Cam and valvetrain longevity....??? low duration high lift...
09-20-2016, 03:46 PM
#212
Geronimo36
Gold Member
Here's the lobe numbers for the cam I pulled out of the "Awesome Engine". You can look them up online for specs. It was a decent cam selection for the engine if you have to factor in warranty but I highly doubt it was making the "claimed" 850hp listed on the website. My best guess is that it was 750hp and now it's an 800-825 with the cam change I made.
09-20-2016, 04:23 PM
#213
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Bob did you well then compared to me loll
Here's the lobe numbers for the cam I pulled out of the "Awesome Engine". You can look them up online for specs. It was a decent cam selection for the engine if you have to factor in warranty but I highly doubt it was making the "claimed" 850hp listed on the website. My best guess is that it was 750hp and now it's an 800-825 with the cam change I made.
09-20-2016, 04:39 PM
#215
Registered
Here's the lobe numbers for the cam I pulled out of the "Awesome Engine". You can look them up online for specs. It was a decent cam selection for the engine if you have to factor in warranty but I highly doubt it was making the "claimed" 850hp listed on the website. My best guess is that it was 750hp and now it's an 800-825 with the cam change I made.
255/263 114 LSA .632/.632 lift hyd roller
09-20-2016, 05:24 PM
#217
Registered
Heres a build. 555ci. Jesel valvetrain, speedmaster drives, going in a fast twin engine light vee bottom. The original , custom spec'd MK cam, was yanked out, after the combo simply wasn't anywhere near the 750HP goal, (he spec'd heads, intake as well). After days of tuning and trying every trick in the book, it was time to yank the cam. What went in, was a howards nitrous 267/279 solid roller, in its place. Lift was virtually the same. As you can see, there was a loss of torque in the midrange with the larger cam. This graph was prior to any significant fuel and timing tuning, pretty much first pull out of the box. That gap , or loss of midrange, ultimately was narrowed to about a 12ft lb torque loss there. The new cam, ended up making over 40HP more in the upper rpm's. Engine idled well with it. Keep in mind, this cam was a cam sitting on the shelf in the shop, not a cam that took months to spec out for that particular build.
Anyhow, the Green line, is the bigger cams HP, red line, the MK cam's HP. The dark blue line, was the bigger cams torque, light blue, the smaller cams torque.
Even if , we forget about the entire concept of HP and its mathmatical equation for a second, can anyone here tell me, at wide open throttle, say anywhere from 5200 to 6500, why the smaller cam, would pull better? Its clear here, that torque wise, the larger cam, is making more torque, from 5200 RPM and up. Now, if a guy was building a 5200RPM max engine, well, than the scenerio changes. That wasn't what this build was. Even though the MK cam peaked at 6200, the bigger cam was still making more torque at 6200 ( as well as HP, thats how it works), which one you think is gonna pull the prop harder at 6000? Going larger on a cam, and seeing the power hang on longer/higher, than the "RPM GOAL", doesn't always mean the cams "too big". I simply want the most power I can get at wot. In this case, 40+HP , a bunch of upper RPM torque, was well worth losing 12 ft lbs between 4000 and 5000.
Anyhow, the Green line, is the bigger cams HP, red line, the MK cam's HP. The dark blue line, was the bigger cams torque, light blue, the smaller cams torque.
Even if , we forget about the entire concept of HP and its mathmatical equation for a second, can anyone here tell me, at wide open throttle, say anywhere from 5200 to 6500, why the smaller cam, would pull better? Its clear here, that torque wise, the larger cam, is making more torque, from 5200 RPM and up. Now, if a guy was building a 5200RPM max engine, well, than the scenerio changes. That wasn't what this build was. Even though the MK cam peaked at 6200, the bigger cam was still making more torque at 6200 ( as well as HP, thats how it works), which one you think is gonna pull the prop harder at 6000? Going larger on a cam, and seeing the power hang on longer/higher, than the "RPM GOAL", doesn't always mean the cams "too big". I simply want the most power I can get at wot. In this case, 40+HP , a bunch of upper RPM torque, was well worth losing 12 ft lbs between 4000 and 5000.
Last edited by MILD THUNDER; 09-20-2016 at 05:33 PM.
09-20-2016, 05:39 PM
#219
Registered
Highly ported heads and tunnel ram, ran numbers for a friend of mine thats a well known engine builder on here that doesnt have dyno simulation software yet for a 555 w good heads and solid cam, when i bumped compression from 9.5 to 10.5 and changed induction fr from aggressive open plenum intake w 1050 dominator to tunnel ram and dual 1050 doms and theoretical hp numbers went from 695 to 765, same cam, same heads etc, fwiw, would a guy want a tunnel ram and dual doms on a everday pleasure boat, prob not BUT if you were looking to go out, kick azz and take names it would be a option, Smitty
evidently somebody is looking to do it otherwise you wouldn't have run the numbers in your simulation software for engine builder. Some of us are just weekend boaters and wouldn't have a problem with tunnel rams or blowers provided height isn't an issue. I would have to assume running a 1,000 hp in a 27 baja you know what I'm saying.
09-20-2016, 06:44 PM
#220
Registered
If it won't ever happen then stop bringing it up and fix your $hit already. You sound like a broken record over and over again. You lose whatever sympathy you had by whining like a little girl on a daily basis about your crappy cams. Just fix it and move on.
