[Formulajones]

Anything worth having is getting extremely expensive.

My son paid $1140 for a set of Johnson hydraulic rollers and not long after that purchase the price jumped to something like $1600 if I recall, I'll have to go back and look at my text from Paul.

Only difference was at that time they at least had them in stock LOL

[Tim Corcoran]

Harland Sharp rockers only $379.99, they are a good rocker I have used them for years without a problem.

https://www.summitracing.com/parts/C...5/applications

[grivera]

Originally Posted by nas t eh

Does not ship to Canada.

Oops- Totally missed that!

[vicgto]

Originally Posted by Cliff R

I've posted our experiences with those rockers many times. From the moment we put them in service (used several sets early on) they start to grind up the rollers where the pins go thru them.

On my own engine I had a few with as much as .018-.019" clearance by the time I figured out where all the metal on the magnetic drain plug was coming from.

Removed them from several other engines we had them in and same thing, found heavy wear at the pins.

I replaced mine with Crower Enduro rockers and no more issues.........

Cliff, I believe you had a similar set up to mine with the OF Hydraulic roller cam and Crower Solid roller lifters with lash at .006". I'm wondering if this combination is putting more load on the valvetrain due to insufficient clearance ramp, what are your thoughts?

I ended up going with 1.6 Crower Enduro rockers. I was planning on going with Harland Sharp but I did not want the additional lift from the HS 1.65 (which are closer to 1.7) as I currently only have about .060" retainer to guide clearance with the 1.65 PRW rocker. Also I I don't want to work the valve train any harder and I'm not sure that exta .020" -.025 valve lift would help my SD ported 295 KRE heads (Daves data sheet stops at .550" with 299 cfm and I'm not sure how much better they are above that).

I had an interesting conversation with Scott form Butler Performance who I ended up purchasing from. I don't know the accuracy of his statements but he said Crower, Harland Sharp, Scorpian and most other US made rockers are bigger than the advertised ratio (e.g. 1.65 is actually closer to 1.7). He said he was told by one of the manufactures this is done to overcome losses due to flexing of components during operation so you end up with advertised ratio, not sure how true it is but that's what he said. He also said the off shore stuff (e.g. PRW) are much closer to advertised ratio.

Anyway I hope I don't get anymore surprises with these rockers.

[turbo69bird]

He’s right they to trend in the bigger side. I guess they figure if it’s gonna be wrong be wrong in the direction people won’t complain about. ��

[Cliff R]

"Cliff, I believe you had a similar set up to mine with the OF Hydraulic roller cam and Crower Solid roller lifters with lash at .006". I'm wondering if this combination is putting more load on the valvetrain due to insufficient clearance ramp, what are your thoughts?"

I ran two sets of them with the "hybrid' deal and they both failed in the same fashion.

This was around 2009-2010. We got the rockers in a "package deal" from Dave at SD Performance. He did a couple of sets of CNC ported heads for engines I was building, one was my own 455. They looked like well made parts, pretty much a "copy" of the Crower Enduro rockers. I noticed a minor issue the first time I checked the valve lash but continued to use them. When I slipped the feeler gauge in to check clearance it would go tight and loose as it tried to roll the roller tip.

What I was seeing at the time was the pin getting a flat spot worn on it and possibly the inside of the roller going out-of-round.

The next thing I noticed was some metal "paste" on the magnetic drail plug at the first oil change.

It took a while but the valve train started getting noisy. So i made adjustments and it quieted right down. Then the noise would come back so I decided to pull all the rockers and found that all of them were worn in the same fashion and some had started to develope a LOT of slop between the pins and rollers, so I replaced them.

One has to consider that IF you have a hydraulic roller set-up the travel in the plungers is going to take up the slack between the rollers and pins and you will NOT get any noise, at least not right away.

I'll bet there are many hundreds of these rockers in service that have wear on the roller/pin end of them and the user doesn't even know about it.

I made PRW aware of it and they admitted they knew about it, but also said that they made changes to correct the issues. I had actually sent mine in for inspection, never got them back, never got a new set either, so moved on........FWIW.....

[djustice]

Originally Posted by vicgto

I had an interesting conversation with Scott form Butler Performance who I ended up purchasing from. I don't know the accuracy of his statements but he said Crower, Harland Sharp, Scorpian and most other US made rockers are bigger than the advertised ratio (e.g. 1.65 is actually closer to 1.7). He said he was told by one of the manufactures this is done to overcome losses due to flexing of components during operation so you end up with advertised ratio, not sure how true it is but that's what he said. He also said the off shore stuff (e.g. PRW) are much closer to advertised ratio.

Anyway I hope I don't get anymore surprises with these rockers.

Yes that is what i have heard too, David vizard and also Eric Weingartner has video's on this subject. Eric also demonstartes the overshoot on Ratio on one of his motors without spring pressure and with full spring pressure. and you can see what the actual ratio is. As for me i have been running Scorpion 1.5 ratio rockers for about 10 years now, first on a ramair 4 cam (edelbrock flat tappet) and now on a comp roller and no issues this far.

[PAUL K]

I disagree that rocker arms are intentionally made with a higher than advertised ratio to account for deflection or any other reason. It would screw a lot of conscientious builders if that were the case. As mentioned in an earlier post a set of 1.6 rockers were chosen because of minimal retainer to seal clearance. With the trend today of hi-lift cams being used in street cars you would have a lot of excessive guide wear, coil bind and smashed valve seals if rocker arms weren't correct ratio or usually a little less.

It's not as simple for the average fellow to check ratio as most would think. First the pushrod length needs to be optimized for each rocker arm because that will affect the net lift. Then one must decide whether to check with the valve spring in place or a test spring. A high RPM race engine will give up .030 or more lift checking this during the assembly if it's checked with a valve spring in place.

My guess is most of the "extra" ratio comes from second hand information that stems from the ratio not being checked properly by the originator of the rumor. I have checked many rocker arms for ratio and how far the rocker moves the pushrod towards or away from the rocker studs.... I do the later due to my dislike for grinding the head for pushrod clearance. I have found very few that have more ratio than advertised. I have found that some can be "tricked" to give more valve action by adjusting the pushrod length. But then one must decide between added valve open time or optimized geometry.

I have never seen a high end rocker shaft have anything but the advertised ratio. For many reason the shafts are dead nutz on, but if any rocker arm builder was going to add extra lift "for a reason" , the most logical being valvetrain deflection, one would think it would be the guys building rocker arms for a 9,000 rpm application using 1500 lbs. of spring pressure.

The only rocker arms I have found that consistantly check out higher than advertised is the Harland Sharp 1.65 and the Comp Cams 1.5 (which used to be advertised at 1.52) Pontiac rocker arms. I believe HS now makes four versions of the 1.65 and only one consistently measures close to 1.7. I asked Randy Sharpe directly about this and he had no idea as to why this is and wasn't aware of it. He said it definetly wasn't done for a specific reason, such as deflection. That might be why their newer 1.65 rockers measure closer to the advertised number.

FWIW


PS..... It'd be nice if a manufacturer would perfect an adjustable ratio rocker arm like Crane offered many years ago.

[grandam1979]

I have a set of used PRW rockers listed for sale cheap you could replace your bad one and have 15 spares Funny I had a set of HS rockers listed for $300 and couldn’t sell them.

[JC455]

After reading through this, I trashed the idea of PRW rockers, so I bit the bullet— I used the discount code on post #5 and placed my order, thinking it’d be a while before I saw anything… Nope!
Ordered Monday midday, arrived Thursday.

[Skip Fix]

My HS 1.65 consistently measure 1.70-1.72 regardless of the spring pressure.
Measured at the valve with roller springs or HFT springs!

[nas t eh]

I placed an order with Butler for Crower Enduro 1.5 ratio about two weeks ago, they said the had 3 sets on order that were due in about two weeks. Butler got them and shipped my set out to me yesterday. So Crower must be getting product on the shelves now.

[indymanjoe]

Originally Posted by JC455

After reading through this, I trashed the idea of PRW rockers, so I bit the bullet— I used the discount code on post #5 and placed my order, thinking it’d be a while before I saw anything… Nope!
Ordered Monday midday, arrived Thursday.

did they say they had them in stock? i just ordered mine no eta as of now.

[pontiacs-r-us]

I haven’t seen any comments on PRW’s aluminum body rockers… do they show the same issues in pin/roller area? Are they questionable also? I just purchased an engine that has the aluminum PRW’s on it. Was built by a reputable race engine builder( of all brands)… this is a milder hyd roller cam,but gives me concern after reading about these for so long…. TY …

[Formulajones]

The only aluminum body rockers I trust are Harland Sharp. Otherwise I prefer a steel rocker from Comp or Crower.

It's really up to you but I'd for sure keep an eye on them.

[nas t eh]

As Cliff has indicated watching them or checking on them in hydraulic cam installations, you don’t get any noise indicating an issue, just metal filings/paste on the oil drain plug. The other check is to remove a few and check how much play there is in the pin and roller tip.

[Steve C.]

1.6:1 Rocker-Arm Comparo

What’s in a Number? More Than You Think

"...deflection present in the body of the rocker arm and the pushrod, as both flex under the load of the valvespring, the stresses of harmonics transmitted throughout the valvetrain, and elevated engine temperatures."

https://www.motortrend.com/how-to/hr...r-arm-comparo/


I've seen flow bench testing on a set of SD Performance KRE D-port 300-305cfm CNC ported heads. Tested to 0.600" lift on the intake with the numbers increasing.
Most all the ported aftermarket alum cylinder heads flow well above 0.600" valve lift.


.

[Dragncar]

Originally Posted by Formulajones

The only aluminum body rockers I trust are Harland Sharp. Otherwise I prefer a steel rocker from Comp or Crower.

It's really up to you but I'd for sure keep an eye on them.

Ever hear of problems with Crower aluminum rockers ? I have a set of 1.7s on the self.
Thinking about picking up a set of those Comp chrome molly 1.65s you run to keep on the self.
320$ is a good deal, cheaper than Harland Sharp.
The only set of real 1.65s I have a Erson with I like a lot, they are forged, not extruded. But the are 3/8" stud, almost useless.
For most there is not much a a reason to buy the Crower Enduro 1.65s.
Doubt anyone would ever hurt the Comps.

[Formulajones]

I've never tried the Crower aluminum rockers but Crower makes really nice stuff and their steel enduros are my favorite. I likely wouldn't be afraid to try any of that stuff made by Crower. The Comp steel rockers I've never seen an issue on the street engines I've used them on. Been a while since I've used them till recently though when I couldn't get the Enduros.

The engine I'm doing now I bought a set of Ultra Pro Magnums because I was told Enduros wouldn't be available for months (this was 4-5 months ago) The Ultra Pros have the oversized trunions, extra retainer clearance, and made of 8650 chrome molly. I don't think I can hurt them with a hydraulic roller on this engine. In fact I could get away with less but I tend to like to overbuild a bit for added insurance.

[grivera]

Larry - a you post a link to the Ultra Pro Magnums? I can’t find them.