Valve train geometry

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Wyrmrider said:
comp says
What is correct valve train geometry? When the rocker arm roller tip rolls from the intake side of the valve tip, across the center of the tip (at approximately mid-lift), to the exhaust side of the valve tip (at full lift) and back. See Diagram A.
now how is that helpful?
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I've found a couple of things in the Comp literature that is bad/wrong/foolish but this takes the cake. Wow....no wonder folks are confused.
 
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Wyrmrider said:
If pattern was off side to side too much I'd move the shaft/ stud never tried (well once) centering the pattern
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Makes sense to me. With a roller the force into the tip is straight down into the valve stem tip as long as the tip end is 90 degrees from the stem axis. Moving the roller off of center one side or the other does not change that force direction. If you get too far off center the roller and tip pressures increase too much but as long as they are near center, they stay pretty constant.

It might be possible to get some sort of rotational motion imparted into the valve (as viewed from the side) when off center with very high lift speeds, that the guides have to control, but I don't have any way to quantify that. But even then I bet spring vibrations and movements nearing resonance far exceed anything like that.

Narrowing the pattern may reduce the low roller side force on the stems due to lower roller-on-axle rotating speeds.
 
Well the only way is to get shorter arms. Tried simulating shimming up and lowering it down with no success.
 
I'm going to rUn it like it is for now. Got it running today but was mis firing at idle but not constant. Looked at my distributor cap and noticed burn marks on the posts but only on the edges and not centerd. Phasing is off I believe , could that cause random shaking at idle?
 
B3's shims are not "flat". They move the shaft CL in other directions besides "up", and "down" along the same line as the saddles. Might be a cheaper alternative to other rockers - especially if the valve job left things in an odd spot. Other rockers may not fix it.
 
N1ce2k1llu said:
Well the only way is to get shorter arms. Tried simulating shimming up and lowering it down with no success.
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Bullshit. You have to move the shaft up and away from the valve.

Run junk if you want but you don't need to.

I can see you didn't bother to go to the website I posted and actually read and learn anything.

The junk **** shims that Hughes sells are an embarrassment. Dave should be sick he sells junk like that to the public.

One more time. Your shafts need to go UP and BACK away from the valve. FIX IT.
 
He's like every other hard headed fool that comes on here wanting help, gets it and then argues against it or completely ignores it. I'm done dealin with this kinda crap. When was the last time you saw me write a book tryin to help someone? Not happenin anymore. TO heck with um.
 
I didn't read though the while thread,but I changed valves to obtain the swipe I was looking for,Notta small block but still........
 
Well guys, I for one definitely appreciate the good advice dished out as a Mopar community service on FABO and regularly see the likes of Rusty, YR and many more helping out with invaluable advice. Just to underline the above, I thought about my build some more after reading the posts then contacted Michael from B3 and spent last night measuring up my valve geometry dimensions to have him supply a geometry correction kit for my own 410.

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Greg Spooner said:
Well guys, I for one definitely appreciate the good advice dished out as a Mopar community service on FABO and regularly see the likes of Rusty, YR and many more helping out with invaluable advice. Just to underline the above, I thought about my build some more after reading the posts then contacted Michael from B3 and spent last night measuring up my valve geometry dimensions to have him supply a geometry correction kit for my own 410.

View attachment 1715172676
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That's making A LOT MORE SENSE....
 
rumblefish360 said:
Oh good gravy! I’m sorry B3RE, that was a quick post and run. Where are you located?

Moper, thank ya buddy!

Yes!

“Contact info” is what it was to read!
LMFAO!
:rofl:
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South Central Pennsylvania. I've got some Chapman Stage 6s in the shop right now from the island that is long.
 
Greg Spooner said:
Well guys, I for one definitely appreciate the good advice dished out as a Mopar community service on FABO and regularly see the likes of Rusty, YR and many more helping out with invaluable advice. Just to underline the above, I thought about my build some more after reading the posts then contacted Michael from B3 and spent last night measuring up my valve geometry dimensions to have him supply a geometry correction kit for my own 410.

View attachment 1715172676
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I checked out the B3 site and found nothing about products for sales. So it must be a custom built order thing. After reading your post, what measurements does he need? What's the average price? What do they look like so I can understand how they work.
And to the other guys, Im just running it like that for now until I work out the other bugs and get more $.
 
Get rid of all the whining... The rest is pretty constructive.. Thanks to those who really contribute.. :)
 
N1ce2k1llu said:
I checked out the B3 site and found nothing about products for sales. So it must be a custom built order thing. After reading your post, what measurements does he need? What's the average price? What do they look like so I can understand how they work.
And to the other guys, Im just running it like that for now until I work out the other bugs and get more $.
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Email Michael at B3 and he will give you all the info you’ll need, you’ll find his email address on the website
 
N1ce2k1llu said:
I checked out the B3 site and found nothing about products for sales. So it must be a custom built order thing. After reading your post, what measurements does he need? What's the average price? What do they look like so I can understand how they work.
And to the other guys, Im just running it like that for now until I work out the other bugs and get more $.
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He has several tech articles on his home page. I can find them. Why you can't is beyond me.

Mike makes up the spacers for your application. There is no one size fits all.
 
I just went to the site and on the home page is part 4 of his tech articles.

At the top of the page you can find all four of the tech articles under the tech corner tab.

If you want to see what Mike makes to correct geometry look in the upper right corner. You can see his spacers under the shaft.

He also has many pictures in the tech articles.
 
"Narrowing the pattern may reduce the low roller side force on the stems due to lower roller-on-axle rotating speeds."
Narrowing the pattern by moving the shaft (and readjusting the checking pushrod) ust shows you are getting closer to optimum
way back in the day we locked the valve in place with a clothespin at half lift- that slipd so we graduated to a stem seal with a screw clamp
then set the cam at half lift and put the rockers and shafts on for a trial- moved the shafts around till we had the valve tip, center of the shaft, and the ball lined up with the ball as far up as we could get it- (and that three point line tangent to the valve stem )which was usually not far enough now we know there are easier ways...
what you will find as a result is less guide wear and rpm stability
lots of variables like longer valves and/or lash caps AFIK there is no easy way
 
Well I know it’s been awhile but today I was finally able to fit up the correction kit Michael from B3 supplied.
The transformation in rocker action and sweep is remarkable and looks to be pretty much perfect now. I’ll let the photos tell the story starting with the sweep I was achieving prior to adding the B3 kit.

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View attachment 1715209155

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Nice Greg thanks so much for the pics

to sumup
roller tip rockers shafts need to be adjusted - simple mechanics, geometry
Small block Mopar rockers are already shorter than SBF or SBC not easy to make them shorter economically and you would loose ratio
Small Block rockers ,not set correctly, ride on the outside of the valve stem and interfere with the springs and the the rocker body can the pushrod cup
which is a good reason to go with the cups in the rocker
High ratio rockers are tougher to do
lash caps and/or long valves make the problem worse
rockers with the fulcurms too low put more acceleration and pressure on the valve past half lift when the cam is trying to go over the nose
makes valve float easier
having the rocker angled way up on the seat makes valve opening SLOW compared to what the camgrinder wanted it to be
I do not care much that the roller always pushes straight down- its the valve motion that's FUBAR (already SNAFUED by the lifter/ pushrod angle
 
looks like hard AN washers in that pic View attachment 1715209157
nice touch
I use a lot of those especially if the faces are not pristine after many bolt cycles directly on cast iron
but sometimes you just have to spotface with a pilot & cutter like rebuilding a faucet seat
 
Moper
It would depend onhow far off you were
we used to mill the shaft holes offcenter over to the shaft wall sometimes with long valves and big tall springs- usually with the stock pedestals milled off and billet stands
the vendor can steer you right get his requirements and send them in for a quote
disclaimer- I've never used his kits but his results are very good
 
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