Coil bind?

BWL

Active Member
#1
Someone mentioned that coil bind was the cause of the camshaft failing on my recent Box Stock mud motor build. I noticed the exhaust valve has a lash cap on it. I don't remember seeing on on my old Predator. Could that be contributing to the possible coil bind?
 

BWL

Active Member
#5
No shims. Guys, this is a bone stock Box Stock Project motor. I thought it was impossible to bind these with 22 lbers, no ratio rockers, or anything, but I figure I'd ask just in case.
 
#8
Ok...well... Here's what's missing:

Yeah... It's not coil bind... It's not Voodoo....

Ya wanna know what I THINK IT IS?

Are you willing to bet a warm , flat beer?

EDIT: One caveat: coulda been a bad cam... ( anything is possible; I was married for over 20 years!)

Check your flywheel key.....
 
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#9
Ok...well... Here's what's missing:

Yeah... It's not coil bind... It's not Voodoo....

Ya wanna know what I THINK IT IS?

Are you willing to bet a warm , flat beer?

EDIT: One caveat: coulda been a bad cam... ( anything is possible; I was married for over 20 years!)

Check your flywheel key.....
check the flywheel key for what????

inquiring minds want to know!

:thumbsup:
 
#10
If your flywheel key isn't sheared, I owe you a warm flat beer!!!

Then it almost HAS to be a bad cam!!!!

I'll shut up now...( for a little while, anyway....)

My thought was a misfiring at the wrong point may have caused something crazy to happen.
 

BWL

Active Member
#11
Bad cam. I yanked the NR 230 and dropped in a MOD2. I'm not buying another NR cam. I'm sticking with Dyno. I'd like to try a BP-2 HT at some point.
 
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#12
I have been waiting on some stamped 1.2 rockers to get back in stock so I can try them with a stock cam. I just ordered some 22LB springs for this but have not got the rockers yet. Hope to make some power with them when combined with a lightly ported head. My thought is that if the cam wears out its only $5 for a new cam. Also its not a regrind cam so should be a little stronger then some of the cheep cams. This might be something to try if your just looking for torque.
 

delray

Well-Known Member
#13
22 pounds seams to be alot for a 230 lift cam? see nrracing recommends 22s Camshaft, 230 Racing Series (GX200s, 6.5 OHV, & 212 Predators)
also see there could be a problem if installed 26#
i would think 18-20 pound would of been more ideal for your engine?
either way that cam must not be heat treated very well? and or could it be a very small part not having any zinc in the oil?

run a 20 pound spring on a 255 dyno cam with no problems(recommended from dyno cams)
hookup a good tach next time you run that engine on on you project. i like to see what really it puts out under a load.
maybe a video of the rpm's
if you ate your cam up? what does the cylinder wall look like? where did all that metal go...
i really like your video's on fishing. looks like some great places to go.....:thumbsup:
 
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#14
22 pounds seams to be alot for a 230 lift cam? see nrracing recommends 22s Camshaft, 230 Racing Series (GX200s, 6.5 OHV, & 212 Predators)
also see there could be a problem if installed 26#
i would think 18-20 pound would of been more ideal for your engine?
either way that cam must not be heat treated very well? and or could it be a very small part not having any zinc in the oil?

run a 20 pound spring on a 255 dyno cam with no problems(recommended from dyno cams)
hookup a good tach next time you run that engine on on you project. i like to see what really it puts out under a load.
maybe a video of the rpm's
if you ate your cam up? what does the cylinder wall look like? where did all that metal go...
i really like your video's on fishing. looks like some great places to go.....:thumbsup:
Good point on the zinc. I use a zinc additive in my oil.
 

BWL

Active Member
#15
Yeah, I already covered all that. The cylinder wall was perfect. The main factors were bad camshaft lobe, poor oil quality, and poor break-in procedure. I put in a MOD2 camshaft, used Shell Rotella 15W40, and broke it in via 30 minutes no load, about an hour running at idle speed on the lake, then a couple high speed run, changed the oil, and now I run AMSOIL Z-rod which has zinc and the anti-corrosion package form their marine oil.

The main thing is the marine environment is so harsh. A water is 800 times a thick as air, and I push 500 lbs of total weight fast fast enough to plane over like an airplane. That NR camshaft would never have held up. Here's the overview:

[video=youtube;T6vuB9bo4w4]https://www.youtube.com/watch?v=T6vuB9bo4w4[/video]
 
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noseoil

Active Member
#16
Great video & synopsis on the motor & its problem. I'm sure I'd enjoy watching a video on a build about these motors. I've worked on car motors more than these small motors, but there's always something to learn & information is always a benefit. I'd say go ahead & do a video.
 
#17
Great video. On cam break on hot rods I run the motor between 2,000 and 3,000 RPM varying the RPM for about 25 minutes and then let the motor fully cool for a few hours. Usually this will be done at night and will let motor set over night. Next day recheck valves, change oil and run motor like normal. I believe the reason for doing it this way is to harden the surface of the cam. If you just run cam for a few hours right off the bat it wears out the surface before it has time to be hardened. I might be wrong about why this works but this is how I was taught to break in a cam. I was told not to let motor set at the same RPM for too long. Not sure why but I have had pretty good luck with cams. Not that this pertains to our motors but on cars if I run duel valve springs I will also break in cam with just the outer spring. If is was a triple spring set up than the outer 2 springs. I have had a few friends wipe out cams and it sucks. I wonder if it would be a good idea to brake in our cams with stock springs as long as the cam dose not coil bind the spring like a car motor being broke in with weaker spring.
 
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SAS289

Well-Known Member
#18
I find this a little odd. You would think that you should be able to use 22lb springs with any performance cam (???).
 
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#19
22s should be good for most cams unless the cam required more spring. If the springs were too stiff it would not wipe it out that quick. It would just wear out fast.
 
#20
There is no way a 22lb spring would cause that kind of cam damage. You cant compare 22lb spring to a car flat tappet cam with at least 150Lbs of seat pressure and a tappet area similar to our engines and a lobe width only slightly wider than ours.Something else was going on. Could he have had a oil dilution issue with gas in the oil or the cam was not heat treated? I have run the early .265 lift Dyno regrind with no treatment whatsoever and they warn of wear. I have them in a few engines with 26lb springs and no wear. Something else was going on here. Were both lobes going or only one?
 
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