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Loosing lash on one valve........ Ever had it?

Posted By: Bigbeep

Loosing lash on one valve........ Ever had it? - 11/01/10 03:51 AM

Run the valves the other day before running the car on Wednesday at HC. #4 exhaust valve was tight. I checked all others and reset #4. Made 4 passes and the car fell off .015 in the 1/8 mile on the last pass. Pulled valve covers off and checked lash again. #4 exhaust valve had NO lash left. All .026" were gone. Only thing I can think off is I have a valve getting ready to break (stretching or tullipping the head) or I have a seat beating itself around in the head. I figure if it was lifter or the cam the lash should get larger not smaller.

Quick run down on combo. 440 block, stock lifter bores, comp roller cam, comp roller lifters, Smith Brothers pushrods, Harland Sharp 1.6 rockers, K-motion springs 245 on the seat- 690 over the nose. Indy 440-1 heads with indy valves.

When I found all the lash was gone I set it again and rolled the motor over(not fired)a couple of times and it was gone again. I just put it away and will inspect this week. I already had planned on pulling it for the winter and doing some work anyway, so now there is a reason. I am just glad I caught it before major damage was done. Anyone else ever have this happen.
Posted By: fishy340

Re: Loosing lash on one valve........ Ever had it? - 11/01/10 03:53 AM

check the pushrod!
Posted By: Cab_Burge

Re: Loosing lash on one valve........ Ever had it? - 11/01/10 04:49 AM

Take both heads off and inspect them carefully
Posted By: 408strokerdart

Re: Loosing lash on one valve........ Ever had it? - 11/01/10 04:49 AM

Quote:

Run the valves the other day before running the car on Wednesday at HC. #4 exhaust valve was tight. I checked all others and reset #4. Made 4 passes and the car fell off .015 in the 1/8 mile on the last pass. Pulled valve covers off and checked lash again. #4 exhaust valve had NO lash left. All .026" were gone. Only thing I can think off is I have a valve getting ready to break (stretching or tullipping the head) or I have a seat beating itself around in the head. I figure if it was lifter or the cam the lash should get larger not smaller.

Quick run down on combo. 440 block, stock lifter bores, comp roller cam, comp roller lifters, Smith Brothers pushrods, Harland Sharp 1.6 rockers, K-motion springs 245 on the seat- 690 over the nose. Indy 440-1 heads with indy valves.

When I found all the lash was gone I set it again and rolled the motor over(not fired)a couple of times and it was gone again. I just put it away and will inspect this week. I already had planned on pulling it for the winter and doing some work anyway, so now there is a reason. I am just glad I caught it before major damage was done. Anyone else ever have this happen.



I think you are on the right track with your first guess. I bet that valve isn't long for this world. Once they start to stretch the metal will yield easily and continue to loose lash until it seperates. I would say you saved yourself some coin by not running it. Interested in what you find though.
Posted By: polyspheric

Re: Loosing lash on one valve........ Ever had it? - 11/01/10 05:01 AM

X2 - the valve head is tuliping, seat receding, etc.
All other changes (rocker tip, pushrod ball, cam lobe) will increase lash.
Posted By: Al_Alguire

Re: Loosing lash on one valve........ Ever had it? - 11/01/10 05:14 AM

If you are loosing lash you definitely soounds like you are having a valve/seat/head issue. Time to investigate further for sure
Posted By: Bigbeep

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 12:38 AM

I am going out to the shop tonight to pull the engine. I will soon know whats up. I was just curious if anyone else has had a similar problem. I am about 99% sure I will find a bad valve/seat on that head.
Now, just asking as I bet I will be in the market for valves in the very near future. Ferrera, Milidon, etc. Who has the best prices on a good valves. Beep
Posted By: super451b

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 12:58 AM

Nice catch John ! That coulda been real ugly.
Posted By: sixpackgut

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 12:59 AM

i would think the installed height growing would be noticable. i cant wait to hear the results
Posted By: Bigcube

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 01:32 AM

Pull the rocker shafts and run a straight edge across the valve tips. I'm interested in what you find.
Posted By: camastomcat

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 01:57 AM

Worn roller lifters can be an issue too.
Posted By: Cab_Burge

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 04:29 AM

Quote:

Worn roller lifters can be an issue too.

Worn roller lifters and cam lobes make the lash get bgger is what I have found on my junk when they went bad Not tighter
Beep, I would and do use Ferea or Manleys, never Milidon again
Posted By: flynbyu

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 02:13 PM

I would look at the keepers and spring retainers..maybe its knockin the keeper lands off the valve stem.....
Posted By: camastomcat

Re: Loosing lash on one valve........ Ever had it? - 11/02/10 03:22 PM

Not nessesarily, they can get bound up if the needle bearing is floating in the bearing body. I'm not saying that's what it is, but I have seen worn out lifters go both ways, tight and loose, but more loose than tight.
Posted By: Bigbeep

Re: Loosing lash on one valve........ Ever had it? - 11/06/10 08:57 AM

Well, tore the top end off the engine the other night. It is a lot better than I was expecting. It comes down to a "stupid human trick". A while back I pulled the rockers and checked a suspect spring problem on another cylinder. While reassembling the valve train I accidently tightened down the rockers with the pushrod out of the lifter cup on #4 exhaust valve lifter. After finding it and replacing a bent pushrod, I reassembled it correctly. Unbeknownst to me, I damaged the top of the lifter. It swelled the lifter at the top edge. My losing of lash was caused by the lifter just barely sticking in the bore. Weird thing is, I had checked the valves 2 times since than and never seen any issues with lash. When I pulled the head and found nothing wrong with the valve or seat, I went to the lifters. It was stuck, but not too tight that I couldn't pull it out with 2 fingers. I could also push it in to the base of the cam by hand. So, all in all not too bad. Chalk this one in to the lessons learned column. Thankfully the roller and camshaft have no damage.
Beep
Posted By: roadhazard

Re: Loosing lash on one valve........ Ever had it? - 11/06/10 09:24 AM

Glad to hear it was nothing major and an easy repair

Hows everything else look
Posted By: moparniac

Re: Loosing lash on one valve........ Ever had it? - 11/06/10 09:25 AM

Quote:

Glad to hear it was nothing major and an easy repair





x2
Posted By: Bigbeep

Re: Loosing lash on one valve........ Ever had it? - 11/07/10 12:30 AM

Thanks guys.
Greg, really haven't tore into the short block yet. Bores all look good though. Need to get the car back in the trailer to free up some space and then get a plan together for this winter. Beep
Posted By: pittsburghracer

Re: Loosing lash on one valve........ Ever had it? - 11/07/10 12:45 AM

Good job on the catch. That could have turned ugly real fast. I think one of the hardest jobs for a racer to do is to load up their car because they fill something isn't right.
Posted By: Bigbeep

Re: Loosing lash on one valve........ Ever had it? - 11/07/10 01:59 AM

I'll be honest. The money I have in the roller valve train and as hard as I spin it, it scares the crap out of me. When I first put it on alcohol this summer, I was a mess when I fired the car up. All of a sudden the car was quieter and I could hear noises in the valvetrain that on gas I couldn't. Now when I lean the fuel out, it goes right back to its snotting self.
Beep
Posted By: pittsburghracer

Re: Loosing lash on one valve........ Ever had it? - 11/07/10 02:34 AM

Quote:

I'll be honest. The money I have in the roller valve train and as hard as I spin it, it scares the crap out of me. When I first put it on alcohol this summer, I was a mess when I fired the car up. All of a sudden the car was quieter and I could hear noises in the valvetrain that on gas I couldn't. Now when I lean the fuel out, it goes right back to its snotting self.
Beep


Are you on straight alcohol or E85? Whiskyrunner is making the switch to alcohol next year and I may try E85.
Posted By: poppaj

Re: Loosing lash on one valve........ Ever had it? - 11/07/10 04:37 AM

John,
If you put all new lifters in I would go with Lunati. The link bar setup is a ton better than the Comps. I have had bad luck with their lifters. The Ferara valves are nice, that is what I put in about all my builds. Inspect the cam bearings as well to make sure you don't have one spinning with the cam it will cause a valve to tighten as well. Good luck with it. poppaj

Attached picture 6289135-IMG_1806.jpg
Posted By: Bigbeep

Re: Loosing lash on one valve........ Ever had it? - 11/08/10 12:47 AM

Pittsburgracer, Straight alcohol
Poppa J, Thanks for the heads up.
Beep
Posted By: pittsburghracer

Re: Loosing lash on one valve........ Ever had it? - 11/08/10 01:25 AM

Quote:

Pittsburgracer, Straight alcohol
Poppa J, Thanks for the heads up.
Beep


Thanks, may have to try that stuff someday. E85 would kinda be a pain in the butt as the closest place that sells it is 25 miles out of my way. I could buy alcohol right at the track.
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