Well, I've had enough of this 440 Mystery Motor

[khryslerkid]

You already spent $180 on push rods , why didn't you just go with adjustable rockers? Just FMI . ........................................MO

I am useing adjustable rockers and didn't have any pushrods. So in order to have the right geometry and to have the correct location of the rocker adjusters where they needed to be, I just measured with a checking rod and ordered them.

Looking through Summits pushrods, they didn't have anything close enough. Same with 440 Source. I guessed at my measurements twice, even bought two sets that I thought might work but they were all way off. It wasn't until I bought a checking rod and took the actual measurement that it all fell into place.

It doesn't take very much to have the wrong lenth pushrod.

 

[khryslerkid]

Given the measurements I'm getting and the cam I'm using, how much shim would you apply here?

I'll give you the shims that I have and you can try them out to see what you get. Just PM me your address and I'll get them in the mail tomorrow morning. There are .010 .020 .030 ten of each.

When I tried them it changed my rocker to valve stem travel way out. This pic was a .030 shim

This pic was without any shim. The starting point on a stamped or ductile rocker is off center at the top of the valve stem. Then it sweeps across to the other side, then back up. I used a marker on the valve stem, then just moved the rocker by hand, horizontally back and forth to scratch a line. This pic was what I was after.

 

[coloradodave]

Thanks, Dave, but I'm reading reviews that say it won't work with a stock hood??
I've been asking repeatedly on here in the Performer (not RPM) is shorter to help with that?

Okay. Here is the height comparison: https://www.summitracing.com/compare

 

[moparedtn]

Okay. Here is the height comparison: https://www.summitracing.com/compare

According to the comparison, the Performer is 4.3" high and the Performer RPM is 5.35"; the Holley Street Dominator is 5.1" high.
Ok, so the RPM is about an inch taller - question again though is does it work with a stock hood (also assuming things like stock throttle linkage working with it)?

 

[moparedtn]

I'll give you the shims that I have and you can try them out to see what you get. Just PM me your address and I'll get them in the mail tomorrow morning. There are .010 .020 .030 ten of each.
View attachment 390050

When I tried them it changed my rocker to valve stem travel way out. This pic was a .030 shim
View attachment 390052
This pic was without any shim. The starting point on a stamped or ductile rocker is off center at the top of the valve stem. Then it sweeps across to the other side, then back up. I used a marker on the valve stem, then just moved the rocker by hand, horizontally back and forth to scratch a line. This pic was what I was after.
View attachment 390058

That's very, very kind of you. Thanks!
I'm trying to interpret what you're saying the results were when using them, though - were the 030 ones giving you acceptable "sweep" or not?

 

[khryslerkid]

That's very, very kind of you. Thanks!
But I think you're confirming what my concern was - that the shims will mess with stock geometry on these critters negatively, right?

Well you could always try them. I'm only familiar with what impact it had on my ductile rockers. Me personally, I would get the correct pushrods.

 

[Ski 61701]

I think weiand still makes a factory looking intake for rb blocks #8009. Or a plain jane edelbrock rb performer intake. At least with these being light weight once you set it on the motor you should be able to see how off your intake angle is off of your heads.
Sounds like you are finally going forward in solving this mystery. All it takes is a little time and patience.

 

[moparedtn]

Well you could always try them. I'm only familiar with what impact it had on my ductile rockers. Me personally, I would get the correct pushrods.

Thanks again.
What is the stock pushrod diameter on these engines anyways?

 

[moparedtn]

I think weiand still makes a factory looking intake for rb blocks #8009. Or a plain jane edelbrock rb performer intake. At least with these being light weight once you set it on the motor you should be able to see how off your intake angle is off of your heads.
Sounds like you are finally going forward in solving this mystery. All it takes is a little time and patience.

Thanks.
Well, maybe - IF anyone can confirm that the length of the current pushrods is so much longer than what I measured as needing - that it is actually probably causing the problem?

I mean, we're talking what, a tenth of an inch too long here (0.100)??
That doesn't sound like a lot to me??

 

[khryslerkid]

Thanks again.
What is the stock pushrod diameter on these engines anyways?

Both ends should be 5/16" on a stock pushrod.
The earlier ones even had a 1/4" at the lifter.
Then a lot of lifters had a 5/16" or 3/8" cup.

So you need to know what your lifters are designed for and know what your rockers are.

 

[Ski 61701]

Have you taken the lifters apart to see if there is any damage to the internals parts? If not Id go through each one to check things out. With a .100 too long pushrod if my math is correct is giving you anywhere from .050 to .060 extra travel in the lifter I'd want to make sure things are ok before buttoning things back up. Wish I had more to offer, I primarily build solid cam engines. If it were mine, id try and get the correct length pushrods

 

[dvw]

When are people going to learn that pushrod length on a shaft rocker does NOT change geometry. The pivot location changes the geometry. Secondly shaft rocker engines have been raced for years with big cams with stock pivot location. Perfect, no. Does it work? Ask the thousands of people who have done it and are currently doing it. How many here have modified there shaft pivot when increasing lift? We are not talking Pro Stock here but basic performance builds. Unless the pedestals are milled off and the shaft mounted in the proper location your geometry is most likely off. That being said not everyone agrees on what is "perfect". Read here and learn.
http://www.crankshaftcoalition.com/wiki/images/a/ad/MILLER_ROCKER_HISTORY_MID_LIFT.pdf

 

[khryslerkid]

The OP has a stock rocker assembly with a possible milled head. He has measured the pushrods that are being used and they appear to be a bit long.

Would .100 be too much? How far down does the lifter cup travel before bottoming out?

When the lifter pumps up at that preload, how far is that sending the valve?

 

[moparedtn]

Have you taken the lifters apart to see if there is any damage to the internals parts? If not Id go through each one to check things out. With a .100 too long pushrod if my math is correct is giving you anywhere from .050 to .060 extra travel in the lifter I'd want to make sure things are ok before buttoning things back up. Wish I had more to offer, I primarily build solid cam engines. If it were mine, id try and get the correct length pushrods

Oh trust me, I don't have a problem fetching "correct" pushrods....or replacing these lifters, for that matter.
My questions are more based on wanting to understand how these things work, in the sense of "could this actually be the root cause of..." sort of thing.
Could this .1 make that much difference, not so much as in I'm leaving some power on the table as more like "this thing sounds awful and runs like crap"?

Every time this has happened, the car started out running fine, idling well, going down the street fairly well with not much fuss.
Then, as it gets warm (and especially after I grab a couple gears half-assed enthusiastically), something goes south...and it stays south until I tear it all down again.

If Comp Cams has a known issue with their lifters, ok, I'll get a set of better ones.
If the too-long pushrods are a definite negative, they're gone, too.

 

[moparedtn]

When are people going to learn that pushrod length on a shaft rocker does NOT change geometry. The pivot location changes the geometry. Secondly shaft rocker engines have been raced for years with big cams with stock pivot location. Perfect, no. Does it work? Ask the thousands of people who have done it and are currently doing it. How many here have modified there shaft pivot when increasing lift? We are not talking Pro Stock here but basic performance builds. Unless the pedestals are milled off and the shaft mounted in the proper location your geometry is most likely off. That being said not everyone agrees on what is "perfect". Read here and learn.
http://www.crankshaftcoalition.com/wiki/images/a/ad/MILLER_ROCKER_HISTORY_MID_LIFT.pdf

See, that's what makes more sense to me.
I have stock heads (with stock rocker shaft pedestals, assumedly) with stock valves and a cam that isn't much more than stock itself, so it makes sense to my shadetree mind that the stock rocker setup ought to be good to go - Chrysler engineers know a ton more than I do, after all.
All I have to do is make sure the connection between the stock heads and the close to stock cam/lifters is the correct length then, right?
At that point, it's a matter of making sure everything is in good shape and installed correctly, I assume.

 

[moparedtn]

The OP has a stock rocker assembly with a possible milled head. He has measured the pushrods that are being used and they appear to be a bit long.

Would .100 be too much? How far down does the lifter cup travel before bottoming out?

When the lifter pumps up at that preload, how far is that sending the valve?

Yep.
That's the question of the moment - is that difference actually enough to cause problems?

 

[miller]

If Comp Cams has a known issue with their lifters, ok, I'll get a set of better ones.
If the too-long pushrods are a definite negative, they're gone, too.

From what I've heard about todays tappets, anything is possible, all on the makers. New? So what. Seen my share of 'new' parts that are junk. Tappets either work, or they don't. The tappet piston goes up and down, or doesn't. Real simple check, but that's your call.
Yeah, on too long push rods...negative.

 

[moparedtn]

From what I've heard about todays tappets, anything is possible, all on the makers. New? So what. Seen my share of 'new' parts that are junk. Tappets either work, or they don't. The tappet piston goes up and down, or doesn't. Real simple check, but that's your call.
Yeah, on too long push rods...negative.

I'll toss still another question in this mess, then:
Are all the various makers' versions of "stock" hydraulic lifters made to the same dimensions? If I fetch a set of whatever you guys concur are the "best" out there, will those new ones give me yet again a different pushrod length measurement?
Could the Comp Cams ones I have now have actually contributed to the incorrect pushrod length I have now, for that matter?

 

[miller]

Answer is yes, long as their tappets made for a Mopar motor. But, there's still differences between them inside, design of the 'cup', or as I call the piston.

Your question on the push rod length...no. Push rod length is decided by the engine builder, period. On a 'stock' hydraulic lifter set-up, stamped rockers, and such...the only adjustment is...push rod length. Builder has to figure that out.
Just 'assuming' all the stock parts will slap back in, doesn't work, unless all factory stock parts are used.

 

[moparedtn]

Answer is yes, long as their tappets made for a Mopar motor. But, there's still differences between them inside, design of the 'cup', or as I call the piston.

Your question on the push rod length...no. Push rod length is decided by the engine builder, period. On a 'stock' hydraulic lifter set-up, stamped rockers, and such...the only adjustment is...push rod length. Builder has to figure that out.
Just 'assuming' all the stock parts will slap back in, doesn't work, unless all factory stock parts are used.

Well, I reckon in order for me to do this properly then, I need to fetch a set of quality lifters and the correct length pushrods - which I assume I can safely order based on my measurements, since the new lifters won't alter the length?