Off the shelf cam options for marine engines
#281
Maybe give these a try, http://www.bulletcams.com/Masters/Rlobes.htm
#282
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Joined: Mar 2004
Posts: 2,696
Likes: 93
From: Pa
#283
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Joined: Oct 2007
Posts: 8,439
Likes: 93
From: yorkville,il
i have made a few posts on this thread and read them all.because of some of these posts i got nervous about the cams in a pair of blown engines i built.i know that in threads like this you will see all kinds of opinions,some from people that know what they are talking about and some from people who don,t have a clue.i also know that a lot of posts will come from personal dislikes from people who have never met in person but for one reason or another just don,t like someone.i have been guilty of forming opinions myself from time to time and even argued with some members.i have no desire to argue with people about this thread and will keep my thoughts to myself about some of the posts.i made some phone calls after posting my concernes about the cams in these engines and i am no longer worried.some people might be surprised to know that bob does not design the lobes on his cams,that is done by kip,the owner of cam motions.i was surprised to learn that cam motions has thousands of lobes they use that are proven time and time again and the lobe profile on my cams in question came from this master list.i will add that every cam i have got from bob has been a high quality part made from an 8620 steel core.imo you won,t find a material better than 8620 for a marine endurance engine.when you buy a cam from bob you also get the correct dist gear at a cost of 1 penny.i am not taking any sides on this thread,i am simply stating some facts i learned today.
#284
I was going to post that info about cam motion mike, but didn't want to get involved in an Internet war. The person who helps me with my stuff has a relationship with them and they confirmed what you just posted yesterday.
Cam motion has been in business for roughly 30 years and I'm pretty sure they know what works and what does not.
As you said, lots of personal and behind the scenes feelings at play here. Unfortunately, this thread may cause, not only marine kinetics some business, but cam motion as well.
Cam motion has been in business for roughly 30 years and I'm pretty sure they know what works and what does not.
As you said, lots of personal and behind the scenes feelings at play here. Unfortunately, this thread may cause, not only marine kinetics some business, but cam motion as well.
#285
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Joined: Oct 2015
Posts: 277
Likes: 1
Very few cam "designers" can actually design a lobe from scratch. Most work from some sort of iteration program and select an existing lobe form someone's library. One reason I respect Chris so much when it comes to cams...he can design a lobe for your Briggs and Stratton if you need one. Calculating the necessary events is the trick. Picking the lobe is easy.I;ve been doing this stuff for a long time now and I won't even begin to try to choose my own cam specs. I have no problem deferring to the experts in some things.
Last edited by horsepower1; 02-16-2016 at 04:23 PM.
#288
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Joined: Nov 2004
Posts: 14,094
Likes: 3,684
From: On A Dirt Floor
I've mentioned this to you a few times over the years, I believe you would do a lot better at choosing cam events and lobes than you think you can.
#289
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Joined: Oct 2015
Posts: 277
Likes: 1
Lift is the distance the valve has to travel. Duration is the time it has to travel that distance. Any time you have to travel more distance in less time, you have to move (accelerate) faster.The shorter the duration and the higher the lift, the faster you have to try and accelerate the lifter. The biggest load on the valve train is not as most people think...when the lifter goes over the nose @ full open spring pressure. It's when you begin to accelerate the lifter off the base circle and that's where most valve train problems stem from. The faster you have to try and accelerate that lifter, the worse it gets. Bigger lobes on bigger cores and bigger lifter wheels help with pressure angle issues and allow quicker acceleration with less ill effect.



