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-   -   jesel shaft rocker system ?????experiences (https://www.offshoreonly.com/forums/general-q/116842-jesel-shaft-rocker-system-experiences.html)

Cam-shaft 11-22-2005 10:20 PM
Re: jesel shaft rocker system ?????experiences
 
190 over the nose on a hydraulic roller that is running only 6000rpms is a little much for sure. Yes a lot of guys run this kind of seat pressure with similiar set ups and it is not needed. However, this is only my opinion. I would agree that comp lifters for sure are not the greatest. I have seen more then one box of hydraulic rollers not make it past my pre-inspection. Example: The locks that hold the roller pin in were half in. Some had two locks on one side of the pin. The roller had some serious drag. These are just some things I found with comp lifters and yes I sent them back and bought a better product.

MESABALANCING 11-23-2005 07:49 AM
Re: jesel shaft rocker system ?????experiences
 
I'm sorry I didn't answer sooner I hadn't seen the post I made a commitment last year that every one of my Top Gun Series Poker Run engines we build from that point on would have Jesel Rocker assemblies in them . Reason for that was that everything that is just fine for a marine engine is sooner or later subject to failure and I can tell you from experience that 95 % of failures in a marine engine are in the valve train when it's not a catastrophe damage . You can break a Jesel part and we have in the past but as far as perfection in geometry and longevity there is nothing you can compare it to aside from one of the other shaft rocker companies such as T&D which is also to of the line stuff. I saw someone say to use the Sportsman Series but for three hundred bucks or so more I would use the better stuff it's worth every bit of it. Sincerely Laz www.mesabalancing.com
P.S.have a great thanks giving guys

mrhorsepower1 11-23-2005 07:04 PM
Re: jesel shaft rocker system ?????experiences
 
[COLOR=Navy][I] The Jesel shaft system is hands down the best on the market. I use them all of our SuperCharged engines as well as N/A applications. We have raced them in many classes such as Modified,A,B,and Super V running 6800-7600 RPM over the years- reliability is second to none! If you can afford them buy em'. I agree with Mesa, spend the extra bucks and invest in the competition series.

Best Regards,

Dean Gellner
Gellner Engineering Custom Marine Engines
"The House of Horsepower"

articfriends 11-23-2005 07:21 PM
Re: jesel shaft rocker system ?????experiences
 
Originally Posted by Cam-shaft
083 wall,the problem I had was on 3 seperate occasions the rocker nuts cracked below the adjuster hex and backed off allowing puchrod/lifter/guideplate damage. Everyone tells me I am tightening the nuts too tight BUT I have built at least 50 motors with adjustable rockers and I had one nut crack once 5 years ago on cheap imported harland sharp rockers. I never had a crane gold nut or even a mr gasket poly lock ever crack,seems strange that 3 nuts cracked within first 15 hours of running this motor (they were all comp pro-magnum nuts). Swapped them all to ARP nuts that were actually thinner where the cracks were occuring and haven't had a problem since. I am done with comp anything as there is a pattern of failure there. I am only running about 190 psi seat/450 open with hydraulic roller,less than 6000 rpm's and barely over .600 lift,Smitty

Wow. sounds like a lot of spring psi for a hydraulic roller cam. 190 over the nose is more than I would like to see on a hydraulic roller cam that is running only 6000rpms. However, that is just me. Thanks Cam-shaft.
Sounds like alot of pressure but my reasoning was this: If springs are installed at 190 psi and lose 5% of there tension during breakin they actually end up closer to 180 psi seat/430 open. At 5800 to sometimes 6000 rpm's with my pump gas pulley on the supercharger I'm seeing at least 10 psi of boost,on race gas the boost may be as high as 14 psi,when you add in the force of the boost lifting the intake valve off the seat,you need to factor in another 20-40 psi of spring pressure. If it takes a valve spring with 160 psi seat/380 open to keep a hydraulic roller lifter in contact with the cam and the valve from bouncing off the seat at 6000 rpm's with a very slight safety margin and you add the extra pressure to compensate for the boost trying to push valve open prematurely then you'll see where I arrived at the pressure I'm running.The morel lifters I'm running don't seem to have any problem at these pressures either although Ive also ran comp cams hyd roller lifters at similar spring pressures without lifter failure in 140 hours between freshening,Smitty

GPM 11-23-2005 07:55 PM
Re: jesel shaft rocker system ?????experiences
 
I agree, I've had more problems with not enough spring pressure vs to much.

RedDog382 11-23-2005 08:24 PM
Re: jesel shaft rocker system ?????experiences
 
2 Attachment(s)
Originally Posted by RedDog382
I have Jesel on my Sterling motors. At 100 hours, I had small hairline cracks at the pivot point in many on the exhaust side. I replaced all exhaust rockers with shot-peaned new. Still highly recommend them. I will try to post pics of the cracked rockers when I have time.
Pics:

RedDog382 11-23-2005 08:25 PM
Re: jesel shaft rocker system ?????experiences
 
2 Attachment(s)
Another:

GPM 11-23-2005 08:30 PM
Re: jesel shaft rocker system ?????experiences
 
That doesn't look good, what kind of spring pressure? what heads?

RedDog382 11-24-2005 05:23 AM
Re: jesel shaft rocker system ?????experiences
 
These are CNC ported Dart heads. Not sure what the spring pressures are ... I will see if I can get that info. Sterling says they have seen this before.

Vinny P 11-24-2005 09:07 AM
Re: jesel shaft rocker system ?????experiences
 
Smitty,
I am running the same lifters in my NA 540. I have an Isky hydraulic roller, Isly silicon springs with AFR 315 CNC heads. I set the spring pressure to 140 lbs. as per Isky's recommendation. I understand your reasons for running 190 lbs on the seat. I just never heard of that much pressure on a hydraulic lifter. That is good news to me. It gives me confidence in the Morel lifters.

Vinny


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