Offshoreonly.com - Cam and valvetrain longevity....??? low duration high lift...

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Quote:

Originally Posted by MILD THUNDER (Post 4483856)

Before we get too excited, anyone see my post earlier, about the throttle cable issue on the same dyno? That would certainly have an effect on tims dyno number if in fact, thats what was happening, but not in the boat. Throttle controls when using a servo, can fuk up. I like when some shops mount a camera above the throttle plates during a dyno pull, where you can see creep back.

A more common cause for both the low measured air flow and vacuum would be that the carburetor was not mechanically at WOT during the pull. Sometimes it is hard to get good carburetor travel with the available leverage and linkage. Older dyno's with the water piston used to creep all the time and loose the WOT during a test session, even the newer ones with servo or cable linkages can creep or loose the WOT capability.

I would think it would cause issues in the boat because if it was dyno'd and tuned at part throttle the tune in the boat (WOT) would be off.

didn't he say he was getting really low AFR numbers or something?? If the throttle was open all the way in the boat he's drawing more CFM and the carb is drawing more fuel (rich).

Quote:

Originally Posted by SB (Post 4485567)

What ?

Just joking that when the carb was looking like a restriction because of the high vacuum at wot the solution would be a bigger cam as they have less vacuum. It was loosely even sensible and just a lame joke.

Quote:

Originally Posted by Full Force (Post 4484153)

330's

How far is the propshaft below the bottom of the boat?

They had different X's based on engine packages and props that the boat was build with.

Just a thought.

Quote:

Originally Posted by Panther (Post 4485573)

Think that got resolved in regards to engines in the boat anyway. Port side was off and running lower AFR's and rpm at wot. He had since installed wideband on both engines and got jetting squared away and same rpm's at wot. Why Tim didn't look down to confirm throttle plates were 100% open while at 6k on dyno is beyond me. Lol. Joke joke. Think we covered that also. SB woulda done it.

Here you go, just pout a couple gallons of this in the tank next fillup....

https://www.summitracing.com/parts/klz-kl-640/overview/

Quote:

Originally Posted by phragle (Post 4485611)

Here you go, just pout a couple gallons of this in the tank next fillup....

https://www.summitracing.com/parts/klz-kl-640/overview/

I have a 30 gallon drum of Nitro Methane and 55 gallon drum of Methanol to mix it if your interested.

Has this been solved yet?

Quote:

Originally Posted by ICDEDPPL (Post 4485642)

Has this been solved yet?

It appears we may be finally halfway there. :helmet:

Quote:

Originally Posted by SB (Post 4485654)

It appears we may be finally halfway there. :helmet:

to what,,completely new engines or 112 pages.:D

Quote:

Originally Posted by sutphen 30 (Post 4485658)

to what,,completely new engines or 112 pages.:D

Close. 114 pages for most of us. 2 long one's for ICDEDPPL :D