Off the shelf cam options for marine engines
02-16-2016, 04:37 PM
#291
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Location: Olmsted Falls,Ohio Marblehead,Oh
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My question is to find out if my chit is a huge problem or not, I have a 50/50 issue chance, just trying to get it from the guy that ground the cam really...
What was the question?
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.
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.
02-16-2016, 04:39 PM
#292
Registered
what was the question?
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.
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.
02-16-2016, 04:56 PM
#293
Registered
02-16-2016, 05:00 PM
#294
Registered
I've basically said that over and over here again, and constantly was argued on that topic of duration vs lift. Maybe you missed that, along with my sarcasm.
02-16-2016, 05:05 PM
#295
Charter Member#568
Charter Member
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.
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02-16-2016, 05:08 PM
#296
Registered
i am no cam expert as an oso member pointed out one day,i used to look in the books and at lobe libraries and did ok but i realized that i might be leaving a little on the table.the day that member made that statement i realized that he was right so i decided to find an expert who could improve my cam selection.because a lot of members posted about the good results they got from bob i decided to give him a call. this was app 3 years ago. i can tell you that if you buy a cam from him it will be cheaper than buying a crane billet core camshaft even if he sells you the exact same cam that crane sells.this also helped my bottom line.once again i am not taking sides but just telling my experience with bob.
02-16-2016, 05:11 PM
#297
Gold Member
Gold Member
Suit yourself, but if you want to know what the guys who ground the cam said, call billy. He talked to his contact at cam motion specifically about this topic and the players involved.
02-16-2016, 05:12 PM
#298
Registered
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.
Alex Haxby has helped hundred and hundreds of people here on oso , as well as fellow engine builders, who have came to him for help on tuning engines they are building for their customers. He started and carried, probably the single handed best thread in oso history.
Sorry, but regardless of my opinion, I find these posts suggesting that ANYTHING negative towards marine kinetics, can ONLY be driven by personal feelings or emotion, is BS, and a slap in the face to those who have came out with FACTS, on issues that have taken place. Only to be discredited, by some who have never logged a single hour with a marine kintecs camshaft or other parts. There's a thousand threads here promoting bob's business, and he obviously has many happy customers. However, its no secret that some are having issues.
It was ok for guys like straub and foxwell to get absolutely fuking tortured here, over some stuff, or when straub did a cam for sutphen30 ages ago, and he had some issues. They pretty much cut those two guys down to pieces, and nobody blinked an eye.
My feelings is , just for once, let those who have something to say, say it, without being accused of having an "agenda" or personal issues, or simply discrediting their posts, because of what YOU want to believe. You like bob, great. You feel comforatable with his cams, great. We heard all that a million times. But, I know for a FACT, that there are some professional engine builders, who have some excellent technical information and experience to share with the boaters of oso. If you wish to close your eyes to it, thats your choice, but for the love of god, lets stop acting like this thread, and all the other threads, were simply some cheap shots being taken based on emotion, because I can assure you, there is MUCH more to be told when the time is right.
02-16-2016, 05:19 PM
#300
Gold Member
Gold Member
The engine builders who have lost tens of thousands on rebuilding customers engines do to valvetrain follies, does their business matter?
Alex Haxby has helped hundred and hundreds of people here on oso , as well as fellow engine builders, who have came to him for help on tuning engines they are building for their customers. He started and carried, probably the single handed best thread in oso history.
Sorry, but regardless of my opinion, I find these posts suggesting that ANYTHING negative towards marine kinetics, can ONLY be driven by personal feelings or emotion, is BS, and a slap in the face to those who have came out with FACTS, on issues that have taken place. Only to be discredited, by some who have never logged a single hour with a marine kintecs camshaft or other parts. There's a thousand threads here promoting bob's business, and he obviously has many happy customers. However, its no secret that some are having issues.
It was ok for guys like straub and foxwell to get absolutely fuking tortured here, over some stuff, or when straub did a cam for sutphen30 ages ago, and he had some issues. They pretty much cut those two guys down to pieces, and nobody blinked an eye.
My feelings is , just for once, let those who have something to say, say it, without being accused of having an "agenda" or personal issues, or simply discrediting their posts, because of what YOU want to believe. You like bob, great. You feel comforatable with his cams, great. We heard all that a million times. But, I know for a FACT, that there are some professional engine builders, who have some excellent technical information and experience to share with the boaters of oso. If you wish to close your eyes to it, thats your choice, but for the love of god, lets stop acting like this thread, and all the other threads, were simply some cheap shots being taken based on emotion, because I can assure you, there is MUCH more to be told when the time is right.
Alex Haxby has helped hundred and hundreds of people here on oso , as well as fellow engine builders, who have came to him for help on tuning engines they are building for their customers. He started and carried, probably the single handed best thread in oso history.
Sorry, but regardless of my opinion, I find these posts suggesting that ANYTHING negative towards marine kinetics, can ONLY be driven by personal feelings or emotion, is BS, and a slap in the face to those who have came out with FACTS, on issues that have taken place. Only to be discredited, by some who have never logged a single hour with a marine kintecs camshaft or other parts. There's a thousand threads here promoting bob's business, and he obviously has many happy customers. However, its no secret that some are having issues.
It was ok for guys like straub and foxwell to get absolutely fuking tortured here, over some stuff, or when straub did a cam for sutphen30 ages ago, and he had some issues. They pretty much cut those two guys down to pieces, and nobody blinked an eye.
My feelings is , just for once, let those who have something to say, say it, without being accused of having an "agenda" or personal issues, or simply discrediting their posts, because of what YOU want to believe. You like bob, great. You feel comforatable with his cams, great. We heard all that a million times. But, I know for a FACT, that there are some professional engine builders, who have some excellent technical information and experience to share with the boaters of oso. If you wish to close your eyes to it, thats your choice, but for the love of god, lets stop acting like this thread, and all the other threads, were simply some cheap shots being taken based on emotion, because I can assure you, there is MUCH more to be told when the time is right.
If there is more to add, please let us in on it.
