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This conversation is a great example of the best of these forums. Giants of the industry discussing the hows and whys of the trade. It is fascinating to me that as hugely successful these guys are, they still have some different theories and procedures. Absolutely wonderful stuff guys. I personally can't thank you enough.
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Spent 3 days combing through this thread , lots of great info and respectful banter.
 

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Sorry I didn't get to respond to your pm soon enough.

I think if you're seeing that much variance in CB.... that is certainly a quality control problem. What exactly could cause the variance if the coils are the same dia spring to spring? Has to be a wire quality issue and that's not a good indicator to the rest of the spring.....

PSI Springs do not vary like that.
I think you mistook or I didn't explain it well. No variance issue. And I do run the PSI and occasionally the Manely NexTek. Thanks.
 

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Agree. We take it a step further and started spinning on our spintron at a low " 250-500 rpm " with a very very light inner spring only to have the laser trace the valve lift curve without deflection in the system affecting it. That's how we figure max lift with actual components being used. Stand installed height, push rod length, adjuster cup height, etc all change the ratio.
Tom,

I don't get, so explain why you would want to do all of that? What you said above is completely contradictory. You first said you spin stuff at 250-500 rpm with a very very light inner spring. Then in the next sentence you said, that's how you figure out max lift using actual components. That doesn't make sense to me!?!?!?!? Using a very very soft spring isn't one of the actual components???? Ya, I agree that all those components you listed above do change ratio. But all those components need to be setup right when designing and building an engine from the start.

I understand everything that your guys are trying to do but what I can't figure out is why? I guess I can make a rocker arm so stiff for measuring purposes so there is no deflection. I'll make a solid pushrod made out of beryllium so I know I have absolutely no flex. I'll take out my Ti valves and stick in steel valves to eliminate any deflection on the stem and I'll then tighten up my guide clearance for a more accurate measurement. So after doing all of that and now mocking everything up and measuring my gross net lift. What do I do then? I then will realize that my new found no flex system has lets say .030, .040 or even .050 more lift than the actual parts that I am realistically going to run. So what do I do with that information?

I know that there is a "pole vault" or "spring board" affect going on in my system. I know I will have loft in my system. But trying to figure out information that I admit is there, as you listed. I just don't see how to make that useful and here's why. Everyone knows you can't run a spring at zero coil bind or parts will break. The thing is not every application will run the same clearance from bind as other applications. My guess is that an everyday street car probably have very minimal bind cause a street car doesn't have or have very minimal "spring" affect in the system and or loft. Warp can verify this or not but I believe some NASCAR stuff has as minimal as .030 bind clearance. I've seen drag stuff vary from .070 to .150 and each spec all depends on the application. So I don't understand how is the time useful figuring out stuff that isn't practical in a running engine using all the parts that are in the engine.

Some rockers are much stiffer than others and same with the pushrods and that would even include cam cores. So why not just put the assembly together and see where the "pole vault" effect comes into play and see where surge comes in and where and how much loft is in the system? Then you change parts and bind clearances to see what combination works the best for that particular combination, right?

So back to my original question, how does doing all of stuff you guys describe change my end result?

Nick
 

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Nick
without spinning every single change a person makes, there is some guesswork involved obviously.


My feelings fwiw. Every spintron trace ive seen got back to "theoritical" lift or beyond. Theoretical being lobe lift X true rocker ratio - lash = theoretical.


So i know that when the motor is running at higher rpm, i will get to that amount of lift at the valve. I dont really care where in teh whole thing the pushrod/rocker,etc all unwind. I just know it does. So i set my shit up for "maximum theoretical lift" as i truly feel i will get there at some point, so i have to account for it.


say i have a .565 lobe with a true (measured at the valve with soft springs) 2.05 rocker i know im going to get to that lift at the valve at high rpm. so i have to set up my valvetrain to make sure im never solid there. Agree 100% that there is deflection, and ill never be close to that until i get the parts to unwind, and loft.



IMO the reason we need to give more distance to bind with more agressive cams is a) spring surge when you excite the spring initially, and b loft. If we knew true loft in every application, we could set up tighter and help things out. I always build in some amount of error in my guess (im not spinning every thing we do, i cant afford it...lol) so ideally we may need to be .060 from solid, but i set up at .080 because i know ill never eat all of that up.


With the 500, its different because i will spend the time to adjust it .015 at a time to find its happy spot. Again, the sportsman stuff i cant do that. But I run the same basic lobe family in my peersonal motor i run in customer stuff, and i have worked that ideal distance on my shit, so i can get it close.



I allow a little bit for what i feel is a safety factor for loft, and send it...lol
for our sportsman shit, its proven very successful. i can run almost an inch of lift at 8200 rpm and go 250 laps without hurting springs, so i feel ive gotten it pretty good....


Again, dont think im saying what you do is wrong, you have obviously worked things out for your system. For me, and for what we do, we have had outstanding results with what we have developed.
 

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I'll add one other thing about trying to set up proper coil bind that I don't think was mentioned. First off, NEVER go off your cam card using whats printed as max lift based off of their calculations. Also, you really never should figure out max lift using just math. Meaning, lift times ratio minus lash... That doesn't work!

I'm not trying to say this to bash Bob with his above comment on the two failures and learning the hard way. But if you are truly trying to set up bind to a specific number those two failures would of never happened.

First off, I have never seen any rocker arm (not that I have checked them all) that has the same ratio as stamped. Most and I believe all rocker arms have more ratio than what is stamped. The extra ratio is not included to accommodate flex but is there because of motion loss due to it being exactly what it is called, a "rocker arm". Through physics a rocker arms motion is an arc which has motion loss. If you truly made an arm with a 1.7 ratio and then actually calculated out what the true ratio is, you would get less than 1.7. I believe most manufactures add a half ratio to compensate for that loss of motion. So by adding ratio when you check the arm it's now much closer to a 1.7 ratio.

The true and I feel the only way to set up coil bind is to mock up the system using all the same parts as you would when its going together for the final time. I will use shim instead of trying to crush a head gasket to make that part easier. I will put the cam in, snug down the head using shim stock to replace the head gasket and put the valve train all together. Again, using all the same parts as you would when if goes together for the final time. Meaning, I don't use "soft" springs or mock-up pushrods. Keep in mind to find max lift, you do not need to go through the process of degreeing in the cam. Unless you are also trying to figure out P2V, then you would have to. I've actually made a tool, so all I assemble is a cam, head and valve train with no crank in the block. I can just turn the cam with the tool I made. You also only have to do just one cylinder so don't mock up the entire engine to do this. You can do one side at a time which can make it easier to do. So set the valve lash accordingly and then put he dial indicator on the spring or retainer and make sure it's on a flat spot. Set zero and rotate the cam and physically see what you have for max lift is.

Then to set you installed height, now it's just math. You then take you bind height of the spring plus your gross valve lift plus your desired coil bind clearance and you have now very accurately come up with a "true" installed height for your engine. If you do it that way, you will never have a coil bind issue. The biggest variable is in the spring itself. Like mentioned above, all springs have a spec bind number. Some manufactures are pretty good being within +/- .010 which is still within tolerance. I have seem some be plus .040 which then would affect things if installed to tight. Hopefully everything above made sense and hopefully to some have a better understanding on the process...

Nick
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Tom,

I don't get, so explain why you would want to do all of that? What you said above is completely contradictory. You first said you spin stuff at 250-500 rpm with a very very light inner spring. Then in the next sentence you said, that's how you figure out max lift using actual components. That doesn't make sense to me!?!?!?!? Using a very very soft spring isn't one of the actual components???? Ya, I agree that all those components you listed above do change ratio. But all those components need to be setup right when designing and building an engine from the start.

I understand everything that your guys are trying to do but what I can't figure out is why? I guess I can make a rocker arm so stiff for measuring purposes so there is no deflection. I'll make a solid pushrod made out of beryllium so I know I have absolutely no flex. I'll take out my Ti valves and stick in steel valves to eliminate any deflection on the stem and I'll then tighten up my guide clearance for a more accurate measurement. So after doing all of that and now mocking everything up and measuring my gross net lift. What do I do then? I then will realize that my new found no flex system has lets say .030, .040 or even .050 more lift than the actual parts that I am realistically going to run. So what do I do with that information?

I know that there is a "pole vault" or "spring board" affect going on in my system. I know I will have loft in my system. But trying to figure out information that I admit is there, as you listed. I just don't see how to make that useful and here's why. Everyone knows you can't run a spring at zero coil bind or parts will break. The thing is not every application will run the same clearance from bind as other applications. My guess is that an everyday street car probably have very minimal bind cause a street car doesn't have or have very minimal "spring" affect in the system and or loft. Warp can verify this or not but I believe some NASCAR stuff has as minimal as .030 bind clearance. I've seen drag stuff vary from .070 to .150 and each spec all depends on the application. So I don't understand how is the time useful figuring out stuff that isn't practical in a running engine using all the parts that are in the engine.

Some rockers are much stiffer than others and same with the pushrods and that would even include cam cores. So why not just put the assembly together and see where the "pole vault" effect comes into play and see where surge comes in and where and how much loft is in the system? Then you change parts and bind clearances to see what combination works the best for that particular combination, right?

So back to my original question, how does doing all of stuff you guys describe change my end result?

Nick

Nick
The spintron peak lift value is a input value you enter. ( based on a measurement you took with the indicator, or in a perfect world lobe lift x rocker ratio - lash ) If your package has deflection or push rod angle sweep you will not know how much loss unless you minimize all or at least as much of it you can. That's how it establishes the max valve lift value based on laser at a set base rpm trace. This is how people get crossed up with a true "loft" value.

If the base line trace is displayed BUT in a deflection state the peak lift value is a deflection peak lift value and with rpm a greater shown trace is a lift value with deflection minimizing. At some point ALL deflection will be gone and a "loft" lift value will be displayed.

You can't determine that without a baseline trace with "0" deflection lift value inputted. Only way I found to establish that is with the least amount of spring in the actual spinning engine at very low engine speed.

Spring bind clearance from my experience is a way to dampen out unwanted spring surge initiated from the opening cycle. A happy system has way less of an issue so not much need for very tight coil bind clearance. I can manipulate the max lift curve by not stacking the spring so tight and still have enough on the seat. End result is my coil clearance.
 

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So,.....in spring set up when considering how close to spring coil bind,....is spring harmonics no longer a consideration. Nobody has mentioned it???.......just curious.
 

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Discussion Starter #5,928
So,.....in spring set up when considering how close to spring coil bind,....is spring harmonics no longer a consideration. Nobody has mentioned it???.......just curious.
Ron, spring harmonics are a big part of it all. But unless you have a spin-tron it's really hard to really know what to do. Good rule of thumb is keeping the spring within a certain amount of coil bind and typically that will control things. Spring companies do a very good job in making sure that the coils have opposite harmonics or close to it anyways. By you asking the question, you know that there are harmonics with each and every part of the engine. Spinning a valve train also helps determine when all the harmonics come into play. the key is trying to keep them all away from one another cause when they all come into play at the same time. That's when parts can break and or have dips in the power curve...

Nick
 

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Ron, spring harmonics are a big part of it all. But unless you have a spin-tron it's really hard to really know what to do. Good rule of thumb is keeping the spring within a certain amount of coil bind and typically that will control things. Spring companies do a very good job in making sure that the coils have opposite harmonics or close to it anyways. By you asking the question, you know that there are harmonics with each and every part of the engine. Spinning a valve train also helps determine when all the harmonics come into play. the key is trying to keep them all away from one another cause when they all come into play at the same time. That's when parts can break and or have dips in the power curve...

Nick
Thanks, thought it was but just curious why it was not mentioned in any of the threads. Like ya say, when you don't have all that great equipment at hand you do the best you can.
 

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Good to see Shane going rounds and being competitive.
Thanks!

There are a lot of changes in the works and the future looks much brighter for me and my business NFR... FYI, I’ll be moving back to the Mooresville, NC area here soon.

Nick
 

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Thanks!

There are a lot of changes in the works and the future looks much brighter for me and my business NFR... FYI, I’ll be moving back to the Mooresville, NC area here soon.

Nick
Congrats on the good results! Are you packing up your whole shop and relocating it?
 

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Thanks!

There are a lot of changes in the works and the future looks much brighter for me and my business NFR... FYI, I’ll be moving back to the Mooresville, NC area here soon.

Nick
Looking forward to having you on the east coast
 

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Hey, anyone. I’m always thinking about stupid shit, so here goes. Would rifle drilling the complete length of the headers do anything positive?
 
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