dropped valve seat?????????

Warpig

Warpig

12V killer
Joined
Aug 29, 2007
Messages
1,067
I think I may have dropped a valve seat. Raced today and my last run I spun the tires real bad. Instead of backing out I stayed in it. Anyways, back in the staging lane I had some time and shut the truck off after idling for about 5 min. The line started to move again so I started the truck. After starting I hear a popping noise in the exhaust and a ticking noise from valvetrain. I took off the valve cover and found one of the #1 cylinder exhaust valves was lower than the other and the lash was way out of speck. I won't know for sure what happened until I take the head of tomorrow morning. I have f-1 valve springs and Hamilton heavy duty pushrods. I also have a Colt/Hamilton cam. An interesting and may be coincidental fact is that I bent a stock pushrod (exhaust #1) while on the dyno about 3 months ago, the reason I now have Hamilton's heavy duty. I believe both problems were related to high rpm's in the neighborhood of 5k, along with some toasty egt's. I'm looking for input from anyone who may shed some premature light on my issue. If it is a dropped valve seat, how do I prevent it in the future?? Does this sound like I floated a valve and had valve to piston contact? If so, what more can I do to prevent that from happening again?
I've heard of guys pinning the valve seats??? Please shed some light on this.

On a positive note, I did run my best time of 11.40 @118

Thanks,
Tim
 
Tim do you have the factory 24v head, if so i think the valve seats are integral and not pressed in ones like the CR heads
 
Sounds like it to me. Had a guy here locally whos truck was doing the same thing. He continued to run it all year and run the overhead on occasion. And it was always way off. We took the head off and 7, I repeat 7 seats had dropped. All were pinned by the valve. Chewed up the top of all the pistons as well. Still ran pretty good haha!
 
I think the later 24V heads are pressed in... Mine was on my 02. I think the spare I have in the garage off an 00 is also.
 
100_1407.jpg


100_0019.jpg


top is an 01' head, bottom an 07' CR.
The gf's 00' head looked the same as my 01'.
 
2Tone12V said:
Sounds like it to me. Had a guy here locally whos truck was doing the same thing. He continued to run it all year and run the overhead on occasion. And it was always way off. We took the head off and 7, I repeat 7 seats had dropped. All were pinned by the valve. Chewed up the top of all the pistons as well. Still ran pretty good haha!
Click to expand...

I don't dare run this thing, it sounds pretty bad. Like I said, it started after I fired it up after a 10 min cool down. That's why I'm leaning towards a dropped seat.
 
kipo said:
100_1407.jpg


100_0019.jpg


top is an 01' head, bottom an 07' CR.
The gf's 00' head looked the same as my 01'.
Click to expand...

So they are pressed in? If I dropped a seat, how do I prevent it from happening again??????
 
get them all replaced with at least ten thousands squeeze on them.
that's what i've been told anyway.
 
Thanks for the replies guys, I'll prolly be up all night trying to research this issue :doh:
 
I would take it to Scheids. I don't do much business with them. But when this happened to my buddies truck. They were VERY concerned as they thought it was the truck with their head on it. Had him send it in to get fixed and found out it was the head on the other truck. Seemed to wanna take care of it after 4 or 5 years
 
You can call Enterprise and talk to Drew about the seats. They've researched several methods including peening, threading and ended up designing their own seats. They have a high nickel content to withstand heat better, they're deeper into the head and larger in diameter. He says with the trucks they have sled pulling at 5500rpms, they've not had a problem. Stock seats just don't get the job done and many shops are still using them.... Anthony, Scheid is one of them.
 
Warpig said:
I've heard of guys pinning the valve seats??? Please shed some light on this.

On a positive note, I did run my best time of 11.40 @118

Thanks,
Tim
Click to expand...

kipo said:
get them all replaced with at least ten thousands squeeze on them.
that's what i've been told anyway.
Click to expand...

Tim,

I just found 8 loose valve seats!!

As kipo said, we replaced them with .010 ovr seats and installed them by heating the head and putting the seats on dry ice. Then peened around the seats to insure they stay in.
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Nice pass by the way!!
 

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Thanks for the replies guys!!!!!!! Like I said, I'll know what happened when I take the head off in the am. I'm just a little worried because I bent a stock pushrod in the same location about 3 months ago. I replaced the pushrod (all pushrods) with a strong Hamilton pushrod and now this. Kinda like chasing the weak link.
Greg, I don't wanna go where you've been :hehe: but I'll take your advise.
Any other advice is really appreciated!
 
triton said:
You can call Enterprise and talk to Drew about the seats. They've researched several methods including peening, threading and ended up designing their own seats. They have a high nickel content to withstand heat better, they're deeper into the head and larger in diameter. He says with the trucks they have sled pulling at 5500rpms, they've not had a problem. Stock seats just don't get the job done and many shops are still using them.... Anthony, Scheid is one of them.
Click to expand...

I will also call Enterprise when I'm sure what my problemo is...Thanks!
 
VMacKenzie said:
I believe 24-valve HOs have pressed in seats whereas SO engines didn't.
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Vaughn, thanks for the reply. I believe my 02 SO engine has pressed in seats. This is not the original head, I bought a new head from Doug Smith about 2 years ago after finding numerous (46) cracks in my old head. Good to see you on CompD!!!!!!!!!!!!!!!!!
 
Also, due to a fairly new cam, is it possible that the cam is the culprit? This is the same cylinder that I had a bent exhaust pushrod 3 months ago. Is it a coincidence that I now have a bad exhaust valve (bent or dropped seat) after replacing the pushrod with a heavy duty.
 
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