Roller rockers, difference between brands?

[Tom68]

I measured center of the trunion to the center of the roller tip and it measures 1.43". That sounds like a sb Ford rocker. I gotta give them a call. Surely scorpion doesn't use the same rocker for both.

I think Jesel said 1.45 for SBC 1.65 for BBC. But that was just in a story about coming up with a shaft rocker system.

A correctly designed Ford rockers pushrod angle will be different to a properly designed Chev one.

[smokie]

Is it possible to get a measurement from the trunnion centre to the pushrod cup centre?

I can try.

[skinny z]

Is it possible to get a measurement from the trunnion centre to the pushrod cup centre?

I can try.

FWIW, it might prove an interesting comparison to the Crowers and others. Which brand, model and ratio have you measured?

[smokie]

Scorpion emailed me back. They said

"The Ford and Chevy are different

Chevy OAL 2.91, center of trunnion to center of roller 1.307

Ford OAL 2.96, center of trunnion to center of roller 1.371"

Mine measured 1.43". Sounds like something made it out in the wrong box.

Skinny z, I thought about doing that myself, buying one rocker at a time to make a list. I need to make a fixture, doing it how I have to do it now is a bitch.

[Tom68]

center of trunnion to center of roller 1.307

center of trunnion to center of roller 1.371"

Wow.

Three different SBC stud mounts here i get about 1.44", a 90's crane shaft mount real rough measurement about 1.45"

[smokie]

I'm just about ready to say f@#k it, shorten the pushrod 100", check it and as long as the sweep isn't over .075" and off the edge, run the shit out of it .

It's hard telling how much crap is out there like this that people never bothered to even check.

I seen a YouTube video of a guy that sets his rocker to 90° at full lift. I tried to tell him but was completely shot down. Everybody's an expert and nobody knows shit. I'm not talking about this board, just YouTube and Facebook warriors.

[smokie]

I'm just about ready to say f@#k it, shorten the pushrod 100", check it and as long as the sweep isn't over .075" and off the edge, run the shit out of it .

It's hard telling how much crap is out there like this that people never bothered to even check.

I seen a YouTube video of a guy that sets his rocker to 90° at full lift. I tried to tell him but was completely shot down. Everybody's an expert and nobody knows shit. I'm not talking about this board, just YouTube and Facebook warriors.

[skinny z]

I'm just about ready to say f@#k it, shorten the pushrod 100", check it and as long as the sweep isn't over .075" and off the edge, run the shit out of it .

Before I was somewhat more enlightened, that approach, or one similar where I focused on centre contact rather than mid lift or minimal sweep, it would wipe out a set of bronze guides in a few thousand miles. Two experiments and two failures.
This go around with new intake valves, guides and the requisite valve job, I'm well past 10k and clearances are still well within any service spec. This is using mid-lift, offset trunnions, a sweep that was somewhere between .030"-.040" and dead centre. So I'd think there's something to be said for that.
Now, if it was drag only car, that only realized a few hundred hours of run time, it would be a different story.
My two cents anyway.

[smokie]

Would having a .060"-.070" sweep pattern be that bad?

I know in the past before learning of pushrod geometry, I have screwed more than a couple sets of guides up. Honestly, it's hard telling just how bad they was. I just slapped parts together than blame the machine shop. Lmfao I owe more than one apology I guess on that on.

What brand rockers with offset reunions did you use? I know crower makes them and Harland Sharp, but I can't find a part number for Harland Sharps. They haven't emailed me back yet. Chris Stroub is out of stock unless I can use a .050" offset intake rocker. I have adjustable guide plates, but to me that's half assing.

[skinny z]

Would having a .060"-.070" sweep pattern be that bad?

I know in the past before learning of pushrod geometry, I have screwed more than a couple sets of guides up. Honestly, it's hard telling just how bad they was. I just slapped parts together than blame the machine shop. Lmfao I owe more than one apology I guess on that on.

What brand rockers with offset reunions did you use? I know crower makes them and Harland Sharp, but I can't find a part number for Harland Sharps. They haven't emailed me back yet. Chris Stroub is out of stock unless I can use a .050" offset intake rocker. I have adjustable guide plates, but to me that's half assing.

It's difficult to comment on whether .060" is going to kill guides.
It may work for some but not for others. One attempt of mine was certainly 60 thou but probably more. Guides didn't last. (I've got build notes I can reference). I was so intent on centering that the width escaped me. It wasn't until later that I started keeping notes on that.
I've got Crowers Enduro SS. It might be worth pointing out that an offset rocker arm isn't what's being referred to which discussing offset trunnions. Two different animals. It the .050" (or as much as .090" IIRC) offset in the trunnion stud hole that pulls the rocker tip back from the outboard edge of valve tip. This allows a longer pushrod when it's needed to correct geometry.
This would be along a line drawn from the pushrod centreline to valve stem centreline.

https://www.summitracing.com/parts/cro-73692-16

This comes up as the .090" backset but it's really .050".

[skinny z]

Crower Rockers.jpg

[smokie]

I know the difference between backset and offset (not being a dick). I was just saying all he has in a backset 1.5 7/16 also has a .050" offset on the intake rockers. That would still probably work with my set-up, just need to change to adjustable guidplates. I would definitely rather have the standard backset. I would take a split of 1.6-1.5.. those crowers are higher than giraffe ass.

[skinny z]

I know the difference between backset and offset (not being a dick). I was just saying all he has in a backset 1.5 7/16 also has a .050" offset on the intake rockers. That would still probably work with my set-up, just need to change to adjustable guidplates. I would definitely rather have the standard backset. I would take a split of 1.6-1.5.. those crowers are higher than giraffe ass.

I wasn't being a dick either. And I see now what you're talking about (makes sense with the adjustable guide plate reference too). That said, it seems to me that "angling" the rocker arm, without the need, might impose some geometry issues of its own.
As for the Crowers, yep, pricey. And I'm in need of rebuilding the ones I have and Crower is of little help.
Speaking about prices, how about a top quality hydraulic roller lifter like Johnson? $$$ Major bucks now. I think the price has doubled since I bought mine about ten years ago!

[smokie]

How many miles are on the crowers you have? What do you mean crower is of little help? Do they sell the new roller bearings and you rebuild them yourself, or send them in and crower rebuild them? Wonder what that costs.

I just don't understand why scorpion doesn't offer a setback rocker. Obviously there's a market for them. I would bet 95% of the people that build their own engines don't check geometry. Hell my machinist told me just to get the sweep In the center and it would be fine. This guy builds race engines for a living. He has a lot of fast cars out there with his builds in them. Drag, circle track, boat motors and street cars. People come from out of state to have him build their motors and he doesn't have a clue about geometry. It blew my mind when he told me that. I asked him about wearing the guides out and he said it wouldn't. I'm on team mid lift myself as that just makes sense.

Talking about lifters, China has flooded eBay with $125 for a full set of retrofit hydraulic roller lifters. While name brands are $450-$1200 bucks. I bet they sell the crap out of them too, then these idiots wonder why their motor runs like shit. The same people probably buying speedmaster parts like crazy too.

[smokie]

I just ordered a set from Chris Straub. I looked and I had .100" shorter pushrods in it than I thought, and the sweep was still that close and around .060" wide. So I definitely need the setback rockers. Just so happens, Harland Sharp are going to be making them some next week.