Cam and valvetrain longevity....??? low duration high lift...
10-05-2016, 10:14 AM
#1241
Registered
I'm on a run so I will continue. LOL.
What's my honest 'azzhole with an opinon' opinion ? Valving. I really think what makes a hero or zero in a hyd type lifter is it's valving when rpm's and valvetrain loads go up. With a limited travel lifter, you obviously don't have to worry about this much, but a nonlimited lifter, it is the valving that's responsible for closing off the oil cavity which the lifter's plunger get'sheld up by.
Ford Racing, with their small blocks, years back was having real issues with instability (and thus power drop) at , if I remember right, around 6200rpm. This was amaor issue for those racing with rules. After a bunch of time spent by the racers, engine builders, and etc trying to play with things to get more rpm and power, Ford started playing with the hyd rollers (for this reason) and came up with a ceramic disc valve that instantly got the same motors/racers/builders to pull 6800rpm +.
GMPP, was able to get their lifters from low 6000's also, to 7k+ plus. Most of this was in the valving material (weight!) and design.
Now, that's small blocks with smaller valves, straight pushrods, smaller rocker arms, lighter valvesprings...etc,etc that is a lot nicer to lifters and the rest of the valvtrain. Take a look at the huge difference in these vs what we have to use in a BBC and you'll realize super fast why BBC's are up against a much larger wall.
What's my honest 'azzhole with an opinon' opinion ? Valving. I really think what makes a hero or zero in a hyd type lifter is it's valving when rpm's and valvetrain loads go up. With a limited travel lifter, you obviously don't have to worry about this much, but a nonlimited lifter, it is the valving that's responsible for closing off the oil cavity which the lifter's plunger get'sheld up by.
Ford Racing, with their small blocks, years back was having real issues with instability (and thus power drop) at , if I remember right, around 6200rpm. This was amaor issue for those racing with rules. After a bunch of time spent by the racers, engine builders, and etc trying to play with things to get more rpm and power, Ford started playing with the hyd rollers (for this reason) and came up with a ceramic disc valve that instantly got the same motors/racers/builders to pull 6800rpm +.
GMPP, was able to get their lifters from low 6000's also, to 7k+ plus. Most of this was in the valving material (weight!) and design.
Now, that's small blocks with smaller valves, straight pushrods, smaller rocker arms, lighter valvesprings...etc,etc that is a lot nicer to lifters and the rest of the valvtrain. Take a look at the huge difference in these vs what we have to use in a BBC and you'll realize super fast why BBC's are up against a much larger wall.
10-05-2016, 10:16 AM
#1242
Registered
SB I'm trying to learn from everyone and garner as much knowledge as possible. I'm asking in a nice manner what you have to offer? You keep mentioning the track. Also you had a mild cammed 502 12+ years ago. Safe to say a lot has changed since then in motors and parts. A smallblock now? What 600+ horsepower big blocks do you have in boats with several hundred hours? What boats are these? Are you an engine builder? Parts replacer? You may have answered these somewhere in the past and I didn't see. I apologize if that's the case. I'm trying to learn the most I can as I get my motors ready for my fountain. Dyno sheets of these motors you've built? Specific combos as far as induction/heads/cams?
If I was in the boat biz, I don't think I'd be on these forums much. Doh !
So as I have mentioned - I'm just another azzhole with an opinion. Not afraid of saying it. But I have to throw in some of my actual experience because I get accused too, sometimes, of having zero. That's all.
Edit in: There are lots of people here with more experience than me, and there are lots with less, and lots with the same.
Last edited by SB; 10-05-2016 at 10:29 AM.
10-05-2016, 10:20 AM
#1244
Registered
Congrats on the new boat BTW Rookie !
10-05-2016, 10:24 AM
#1245
Registered
Morel still supplies howards, lunati, PBM, Bullet , Cam motion, i believe crower, and as far as i know, isky, for hyd roller stuff. I have nothing bad to say about them. I have them, icdeddple has them, neither have had any signs of lifter troubles.
We are running 200/500ish spring pressures, have pulled them to 6500rpm on dyno pull after pull after pull, as well as 6k rpm in the boat.
Are they a little noisy? Yes, they can be . Sorry, but i wouldnt try 6500rpm , with a cheap 300 dollar a set of hyd lifters , in a boat. I have no experience with the johnsons , but have heard good things.
With that being said , the next time my engines are out, in going solid roller lifters on an endurance profile.
We are running 200/500ish spring pressures, have pulled them to 6500rpm on dyno pull after pull after pull, as well as 6k rpm in the boat.
Are they a little noisy? Yes, they can be . Sorry, but i wouldnt try 6500rpm , with a cheap 300 dollar a set of hyd lifters , in a boat. I have no experience with the johnsons , but have heard good things.
With that being said , the next time my engines are out, in going solid roller lifters on an endurance profile.
10-05-2016, 10:38 AM
#1248
Registered
Btw. Your not doing circles at full throttle? .030 over and .070 over. Lol.
10-05-2016, 11:52 AM
#1249
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10-05-2016, 12:22 PM
#1250
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Last edited by MILD THUNDER; 10-05-2016 at 12:26 PM.
