[Mean Green]

What's involved when switching from stud mount rockers to shaft rockers on an already assembled engine?

The engine currently has Harland Sharp 1.65 rockers with .250 offset and Isky lifters with .180 offset. The heads are 380 cfm High Ports.

[Probird]

You will just have to re-measure pushrod length once you get the stand height set. Probably won’t be able to use the same pushrods. That’s about it.

[Skip Fix]

For my Crower shaft they had a tool to get the stand height correct. Then you go to measure for pushrod length, but no direction where the adjusters should be in the rocker for that. I set mine with them halfway through their adjustment to give plenty of room either way to play with lash.

[mysticmissle]

t and d rockers are no where near half out by the directions. I was just looking at this the other day. I think its a turn and a half from all in?

[Mean Green]

I already need new pushrods, so that works out good.

I plan on getting T&D rockers. What about the offset? Does that come into play?

[Stan Weiss]

Originally Posted by mysticmissle

t and d rockers are no where near half out by the directions. I was just looking at this the other day. I think its a turn and a half from all in?

X2

From a long time ago and I am talking 426 Hemi. You wanted the min out of the rocker. This shorted the push rod a small amount which reduced total valve train weight a small amount.

Stan

[Dave Polichena]

Be very careful when measuring geometry. I had to shave +/- .090 off my rocker pads to get that where it needed to be for my HP heads.

[Probird]

Originally Posted by mysticmissle

t and d rockers are no where near half out by the directions. I was just looking at this the other day. I think its a turn and a half from all in?

My directions for T&D are to back the adjuster counterclockwise till the bottom of the screw is up against the rocker arm. Turn clockwise one full turn. That’s the initial setting. Don’t go more than one full turn in either direction from this setting. Otherwise it will cut off the oil supply to the rocker.

[Probird]

Originally Posted by Mean Green

I already need new pushrods, so that works out good.

I plan on getting T&D rockers. What about the offset? Does that come into play?

Yes. You need the correct offset for your heads.

[Mean Green]

Originally Posted by Probird

Yes. You need the correct offset for your heads.

According to the T&D website you measure the center of the #1 and #3 intake valves and the center of the #1 and #3 intake pushrods, subtract, and then divide by 2. and then add .050 for pushrod clearance.

My pushrod centerline width is 3.750 inches. My intake valve centerline width is 2.850 inches. 3.750 - 2.850 = .900.

.900 divided by 2 = .450

.450 + .050 = .500

So .500 is my rocker offset? Does that sound right?

[Mean Green]

Pics

[Dragncar]

Originally Posted by Dave Polichena

Be very careful when measuring geometry. I had to shave +/- .090 off my rocker pads to get that where it needed to be for my HP heads.

This^^^^

[slowbird]

Originally Posted by Dave Polichena

Be very careful when measuring geometry. I had to shave +/- .090 off my rocker pads to get that where it needed to be for my HP heads.

My hp heads needed spacers made to run t&d shafts. Goes to show you that things need checked carefully to determine what's needed.

[GTOGEORGE]

Do you have offset lifters?



GTO George

[Mean Green]

[QUOTE=GTOGEORGE;6125536]Do you have offset lifters?GTO George[/QUOTE


Yes, .180 offset.

[GTOGEORGE]

[QUOTE=Mean Green;6125538]

Originally Posted by GTOGEORGE

Do you have offset lifters?GTO George[/QUOTE


Yes, .180 offset.

Ok.......just checking!


GTO George

[grnmnstr]

Not something I would do on an already assembled engine. But that is just me.

[Stan Weiss]

Originally Posted by Dave Polichena

Be very careful when measuring geometry. I had to shave +/- .090 off my rocker pads to get that where it needed to be for my HP heads.

Originally Posted by slowbird

My hp heads needed spacers made to run t&d shafts. Goes to show you that things need checked carefully to determine what's needed.

Did either of you have other than standard length valves?

Stan

[Mark G]

I never thought it was worth it anything up to 1200 hp I don't see the advantage of using shaft rockers conventional rockers will work fine unless you have some really large lift camshafts but besides that waste of money just my opinion my current combo is close to 1100hp on nitrous no problems don't get me wrong they have their place

[Stan Weiss]

Mean Green, Dave and Brian,
What do you have for over the nose valve spring pressure?

Stan