FieroGT/4E introduction (Page 9/13)
fierogt4e JUL 14, 12:01 AM
OK ericjon262 that's genius! Well maybe not genius, but a good job well done, and may help solve one of my rocker problems. The little spools they use on an LS for a pedestal dose not align the rocker. On the bottom of the shaft is a counter-bore for that spool. That makes it difficult to use something similar to the 3900 pedestal.
I could make your little device in my old bridge port mill in my garage. The details are all on one side, and that makes it a simple one setup part. KISS, keep it simple stupid.
The spool is only moderately hard, and could be cut to the height for correct geometry of the rocker to valve stem when sitting on your (262)guide plates.
OK ericjon262 it's genius!

[This message has been edited by fierogt4e (edited 07-14-2016).]

fierogt4e JUL 14, 12:38 AM

This is the little spool like pedestal.


You can see on the outer end of the shaft where I cut the shaft in half.
Good Clarence between the rockers and the shafts on this set.


On this set, the bodes would clear but not the shafts. They need stock type bearing and shafts that do not extend beyond the body to work well.


This is just to see if the new rockers sit in the right neighborhood. I will have to assemble the motor to tell better.


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Sincerely
George

ericjon262 JUL 14, 05:17 AM
fwiw, this rocker is probably a bolt on and go solution for a 3900...

https://www.summitracing.co...rview/make/chevrolet

I have some at the house right now, and they fit my non VVt 3500 heads about like the 3900 rocker did, is there a reason you want a rocker with an adjustable pushrod cup?it seems like that would be a PITA to adjust, hell, stud mount rockers will be bad enough. have you tried using the stock 3900 pedestal with your new rocker?

the big concern I have with my rocker is the potential for the guideplate to cause thrust loading to be applied to the roller tip.
dobey JUL 14, 09:31 AM
@ericjon I don't have a 3.5/3.9 valve train sitting in front of me, but it looks like you should perhaps machine the pedestal into the guide plate design, to avoid needing longer studs to mount them. Otherwise, you need to machine an alignment groove in the top side of the plate as well, which means you probably need to make them even thicker. No?

Or, how deep is the alignment groove in the head for the pedestal? Could maybe laser cut or stamp some guide plates out of thinner steel and harden them, instead of milling. Might save a few mm of needed extra bolt length.
ericjon262 JUL 14, 12:07 PM

quote
Originally posted by dobey:

@ericjon I don't have a 3.5/3.9 valve train sitting in front of me, but it looks like you should perhaps machine the pedestal into the guide plate design, to avoid needing longer studs to mount them. Otherwise, you need to machine an alignment groove in the top side of the plate as well, which means you probably need to make them even thicker. No?

Or, how deep is the alignment groove in the head for the pedestal? Could maybe laser cut or stamp some guide plates out of thinner steel and harden them, instead of milling. Might save a few mm of needed extra bolt length.



the guideplates would be used to convert to an adjustable stud mount rocker setup from the stock pedestal, so the pedestal would be eliminated completely. the alignment groove in the head is a little deeper then the ridge on the pedestal.
ericjon262 JUL 14, 11:21 PM
a little more looking at my engine, and I determined the guide would need to be raised higher to clear the LIM gasket and maybe the LIM too. this helps minimize the thrust loading on the roller tip as well, but is also harder to machine



the only real problem now, is the fundamental engineering problem... will it all fit where it needs to go?

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

"The day I tried to live, I stole a thousand beggars' change and gave it to the rich."
http://www.fiero.nl/forum/Forum2/HTML/119122.html

dobey JUL 15, 09:38 AM

quote
Originally posted by ericjon262:
a little more looking at my engine, and I determined the guide would need to be raised higher to clear the LIM gasket and maybe the LIM too. this helps minimize the thrust loading on the roller tip as well, but is also harder to machine



That new design looks even more to me like it would be a bit easier to go laser cut or stamped steel, bent to shape, and hardened. For the alignment tab, a square wave like pattern could be cut/stamped in, along the center, for the length of the mount area on the head, and the tabs could be bent downward to sit in the notch in the head, to help align the plates, and help keep the two sides of the mount side from spreading apart.
ericjon262 JUL 16, 08:26 PM
maybe, this project has been semi back burner-ed. got a few other things I want to finish up first before going on to upgrades like these.

Edit:

but if anyone wants to take over where I have left off, please be my guest.

[This message has been edited by ericjon262 (edited 07-16-2016).]

sleevePAPA JUL 16, 08:29 PM
Had some time measure today...

used the #4 piston:

CH= 1.302"
Pin= .944"
BE= 2.378"
C2C= 5.830"

Rod+Piston CH= 7.132

Still need to measure stroke, but if I plug in the numbers from others:

7.132"+ 3.307/2"= 8.7855"

If deck height is 8.818":

8.818"- 8.7855"= 0.0325" to zero deck

I also measured the head gasket around the fire ring= 0.065"

Then measured the new replacement head gasket= 0.085"
sleevePAPA JUL 17, 08:44 PM
Took a bit more time to measure the rod, it is 5.827" C2C

Stroke was about 3.31"

Piston in the hole about 0.040", average of four positions.

Added up and total deck height is confirmed 8.818"

So the plan is to run the wiseco pistons, with a 1.050" CH, they will be proud of the deck about 0.0105", will need to call and ask how thick the ring land is, otherwise the quench will be about 0.055" without any deck machining.