International Full Size Jeep Association

International Full Size Jeep Association (http://www.ifsja.org/forums/vb/index.php)
-   Street & Performance (http://www.ifsja.org/forums/vb/forumdisplay.php?f=97)
-   -   LS rockers (http://www.ifsja.org/forums/vb/showthread.php?t=187030)

babywag 04-05-2019 09:11 AM

Quote:

Originally Posted by jcisworthy
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 04-05-2019 10:14 AM

Not right now.

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

babywag 04-05-2019 04:58 PM

Quote:

Originally Posted by jcisworthy
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 04-06-2019 03:54 AM

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 04-06-2019 06:59 AM

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 04-06-2019 12:16 PM

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 04-06-2019 03:11 PM

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 04-06-2019 07:31 PM

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

babywag 04-06-2019 07:41 PM

Quote:

Originally Posted by wiley-moeracing
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/c...merican-motors

https://www.summitracing.com/parts/s...merican-motors

https://www.summitracing.com/parts/c...merican-motors

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

jcisworthy 04-07-2019 04:45 PM

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 04-07-2019 10:46 PM

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 04-08-2019 07:09 AM

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

Cecil14 04-08-2019 08:01 AM

Quote:

Originally Posted by 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?


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 04-08-2019 10:41 AM

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 04-08-2019 11:48 AM

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 ;).

babywag 04-08-2019 06:01 PM

Quote:

Originally Posted by 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 ;).


Didn't you find/use 1.7 stamped rockers on a few engines? Thinking they are no longer available IIRC as well.

Ristow 04-08-2019 07:52 PM

yeah,from jim miller. they were his now gone "econo series" and they were some nice rockers. go look in my 401 thread for pics. they had a big fulcrum,and you would set them at mid lift on the cam,and the top of the rocker would be 90 degrees from the stud when the installed height and pushrod length were correct.


he told me 90 bucks as i recall,came with poly locks. i shoulda bought every set he had,he was cleaning his shop out for a move. met my truck down in florida and handed them to my driver.


edit...it was 60 bucks. http://www.ifsja.org/forums/vb/showp...4&postcount=79




worked real nice with the performer grind cam.


http://www.mid-lift.com/PVS-PF.htm

babywag 04-08-2019 08:03 PM

I have a 360 in the garage I can use to mock up a set.
We shall see what things look like.
It is my opinion that it has many pros...and few if any cons.

jcisworthy 04-09-2019 01:52 AM

You can get the rockers with trunion upgrade without stands on ebay for about 150 delivered I believe.

I recommend the trunion upgrade and stands are available from GM relatively cheap. It has been a while but I think they are 15-20 dollars each

Stands are on ebay cheap also

pickledtoast 04-09-2019 11:23 AM

I am planning on running LS1 rockers after my cam is broken in. I made new stands as the factory LS stand places the shafts too high. Milling the stand surface on the head is an option, but the $15 worth of bar stock and my free time was better. Plus I can run the factory 1.6 ratios for break in.

Difference between the LS1 and AMC pushrod cup is ~.040. LS is lower. I will know if there is an extra .040 worth of compression in the hydraulic lifter after I get this damn engine together.

I can't seem to upload photos here. Too new?

https://scontent-lga3-1.xx.fbcdn.net...&oe=5D361A 7C

https://scontent-lga3-1.xx.fbcdn.net...&oe=5D023A 47


All times are GMT -6. The time now is 05:53 PM.

Powered by vBulletin Version 3.5.4
Copyright ©2000 - 2019, Jelsoft Enterprises Ltd.