Cam and valvetrain longevity....??? low duration high lift...
Gold Member
11-03-2016, 09:46 PM
#1512
Registered
152 !!!!!
11-03-2016, 10:57 PM
#1516
Registered
152 pages, still not a single person with proof of a couple hundred hours with a short duration 680 lift hyd cam from bob.
Plenty of posts with cam wear issues, nearly identical cam specs whether a custom cammed 502, or custom 548, or a blown 540...
241/246, 239/246, 242/247, GM iron heads, afr heads, brodix heads, cnc ported, as cast, 4 inch stroke, 4.25 stroke, roots blown, centrifugal blown, doesnt matter.
The custom marine specd afr heads, that are an off the shelf automotive head , with entry level pac spring upgrade, shimmed no different if you have a 640 lift bob cam, or 680 lift cam,.....distance from full stack is important tech talk, but doesnt matter on the afr heads youre buying from him, then that topic is irreleveant
The posts about the great benefits of a .750 wheel lifter over a .700 lifter wheel when it was time to sell morels, put aside when he became a dealer for johnson and their lifters have .700 wheels....
What a coincidence i suggested to tim to pull his intakes and look at his cam lobes...and what a surprise, they looked like the other madera cams several engine builders found wear wise after 50 hours, or some with dyno time only.
The customers who called bob as a friend/customer, who asked about running a brodix head , with 9:1 compression and a cam they had laying around, asking for his advice, to be told "that will never work, it will be a dog, but i can supply you with the right parts ", only to find nearly identical cams in nearly the identical combo of parts specd for another customer.
Must all be a big conspiracy against bob! Just guys hating on the guy for no reason !
Even kip fabre saw the pictures of tims cams, and said it looked to be a hardening issue or taper issue on the lobes... but
Lololololololololololololololol
Lol
Lol
How silly this thread is.
Lol
Lol
Lol ol.
Plenty of posts with cam wear issues, nearly identical cam specs whether a custom cammed 502, or custom 548, or a blown 540...
241/246, 239/246, 242/247, GM iron heads, afr heads, brodix heads, cnc ported, as cast, 4 inch stroke, 4.25 stroke, roots blown, centrifugal blown, doesnt matter.
The custom marine specd afr heads, that are an off the shelf automotive head , with entry level pac spring upgrade, shimmed no different if you have a 640 lift bob cam, or 680 lift cam,.....distance from full stack is important tech talk, but doesnt matter on the afr heads youre buying from him, then that topic is irreleveant
The posts about the great benefits of a .750 wheel lifter over a .700 lifter wheel when it was time to sell morels, put aside when he became a dealer for johnson and their lifters have .700 wheels....
What a coincidence i suggested to tim to pull his intakes and look at his cam lobes...and what a surprise, they looked like the other madera cams several engine builders found wear wise after 50 hours, or some with dyno time only.
The customers who called bob as a friend/customer, who asked about running a brodix head , with 9:1 compression and a cam they had laying around, asking for his advice, to be told "that will never work, it will be a dog, but i can supply you with the right parts ", only to find nearly identical cams in nearly the identical combo of parts specd for another customer.
Must all be a big conspiracy against bob! Just guys hating on the guy for no reason !
Even kip fabre saw the pictures of tims cams, and said it looked to be a hardening issue or taper issue on the lobes... but
Lololololololololololololololol
Lol
Lol
How silly this thread is.
Lol
Lol
Lol ol.
11-04-2016, 10:38 AM
#1518
Platinum Member
Platinum Member
People seen tims cam and say it might be soft and tapered. How come nobody took a micrometer and measured the taper on the lobes yet? How crooked are the lifter bores? Anyone check this stuff yet? And are the axels on the lifters 90* to the body's?
How many people check the roller on the rocker to see if it sits flat on the valves? Had to machine several sets of jesels to fix this problem.
How many people check the roller on the rocker to see if it sits flat on the valves? Had to machine several sets of jesels to fix this problem.
Last edited by 14 apache; 11-04-2016 at 10:42 AM.
11-04-2016, 10:49 AM
#1519
Registered
http://www.offshoreonly.com/forums/b...recovered.html
Rice hauler was an epic cig before epic oso threads became epically epic.. So pre-epic epicness if you will....
Rice hauler was an epic cig before epic oso threads became epically epic.. So pre-epic epicness if you will....
11-04-2016, 11:07 AM
#1520
Registered
People seen tims cam and say it might be soft and tapered. How come nobody took a micrometer and measured the taper on the lobes yet? How crooked are the lifter bores? Anyone check this stuff yet? And are the axels on the lifters 90* to the body's?
How many people check the roller on the rocker to see if it sits flat on the valves? Had to machine several sets of jesels to fix this problem.
How many people check the roller on the rocker to see if it sits flat on the valves? Had to machine several sets of jesels to fix this problem.
Tim didnt start this thread to bash bob, or talk about cam lobe wear issues. He asked about who has any proof or experience running short duration high lift (680) cams in a marine setup. Which has not been answered. If you ask bob, he will tell you he has hundreds of these combos in the field . Wheres all these 241 680 lift cams if thats the case? Or was tim just another one of bobs experiments for something he drew up ?
He has a 241* , .400 hyd roller lobe. From the beginning, I didnt like it. Comp cams, or crane, does not offer anything like that in their custom master lobe profiles. Not with that short of duration. Neither does howards, lunati, crower, or any of them from what ibhave seen, especially in an endurance application. Now, i know some guys like running drag race lobe profiles, and dont mind tearing down their boat engines after 50 hours, making big power. I dont think Tim was looking for anything of the nature.
So, the companies that spend millions in R&D, developing fuctional cam lobes, have decades of real world experience, spintron machines in house, grind cams in house, manufacture camshafts and many other valvetrain and engine hardware, are not able to do, what a guy who works out of his house in upstate new york can do. Not a single machine on hand, or parts in stock, but is smarter than the engineers at crane , comp, crower, isky, etc.
It was so worth it. Even if the cams werent junk, and it was tims engine building fault, or johnson lifters fault , he has a 630hp 540 with afr heads. That be pretty impressive if it was 1998.
