.
The Texas Speed calculator you show is also at @ .050 in. lift I think you will find.
54 degrees of overlap would be undriveable I think. I've experienced an LS1 cam with 12 degrees overlap and that thumped way too hard for a regular street car in my opinion. Others would disagree. I'm not even sure what one would hope to achieve by so much overlap.
I like low down to mid range power, without too much overlap. I stick between -5 and -8 degrees overlap. However, the IVC seems to have had the most affect on low down performance for me.
I think what people try to achieve with the low LSA you mentioned is with big duration cams, bring the IVC down to help low to mid range. That has the result of also running a lot of overlap. Some love that, for me, it's not ideal on the street. It's also less important if you're running a big stall, if I'm not mistaken. I've only owned manual LS myself.
you work it out any way you want. But i can assure you that how I've shown is the true way to work it out. Here is a screen shot off a YouTube video David vizard has done to give guide lines for overlap. Also what overlap is best suited for what purpose.
I've had enough experience with engines and racing over 30 plus years to know and agree with what he list is true and correct.
you work it out any way you want. But i can assure you that how I've shown is the true way to work it out. Here is a screen shot off a YouTube video David vizard has done to give guide lines for overlap. Also what overlap is best suited for what purpose.
I've had enough experience with engines and racing over 30 plus years to know and agree with what he list is true and correct.
Ok, mate, that's fine. I'm not trying to educate you, just saying what I believe those calculators are actually showing and why you will confuse people when asking questions on here if you use those figures. Also, sharing what my experience has been with the same engine. Although, I would like to see your tuners face when you rock up with a cam with 54 degrees overlap and ask for a nice street tune. I'm sure it will all work out in the end anyway. Best of luck.
12-12-2022, 04:30 PM
Comp cam 54 458 11 
I'm sure it will all work out in the end anyway. Best of luck. 