spring pressure

Ian Hill · 12-23-2011, 03:08 PM

i have been adding shims along the way this year and the motor has liked it each time i did it. F/CM 350 ci 330 hp. shift at 6500 and cross at 7200. i haven't heard the coils binding yet, so i am going to add another shim under the exhaust side for the next race and see what happens :-) i love this sport!

i look forward to the day i cross the line and the car shuts off and the parachute deploys automatically....in my stocker! LOL

Ian

junior barns · 12-23-2011, 04:06 PM

Quote:

Originally Posted by Ian Hill

i have been adding shims along the way this year and the motor has liked it each time i did it. F/CM 350 ci 330 hp. shift at 6500 and cross at 7200. i haven't heard the coils binding yet, so i am going to add another shim under the exhaust side for the next race and see what happens :-) i love this sport!

i look forward to the day i cross the line and the car shuts off and the parachute deploys automatically....in my stocker! LOL

Ian

So, what kind of pressure are you up to???

Jeff Lee · 12-23-2011, 09:44 PM

Quote:

Originally Posted by Ian Hill

i have been adding shims along the way this year and the motor has liked it each time i did it. F/CM 350 ci 330 hp. shift at 6500 and cross at 7200. i haven't heard the coils binding yet, so i am going to add another shim under the exhaust side for the next race and see what happens :-) i love this sport!

i look forward to the day i cross the line and the car shuts off and the parachute deploys automatically....in my stocker! LOL

Ian

So what does coil bind SOUND like?

Bub Whitaker · 12-23-2011, 11:18 PM

Quote:

Originally Posted by Jeff Lee

So what does coil bind SOUND like?

Dink, dink, dink, dink, ......

Chad Rhodes · 12-24-2011, 12:08 AM

Quote:

Originally Posted by Jeff Lee

So what does coil bind SOUND like?

it sounds a lot like the head of a valve coming out the header collector.

Ian Hill · 12-24-2011, 12:41 AM

Ahh, you have gone too far too! My "valve through the exhaust" sounded like a death rattle at 1100 feet. Ended by splitting the piston in two, one half embedded in the block, half way up the bore, the other half scattered throughout the other 7 holes!

It was actually caused by coil bind, but I'd imagine similar results if it did happen.

I have been increasing valve pressure buy .01" shims and am up to .06" intake and .03" exhaust over recommended and each time I add shims the car picks up. The next race I go to I will be matching the ex with the intake. It is a largerjump than I've done so far, but I am guessing it will be good as I did the intake first and have been catching up with exhaust with good results. I've discussed this lots with my engine builder and we decided to go with the idea that more is better, to the point we wipe the cam shaft out. This will be season two coming up, the last cam had three seasons without fail. As far as telling you what my spring pressure is, I don't think it matters. My combo likes the springs stiff. Just like valve lash, my combo runs near to zero as I dare go... I set them cold and I set them tight. But that's for another thread I am sure.

What I will tell you is at what spring pressure I wipe the cam out...if it happens. I switched Joe Gibbs oil this past seaon, this is the first time I am not freshening my engine, everything, including the cam looks good. I figure I'll get to coil bind before hurting the cam.
Ian

Ed Wright · 12-24-2011, 02:22 PM

Your kidding about "getting to coil bind", right? .050" from coil bind should be close enough.

Adger Smith · 12-24-2011, 02:28 PM

Ed,
Don't you remember...?? You want it to coil bind just as it reaches the peak of the "Loft" or "Toss" off the cam profile?

Ed Wright · 12-24-2011, 02:53 PM

Quote:

Originally Posted by Adger Smith

Ed,
Don't you remember...?? You want it to coil bind just as it reaches the peak of the "Loft" or "Toss" off the cam profile?

Guess I've been doing it wrong

Reed Granrt · 12-24-2011, 03:11 PM

Quote:

Originally Posted by Ed Wright

Your kidding about "getting to coil bind", right? .050" from coil bind should be close enough.

Ed
Here you go again. You missed it. You put in a safety factor of setting it up to get .05 before you get max lift. That way you cant ever float the valves. Ive been doing this for years and I aint never floated a valve. Well wait a minute I think I floated a couple out the headers. HeHeHe
reed

12-23-2011, 03:08 PM	#1
Ian Hill Member Join Date: Sep 2008 Posts: 216 Likes: 0 Liked 6 Times in 3 Posts	Re: spring pressure i have been adding shims along the way this year and the motor has liked it each time i did it. F/CM 350 ci 330 hp. shift at 6500 and cross at 7200. i haven't heard the coils binding yet, so i am going to add another shim under the exhaust side for the next race and see what happens :-) i love this sport! i look forward to the day i cross the line and the car shuts off and the parachute deploys automatically....in my stocker! LOL Ian

12-24-2011, 12:41 AM	#6
Ian Hill Member Join Date: Sep 2008 Posts: 216 Likes: 0 Liked 6 Times in 3 Posts	Re: spring pressure Ahh, you have gone too far too! My "valve through the exhaust" sounded like a death rattle at 1100 feet. Ended by splitting the piston in two, one half embedded in the block, half way up the bore, the other half scattered throughout the other 7 holes! It was actually caused by coil bind, but I'd imagine similar results if it did happen. I have been increasing valve pressure buy .01" shims and am up to .06" intake and .03" exhaust over recommended and each time I add shims the car picks up. The next race I go to I will be matching the ex with the intake. It is a largerjump than I've done so far, but I am guessing it will be good as I did the intake first and have been catching up with exhaust with good results. I've discussed this lots with my engine builder and we decided to go with the idea that more is better, to the point we wipe the cam shaft out. This will be season two coming up, the last cam had three seasons without fail. As far as telling you what my spring pressure is, I don't think it matters. My combo likes the springs stiff. Just like valve lash, my combo runs near to zero as I dare go... I set them cold and I set them tight. But that's for another thread I am sure. What I will tell you is at what spring pressure I wipe the cam out...if it happens. I switched Joe Gibbs oil this past seaon, this is the first time I am not freshening my engine, everything, including the cam looks good. I figure I'll get to coil bind before hurting the cam. Ian

12-24-2011, 02:22 PM	#7
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: spring pressure Your kidding about "getting to coil bind", right? .050" from coil bind should be close enough. __________________ Ed Wright 4156 SS/JA

12-24-2011, 02:28 PM	#8
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: spring pressure Ed, Don't you remember...?? You want it to coil bind just as it reaches the peak of the "Loft" or "Toss" off the cam profile? __________________ Adger Smith (Former SS) Last edited by Adger Smith; 12-24-2011 at 02:28 PM. Reason: sp

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