If the valve stems get mushroomed. Is their any possible issue with having the valve break?

I realise that one of the main concerns, is that the valves will need to be adjusted more often.

What other problems are there if the stem begins or has mushroomed?

 

Not breaking so much but hell to get out of the head. Can be caused by floating valves or bad rocker arm geometry.

 

were there any imprints on the piston valve reliefs ?

Greg

 

coil bind

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">Not breaking so much but hell to get out of the head. Can be caused by floating valves or bad rocker arm geometry.</TD></TR></TABLE>

yeah, cause the valve guides are now smaller the diameter of the valve stem

it could have floated, but based upon the rpm I was going to i doubt it. and i was using 98 itr cams

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CHEETAH &raquo;</TD></TR><TR><TD CLASS="quote">were there any imprints on the piston valve reliefs ?

Greg</TD></TR></TABLE>

the head is still on, without a cool video on a stick device, I have no way of knowing right now.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by MAX_CFM &raquo;</TD></TR><TR><TD CLASS="quote">coil bind</TD></TR></TABLE>

you mean coil bind can happen?
is this because spring height changes?

not saying it couldnt happen, I just cant visualize why coil bind could happen from the valve stems mushrooming

 

howmuch lift andwhat springs are u running

you mean coil bind can happen?
is this because spring height changes?

not saying it couldnt happen, I just cant visualize why coil bind could happen from the valve stems mushrooming[/QUOTE]

 

-98 itr cams
-95gsr head with 150k miles on it as of now
-portflow inners
-itr intake/exhaust springs
-portflow ti retainers
-rev flat faced SS valves
-new itr lma's
-hondata rpm limiter set at 8.3krpm.
-never mis-shifted or over revved valvetrain with current setup
-there is 12k +/- 500miles on the new setup

 

It's the valves. The flat face valves are all from Supertech and there's been a rash of tips getting hammered recently.
Supertech makes our valves for us, as well as Skunk2's valves, and the flat face valves for REV.
I've raked them over the coals over the problem this week and they're supposed to solved it.
We've only noted the problem with a few sets recently, so the problem isn't widespread and they're moving quickly to take corrective measures.
T.O.O.
I should also mention that this will not cause the valve to fail and we've noted that any lash changes were less than .001" on all the engines we've had back for maintenance.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Woofer &raquo;</TD></TR><TR><TD CLASS="quote">It's the valves. The flat face valves are all from Supertech and there's been a rash of tips getting hammered recently.
Supertech makes our valves for us, as well as Skunk2's valves, and the flat face valves for REV.
I've raked them over the coals over the problem this week and they're supposed to solved it.
We've only noted the problem with a few sets recently, so the problem isn't widespread and they're moving quickly to take corrective measures.
T.O.O.
I should also mention that this will not cause the valve to fail and we've noted that any lash changes were less than .001" on all the engines we've had back for maintenance.</TD></TR></TABLE>

yeah, I was just talking with ***** at supertech on wednesday about this very topic. I did not know that supertech made the flat faced valves for rev. They both come from argentina, I kinda guessed that they were from the same factory.

***** wasnt being finite though on what they did change. He just said the problem has been resolved. Which still leaves me a bit skeptical. What did you take away from the conversation you had with him?

On the eninges that have come back for maintence, were they mushroomed at all? because my valve lash specs were more than .001" when i measured everything before I took the cams out.

 

We've had many heads that have been put through all sorts or (hell) by their owners, including mis-shifts (14,000rpm), outrageous detonation due to owners' poor tuning, and of course, the normal freshen-ups, but until two months ago, I'd never seen the valve tips getting beat-up.
We first observed the "situation" when repairing the head that Mike and Earl Laskey won the Nopi race with. The valves in the head were NOT Supertech....however, someone said they may have been Crower's which are Supertech nowadays, and I had to grind the crap out of the stems just to remove them from the guides.
We originally thought the problem was the small base-circle cams they were running, but the same problem's popped up on damned near every set of valves since then.
I've also chewed on ***** last week and this week. He claims they've had no heat treat problems, etc....but there will be harder tip valves coming.
The tips on their valves are stellite right now, which is hard as hell, but I think the area effected is just above the keeper groove, and not necessarily just the tip.
I'll know more in a few hours as the head we did for the Laskeys a couple weeks ago is in for service. I'll keep you posted on what we find.
Larry

 

The REV valves had to be cut out of the head this morning too.....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Woofer &raquo;</TD></TR><TR><TD CLASS="quote">The REV valves had to be cut out of the head this morning too..... </TD></TR></TABLE>

what kind of setup?
RPM
seat pressure

FI or allmotor

 

It's happening on combinations with as little as 60PSI on the seat as well as heads running as high as 80 on the seat...and everything in betwen. Many of the heads are running mild cam timing too by our all-motor standards.

 

can valve mushrooming happen if there is not enough seat pressure or if you are running a very lightweight flywheel (fast change in piston speed, and valve cant keep up with the piston)?

if someone is running bigger cams, then there should be more seat pressure and less possibiltiy for valve float

or supetech just hasnt designed the valve stems properly

 

We're convinced that the problem is with the heat treat of the valves that were sold during the last 3 months because we've seen no evidence of the problem on valve porduced prior to then. I don't know if Supertech attmepted to take a shortcut in production or what, but the problem is the vlaves, not the springs, valve float, etc.
We're having several of the valves (new ones and old (never run) ones) tested at a lab here Monday to get to the bottom of it.
As for valve springs, yes, it's always necessary to use sufficient spring to keep the components in the valvetrain contacting each other at all times, or excessive wear will result.

 

any news with testing out the different vavles?

 

We tested a LOT of valves Monday and the hardness tests showed nothing significantly different between the old valves and the new ones we've had problems with.
We left several at the lab for a more in-depth look and I should hear something Thursday.

 

How recent did this problem start occuring? I got some supertech valves about 4 months back, maybe more.

 

The problems began about three months ago, but we've found that the valve stems are all the same hardness in our testing. Supertech is replacing the tips on all the new valves we get with a friction-welded piece. This should cure the tip pounding problem.
I'm of the growing opinion that the engines we've seen the problems with have been floating the valves rather violently.
One head we're working with has floated the valves to violently that the seats have pounded down into the aluminum casting .010" on every intake.
While we've seen no pitting from detonation on this head, the tuning was way off, melting one piston too, so there was a LOT amiss. Assuming we can "fix" the head, we're going to throw the baddest valve springs we have on it for the next outing...
I spring these heads for abuse, but some racers can dish out a lot more than you can anticipate.

 

Gee, I wonder whose head Woofer is talking about?

 

I'll throw this out here.

More spring pressure (seat pressure) = more control. Ohterwise your spring/valves become little impact wrenches and hammer the seats, retainers, keepers rockers etc.

FYI, ITR outer springs are softer than stock B16 (even used stock B16 outers). Just for those who think ITR outers have more pressure.

 

Here are some nice Manleys for a customer of mine.

These Manley valves come with thick hardened pads on the top of the tip. Also note that the valve contact area is not nitrided. This promotes better sealing and cooling.