PRW/PQ rocker failure

[yellow rose]

Dave Hughes can kiss my furry ***. I'll find other products. Haven't used anything from him, and the cam and lifters I bought in the early 90s is still in it's box.

Could of maybe left the furry assed part out. More than I needed to know. My wife thought it was funny though.

 

[AJ/FormS]

Yeah, that's true; but wasn't Dave the guy who promoted them a little better in the non- racer-world? and with higher lifts and split patterns.

 

[mopar head]

There is so much bad information in that one page, that it's no wonder Mopar valvetrains are so problematic. Centered sweep....wrong, adjust pushrod for max lift....wrong, etc., etc. There is a real misunderstanding of what rocker geometry is, and this kind of information perpetuates that misunderstanding.

Great, I have 2 engines set up wrong by following directions to the T.

 

[yellow rose]

Yeah, that's true; but wasn't Dave the guy who promoted them a little better in the non- racer-world? and with higher lifts and split patterns.

Yep. Marketing. If you read the B3 tech pages (and Mike can correct me if I'm wrong) guys spend money for the .904 lobe and then set the geometry up incorrectly and give up everything they gained with the .904 lobe.

 

[fishmens67]

Geometry and cockeyed roller on the stem. hum. I wonder why the fracture is starting on the top of the arm.

 

[B3RE]

Yep. Marketing. If you read the B3 tech pages (and Mike can correct me if I'm wrong) guys spend money for the .904 lobe and then set the geometry up incorrectly and give up everything they gained with the .904 lobe.

That is correct.

 

[B3RE]

Dave Hughes can kiss my furry ***. I'll find other products. Haven't used anything from him, and the cam and lifters I bought in the early 90s is still in it's box.

I try very hard not to bash other engine builders, unless they willingly do something egregious that harms people. When it is something done by parroting bad information, or just simple ignorance, I give them the benefit of the doubt that they are truly trying to be helpful. I will call out that bad information though, to keep guys and gals from damaging their engine, and or, spending unnecessary money.

Dave has brought a lot to the Mopar market, and I am thankful for that. But, when it comes to tech, I want people to think for themselves, not believe something simply because it is written somewhere. That includes my tech info. If it doesn't make sense, questions should be asked. And, if the answers don't make sense (You're an idiot isn't an answer) , it's time to raise the bovine excrement flag.

When it comes to rocker geometry, by design a pushrod V8 uses a rocker arm ,ie fulcrum to deliver the critical information ground into the cam lobe to the valve. It is not 100% efficient by nature of the sweeping motion of the fulcrum. Compare that to a valve that is opened directly from the cam lobe, and you will see the inefficiencies that are present with a rocker arm, as well as the drastic visual differences between the cam lobes of those two examples.

If you want to get the most efficient transfer of the cam lobe to the valve in a pushrod engine, then you have to reduce the amount of rocker/fulcrum sweep to the minimum amount possible. How does centering the roller on the valve tip accomplish this? It doesn't. How does setting for maximum lift at the top of the cam lobe accomplish this? Again, it doesnt.

All this bad information has been around for as long as I can remember, so it's no wonder so many people are ill educated on this subject. It's too bad, that after all this time, that info hasn't been changed to reflect technology and understanding. People used to think that the earth was flat, and maybe some still do, but it makes sense that it isn't, because we have learned to recognize the facts that prove it isnt. And, technology helped us discover those facts.

 

[B3RE]

Great, I have 2 engines set up wrong by following directions to the T.

Don't feel bad. You're not alone. Feel free to contact me if you want to make sure it is right. It usually only needs longer pushrods in conjunction with a correction kit. All bolt on stuff with only the valve covers removed.

 

[mopar head]

Don't feel bad. You're not alone. Feel free to contact me if you want to make sure it is right. It usually only needs longer pushrods in conjunction with a correction kit. All bolt on stuff with only the valve covers removed.

Thanks, but how do you determine the new pushrod length if hydraulic? if lifters bled down?
Seems one would have to yank the intake and use a mockup lifter again.

 

[IQ52]

Hydraulic lifters don't collapse or shrink when the oil pressure is off. They have an internal spring that holds them up against the retainer clip. It just takes a delicate hand to feel the pushrod pressure against the lifter. I've never had to use a mockup lifter when determining hydraulic lifter pushrod length or setting the preload.

 

[Jadaharabi]

Feel free to contact me if you want to make sure it is right. It usually only needs longer pushrods in conjunction with a correction kit.

Where do you get the "correction kit" from?
Is that what is on the head on the right side of your home page? If so how or where do you have it listed for veiwing?

 

[B3RE]

Hydraulic lifters don't collapse or shrink when the oil pressure is off. They have an internal spring that holds them up against the retainer clip. It just takes a delicate hand to feel the pushrod pressure against the lifter. I've never had to use a mockup lifter when determining hydraulic lifter pushrod length or setting the preload.

Same here Jim. I go to zero and then count the turns for the preload I want, unless of course I'm getting cozy with the bottom of the plunger travel.

 

[mopar head]

Hydraulic lifters don't collapse or shrink when the oil pressure is off. They have an internal spring that holds them up against the retainer clip. It just takes a delicate hand to feel the pushrod pressure against the lifter. I've never had to use a mockup lifter when determining hydraulic lifter pushrod length or setting the preload.

Same here Jim. I go to zero and then count the turns for the preload I want, unless of course I'm getting cozy with the bottom of the plunger travel.

Well I`m sure you guys pre pump up new lifters in a container of oil right? Seems you would have to.

 

[B3RE]

Where do you get the "correction kit" from?
Is that what is on the head on the right side of your home page? If so how or where do you have it listed for veiwing?

Yes, that it part of the kit. There are multiple images of the kit installed, both in the tech articles, and on the Facebook plug in located on the home page. The reason they don't show for sale on the site is a long story, but it involves a lot of wasted time with computer geeks. It will get there eventually.

 

[B3RE]

Well I`m sure you guys pre pump up new lifters in a container of oil right? Seems you would have to.

Nope, they will do that at start up. And, to a degree, when priming the oiling system before start up.

 

[IQ52]

Well I`m sure you guys pre pump up new lifters in a container of oil right? Seems you would have to.

I haven't pre pumped lifters before I installed them for over 40 years. And for 50 years I've primed the engine before I started it for the first time.

 

[mopar head]

Nope, they will do that at start up. And, to a degree, when priming the oiling system before start up.

OK, Now I`m really lost and confused. You must have a way to determine pushrod length totally 180 from hughs instructions. If so I wish you guys would explain.
Thanks

 

[B3RE]

OK, Now I`m really lost and confused. You must have a way to determine pushrod length totally 180 from hughs instructions. If so I wish you guys would explain.
Thanks

I'm sure it's different, and depending on the rocker arm used, it's possible that it would be impossible to get the correct length pushrod in the motor, at least from a geometry perspective. Hughes says to adjust for maximum lift by altering the pushrod length, which is incorrect. All that is happening is the rocker ratio is being manipulated by running the adjuster in or out. That has nothing to do with proper pushrod length or geometry. Jim, can I retire and go hunting with you, Please!!!?

 

[IQ52]

I'm sure it's different, and depending on the rocker arm used, it's possible that it would be impossible to get the correct length pushrod in the motor, at least from a geometry perspective. Hughes says to adjust for maximum lift by altering the pushrod length, which is incorrect. All that is happening is the rocker ratio is being manipulated by running the adjuster in or out. That has nothing to do with proper pushrod length or geometry. Jim, can I retire and go hunting with you, Please!!!?

I'd have no problem with that.

I'm sitting here thinking if I want to explain how I check the pushrod length after I get the geometry correct on a shaft system. That, among other things like.........Do I want to tell about all I go through to get the valve tips equal length from the centerline of the camshaft? How I've practiced feeling the drag of the pushrod as I rotate it between the new lifter and the adjusting screw of the rocker? How I determine the proper length of the adjusting screw out of the lifter body for each style of rocker before getting the pushrod measurement.

I don't wanna write a book.

Retirement seems a lot easier......come on along.

 

[mopar head]

Thanks fellas, It seems all proprietary. Have a nice hunting trip...

 

[B3RE]

I'd have no problem with that.

I'm sitting here thinking if I want to explain how I check the pushrod length after I get the geometry correct on a shaft system. That, among other things like.........Do I want to tell about all I go through to get the valve tips equal length from the centerline of the camshaft? How I've practiced feeling the drag of the pushrod as I rotate it between the new lifter and the adjusting screw of the rocker? How I determine the proper length of the adjusting screw out of the lifter body for each style of rocker before getting the pushrod measurement.

I don't wanna write a book.

Retirement seems a lot easier......come on along.

Well, if it gets to the point where I have to decide between working and being broke, or retiring and being broke, I would certainly have to consider it. I have a friend in Nampa that I wouldn't mind visiting if I got out that way. He's a Mopar stepchild. Likes playing with AMC stuff.

 

[Killer6]

I can only read the one page that shows the .040 number so I can't comment on what the rest of it says but I will say Hughes is full of ****. I'm not the sharpest tool in the shed but I can do simple math, and I'll post it here so anyone who comes along can see what's wrong.

Hughes says the sweep pattern needs to show .040 on each edge of the valve not being rolled on by the roller. Sooooooooo, if you have a 3/8th stem valve this is the math.

.372-.040-040= .292!!!

That is a sweep of .292 thousandths. That's crazy. Beyond crazy.

If you happen to run an 11/32 valve (.342) here is the math.

.342-.040-.040= .262 sweep without correcting geometry. That's insane. You still have the same sweep, but it can't be, because you didn't make the sweep change! Just by going to a smaller valve, you have the exact same sweep, but you can't get .040 from the edges. It's impossible. The sweep is the same but the valve is smaller. In reality in this scenario, you still have the exact same sweep, but instead of having .040 from each edge, you will have only .025 per side. Am I the only one who sees how crazy this is?

Again, what if you have 5/16 stems (I use a lot of them...and the magnum junk comes with 8mm [~.317-318 diameter] so it's not uncommon)? The numbers are even more bizarre.

.311-.040-.040=.231 and yet nothing was changed! That's crazy. Again, in reality the sweep is still .292 you just have even less valve at the edge. You would be .008 from each edge with 5/16 valves.

This isn't to embarrass anyone, or make fun of what is published but that method is as ignorant as it is wrong. You need to know how wide the SWEEP is, not how much valve there is not covered by the sweep pattern. Sooooooo.....

I have a sweep of .045 on a .372 valve. Simple math says I have .163 from the edge on each side, if the sweep is centered.

I'm going to say Hughes is wrong and they should update their tech or stop publishing it. They are responsible for making people ignorant.

Hope that's not too harsh. But fact is fact. You have geometry issues. A sweep that wide is death on parts.

I didn't quite interpret that the same, My impression was that no matter which side of the stem the sweep is on, it should never get closer than .040" from the edge of the
stem. I don't think it indicated a full sweep from .040-.040" was OK. I watched a Hughes vid on Their rockers & pattern, with the pattern centered on the stem on the seat
and at full lift, with the sweep moving out away & back from the rocker through the lift cycle.

 

[B3RE]

Thanks fellas, It seems all proprietary. Have a nice hunting trip...

Please don't take it the wrong way. I was only alluding to Jim's, and my frustrations with the bad information out there. While I love to hunt, I haven't had the time to do it for years, so it was more of an envious joke about retiring and going hunting with him to get away from all the stuff that makes me want to pull my hair out.

In some instances, I have rockers custom made to my spec because the off the shelf rockers are not designed properly. That is why I said it is possible for it to be impossible to have the right length pushrod, because the rocker design has the adjuster too low where the pushrod should be. Nothing proprietary there. I give instructions on pushrod length, after getting the geometry corrected, based on the rocker used.

 

[B3RE]

I didn't quite interpret that the same, My impression was that no matter which side of the stem the sweep is on, it should never get closer than .040" from the edge of the
stem. I don't think it indicated a full sweep from .040-.040" was OK. I watched a Hughes vid on Their rockers & pattern, with the pattern centered on the stem on the seat
and at full lift, with the sweep moving out away from the rocker through the lift cycle.

They have a disclaimer on the printed tech article about that sweep pattern. There is a checking spring on the head, and they admit that the lift used for the example is not possible with a real spring installed because there isn't enough installed height. That would mean a lower net lift, and a wider pattern than there should be for that amount of lift. I'll have to look for the pages I printed of that article, because I noticed the sleight of hand immediately. The math never lies.

 

[yellow rose]

Thanks, but how do you determine the new pushrod length if hydraulic? if lifters bled down?
Seems one would have to yank the intake and use a mockup lifter again.

You need to change your thinking that pushrod length affects geometry other than B3 has said, as PR length affects rocker ratio.
You correct your geometry and then measure for PR length.