As you all may know, we are new to Mopar. We are planning our engine build. We are planning to stroke the 383. We have not made a final decision to go 432 or 489. We are going to run the 906 heads with the 2.14 valves. I picked up a very nice set that a guy was using on a drag car when he upgraded to a set of trick flows. I am trying to build a good engine with a performance upgrade, but want to control cost. To be honest, I am a bit shocked at the price of the Mopar stuff compared to the Chevy small block stuff. I have a guy that has a crane roller rocker assembly with the shafts and everything for $200. They are 1.5 ratio and adjustable.
What is the purpose of the adjustable rockers when using a hydraulic lifter? I am not used to the concept of the rockers on a common shaft. The Chevy has each rocker on its own stud. The nut adjusts the lash. Don't get me wrong, I am not an expert on Chevy by any means either, but I have done it a couple times.
I have a quote from an engine builder that I saw at the Indy swap. He was quoting me a stoker kit along with the cam and the rocker assembly. The rocker price was close to $900. The $200 used but nice option seems like a better choice for me. Also, the ratio is different, 1.5 vs 1.6.
My questions are,
1. What is the purpose of the adjustable rockers vs the stamped ones that came from the factory?
2. Can I get away with using a set of stamped factory rockers?
3. I assume that 1.5 vs 1.6 can be dealt with by the amount of lift in the selected cam?
Thanks
:thinking: Are you talking roller of non roller?
The rockers that I have the chance to buy are adjustable roller rockers I believe.
It depends on what camshaft you may want to run. The stock rockers will work adequately on a hydraulic, flat tappet camshaft with a lift in the .500 range. After that you will need a set of adjustable rockers. Crane makes good stuff, I would be tempted to pick those rockers up if they are in good condition.
1. Adjustable is just that. You have the opportunity to fine tune lifter preload for each lifter. This assumes a hydraulic cam. With solid lifters you need the rockers to be adjustable.
2. Depends on what cam and valve springs you run. High lift cams and high spring pressures may not be compatible with stock rockers and shafts. Cam profile and spring pressure will determine this.
3. Pretty much. I would not stress over this on a street motor.
Bottom line your engine combination (cam profile, spring pressures, intended use) should dictate what you need. Personally I would buy the Crane stuff you are looking at if you want to upgrade. Others will give you some alternatives.
Quote from: RUNCHARGER on April 13, 2020, 10:38:04 AM
It depends on what camshaft you may want to run. The stock rockers will work adequately on a hydraulic, flat tappet camshaft with a lift in the .500 range. After that you will need a set of adjustable rockers. Crane makes good stuff, I would be tempted to pick those rockers up if they are in good condition.
I agree with Runcharger. For the price I would go with the crane rockers. Make sure you check the rocker roller tips for excessive wearing and or missing or lose bearings. PRW also makes reasonably priced roller rockers. As Runcharger stated a lot depends on which cam you're going to run. Lunati has an excellent selection of cams for all purposes. Keep in mind, that depending on which cam you use you may have to buy custom built push rods. I ran a high performance Lunati street cam in my 440/512 stroker with PRW rockers and needed custom built push rods. I later changed to a Bullet custom ground cam with roller lifters and needed custom push rods again even though I'm still running the PRW rockers. Good luck and keep us posted on your decision. :wrenching:
Roller rockers alone will increase horse power by freeing up friction! I would buy them. :yes:
:iagree:
For $200 if they are in good shape I would use them .
I do prefer the Iron rockers if you can find a set tho .
The Chev rockers do allow individual adjustment But they limit travel if the slot is not long enough.
the shaft style do not limit travel & are far more stable overall & provide better oiling .
Lunati does offer some great grinds for Mopar so you can get a lot of lift / duration due to the wider Mopar lifter without the need for 1.6 rockers
I was also going to mention that the ratio on a roller rocker is generally far more accurate than a stamped rocker & you can control the lifter preloadfar more accurately .
My opportunity in the Crane roller rocker assemblies did not work out. They were sold before I could get them. Has anyone had any experience with these? They seem like a good value, especially given that they include the pushrods.
https://www.manciniracing.com/mre5700192841.html
I would look for a set of PRW rockers , Stainless are better for long term street use or find a set of the Iron rockers , alum are more of a race part
https://www.ebay.com/itm/Set-of-16-Crane-Mopar-Big-Block-383-440-Ductile-Iron-Adjustable-Rocker-Arms-1-5/264590326982?hash=item3d9acffcc6:g:VX4AAOSwAUpeE2RY
These are indestructable & will out live us
Prw , I have used htese in a lot of the engines I have built , never had a problem with them . Both the Crane Iron & the PRW Will fit under stock covers too .
https://www.ebay.com/itm/PRW-3244011-Stainless-Steel-1-5-Ratio-Rocker-Arm-System-Big-Block-Mopar-361-440/133383005305?epid=19017020146&hash=item1f0e3f2479:g:mR8AAOSwsidejyVJ
I generally source used ISKY or Crane iron rockers and use new adjusters on them. They'll never break and usually they sell in the $200 range.
Does anyone know where the PRW rockers are made?
I like the PRW rockers, the quality is good, and price is right. The one thing to watch for, at least on small blocks with larger than stock diameter springs and retainers, there can be a clearance issue depending on parts variation. It only take a little clean up on the mill or with a grinder, but for some folks, that is a deal killer.
Quote from: Chryco Psycho on April 16, 2020, 08:26:51 AM
Prw , I have used htese in a lot of the engines I have built , never had a problem with them . Both the Crane Iron & the PRW Will fit under stock covers too .
https://www.ebay.com/itm/PRW-3244011-Stainless-Steel-1-5-Ratio-Rocker-Arm-System-Big-Block-Mopar-361-440/133383005305?epid=19017020146&hash=item1f0e3f2479:g:mR8AAOSwsidejyVJ
I agree with Chryco. These are what I run in my 440/512 stroker that is pushing 500 HP+ and I've had no issues with them. Great quality for the price. :twothumbsup:
My bet is PRW is made in China but engineered in the USA , I have not seen 1 failure in all of the engines I have built & these are not babied engines , some over 700 hp !!
I have used at least 12 sets . Comp makes similar rockers but they are a Lot more $$
If you can find the Iron Cranes for a good price grab them
Use lash caps with all of these
Quote from: Chryco Psycho on April 16, 2020, 01:31:35 PM
Use lash caps with all of these
Why do you recommend the lash caps?
3 reasons
- the rocker especially non roller wipe across the tip of the valve , why wear the valve tip
- it seriously increases the surface area & if the rocker is not aligned perfectly it allows more surface area to 1 side
- it can help the rocker geometry running the tip a bit higher