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

endeavor1 09-16-2016 10:04 AM


Originally Posted by Full Force (Post 4481804)
FYI this is not a Bob bash thread, or Poor Full Force thread, this is for FACTUAL info that's been on my mind since last winter, it sucks to spend what I did and wonder if and when my valvetrain will fail and cause me headaches...

Thx for input maybe even myself can keep on track this time lol


:nicethread::wizard::signs069::lolhit:

Full Force 09-16-2016 10:07 AM

Trying to make it serious ... I want factual info that's all

MILD THUNDER 09-16-2016 10:10 AM

Dont forget, what happens on one dyno, may not happen on another.

Better question would be, did these 540s msking 700hp, do it thru wet gils/sm , with accessories ?

KAAMA 09-16-2016 11:20 AM

I honestly don't know the compression ratio or duration or numbers on those cams or how the engines were exactly dyno'd during testing. I would say 680-700hp would be a pretty good power number for a naturally aspirated 548cid engine @5900rpm with a single carb. My friend runs full length CMI tubular headers on his engines. He picked up a 12mph increase in a 45' Sonic.

The shop that built the engines (Performance Engineering) usually build circle track racing stuff, but for over 25 years they know what it takes for correct clearances, etc. for building hi-perf offshore marine engines----It's just that they do not really advertise much on the marine hi-perf side of their business, but they have a full machine shop with all the high dollar machining equipment to completely blue print, balance, assemble, and dyno engines.

I know of guys who build marine offshore hi-perf engines, but do not own machining equipment...they take their parts to there for their reputation for excellent machine work. Performance Engineering in Jenison, MI. 616-669-5800 ask for Don.

Knot 4 Me 09-16-2016 11:41 AM


Originally Posted by Full Force (Post 4481967)
why would I redo it all for another 30,000 plus to have a guy build what I can myself? That's dumb, I cannot spec my own combo from heads up, I can build engines clearly, that being said... I relied on Bob to design my setup like he did other, it did not work and that's not my fault, I am taking a cam change to make it last and maybe gain Hp not a complete start over here, it's easy for others to say that but in the end it's my bank getting spent.... I can simply add 5 lb pro chargers and gain 150+ hp all day, that's not the issue.... Longevity concerns are....

No one said to drop another $30K to start over. I'm saying let a builder sort out and maximize what you have.

Knot 4 Me 09-16-2016 11:46 AM


Originally Posted by Full Force (Post 4481970)
As far as reputable builder or spec? Thought Bob was.... You see how that worked out... Fail!

All I know, and these are just two examples of guys I boat with all the time, is that when said guys went to Brad Smith (RIP) and Eddie Young, their mills surpassed their expectations and have been running trouble free for years. And neither guy knows how to turn a wrench. You do. So I'm not saying start over. But a builder with a proven track record on the poker run circuit, Shootouts, etc. should be able to take what you have and with hopefully minimal changes optimize the package for your goals. Again, let them do the thinking, spec'ing, tuning, etc.

MILD THUNDER 09-16-2016 11:49 AM

Bring them back the dyno you used last time. Lets swap cams out, and see what happens. Then you can either further bash bobs cam , or offer him an apology lol.

We will have to video tape the entire process, so this time me and ryan wont be accused of sabatoging your build "to further our agenda"

endeavor1 09-16-2016 12:11 PM

Fun little video/time waster. I'm sure you guys already know this stuff but still interesting.

https://m.youtube.com/watch?v=8UaXhfbAMF0

Knot 4 Me 09-16-2016 12:41 PM


Originally Posted by MILD THUNDER (Post 4482068)
Bring them back the dyno you used last time. Lets swap cams out, and see what happens. Then you can either further bash bobs cam , or offer him an apology lol.

We will have to video tape the entire process, so this time me and ryan wont be accused of sabatoging your build "to further our agenda"

Did Retter offer any suggestions or was it strictly a dyno session to see what the numbers were? The engines will end back up at someone's dyno to see what the numbers are after the cam change. Some tuning will also be going on to dial in the changes. All I'm saying is since FF will already be into parts, dyno, and tuning why not go the extra whatever the percentage may be of those costs and pay the builder to decide what should/should not be changed in terms of the valve train and possibly other items (leaving the long block alone).

Eliminated572 09-16-2016 01:02 PM

Seems everyone was suggesting he do that... He didn't want to spend the money at that time to do it... And the season was getting started. I'm sure he knows it needed to be done, and inevitably will be done but boating needed to come first, then worry about it later. Later is now. Tim quit blabbing on OSO and get your parts coming :7160: :signs069:


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