Offshoreonly.com

Offshoreonly.com (https://www.offshoreonly.com/forums/)
-   General Q & A (https://www.offshoreonly.com/forums/general-q-20/)
-   -   Cam and valvetrain longevity....??? low duration high lift... (https://www.offshoreonly.com/forums/general-q/341258-cam-valvetrain-longevity-low-duration-high-lift.html)

articfriends 09-24-2016 08:31 AM


Originally Posted by jsand117 (Post 4484532)
like I said, I will post for sure where the final comp. ended up, think the pistons were 10 in the hole but will verify exact numbers. motors still with the builder.

I assembled my blown 540 in 2012 with zero decked Pistons that were between 0 and
003 in the hole , .039- .041
0 head gaskets with .0065 wall and they touched hot enough to knock the ring seal out of the tightest one's but not physically damaged the piston but gimmefuel ran .027 head gaskets with a motor close to zero and it beat the Pistons right out of it, this isnt nascar, if they dont hit hot at first they will when they get some carbon, fwiw, Smitty

fbc25el 09-24-2016 09:48 AM


Originally Posted by jsand117 (Post 4484522)
I am a few weeks away from my 540's being finished. similar to Tim, Bob M. spec the cams and heads. afr 325 114 cc the cams are 242.2 664 on intake 247.1 656 on exhaust flat top JE pistons, merlin 3 blocks zero deck and the head gasket he set me up with from cometic is .027. I am running Nickerson 4150 on merlin single plane intakes. carbs flow 994 CFM. as soon as the engines are complete they are going to Nickerson for dyno and tune. I will be happy to provide the results here. I can find out from my builder what the final comp. ended up, our target was 9.8 :1. will post more info as I get it.

You have almost the same set up as mine except I have a 1050 dominator from Nickerson. He is going to tell you the cam is too big! My advice is to learn how to tune it for your self.

MILD THUNDER 09-24-2016 02:09 PM


Originally Posted by rmbuilder (Post 3831388)
Tom,
The compression ratio will increase from 8.52 to 8.69 with the move to a .027” gasket from a .039”. That is an increase of .17 of a point and while that may seem insignificant, any increase is worthwhile at that low of a ratio. A .035” piston to head clearance is ideal in a sub 6000 RPM engine with a steel connecting rod. I would advise you to check the RA of both deck surfaces to verify the finish is compatible with a MLS gasket.

Bob

Maybe his "ideal" clearance. I wouldn't run that.

As stated, this isnt nascar.

jdf4068 09-24-2016 02:49 PM

I can here a big boom coming

Full Force 09-24-2016 04:44 PM

Damn, for a second I thought Bob replied lol


Originally Posted by MILD THUNDER (Post 4484709)
Maybe his "ideal" clearance. I wouldn't run that.

As stated, this isnt nascar.


getrdunn 09-24-2016 04:50 PM


Originally Posted by MILD THUNDER (Post 4484568)
Lets not get off topic just yet. We havent hit 50 pages yet. :helmet:

I wonder what the science is, behind the fact, Timmys 540ci engines, with AFR 325 heads, got a 241/246 cam, and the tight quench guy, gets a 242/247 cam, with a little less lift? Both have flat top pistons, 4150 carbs, both heads milled to 114cc... Why the change?

So close but... Why the difference? Curious if valve timing is same or the different as well. Regardless this will be very interesting to see the outcome. Wonder if it will be dressed with marine exhaust or dyno headers. I will step up SB's number. 681.

Full Force 09-24-2016 05:19 PM

I say.... 674hp 640tq

Originally Posted by getrdunn (Post 4484727)
So close but... Why the difference? Curious if valve timing is same or the different as well. Regardless this will be very interesting to see the outcome. Wonder if it will be dressed with marine exhaust or dyno headers. I will step up SB's number. 681.


SB 09-24-2016 09:03 PM


Originally Posted by getrdunn (Post 4484727)
S I will step up SB's number. 681.

My brain dyno is the most stingy I've been too.:lolhit:

jsand117 09-24-2016 09:10 PM

what kind of power did you make with the dominator? what intake did you use? was intake matched to heads?

fbc25el 09-25-2016 08:41 AM

Did not dyno the engine. Wilson manifold matched & ported the manifold to the heads. 28 pitch prop 1.5 gears pulls strong a little past 6000 RPM. 25' cat.


All times are GMT -5. The time now is 05:42 PM.


Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.