PRW Roller Rocker side clearance.

[adk-roadrunner]

I ended up buying a set of PRW 1.6 steel roller rockers. I went ahead and got the rockers setup and shimmed so they are centered over the valve tips. I also kept the side clearance that the instructions called for of between 0.0015 and 0.0020. I used a .0015 feeler gauge to check this but was surprised how thin that feeler gauge is doesn't seem like a lot of clearance to me. Everything was nice and free and seemed good. I cleaned everything up, assembly lubed, installed pushrods and adjusted everything for zero lash + an extra half turn per instructions. I found this to be around 25 thousandths with my dial indicator which is right in the ball park for lifter preload that comp called for. I also primed the engine and made sure oil was getting to all rockers and everything seemed good. The thing I noticed which concerned me was when a lifter was at max lift on the cam that rocker would have no space between it and the shims anymore. I asked PRW about this and they said that this is normal and as long as the play is there when the rocker is on base circle it should be good. What do you guy's think? has anyone experienced this where there is no side clearance when the rocker is under full lift? I understand there are people who aren't going to agree with the brand of rocker I purchased and that's fine. I'm not starting a thread to have a brand debate just to get some info that might be useful towards what parts I'm using. Thanks

 

[diesel_lv]

When the engine in running, the cam will be spinning fast and have plenty of oil to create the needed cushion between rockers, shims, clamps.

 

[440Coronet500]

I have no experience with those particular roller rockers. But if the clearance is there under a no load condition, loading it can cause the rocker to move and appear to have little to no clearance. As long as there's no binding it should be fine. That's why there's a clearance specification to begin with. If you're not comfortable with that go to the high side of the specifications and remeasure. 440'

 

[440Coronet500]

May I ask how you "Shimmed" the rockers to get the roller properly positioned on the valve stem, B3 kit? 440'

 

[adk-roadrunner]

May I ask how you "Shimmed" the rockers to get the roller properly positioned on the valve stem, B3 kit? 440'

The kit comes with shims in 3 different thicknesses that you use to position things. Its a pain because you have to keep taking the whole rocker shaft assembly apart to add or remove shims but seems to get the job done. When I say centered I mean the roller side to side over the valve tip.

 

[440Coronet500]

Thank you! I have to do this on a 440 HP build I'm doing. Did you fill out the sheet from B3 to get the proper shims? Could you post a photo of the shims please. 440'

 

[adk-roadrunner]

Thank you! I have to do this on a 440 HP build I'm doing. Did you fill out the sheet from B3 to get the proper shims? Could you post a photo of the shims please. 440'

I did not do anything with B3. The shims I'm speaking of came with the rockers and slide over the shaft to move things side to side. You are thinking about the kits that change how they ride on the valve tip front to back mine were fine.

 

[440Coronet500]

Okay, I understand. Great pattern on those stems. Looks like you're geometry is properly set! 440'

 

[1 Wild R/T]

Did the side clearance spec say .0015? Or .015.... Cause .015 is what I normally see.... If it's .0015 I think I'd be trying to contact the manufacturer/supplier... And when nobody answers your question I'd default to .015....

 

[beanhead]

Did the side clearance spec say .0015? Or .015.... Cause .015 is what I normally see.... If it's .0015 I think I'd be trying to contact the manufacturer/supplier... And when nobody answers your question I'd default to .015....

I was just thinking that, one-and-a-half thousandths would seize up before he got out of the driveway...hopefully the OP just typed an extra zero in there!

The thing I noticed which concerned me was when a lifter was at max lift on the cam that rocker would have no space between it and the shims anymore. I asked PRW about this and they said that this is normal and as long as the play is there when the rocker is on base circle it should be good.

.015" is good especially with steel rockers, and yeah when they're lifting they tighten up, that's normal.

 

[adk-roadrunner]

Did the side clearance spec say .0015? Or .015.... Cause .015 is what I normally see.... If it's .0015 I think I'd be trying to contact the manufacturer/supplier... And when nobody answers your question I'd default to .015....

Here's a picture of the instructions I'll call them again maybe it's a typo.

 

[beanhead]

Here's a picture of the instructions I'll call them again maybe it's a typo.

View attachment 1148943

Yeah....that's basically no clearance. Remember, things get bigger when they get warm (down RC, down boy!) so those will gall together in no time...If they tell you it's correct ask them to provide in writing that they'll pay for your engine to be fixed

 

[adk-roadrunner]

Yeah....that's basically no clearance. Things get bigger when they get warm (down RC, down boy!) If they tell you it's correct ask them to provide in writing that they'll pay for your engine to be fixed

I agree that's why I posted this because I'm using this paper thin feeler thinking there is no way this is enough clearance. I called once already and was told it was fine but I'm not sure if he understood what I was looking at on the instructions.

 

[adk-roadrunner]

honestly I probably will just go through the process again even if they say different but go .015. I would have to assume that more loose is better than too tight anyways. I called in and asked for tech help but who's to say if they have a clue what they talking about. so let me get this straight 15 thousandths should be .015? so what is .0015? Thanks

 

[beanhead]

I agree that's why I posted this because I'm using this paper thin feeler thinking there is no way this is enough clearance. I called once already and was told it was fine but I'm not sure if he understood what I was looking at on the instructions.

Gotta be a typ-o. The problem is the person on the other end of the phone likely has no clue what a Mopar rocker arm even is and is just reading the same paper you have...
Here's the thing...being extra-loose won't hurt anything. Being extra tight (per their instructions) will cause you to have a very bad day!

 

[beanhead]

honestly I probably will just go through the process again even if they say different but go .015. I would have to assume that more loose is better than too tight anyways. I called in and asked for tech help but who's to say if they have a clue what they talking about. so let me get this straight 15 thousandths should be .015? so what is .0015? Thanks

Yes! If it's too loose it will just be a little noisy.
And yes, .015 is fifteen-thousandths, .0015 is one and a half thousandths or 15 ten-thousandths....pretty frickin' small!

 

[adk-roadrunner]

Yes! If it's too loose it will just be a little noisy.
And yes, .015 is fifteen-thousandths, .0015 is one and a half thousandths or 15 ten-thousandths....pretty frickin' small!

That's crazy how many people out there are using that spec lol. I bought a new set of feeler gauges because mine didn't go that small lol and the whole time I'm setting it up I'm thinking that's not a lot of clearance.

 

[adk-roadrunner]

I just spoke to the tech at PRW he said it's definitely a typo and it should be 15 to 20 thousandths and the absolute bare minimum allowed would be 5 thousandths if needed. So I'll be doing that again glad I didn't run the engine like that. I told him he better let people know there's a typo on the instructions. He actually said he was surprised I had a feeler gauge small enough for .0015.

 

[440 Charger]

I ended up buying a set of PRW 1.6 steel roller rockers. I went ahead and got the rockers setup and shimmed so they are centered over the valve tips. I also kept the side clearance that the instructions called for of between 0.0015 and 0.0020. I used a .0015 feeler gauge to check this but was surprised how thin that feeler gauge is doesn't seem like a lot of clearance to me. Everything was nice and free and seemed good. I cleaned everything up, assembly lubed, installed pushrods and adjusted everything for zero lash + an extra half turn per instructions. I found this to be around 25 thousandths with my dial indicator which is right in the ball park for lifter preload that comp called for. I also primed the engine and made sure oil was getting to all rockers and everything seemed good. The thing I noticed which concerned me was when a lifter was at max lift on the cam that rocker would have no space between it and the shims anymore. I asked PRW about this and they said that this is normal and as long as the play is there when the rocker is on base circle it should be good. What do you guy's think? has anyone experienced this where there is no side clearance when the rocker is under full lift? I understand there are people who aren't going to agree with the brand of rocker I purchased and that's fine. I'm not starting a thread to have a brand debate just to get some info that might be useful towards what parts I'm using. Thanks

Some times overthinking is bad.

 

[Mark Barnes]

I just spoke to the tech at PRW he said it's definitely a typo and it should be 15 to 20 thousandths and the absolute bare minimum allowed would be 5 thousandths if needed. So I'll be doing that again glad I didn't run the engine like that. I told him he better let people know there's a typo on the instructions. He actually said he was surprised I had a feeler gauge small enough for .0015.

I know this thread is a couple months old, but I'm getting ready to fire up my motor with the same PRW 440 rockers. I know they actually require .015 side clearance, but where is that measured? Either side of the rocker, or .015 total between the mounting blocks, or ??? A little confusing to me.