Need help with rocker geometry

[Anonymous]

Well, i broke ANOTHER cap bolt holding my roller rockers on (3rd time)! DAMN. Something is just not right.

Here is the setup:
OZ2502V with original springs(shimmed .060)/valves
Yella Terra full roller rockers from Mike (his site says 1.65 ratio)

DUR @.05 @1.5 @1.6 @1.65 lobes
Cam: 264/274: 214/224 : .450/.450 : .480/.480 : .495/.495 : 110*


Based on YellaTerra's site, this is what I have:
144 - 250 Inline 6: Shaft type (1.65) ST2014
*requires Cleveland lifters and 9.130" pushrods (i would say it's safe to assume that mike sold me the right lifters and pushrods BUT he was getting seriously dicked around by his PR vendors when trying to get mine...maybe I should check them to make sure!)


To me, it would seem that the range of motion for the rocker is being exceeded for some reason at some point causing enough forward (toward the spring) pressure to snap the cap bolt. Each time it would seem that it's hapened right at the top of the bolt near the first threads (I guess the threads are the weakest point not the solid shoulder area).

When last I adjusted the rockers, I purposely left them a little loose to avoid this. I figured that it has to be related to too much push rod lift right? So by leaving the adjuster a hair looser, maybe it would leave enough room for that extra lift that happens for some reason. Guess not.

I thinking that maybe these pushrods are just too long for my setup since the block was decked to .010 and the head milled a bit and I'm using an NOS steel headgasket. Could that be it? Combine all of this deck lowering changes = too long on the pushrods? If that be the case, how then do I get an accurate measurement for the right lenght PR's?

When it happened this am (after I got my replacement cap screw), I started to bolt the rocker head back on. I could not get it to tighten down to the pedestal as it was contacting the tip of the pushrod even with the adjuster backed out all the way. It was like the lifter was pumped way up. I turned the motor over a bit to get it back down so I could install it, but that just didn't seem right. What would cause this to only happen sometimes?

from YT site:

"All rocker arms have a limit to their rotation, at some point the arm will hit on the stud, posilok, pedestal or head of the retaining bolt. It is vital to ensure the operating range of the rockers on each engine configuration is within these limits to avoid severe damage."

Sound like what I'm experiencing.

The YT rockers came with washers that apparently are used to raise them up a bit. We did not seem to need them when first intalling the rockers, but maybe I need to go back and add them now to take up some of this lenght?

The way the YT's fit is this (pics at bottom: http://cquesttechnologies.com/fspp/rockers.asp?cat=24):

- there are 2 thick steel "pedestals" that bolts to the existing rocker shaft mounts. The rockers bolt to them.
- the rocker arms bolt to the pedestal through small (maybe 1/2" tall) steel cylinders that the cap screws slide threw. The rockers actually rest on top of these cylinders

The part in the instructions that was not clear at all was where fo the washers go if you want to use them? Under the pedestal? Under the cylinders? On top of the cylinders?

I know I'm supposed to adjust them with the motor warmed up, but when I remove and replace them, should I wait for the motor to completely cool down so that the lifters can settle?

Thanks much guys.

 

[wsa111]

Bryce, at mid camshaft lift the roller should be close to the center of the valve, either at full opening or at full closing there is mechanical bind at one end of the fulcrum where the rocker shaft bolts to the steel mounting plate. You need to find where the interference is. Either at opening or closing. If you have to shim the rocker stands the washer goes between the spacer & the steel mounting plate. Keep us informed. William

 

[Anonymous]

THANKS! I'll check to see if there is some interference.

 

[wsa111]

Bryce, i forgot to mention, you visually need to check for mechanical interference involving rocker arm travel. With hydraulic lifters you will not be able to do a check of the interference without pulling the head & installing a solid lifter or the best way would be to pull out the distributor & with a drill & oil pump shaft supply oil pressure to the hydraulic lifter just like you should do when you prime an engine with oil. With proper oil pressure the hydraulic lifter will pump up to full lift at your full valve opening. Check it out. William

 

[AzCoupe]

Bryce,

So far, your the only customer that is having problems with them. At least that I've heard about. Don't go by the pushrod lenght YT gave you as it is incorrect. The lenght they gave you is for the Oz250 which of course, has a taller deck height. We installed them on two different motors, then used an adjustable pushrod to determine the correct lenght for the 200ci. So they should be correct. I haven't look at the instructions in any detail, but will do so over the weekend. I'll also call YT on Monday to see what they have to say about it, and what they suggest.

I was also thinking it might be the coils binding on the valve springs. :roll: IIRC You used the stock single springs, right? With a high lift cam and 1.65 rockers, that could easily be the problem. If so, you may cause harm to the cam as well. Did you check for that when rebuilding the head?

 

[Anonymous]

Thanks for piping in Mike. I was only worried that your pushrod vendor was giving you so much grief that maybe he wasn't carefull when selecting them.

If spring issues could cause this then I'd alomost garauntee that is the problem. I didn't think that that would lead to this type of issue. I've still got the stock springs on and have been planning to change them really soon. I had a thread running here trying to select the right single springs to replace these with:

http://fordsix.com/forum/viewtopic.php? ... ht=#149714

I don't know that we ever came up with a selected solution. Do YOU know which springs I can use in place of the stock ones WITHOUT having to machine the head? I want to be able replace them on the head.

Thanks again all!

 

[Anonymous]

Forgot Mike, you guys tested on a 200 block...was it decked at all or stock? Mine is decked to .010 (1968 block). Anyone know how much material that means was removed? What's the stock deck on a '68 block? Would that maybe make the pushrods too long or would the adjusters be able to make up that difference fine?

 

[Junk-Falcon]

ive c

 

[Anonymous]

so if mine was .035 and I had it cut to .010 that's a removal of .025. Add that to a head milling of .020 means I've lowered my overall height by .045. Would that make a difference in the pushrod lenght needed since I'm going with adjustable rockers?

 

[xctasy]

There are over 25 2v heads in America, so youre in good hands.

My notes as follows.

1. The head and block shave should result in a need to have the stock pushrod size reduced the same amount. In my calculations, the stock 7.875" rod, on a block and head down 45 thou on stock, would need to be 7.820 long. Ford made minus 50 and 100 thou shorter pushrods.

2. Stock pushrods total length of a 'ball base (for the lifter) and cupped top' pushrod, standard on our Aussie Falcon 200's, , with 7.803" decks, were 7.875" long. IT'S IMPORTANT YOU IDENTIFY THE PUSH ROD YOU ARE USING.

'Ball base and ball top' pushrods can tend to break if not arranged correctly.

3. Will (was3) and AzCoupe noted that there are two different lengths of hydraulic lifter which have a need for a 150 thou difference in pushrod length. There are many combinations;-

oil through,

and non oil through,

and then Solid,

and hydraulic items.

These alter the effective length of the pushrod, which makes it a little bit tricky to work out the ideal pushrod size. IT'S IMPORTANT YOU IDENTIFY THE LIFTER YOU ARE USING, as it can make your standard pushrod length invalid. YT suggested 9.13" becauue that works on the 1.58" taller Aussie 250 2V block and head. Your stock US 200 block is 1.58" shallower at 7.803", not 9.380" as it is in the Aussie 250 2V. The 200 camshaft sits closer to the crank than in the 250, which requires a longer rod. (This is because the 250 crank in a 200 cube US block hits the camshaft)

So straight away, the ideal pushrod on your 200 is 9.13-1.58" or even lower. Thats a minimum of about 7.550 or taller. The cam sits up about 150 thou, so that suggests about 7.800" being ideal.

The YT guys said use there recommended correct lifter. THAT LIFTER MAY BE 150 THOU TALLER THAN THE STOCK 200 LIFTER.

4. French Town Flyer and David Vizard concur that you must identify on the first cam lobe where 'half the cam lift' is. Then buy an adjustable pushrod, and adjust the height until the rocker is exactly 90 degrees to the pushrod at 'half the cam lift'. This will result in all adjustment and valve geometery being ideal. IT'S IMPORTANT YOU IDENTIFY THE ROCKER ARM AND PEDASTAL AND WASHERS YOU ARE USING, as these nullify the stock factory lengths.

Shimming the valve gear alters the ideal pushrod length.

 

[wsa111]

Bryce, i'm also running the 1.65 full roller rocker arms. mike supplies the correct 5/16 oil through hardened pushrod with 5/16 ball at both ends. The length is correct @ 7.850 " If you did excessive milling you could drop .030-in length, but should not be necessary.. The correct lifter to use is the SBF oil through lifter which is .150 taller above the oil annulus on the lifter. I have the same setup on my new 80 head which is milled .070 & the block decked .035. I am using the felpro headgasket which probably compresses to about .038. So far i have had no problems. Make sure you torque the rocker shaft to the plate @ 35#.
You also need decent valve springs & retainers. You need at least 100# on the seat & at least 200 open pressure. I am using dual springs.
On my installlation i did not need the spacer washers as my rocker arm geometry was right on.
The engine is vastly improved with the 80 head with modified log, FSPP 264 camshaft & the roller rockers plus the hooker headers with dual exhausts. Hope you find the problem. William

 

[Anonymous]

THanks you all for this bank of amazing knowledge! If the springs could result in this problem, I would BET that that is where my issues lie. Mike has sold plenty of the OZ setups to know his stuff. I'm sure what he provided me was right. I made the error of sticking with stock springs instead of upping them as well. That is next on my list of to-dos. If you haven't seen my thread on valve springs http://fordsix.com/forum/viewtopic.php?p=149714&highlight=#149714 I'm trying to pick the best spring I can swap in without removing the head to mill the spring step area. Any opinions here?

 

[AzCoupe]

I'm almost certain your problem is with the single springs, rather than pushrod lenght. Coil bind on a stock single spring is at .430 lift (barely enough for a stock cam). The cam you are running, with the 1.65 rocker ratio, equals .495 total lift. Then on top of that, you stated you shimmed the springs, which only compounds the problem.

Using a single spring with a damper, or dual springs can double the coil bind rating, over stock springs. All of the FSPP springs are rated at .925

 

[Anonymous]

Yep, you are probably right Mike. I REALLY don't want to take the head off to machine for spring setups so i think I'm going to try a set of springs from Crow or Isky as the guys here pointed to in the other thread.

 

[AzCoupe]

I can understand that. I am looking into some other spring sets (that don't require machining) for that very reason.

 

[wsa111]

Bryce, why would you go to isky or any other supplier. Mike has a spring with dampner with about 100# seat pressure & the retainers to match. Why would you go with isky which i personnally hate to do business with for personnel reasons. You need to go with a matched combination to do the job. I can't beleive you purchased a camshaft from FSPP then would go to another manufacturer for springs & retainers.
you need to match apples with apples. for god sakes don't buy isky crap.
My personnel feeling is to purchase the springs & retainers from where you got the camshaft . William

 

[Anonymous]

Geez dude. Sorry you have issue with Isky but lighten up. You are talking to a guy that has enough knowledge to be dangerous but not enough maybe to know that a 100# spring with certain ratings is any different from one vendor to the next. I would LOVE to buy from Mike but he doesn't offer a spring that I can use that does not require machining of the head. What then would you have me do? Buy a cam from a different vendor jsut because they have springs to match?

 

[wsa111]

Bryce, i'm sorry you are the one with the problems, sorry to be blunt, but i deal with service customers every day, i do this for a living, i'm not trying to be negitive, but get with mike & i am sure he has the right valve spring for every cam he sells.
the finished product is a matched combination.
when you get it all sorted out you will be very pleased with the results. Best of luck,looks like you have all the right parts to make a potent rice killer. William

 

[Anonymous]

Do you buy rims every time you buy tires and do you by the same brand rims and tires? Do you only by clothes from one retailer? If so, it sure would suck if they stopped carrying your size!

Like I said, Mike has put together great matched parts but unfortunately, he does NOT offer a spring that I can swap in without removing the head for machining.

I do appreciate the help you have offered in the past, but if you don't have a suggestion that suits the need, then why be negative and blunt at all. I don't have the luxury of being in the mechanics biz for a living. For me, it's a hobby. Now if you needed a website application built and you came to me and said, "hey, I need help...this is what I have currently...it's not perfect" I don't think you'd hear from me "geez, that sucks...you have issues and made some bad choices in the past, so ask for help somewhere else."

I hope that I'm reading the attitude in your posts wrong and can just attribute it to being a fellow Eagles fan . I truly value the help you've offered in the past and hope to benefit more in the future.

Now I'm off to wallow in my Superbowl sorrow.

 

[AzCoupe]

Bryce,

I understand why you are going elsewhere for the springs, I wouldn't want to pull the head either. Plus it will be a week or two before I have a comparable springs in stock, and I know this is your daily driver.

I'm going to call my cam supplier today, to see what springs they supply. I'm not sure where my current springs come from, but guess I need to ask so I'm more informed.

I'm not sure on this next point (and will ask my supplier to verify) but I think any of the dual spring combos (no matter who makes them) need to have the step machined off to install them the way the manufacture intended. I am assuming with all dual spring combos, that the inner spring has the same installed height as the outer spring. In other words, the springs are the same height and not of different lengths. If you don't machine the step off (on our heads), the inner spring will not be installed at the same installed height as the outer spring, thus changing its intended rating. Which is why my cam supplier suggest/recommends removing the step. Our heads were produce to use single springs only, not duals, and the step was designed into the casting to prevent the stock single springs from walking.

What ever you do, don't drive it until you replace the springs. Hopefully you didn't damage the cam. And you need to take a close look at the pushrods too.