howards cam/lifters? weird valve lash problem

[rustbucket]

I have a 383 sbc with a howards solid roller cam and roller lifters. Anyone know anything about them or had any valve lash issues?
I first adjusted the lash at .018 cold and started and warmed the motor.After hot, re-adjusted valves. Howards calls for .024 hot.
I set them a tad tight @.022. Restarted the motor and it ran smooth for about 10 minutes and then started misfiring. Pulled the valve cover and one of the exuast valves had about 1/4 inch lash!
readjusted and repeated the process. After getting completly warm it started claddering again what the hell? I am using a stud girdle and have used 2 different sets of rockers. New valve springs and the push rods are not deforming.
thanks for any input, tony

[JES]

If it were lash alone, a 1/4 inch will not make it missfire, but if it is on the same rocker each time, it may be that the lifter has roller bearings going away and caming enough to not let the valve seat while running, and cuse your missfire. Then when you check for valve lash all the rollers are on the top side of the lifter, making for the extra lash. John Eric.

[stroker1]

I had similar experience with a Howards cam but it was a mechanical flat tappet. Wipped off 3 lobes. Everything John told me to check was not the problem. But I checked the hardness of the cam (I am a tool & die maker), and it was too soft. John with Howards cams told me that was impossible because every cam is 100% inspected before it goes out the door. I sent it back and he told me my pushrods where binding and not spinning and the lifters wore in 1 spot instead of rotating. That was NOT the problem as I triple checked the valvetrain before and after firing it. However that was the end result, not he cause. We decided (after much debate and inspection) that he should grease that cam real good and slide it in and out of his rectum a few times to make him feel better about himself.

John at Howards is a smart guy, he can probably help ya alot. Or he can make you want to choke the life out of him. Let us know which is your experience when this is over.

As for my opinion of your problem, I hope it's a lifter gone bad and the pin fell out of the roller making the lifter body straddle the lobe. But I fear you may have a piston that came a little too close to a valve, although that is usually more of a problem with the intake instead. Hope it's nothing too bad.

BTW, as for me I will be a CamMotion man with everything from here forward.

[rustbucket]

But I fear you may have a piston that came a little too close to a valve, although that is usually more of a problem with the intake instead. Hope it's nothing too bad.

The pistons were flycut. If it was a valve and piston issue, what exactly would cause the exessive lash? Would it not bend a pushrod or something? thanks again, tony

[TubbedTruck67]

If youve got a solid roller with that much lash all of the sudden something is wrong. Take the intake off and check the lifters is what Id do if it was mine.

[stroker1]

But I fear you may have a piston that came a little too close to a valve, although that is usually more of a problem with the intake instead. Hope it's nothing too bad.

The pistons were flycut. If it was a valve and piston issue, what exactly would cause the exessive lash? Would it not bend a pushrod or something? thanks again, tony

Would probably bend the valve and/or pushrod. If it didn't bend the pushrod, I'd try a compression test on that cylinder, or maybe a leak down. The valve might be hanging open. I sure hope it's nothing serious like that.

Is this on the 406 or the Patriot 383?

[rustbucket]

Is this on the 406 or the Patriot 383?

neither. The patriot 383 runs stronger than my 406 for some reason. It has the same heads with flat tops and is almost a tenth faster in the same car. Of coarse the 406 has a nitrous cam with 111 lsa compaired to 106 lsa in the patriot motor. I havent run the bottle on the patriot motor.

Me and my racin buddy have collected a shop full of motors over about a 3 year period. We start building and testing out of bordem.
With mostly good results. heres what weve built and tested over the past year.
406 cid 6.70 motor 6.0 on a 200 hit
468 cid 6.70 something on motor, 5.71 on a 200 hit
496 cid 6.50 motor 5.51 @ 128 on a 200 hit
565 cid still testing. hoping for some low 5 teens on the bottle.
patriot 383 6.70 motor. no test on nitrous
406 cid 6.84 with no tuning or nitrous
383 cid no testing yet.

Ive got my new 406 listed in the classified. Ive decided after testing
between the small blocks and big blocks, Ive got to build me a 496-540 cid.

by the way stroker, those are some damn big fish

[morpheus]

rustbucket.... sure am glad you brought them up, been thinking about them myself. Nothin better than a couple of lunkers....

[wikd69]

Is this on the 406 or the Patriot 383?

neither. The patriot 383 runs stronger than my 406 for some reason. It has the same heads with flat tops and is almost a tenth faster in the same car. Of coarse the 406 has a nitrous cam with 111 lsa compaired to 106 lsa in the patriot motor. I havent run the bottle on the patriot motor.

Me and my racin buddy have collected a shop full of motors over about a 3 year period. We start building and testing out of bordem.
With mostly good results. heres what weve built and tested over the past year.
406 cid 6.70 motor 6.0 on a 200 hit
468 cid 6.70 something on motor, 5.71 on a 200 hit
496 cid 6.50 motor 5.51 @ 128 on a 200 hit
565 cid still testing. hoping for some low 5 teens on the bottle.
patriot 383 6.70 motor. no test on nitrous
406 cid 6.84 with no tuning or nitrous
383 cid no testing yet.

Ive got my new 406 listed in the classified. Ive decided after testing
between the small blocks and big blocks, Ive got to build me a 496-540 cid.

by the way stroker, those are some damn big fish

So, did you determine what the issue was ?

[rustbucket]

not really, ive run it several more warm ups with no issue. i did have to clearence a little more on the rockers to clear the springs.
Im taking it to the track sunday if its not raining.

i also rechecked the piston to valve clearence again and ive got about
.100.

[rustbucket]

I spoke with Howards and they are scratching their heads also. The car is in the pain shop so I cant get my hands on it for another week or so. I readjusted the valves and loaded it onto the trailor to take to paint. Before I got it off the trailor I dropped a cylinder. Si when its back home I will pull the intake.
My question is this. The block is a later model block with the one pc. rear main seal, I think its a 1990 model block. Dont they take a .300 long lifter? And does anyone have one on the shelf they could measure and give me the lenth. The wrong lifters may be in it. I dont have a lifter to measure without tearing apart another motor. Thank you, tony