Nowhere did I say clay will bend a valve, so you're being disingenuous. In fact, I mentioned multiple times when I measure with clay and heavy springs, which I've bolded below. While you may not, I have the time to relax and check in the fashion I explained, which usually requires checking once and not twice. If a tight clearance requires that I check with clay, I also have time to do that.
Valve Clearance on Larger Camshaft and Flat Top Pistons
- Thread starter Fish Bite
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Nowhere did I say clay will bend a valve, so you're being disingenuous. In fact, I mentioned multiple times when I measure with clay and heavy springs, which I've bolded below. While you may not, I have the time to relax and check in the fashion I explained, which usually requires checking once and not twice. If a tight clearance requires that I check with clay, I also have time to do that.
Newbomb Turk
Well-Known Member
You’re shitting me right. You are this obtuse.
I’ll say it again. If you are bolting the junk you build together and the pushrods are bending turning the crank BY HAND you should find another line of work.
I’ve said it multiple times as nice as I can.
ON THE STAND THE PUSHRODS MIGHT DEFLECT WHILE TURNING THE CRANK BY HAND BUT WHEN YOU STOP TURNING THE CRANK THE PUSHROD DOES NOT STAY BENT.
If it does stay bent what does that tell you? It’s permanently bent.
I know you want to be right but you are so ******* wrong it’s senseless.
I told you to call Jesel but you didn’t and you used the lame assed excuse they would be busy. It’s their JOB to answer questions and educate the customers.
You didn’t call because you didn’t want to be wrong. That’s chickenshit.
You don’t have to call and say “there is an argument on the web and a fat old guys says the rockers flex” or something like that.
You’d call and ask a question like “I’m working on my junk and I’m checking P/V with checking springs and the ratio is higher than nominal. Why is that”?
I guarantee you that he won’t say “your pushrods are bending so don’t worry about it”.
He will tell you EXACTLY what I’m saying. How do I know.
BECAUSE I ASKED THE VERY QUESTION MYSELF.
Just to make you look even more foolish, my last engine for the race car had 350ish on the seat and over 900 over the nose.
I had to use 3/8 x 7/16 .120 wall double tapered pushrods to make it live.
With checking springs my Norris rockers had the ratio way over 1.6, but loaded they were 1.61.
Do you actually believe that turning that engine over by hand with the springs I ran that those pushrods were bending and staying bent?
Think about it before you answer because any answer other than no is wrong.
Newbomb Turk
Well-Known Member
See post 45 where you say you can’t sneak up on it or however you worded it. The inference is the valve will hit the piston and bend it.
You already know your valve notch depth and in post 49 Bewy gave you your Valve Opening At TDC numbers.
Those are with no head gasket or lash. You have a MILE of clearance.
If you check p/v with checking springs you will have significantly LESS clearance than if you used clay.
If you grasp that concept then go ahead and do it with checking springs.
Like I said, I knew from your first post you were going down a rabbit hole and no matter what the logic given you’d want to do it with checking springs.
What you really wanted was everyone to jump in and say checking springs are how I do it and that’s the best way.
I say they are correct and I’m wrong.
I’ve seen some absolutely ridiculous ways to check p/v and one was in a video by one of the best know engine building shops in the nation.
The builder set the piston at 10 or 12 degrees or whatever position ATDC that he knew would be the tightest.
Then he put a dial indicator on the retainer, and then…get this…he turned the adjusting screw DOWN until the valve just touched the piston!! I could not grasp the level of stupid that is, especially since the rocker is aluminum and IIRC it had 380 on the seat. So at whatever lift it was probably close to 500 pounds of spring load. To do that to the rocker and adjuster was just mind boggling to me. And unnecessary.
Things like this start back in the “day” like the 1970’s or early 1980’s when 180 on the seat and 450 over the nose were Pro Stock spring loads.
That’s when and how they learned how to do it the quick and dirty way. And they keep on doing it because “it always works for me”.
Use the checking springs. Just understand that you’ll show significantly LESS clearance than you’ll have with the springs you are going to use.
It sounds like what your saying is that the information in my response is " dead wrong". Maybe, but the responses I quoted are direct quotes from Billy Godbold's new book on camshafts. In the section titled "checking undeflected and deflected lift". It's possible you are right and those quotes are errors in his book. I still recommend reading it.
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Newbomb Turk
Well-Known Member
Pay attention because I’m typing very slooooooooooow so you can possibly grasp the concept.
I never EVER said the valve train doesn’t flex. I’m betting all I have I’ve fucked with more engines with more spring pressure than you ever have.
I can tell you the pushrod is the single most overlooked component in the engine. I see guys building engines with pushrods too small for a SFT cam and I see the results.
I had an engine on the dyno, a BMM 471 built by some other dude and the moron used a 5/16 pushrod. With just a SFT cam.
After a few warmups and pulls on the dyno that 5/16 pushrod was bending so far that it was rubbing the tunnel. It left a CLEAR witness mark. Do you how big the pushrod tunnel is on a TF 240 head? It’s HUGE and the pushrods were bending that much.
And yet, they didn’t stay bent.
Now what YOU want ME to believe is that you are so stupid you can’t grasp the concept of bending loads and plastic deformation. If you don’t know what that is LOOK IT UP because that’s what you want me to believe.
When you are turning an engine BY ******* HAD if the pushrod does deflect and that’s a giant IF by the way, that it STAYS BENT when you stop turning it.
Do you want me to think you are that thick? That dull? You are leaving me no choice to not think otherwise.
I’ll say it one more time.
If you turn the engine by hand and the pushrod bends, and you STOP TURNING IT the pushrod is no longer BENT.
If it was you’d need to replace the pushrod
You know exactly what I’m saying. You get it. But you want to continue on, trying to goad me into something. That’s grade school ****. I’m now leaning towards he fact that is your education and maturity level.
Go read the Godbold book and post the page number where Billy says that while checking cam timing the pushrods bend and stay bent when you stop turning the engine over.
Again, you are DEAD WRONG. Shame on you for putting bullshit like this out for the world to read.
Stop moving the goal post. Stop putting words in my mouth. Quote me where I say the pushrod stays bent. My post was a direct quote from Billy's book. Either you agree with it or you don't.
Newbomb Turk
Well-Known Member
Just so everyone can read what Godbold wrote I have it here. He says EXACTLY a what I’m saying. EXACTLY.
Later on he also talks about a Pro Stock Valve spring at 10k (IIRC) not touching the retainer or the head. Take away the RPM and abracadabra the spring is now touching the retainer and the head.
You can always mentally masturbate your way into a corner. It’s a lot harder to get out of it.
Later on he also talks about a Pro Stock Valve spring at 10k (IIRC) not touching the retainer or the head. Take away the RPM and abracadabra the spring is now touching the retainer and the head.
You can always mentally masturbate your way into a corner. It’s a lot harder to get out of it.
Newbomb Turk
Well-Known Member
Newbomb Turk
Well-Known Member
I call it pushrod whip.
That's something a checker spring won't take into account.
All valvetrain components being used at final assembly, should be used to check clearance.
I can usually get a good idea by placing the head on a table before assembly and measuring valve drop on the stem and and adding gasket thickness and pocket depth, a general idea
Newbomb Turk
Well-Known Member
Right. But once you stop turning the crank by hand the pushrod is no longer in “whip”.
No one I know checking p/v or rocker ratio reads the dial indicator while the crank is turning. That’s an idiotic thing to suppose.
Also of note in the Godbold book is that the ratio is not at nominal all time, but when the valve is WFO it better be the nominal ratio or the guy who engineered the rocker doesn’t understand anything but what he read in a book.
What post and by who?
Newbomb Turk
Well-Known Member
So, if you agree with my post with the quotes from his book then just hit the green checkmark icon and move on.
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Newbomb Turk
Well-Known Member
Thank you for keeping it civil.
If the he your refering to is Billy Godbold and the subject Billy is talking about is the section titled "checking undeflected and deflected lift" then I think he is refering to the amount of deflection remaining after you stop turning the crank. I'm not sure how you could measure it while turning the crank by hand. refer to image 2-33 page 37 the column labeled "stock deflection".
Newbomb Turk
Well-Known Member
You’re arguing with a book. Not me.
Newbomb Turk
Well-Known Member
No, I’m saying you can’t read. If you think the Godbold is saying the pushrod stays bent under load you are nucking futs.
Thats exact'y what you are saying.
I’ve told you several times I’ve tested this.
I can test with a 5/16, 3/8, 7/16 and a 3/8-7/16 double taper pushrod and guess what?
The unloaded and loaded ratios are the exact same. Every time I’ve tested it.
I’m done dealing with your stupid ***. Figure it out. YOU cant read because Godbold says nothing you claim.
The ******* pushrod doesn’t bend and stay bent. It can’t.
Do you understand that?
Don’t answer. You’ll be wrong. Again.
Newbomb Turk
Well-Known Member
Newbomb Turk
Well-Known Member
Newbomb Turk
Well-Known Member
I need to read that on my iPad. On my phone it’s too small.
Newbomb Turk
Well-Known Member
I know he doesn’t like clay. I’ve read that before.
We agree on the fact you have to mock it up like it runs.
We agree if you do it any other way you end up with too much clearance and that’s a power loser.
Where we disagree is with clay. I have, since about 1995 when I realized that the intake valve only needs the same clearance as whatever the piston to head clearance is and, when I tightened the clearance up it would make more power.
Since then I almost never make the intake valve pocket deeper.
On steel rods I’ve run as tight as .040 and never touched a piston. On aluminum rods I’ve run .055 and never touched the piston.
I don’t run them that tight without a gear drive. With a belt I add .010 and with a chain I add .020.
That’s what started this whole **** show. The OP was going down a nasty rabbit hole and I tried to stop him and help him learn how to do it and save some time and get far more accurate results, and potentially keep him from notching a piston for no reason.
The other interesting point is how these guys can’t measure clay to within .005 or less.
I’m going to do videos for my new YouTube channel and I’ll cover this.
It ain’t hard to do.
BTW and FWIW, if 92b would continue to read the Godbold book, he’d learn about buckling loads and why pushrod flex isn’t the issue when checking this stuff.
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