Wtf - roller rocker

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1967formulaS

1967formulaS

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This is the second time a pushrod has come out and also pushed the lifter out of its bore.
Lunati solid cam and lifters.
Pwr 1.6 rockers. ( yes I know, that's all I can afford)
I've done the lash a few times now at 0.14" as suggested on the lunati cam card.
Shouldn't try 0.10"?
Only does it when I give it a boot full.

DSC_0884.JPG
 
I have the same rockers but no driving time yet on them. Just engine-stand time.
Before installation I gone over the rockers and cleaned, broke any sharp edges and generally smoothed them up a bit.
But my main concern with these things are the adjusters. They don't seem well designed and the huge oil band in their center sure removed a lot of threads I think would be needed better.

Is the rocker alignment over the valve tips good?

I have these on a hydraulic cam but I'm thinking of modifying the lifters into solids for better control.
I hardly ever go by what the camcard lash specs say. Most of the time there's just too much lash I found. Usually I tighten them a bit until they 'sound good'.
 
Hi there,
I spent a fair bit of time getting these to fit correctly.
At first, they sounded a little noisy, kinda like an overgrown sewing machine. Readjusted and not as bad.
Gave it a good test out, you know 5500 rpm gear changes etc and that's when the #8 intake pushrod jumped out and also spat the lifter out of its hole. Luckily I was just around the corner and quickly shut it down and coasted back into my driveway. Pulled intake off, no damage to pushrod or lifter or the rocker cup. Put it back in, readjusted them all again and was fine for a week and she started getting noisy again. Readjusted and gave it a boot full. Same issue again but on #4 intake. No damage just like last time.
I'm going to try 0.08" on intake and 0.12" on exhaust in the morning and see how that goes. I'm not going to stuff around too long on this issue. If it continues I'm going back to a decent hydraulic cam, lifters, STD length pushrods and original stamped steel rockers.
 
1967formulaS said:
Hi there,
I spent a fair bit of time getting these to fit correctly.
At first, they sounded a little noisy, kinda like an overgrown sewing machine. Readjusted and not as bad.
Gave it a good test out, you know 5500 rpm gear changes etc and that's when the #8 intake pushrod jumped out and also spat the lifter out of its hole. Luckily I was just around the corner and quickly shut it down and coasted back into my driveway. Pulled intake off, no damage to pushrod or lifter or the rocker cup. Put it back in, readjusted them all again and was fine for a week and she started getting noisy again. Readjusted and gave it a boot full. Same issue again but on #4 intake. No damage just like last time.
I'm going to try 0.08" on intake and 0.12" on exhaust in the morning and see how that goes. I'm not going to stuff around too long on this issue. If it continues I'm going back to a decent hydraulic cam, lifters, STD length pushrods and original stamped steel rockers.
Click to expand...
 
1967formulaS said:
This is the second time a pushrod has come out and also pushed the lifter out of its bore.
Lunati solid cam and lifters.
Pwr 1.6 rockers. ( yes I know, that's all I can afford)
I've done the lash a few times now at 0.14" as suggested on the lunati cam card.
Shouldn't try 0.10"?
Only does it when I give it a boot full.
Click to expand...

I would be wondering about a lack of spring pressure or overly tight guides.
Once could be a fluke, but twice and both at higher RPM's?
 
What Trailbeast says,
The springs aren’t maintaining control. If the pushrod isn’t in a pretzel shape, it can’t get out of place, unless something is allowing the clearance it needs, to get past the rocker.
 
On the lash, if you talk to a cam grinder he will tell you the lash is designed into the way the ramp is ground, you can get a custom ground cam with a low lash if you want, he just has to grind it for that.
 
First, I know it's a typo, .014" & .010", not .14 & .10. Second, this head & bottom end combo has been run as is with a different cam & valve-train, with no issues?
 
Also to add, I built a 455 Olds that had a Lunati solid in it prior, the lash kept opening up on it. The cause was the "solid" tappets were basically hyd. units w/a hardened
tube for a spacer that supported the pushrod seat, the seat was knocking the edge off the tube and opening the lash, but it took weeks & never threw any pushrods.
 
How many treads are out the bottom of the rocker when adjusted that could be the problem if there's to many the push rods are to short ask me how I know..t&d recommend no more then 2 treads..not sure what your company like just a thought..
 
Hi guys,
Yep, sorry was a typo. As suggested above.
Heads and bottom end ran fine with a hydraulic setup. The heads have been rebuilt by a shop with new everything to suit the cam.
I have 5/16 pushrods and I have 2 threads showing under the rocker on the adjuster screw.

1510442018894535160220.jpg


15104421426801944964782.jpg


1510442236389912493134.jpg
 
Could be the play of light, but that pushrod looks tweaked to Me, roll it on a plate of glass?
 
The top end isn't good if it's spitting those out. What about the lower end? You know you lose oil pressure to the crank when the lifter pops out... This is why one bushes lifter bores.
 
well, a valley pan will keep the lifter from popping out and you losing oil pressure, but the root of the cause sounds like lack of spring pressure. Lunati recommended:
  • Seat Load: 125 lbs/in @ 1.850
  • Open Load: 325 lbs/in @ 1.250
  • Coil Bind: 1.110"
  • Rate: 333 lbs/in
  • When the valve starts to close the spring needs to push the valve up fast enough and with enough force (open pressure) to never allow the pushrod to lose contact with the rocker or the lobe, eg. Rollers need some stiff springs because their ramp rates are so fast. Mopars best stock springs were 96#/242# on a 340 manual so if your reusing your springs, thats a problem.
 
Is it elusion, are those guided roller tips. if so, I didn't think PRW was guided.
is the roller tip square on the valve or slightly cocked.
 
First things first.

You need to contact Mike at B3 racing engines. You need to correct the geometry. There is no way those rockers just bolt on. No rocker with a roller tip will just bolt on. Well...they will bolt on but they won't be correct.

There are many threads in the small block forum covering this.

After you correct the geometry, then we can discuss other issues you may have. Start with geometry first.
 
First it must be a RB with 9.5" push rods, and the cam card says B/RB
 
brian6pac said:
First it must be a RB with 9.5" push rods, and the cam card says B/RB
Click to expand...
Correct, I believe YR just meant to read the discussion about geometry there, because it has been discussed intensively in a couple of recent SB threads.........................
 
Killer6 said:
Correct, I believe YR just meant to read the discussion about geometry there, because it has been discussed intensively in a couple of recent SB threads.........................
Click to expand...


Yeah, that's what I'm saying. Doesn't matter what it is if it has shaft rockers it's all the same. Even with a Chevy.
 
Hi guys,
I'm using 383 closed chamber heads.
The motor is a fresh build. Icon pistons, H beam rods, coyles timing chain kit etc.
The heads were all built for that cam. New springs retainers, locks, valves etc all new.
It took me a couple of weeks and some machining to get the rockers correct, they sit central and flat on the valve.
That pushrod does look bent in the pic, but I rolled it on a piece of glass and it's perfect.

I readjusted it to. . 08" int and. 012" exhaust, took it for a drive and it was much quieter and smoother. Gave it another boot full and everything went well. Bought it home, Pulled the covers and checked them all. Everything seems fine at this stage.
Will see how it goes over the next few days. Hopefully the issue is resolved.
 
If it happens again, you need to be contacting me. Pushrods don't just pop out unless there is valve float opening up lash. (Edit) And, it's not low spring pressure. It's valvetrain instability from poor geometry. It's amazing, after all this time, that spring pressure is still the "go to" culprit as soon as valvetrain issues raise their ugly head.

Also, if you purchased the rockers as PRWs, I'd have some serious questions for the seller. PRW does not use a guided rocker, at least not in the last ten years, that I'm aware of. I think someone sold you a set of Speedmaster rockers.
 
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