Cam and valvetrain longevity....??? low duration high lift...
10-07-2016, 10:53 PM
#1372
Charter Member#568
Charter Member
Did you try tuning out that dip in torque at 3400?
I remember seeing a video you had posted of one of your dyno pulls. Im no dyno expert, but that was like the fastest dyno pull i had ever seen. What was the sweep rate ? If i recall , seemed like it rev'd from 3000 to 6000 in like a few seconds.
On mine , it was the opposite. 3000-6500rpm took a long time. Wanna say it was like 150rpm per second sweep. I found it quite nerve racking loading the engine that long and hard. My engines would never accelerate that slow in the boat.
I remember seeing a video you had posted of one of your dyno pulls. Im no dyno expert, but that was like the fastest dyno pull i had ever seen. What was the sweep rate ? If i recall , seemed like it rev'd from 3000 to 6000 in like a few seconds.
On mine , it was the opposite. 3000-6500rpm took a long time. Wanna say it was like 150rpm per second sweep. I found it quite nerve racking loading the engine that long and hard. My engines would never accelerate that slow in the boat.
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Straight bottoms and flat decks
Straight bottoms and flat decks
10-08-2016, 08:48 AM
#1374
Charter Member#568
Charter Member
As far as making more power, I think what I got from these heads is decent. I have no opinion on the 112 lsa. Someone else can spend a few days on a dyno swapping cams, checking for reversion, idle quality, powerbands, peaks etc. and post the results. I think my new philosophy is going to be, if I don't see it on a dyno it doesn't exist. If I change any component on an engine to make more power I'm automatically adding $600 and a day on a dyno into the equation. Edit- actually I don't think I'm really interested in making changes or being involved with a build again based on my past experience. I think I'll just write a check to Innovation Marine and let an engine show up and if that doesn't work I'll leave the sport. As far as hands on engine work goes I have yet to meet anyone in this industry that I'd ever go back to and I don't have unlimited funds to find a new builder to spend thousands of dollars with every year or two .
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Straight bottoms and flat decks
Straight bottoms and flat decks
Last edited by bck; 10-08-2016 at 10:10 AM.
10-08-2016, 10:09 AM
#1375
Registered
see the 
,,I was making a funny.I use cams in the 112 range all the time,,unless I'm building a really big cube motor.
,,I was making a funny.I use cams in the 112 range all the time,,unless I'm building a really big cube motor.
10-08-2016, 10:26 AM
#1376
Charter Member#568
Charter Member
Sorry, that's ok. Whether kidding or not that's still my thoughts on the whole thing. But it does get tiring hearing what people think should have been done after the fact.
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Straight bottoms and flat decks
Straight bottoms and flat decks
10-08-2016, 12:19 PM
#1377
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Me too lol and that 5 minute 4200 run we did lol
Did you try tuning out that dip in torque at 3400?
I remember seeing a video you had posted of one of your dyno pulls. Im no dyno expert, but that was like the fastest dyno pull i had ever seen. What was the sweep rate ? If i recall , seemed like it rev'd from 3000 to 6000 in like a few seconds.
On mine , it was the opposite. 3000-6500rpm took a long time. Wanna say it was like 150rpm per second sweep. I found it quite nerve racking loading the engine that long and hard. My engines would never accelerate that slow in the boat.
I remember seeing a video you had posted of one of your dyno pulls. Im no dyno expert, but that was like the fastest dyno pull i had ever seen. What was the sweep rate ? If i recall , seemed like it rev'd from 3000 to 6000 in like a few seconds.
On mine , it was the opposite. 3000-6500rpm took a long time. Wanna say it was like 150rpm per second sweep. I found it quite nerve racking loading the engine that long and hard. My engines would never accelerate that slow in the boat.
10-08-2016, 12:23 PM
#1378
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We can agree there no doubt, if I listened o a select few I would have been in a better place but most came up after I was done shopping, oh well ..hoping this is my last round, as far as trusting? Well the best can have issues so I guess I am ok with learning and building mine...
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10-08-2016, 02:55 PM
#1379
Registered
10-08-2016, 03:35 PM
#1380
Platinum Member
Platinum Member
I see that MK was spec'ing high lift short duration for pretty much everything. So what is the theororetical value of such relative short duration? I'm flipping through a comp cams catalog and all of their cams for marine use ~.550 lift but about +20* on the duration. These seem flat and wide compared to the MK cams.
