What to do With My MK Cams
10-09-2016, 07:07 PM
#11
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It appears that you have a 0.385" lobe. If you look in the Comp Master Lobe catalog it appears that they will run a 0.390" lobe on a 236. Others correct me if I'm wrong but the concern is a 0.400" lobe on the shorter duration cams? 236-244 degrees?
10-09-2016, 09:29 PM
#12
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That's where the problem seems to be come into play. Jim v has I think close to .393 lobe lift with similar duration like you mentioned with 1.8's but that's a comp grind. Not sure if it's a 8620 core or not but seems to be bullet proof with short duration high lift.
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10-09-2016, 10:24 PM
#14
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I'm not saying his setup is or isn't bullet proof. He just has the means and knowledge to maintain it.
Last edited by Rookie; 10-09-2016 at 10:26 PM.
10-10-2016, 08:08 AM
#15
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I dont think everyone who has a MK cam, needs to remove it and throw it in the trash.
However, besides the issues some have had, I have never seen so many guys put so much emphasis on their camshaft. I see guys talking about how great their engines idle, how great it pulls, and so on.
I have the same crower hyd roller cams in my engines for years. Ive changed everything but the cams. I started out at 75mph when i first installed my engines in my boat. Just this past friday, i ran 95.4mph , and was still pulling.
Whats my point? Ive had 3 different ign systems on these engines, 4 different carburetor styles, 3 differrnt superchargers, and 2 different sets of heads, and two different static compression ratios. My engines behaved, idled, accelerated, and overall ran different with each combo, while the cam remained the same. Granted its a supercharged engine, but.....
At the end of the day, its a friggin cam. I dont go around praising crower for how great my engines idle, how great it runs, or any of that. Theres a ton more to that story, than just the cam.
If the cam is in there, nothing showing wear, and you are happy with the performance, id run it. I never liked tims 241 deg .400 lobe cam , from day 1. Hence my suggestion, to tear into the engine, and take a look. It wasnt because of some sort of anti bob conspiracy. Its called science.
However, besides the issues some have had, I have never seen so many guys put so much emphasis on their camshaft. I see guys talking about how great their engines idle, how great it pulls, and so on.
I have the same crower hyd roller cams in my engines for years. Ive changed everything but the cams. I started out at 75mph when i first installed my engines in my boat. Just this past friday, i ran 95.4mph , and was still pulling.
Whats my point? Ive had 3 different ign systems on these engines, 4 different carburetor styles, 3 differrnt superchargers, and 2 different sets of heads, and two different static compression ratios. My engines behaved, idled, accelerated, and overall ran different with each combo, while the cam remained the same. Granted its a supercharged engine, but.....
At the end of the day, its a friggin cam. I dont go around praising crower for how great my engines idle, how great it runs, or any of that. Theres a ton more to that story, than just the cam.
If the cam is in there, nothing showing wear, and you are happy with the performance, id run it. I never liked tims 241 deg .400 lobe cam , from day 1. Hence my suggestion, to tear into the engine, and take a look. It wasnt because of some sort of anti bob conspiracy. Its called science.
10-10-2016, 09:10 AM
#16
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A quote from Kip at cam motion
Someone came up with this statement and it stuck, “THE MORE AGGRESSIVE THE RAMP RATE, THE MORE OVERALL AND UNDER THE CURVE POWER”. It was probably some cam lobe designer trying to BS people. Ramp rate? What is that? Velocity? Acceleration? Degrees from .006” to .050”? You must have high acceleration and jerk to have a lobe that has a low .006” to .050” number like 49 degrees, and that will beat the snot out of the lifters and be noisy. We use a smoother ramp of about 55 degrees. The .050” to .200” can be pushed if you want a high duration @.200”, but you will have higher accelerations before and at the nose which will float sooner. If you have two cams, both having [email protected]”, one with .340” lobe lift, one with .360” lobe lift, the lobe with the higher lobe lift (.360”) will always have a higher .200” duration.
Why does everyone want to know the .200 number? because some said the higher the .200 number the better the lobe? Or is it more power it will make?
Someone came up with this statement and it stuck, “THE MORE AGGRESSIVE THE RAMP RATE, THE MORE OVERALL AND UNDER THE CURVE POWER”. It was probably some cam lobe designer trying to BS people. Ramp rate? What is that? Velocity? Acceleration? Degrees from .006” to .050”? You must have high acceleration and jerk to have a lobe that has a low .006” to .050” number like 49 degrees, and that will beat the snot out of the lifters and be noisy. We use a smoother ramp of about 55 degrees. The .050” to .200” can be pushed if you want a high duration @.200”, but you will have higher accelerations before and at the nose which will float sooner. If you have two cams, both having [email protected]”, one with .340” lobe lift, one with .360” lobe lift, the lobe with the higher lobe lift (.360”) will always have a higher .200” duration.
Why does everyone want to know the .200 number? because some said the higher the .200 number the better the lobe? Or is it more power it will make?
