PRW/PQ rocker failure

[moper]

Yup... Dead last parts I ever order are the pushrods.
I will give benefit of the doubt to pretty much anybody. Right up until they attack me. Dave did just that, after I called about the cam I bought. I'll never use his product. None of it is or ever has been cutting edge, and most everything he likes to take credit for started somewhere else with smarter people than him. People who read him and treat him like some Mopar deity are sadly falling for the loudest voice on the carnival's midway.

 

[RustyRatRod]

I farted.

 

[yellow rose]

I farted.

I wondered who did it. I blamed my wife and it was you. Now I have to sleep on the couch.

 

[Killer6]

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.

I think He means after You fix the geometry, in which case You would check it the same as any other case. I think he is asking how to tell when the adjuster end is in the
"ideal" position which will determine ideal pushrod length for the amount of lifter preload You want.

 

[Killer6]

I farted.

Is that what that cloud outside is from...............

 

[yellow rose]

I think He means after You fix the geometry, in which case You would check it the same as any other case. I think he is asking how to tell when the adjuster end is in the
"ideal" position which will determine ideal pushrod length for the amount of lifter preload You want.

Ok, I get it now. If that's what he's asking...if the rocker has Chrysler oil timing, like a 273 rocker, or some of the crane gold rockers and all of the DC/MP rockers I've seen, and it's a ball adjuster then it's 9/32 inch down.

If it's a cup adjuster it's bottom (actually top) the adjuster in the rocker and then the adjuster 1-2 turns down.

 

[IQ52]

I think He means after You fix the geometry, in which case You would check it the same as any other case. I think he is asking how to tell when the adjuster end is in the
"ideal" position which will determine ideal pushrod length for the amount of lifter preload You want.

The style and the construction accuracy of the rocker arm, adjuster ball or cup oiling requirements, is the rocker shaft parallel with the camshaft, block decking and head milling, each valve tip distance from cam centerline, all effect pushrod length. The old saw............2 threads showing............is just to hope that when you get your pushrods, there is enough adjustment in the rocker to make up for tolerance stack in the engine assembly.

 

[IQ52]

I farted.

Again Rob? Again?

 

[75Sport]

I farted.

Rob lay off the jalapeno nachos!

 

[B3RE]

I think He means after You fix the geometry, in which case You would check it the same as any other case. I think he is asking how to tell when the adjuster end is in the
"ideal" position which will determine ideal pushrod length for the amount of lifter preload You want.

This is what I was getting at. Sometimes it's not possible to get the adjuster in the ideal position, especially with a ball style adjuster. The pushrod should have a minimal amount of sweep as well to maximize efficiency. That is when the adjuster is in the correct position and angle, and the pushrod is sized accordingly. Sometimes, due to improper rocker design, that just isn't possible, and it happens a lot.

 

[Jadaharabi]

This is what I was getting at. Sometimes it's not possible to get the adjuster in the ideal position, especially with a ball style adjuster. The pushrod should have a minimal amount of sweep as well to maximize efficiency. That is when the adjuster is in the correct position and angle, and the pushrod is sized accordingly. Sometimes, due to improper rocker design, that just isn't possible, and it happens a lot.

Is it possable to use the cup type adjuster in the 273 rocker?

 

[yellow rose]

Is it possable to use the cup type adjuster in the 273 rocker?

I'm not sure, but how would you get oil to the adjuster?

 

[Jadaharabi]

I'm not sure, but how would you get oil to the adjuster?

Good question.
If you turn the rocker arm upside down you notice that the body of the rocker is opened up where the oil comes in to run down the adjusting screw.
With the cup type the oil would probably be flung off and then roast the end of the pushrod. Any ideas how to keep the end lubed?

 

[yellow rose]

Good question.
If you turn the rocker arm upside down you notice that the body of the rocker is opened up where the oil comes in to run down the adjusting screw.
With the cup type the oil would probably be flung off and then roast the end of the pushrod. Any ideas how to keep the end lubed?

B3 will have better answers than I have. I'm sure he's looked into it.

 

[MopaR&D]

This seems like a great subject for an engineering design study... "Rocker Arm Geometry in Internal Combustion Engines with Pushrod Valve Actuation"

Makes me wonder if Dave Hughes even employs any engineers at his company... he probably wouldn't like being told he's wrong so much LOL. But that's the nature of these things, they're either correct or they aren't, and having personal/emotional interest involved gets in the way of real progress and truth in design.

Hughes Magnum valve springs and retainers are pretty nifty though, gotta admit... nobody else sells parts like that (do they???)

 

[Jadaharabi]

I used to sell Hughes engine cores blocks cranks heads but after the last hosing I got from him I will never do that again.

 

[Killer6]

I'm not sure, but how would you get oil to the adjuster?

Easy, AMC lifters and hollow pushrods, same as Magnum conversions..............

 

[Jadaharabi]

Easy, AMC lifters and hollow pushrods, same as Magnum conversions..............

Would it be possible to oil through the pushrods to lube the tips and also through the block to lube the Rockers at the same time.

 

[yellow rose]

Easy, AMC lifters and hollow pushrods, same as Magnum conversions..............

That's the easy part of you want to run PR oiling. The other issue as B3 has pointed out is not just the geometric relationship between the shaft/roller/valve is the relationship of the pushrod to,the adjuster. It's way over my head and for most of us not easily changed.

I'm not sure the 273 rocker would let the adjuster get far enough up (for lack of a more technical term) to get the geometry close on the adjuster side of the rocker.

 

[Killer6]

Would it be possible to oil through the pushrods to lube the tips and also through the block to lube the Rockers at the same time.

Absolutely, every 3.3/3.8L V-6 in every Dynasty, Caravan/Voyager/Town & Country uses that exact system.

 

[yellow rose]

BTW, you'd have to run PR oiling and oiling to the shaft. Otherwise you'd have oil to the adjuster but not to the shaft.

 

[Killer6]

BTW, you'd have to run PR oiling and oiling to the shaft. Otherwise you'd have oil to the adjuster but not to the shaft.

Correct, I should have made sure to mention it's not just absolutely possible, but mandatory.

 

[Killer6]

This is what I was getting at. Sometimes it's not possible to get the adjuster in the ideal position, especially with a ball style adjuster. The pushrod should have a minimal amount of sweep as well to maximize efficiency. That is when the adjuster is in the correct position and angle, and the pushrod is sized accordingly. Sometimes, due to improper rocker design, that just isn't possible, and it happens a lot.

With You there, if the relationship between the tip & adjuster isn't correct, You can only make one of them right in relation to the valve/head/block. And the valve end has
top priority, then We're left with making the best out of what's left on the pushrod end. Or look for/build better rockers,......

 

[B3RE]

Don't know why, but all of a sudden I'm not getting email notifications of new posts. Discussed the adjuster conversion, and a whole lot of other stuff with Jadaharabi today. It's not worth the effort on a set of ductiles, in my opinion, but it certainly helps a most roller rockers. It's just pricey, and that is what determines the practicality over a different set of rockers designed for that adjuster style.

 

[yellow rose]

Don't know why, but all of a sudden I'm not getting email notifications of new posts. Discussed the adjuster conversion, and a whole lot of other stuff with Jadaharabi today. It's not worth the effort on a set of ductiles, in my opinion, but it certainly helps a most roller rockers. It's just pricey, and that is what determines the practicality over a different set of rockers designed for that adjuster style.

I'm going to start on my W-2 junk soon. Do you think it's worth it to convert the MP rockers I have (which I think are blue crane rockers) to cup style adjusters? If it's worth it I'm down for it. What do you think?