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Home » Public Forums » GMCnet » Burned valve (The Lady isn't going to make Patterson)
Burned valve [message #274177] Sun, 22 March 2015 10:06 Go to previous message
kerry pinkerton is currently offline  kerry pinkerton   United States
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma:
Senior Member
Well crap. The fun just keeps on coming. I've been noticing a 'cough' for the past couple thousand miles...getting progressively worse. Not a backfire...just a cough. Not often, every hundred miles or so.

Had a carb problem and got that resolved and the motor was running good but the cough persisted. Compression check showed 170-165 on 7 cylinders and 130 on #7. Down from #140Psi a thousand or so back so it wasn't getting better...not that it ever does... Laughing Pulling the #7 spark plug wire at the distributor didn't produce any change in RPM or vacuum which indicated it was pretty dead. So Thursday evening I pulled the head and found the exhaust valve recessed a good 3/32nd into the head.

http://www.gmcmhphotos.com/photos/misc/p57603-burned-valve.html
http://www.gmcmhphotos.com/photos/data/6256/IMG_20150319_211606_061.jpg

http://www.gmcmhphotos.com/photos/misc/p57605-burned-valve.html
http://www.gmcmhphotos.com/photos/data/6256/IMG_20150319_211654_591.jpg

Tried to find a shop to do a valve job on Friday but no luck so we're not going to be taking the Lady to Patterson. We'll drive down and have motel. ((*%%^*

Took it to a shop to have the head done and took a couple bare 403 heads. The guy recognized them as Olds heads from 10 feet away...good sign #1. Told him I need a good head and he could put a seat in this one or build one from one of the cores. Good sign number 2 was when he said "Have to use Olds seats, Chevy seats cut into the water jacket. About that time his helper drove into the lot and as he walked past us, he said "Gotcha some Olds heads huh...we don't get too many of those." Good sign #3 I feel pretty good about it.

I don't reallu understand why this ONE cylinder on a 5000 mile engine did this but #7 will always run a bit hotter I think. The shop guy said that he'd prefer to use one of the bare heads rather than put a seat that one because they have had problems with seats due to different expansion rates and crappy fuel.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L

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