BTR sells a shaft rocker kit for sale on their site. I could not find a description of what its for and the benefits. All I could find is a video of Brian explaining it was developed to reduce deflection in the rocker, something spintron, something something. I get the principle but....rocker shafts are usually found on 15 liter diesel engines and, have a 2000rpm redline, and don't use needle bearings........OK great! I am interested.

I wonder how well it works. Would it work on PRC heads? Anyway here is a ton of pictures and what I found out so far about it. I have yet to run this engine, will post more info when I do.

These install just like any other trunnion kit.

You get this box when you buy it.



You get this stuff with it and instructions. It comes well packaged, layers of styrofoam holders



The instructions are very clear and precise. They even mention to get away from engines if the instructions don't make sense.
Step 10 shows a BTR logo on the rocker stand in the wrong spot, that is a bit misleading because the logo on mine ended up facing the exhaust flange. The logo doesn't matter just pay attention to the grooves on the bottom of the stand and where they are supposed to go.






You can use a vise for this, use some tape to hold the sockets to the vise. I call it a horizontal press.
Use a socket big enough to let the stock bearing come out of the rocker on the flat side. I used a 24mm I think. A 14mm fits tight inside the rocker but its better to use a 13mm socket in case you don't line it up correctly.





This is what you want to end up with:




This is what you need to install back into the rockers. DO NOT REMOVE THE PLASTIC COVERS FOR NOW. The needle bearings can and will fall out one by one, they are packed in with grease and the plastic covers are the only thing holding them in. The plastic covers will pop out on their own when you slide them onto the shaft. The lettering on the bearing faces the outside of the individual rocker.





Like so:




Set up your press:
I used a 3/8" drive 24mm socket because I was too lazy to find something better. You want something flat and smooth to face the bearing. The 24mm end faces the vise and the 3/8" drive end faces the bearing. You want to center this when you press it in or you will damage the bearing or the rocker. I like using wood on the other end because it compresses before you are able to damage the rocker. You will end up making an imprint of the rocker on the wood, that is how it should be. If not then your bearings probably stick out of the rocker.








This is when I realized I could just use tape to hold up the wood and the socket.

The sad part is...that's a 75 ton press in the background behind the vise, I was too lazy to set up the height on it.



GM vs BTR rocker stands. The height looks deceivingly unequal, I did not measure it but its actually pretty close. My pushrod preload also barely changed, maybe 0.005" difference.
The BTR stands do not have the locating tabs like the GM stands. They do not affect height when on the cylinder head but on my work table they look like they do.
The grooves on the bottom of the BTR stands are for cylinder head clearance and nothing else.






This is how you set it up:
You do not have to oil the rocker shafts but you can use whatever little grease is stuck on the outside of the caps and smear it on the shaft. You can oil the rocker shaft later when it is installed on the cylinder head or whatever.
Do not forget to install the inner snap rings first, you might end up loosing some needle bearings if you did forget.





Push the rocker on the shaft and the cap will pop out. Before continuing to slide the rocker remove the first cap out of the way.



Snap ring pliers.... TA-DA!


Blah blah blah, blah blah something blah and you end up with this:
















So they fit the PRC heads just fine and may affect someone using a short travel lifter.
They are a pain to bolt down though, each pair of rockers has to be installed when the cam is on the base circle for that cylinder. So no more going ham with the impact to remove & install rockers.

I installed my CHE bushing kit on old shitty worn out rockers with horrible pushrod wear patterns, I am still revving to 7,500rpm with them. I actually picked out good condition rockers for this setup so hopefully it makes power after 7,000rpm.


SOHC subaru engines have rocker shafts and adjustable rockers, they almost never need adjustment but the redline is 6,250 with stock valve springs. This is mostly why this caught my attention.
Subaru also have the adjustment over the valve, and the roller tip is on the camshaft lobe, completely backwards right?

edit: you are also supposed to tighten down the bolts alternately on one shaft at a time so the shaft sits down straight. You should not be able to precisely measure preload using the rocker bolt method because of this, however this is debatable.

 

Theoretically they should deflect less than stock rockers. Not sure of the price difference but the Comp version comes assembled. And Hemi's come from the factory with shaft rockers.

 

Modern Chrysler hemi engines usually have a sub 6,400 rpm redline and peak close to 6k. Mercedes also likes to use rocker shafts, even on the AMG engines. They make peak power below 6k rpm, then again it was Daimler-Chrysler at one point.

Maybe I should have said rocker shafts are unusual on high rpm engines? I don't disagree that they are very stable design and common on "work horse" engines.

 

Nice write up. What do you consider high rpm?

 

On a typical modified LS? 7,400+ at high load, 7,600+ at low load
In general? Over 7,200rpm for a lot of production car engines is high in my opinion.

 

Interesting... I have the same heads running bronze trunnions with the limiter at 7000.
Do a follow up review after engine installation

 

I just want to add to this post since it was brought up costwise. This kit is $300 base price from btr. You can upgrade the rocker bolts to a couple different options (like arp bolts) which increases the price a decent amount. If on a budget you are getting shaft mount factory rockers for $300 without any upgrades. Comp cams shaft mounted rocker set I found in the range from $617-650. The upside to this is it’s all brand new including rockers and it’s completely assembled. I mentioned it comes down to budget what fits best for each person wallet/build.

 

I put the engine in the car and I got it running but I can't even test it.

LS7/LS9 exhaust manifolds do not clear 6 bolt heads apparently. They touch just enough to prevent the manifold from sealing at the gasket.






Bit of a pain to line up the push rod with johnson link bar lifters and PRC heads.




Pushrod bore clearance:





OG valve covers will not fit with the rocker shaft kit for obvious reasons. I believe those are 1998 LR4 van valve covers, they are stamped 97.

 

Bit of a thread revival, but I have PRC 215s and I plan on installing the BTR Shaft system. Thanks for the writeup!

 

It's a good thing you did. I forgot to report on this setup.

It's good for over 8,000rpm and at least 0.630" lift with 5/16 pushrods. I would go to a higher rpm but my ecu is limited to 8k

 

I’m using them on my BTR TFS 235 heads with Manton 3/8 Series 5 pushrods. Only have a little over hundred miles on it. So far so good.

 

Thanks for the info - I only plan to touch 7000...for now.

 

Don't be scared. I am doing that with stock bottoms ends. They are refreshed though. New bearings, new stock rod bolts, new stock piston rings. Chain guide, newer style LS chain, aftermarket oil pan, and oil pump is must though. Dry sump isn't necessary.

 

From the pics, it looks like you could easily run a 1/2” pushrod with those heads. The pushrod is the second softest spring in the valvetrain. You should consider at least a 3/8” rod for big rpm. Will improve performance and help cam/lifter lifespan. I like the rocker setup btw.

 

You are right about the pushrods, larger diameter would probably help make more power at a higher rpm.

The exhaust valve pushrod has plenty of clearance. It is the intake pushrod that I am not sure if a 3/8 will work. The intake valve pushrods are at the edge of the pushrod bore, I am not really sure how much I can or even need to cut into the intake port. I tried to get 11/32 7.625" pushrods but there weren't any in stock when I assembled this engine.
I was in a rush and uncertain about 3/8" at the time and now I regret it. This particular motor needs an overbore so now I have time.

I remember some hearsay about Texas Speed mentioning there is no need to run larger than 5/16" pushrods nor did they have that in mind when designing it. They may have been referring to a specific setup though.


As much as I complain about installing BTR shaft rockers because it actually has to be done on base circle while tightening, I like them as well.

Forgot to mention: This engine only made around 440ish whp based on logs but that's through stock ls7 exhaust manifolds, bad cylinder bores, and an awd trans

 

Gotcha. If you haven’t tore it down yet, order a set of 3/8” rods and do some mock-up work. Might need to do a little clearancing on the heads, but you could make it work easy enough, just cut slowly and little by little. Won’t take much. Or if it’s apart, do the mock-up work at assembly, but before final assembly.
I run 3/8” Manton rods, and recently purchased a couple different sets of 7/16” and 1/2” rods to do some experimenting with. Tony opens up the pushrod tunnels in these heads a lot, and I’m thinking I might can go bigger. I’m always tinkering with something….the shop is my man cave.

 

Hmm, my PRC 215s are currently off the car - might do some pushrod checking - maybe open up the bores a little?

 

Let me know how close the intake port is to the intake pushrod bore. I am considering a set of 215s for my turbo 5.3 since the 225s dont fit.

 

I won't be looking for a couple of months, but I will post what I find.

 

I just got done installing the 225 heads on my LS1. I had to clearance .060 off for the intake side pushrods to get 3/8 to fit. The 3/8 exhaust pushrods without any trouble.