LS rockers

[babywag]

I adapt LS mini shaft rockers to AMC bridge heads. They have a 1.7 rocker ratio

Any more info on this? Be interested in seeing this.

[jcisworthy]

Not right now.

Takes some modification to the LS shaft stand, additional clearance on the pushrod slots and pushrods but nothing major.

[babywag]

Not right now.

Takes some modification to the LS shaft stand, additional clearance on the pushrod slots and pushrods but nothing major.

Found your thread on AMC forum...looks like stockers are an option as well.
Who knew!

[jcisworthy]

I have a 401 engine in Australia with factory LS rockers, stands, and Comp Cams trunion upgrade.

That setup is not adjustable, similar to the factory bridge rockers. That engine made 531 hp and it in a left hand drive, very nice, 68 or 69 Javelin.

[babywag]

I moved these to a new thread. Pretty cool that you found this.

On a stock 360 the LS rockers would give ~.0266 additional lift.
A poor man's cam swap kinda.
Local yard charges 2.30/ea for rocker arms so ~$40 set.
But I have seen stock sets for sale too for cheap on CL.
Some new pushrods obviously needed as well.

Would a stock or mild cam like "RV" cam need the pushrod holes slotted?

[jcisworthy]

I do not remember having to slot the pushrod holes with the stock LS rocker setup but it was about five years ago when I built that engine

Trunion upgrade is not needed to about .600 lift with the factory LS rocker as well.

Swap out the 8mm bolts with 5/16 cap screws, cut the LS stand in four sections and mount one pair per intake/exhaust. I think the factory LS may even work with a stock length pushrod. Geometry was pretty close as a bolt on if I remember correctly. I do not remember having to shim the rocker stands but again, I can be wrong, it all has to be checked as well as preload on the lifers.

The mini shafts I use now are / seem like, a T&D copy and they require additional clearance and pushrod length. They have a different installed height than the factory setup and they are adjustable.

[babywag]

I may give this a try be cool to get the little extra lift w/o swapping the cam!
Pretty cool you discovered this! I applaud your outside the box thinking.

Do you recall if they cleared stock valve covers?

[wiley-moeracing]

or purchase a set of roller rockers designed for the motor?

[babywag]

or purchase a set of roller rockers designed for the motor?

Uh they are rollers and cheap.
A set of AMC 1.7 rollers not so much and a HUGE waste of money on a stock engine.

https://www.summitracing.com/parts/crn-36757-16/make/american-motors

https://www.summitracing.com/parts/scc-scp3102/make/american-motors

https://www.summitracing.com/parts/csp-s4004-77/make/american-motors

All $400+ stock LS rockers can be bought dirt cheap.

[jcisworthy]

They clear stock valve covers.

Make sure you have enough distance to coil bind before doing anything. If the extra lift ends up in coil bind you will have issues.

Should have enough but it needs to be checked.

Factory LS rockers are very strong. They are also lighter over the valve compared to aftermarket rockers.

[wiley-moeracing]

You are talking about trying to get tiny amounts of horsepower in your stock motors. It all seems to be a bit of a waste of time and funds. you will have to replace pushrods, may have to have machine work done and may have to replace valve springs? Again for what, to say I have roller rockers on my stock motor?

[babywag]

For same reasons folks install EFI, headers, etc. I like to modify things.
It is more about the added lift than having rollers.

[Cecil14]

You are talking about trying to get tiny amounts of horsepower in your stock motors. It all seems to be a bit of a waste of time and funds. you will have to replace pushrods, may have to have machine work done and may have to replace valve springs? Again for what, to say I have roller rockers on my stock motor?

There isn't exactly anything practical about having one of these vehicles in the first place. What does it matter if someone sticks to the "most practical" build on a motor? It's pretty laughable that this is a question in the first place. We're all here because we're crazy, no two ways about it.


aa

[rang-a-stang]

I see a huge benefit to this idea!

If I am in the market to rebuild a mid 70's to early 90's 360 (or even just do the heads) with bridged rockers, then this would be right up my alley because its a cheap/reliable "upgrade".

When I pulled my 401 apart the studs, fulcrums, and rockers all had wear on them and needed to be replaced. So instead of paying $180 for a set of replacement rockers and another $30 for the studs, this option would give a rebuilder a cheaper route AND the benefit of a more stable valve train. The extra lift is nice but shaft mounted rockers is awesome. If someone were to do a warmed up engine rebuild and this idea works, why would you NOT do this?

[Ristow]

as a fellow gearhead....sitting around talking about the time you bought new rockers for your engine and bolted them in is boring.


id rather sit around and talk about stuff like this. oddly enough,the why of it all rarely comes up .