They all look pretty good. Nothing to worry about. 
Pulled a cylinder head and found....
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Pulled a cylinder head and found....
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....#7 cylinder has an exhaust valve with a light white powery-looking coating on it. Anything to be alarmed over? Rest of them look fine. Chamber looks wet from wiping off water, it's not oil
This is a Brodix IK200 head, I removed it so I can drill and tap for the water temp sender. Wish I'd done this before putting the heads on in the first place
[/IMG]....#7 cylinder has an exhaust valve with a light white powery-looking coating on it. Anything to be alarmed over? Rest of them look fine. Chamber looks wet from wiping off water, it's not oil
This is a Brodix IK200 head, I removed it so I can drill and tap for the water temp sender. Wish I'd done this before putting the heads on in the first place
Last edited by 682XLR8; Feb 21, 2010 at 12:38 PM.
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Randy, you may have had a vacuum leak on the intake manifold, valve in adjacent chamber looks way richer in fuel mixture by the coloration of the #5cyl intake valve compared to #7.
Other possible cause might be a slight coolant leak that would keep the valves looking like they had been steam cleaned while you drove.
Take some photos of the other chambers or the entire head so we can see the complete picture (I take it only #7 came out looking that clean.)
What kind of head gasket was on the head?
Other possible cause might be a slight coolant leak that would keep the valves looking like they had been steam cleaned while you drove.
Take some photos of the other chambers or the entire head so we can see the complete picture (I take it only #7 came out looking that clean.)
What kind of head gasket was on the head?
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
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Thanks for the reply Eric, I'm using a Fel-Pro 1003 headgasket. Doesn't show any signs of leaking, as it appears to compressed evenly all around.
I have to top off with coolant from time to time. Sometimes after a drive I notice coolant on the floor under the reservoir, thought maybe that's where my coolant is going, never occured to me it might be a headgasket
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[/IMG]Thanks for the reply Eric, I'm using a Fel-Pro 1003 headgasket. Doesn't show any signs of leaking, as it appears to compressed evenly all around.
I have to top off with coolant from time to time. Sometimes after a drive I notice coolant on the floor under the reservoir, thought maybe that's where my coolant is going, never occured to me it might be a headgasket
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Randy looking at the entire head gives a much better picture, everything looks fine. There is a natural tendancy for #7 cylinder to run a little leaner than the rest because it's next door "buddie" #5 steals away some of the fuel mixture from it and causes local area heating (runs a little hotter because both cylinders fire in sucession.) Powder is probably fuel additives deposited on hot exhaust valve head.
Looks like your running a good grade of fuel like Chevron, 76, or Shell because of the cleanliness of parts (how many miles on motor?) Look to the back side of the intake valves and see if you have depositis building up behind the intake valve heads if you get a chance and let us know what gas brand you run.
If you need any parts, call my friend Dan at AEPM (510) 656-9352 for gaskets at great prices.
Looks like your running a good grade of fuel like Chevron, 76, or Shell because of the cleanliness of parts (how many miles on motor?) Look to the back side of the intake valves and see if you have depositis building up behind the intake valve heads if you get a chance and let us know what gas brand you run.
If you need any parts, call my friend Dan at AEPM (510) 656-9352 for gaskets at great prices.
Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
Yeah, I've heard of the #5-7 cylinder thing before & a lean condition was the first thing I thought of when I saw it, needed to ask first before continuing on to be certain
Looked in the ports with a flashlight, no deposits that I can see
I always fill the 68 up with 92 at the Chevron on Bollinger Canyon and San Ramon Valley blvd(only a half mile from my house), plus it's a covenient beer stop
Looked in the ports with a flashlight, no deposits that I can see
I always fill the 68 up with 92 at the Chevron on Bollinger Canyon and San Ramon Valley blvd(only a half mile from my house), plus it's a covenient beer stop
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Thread Starter
Safety Car
Joined: Dec 2005
Posts: 4,270
Likes: 20
From: Central Michigan
I was running an RPM Air-Gap, Holley 650 vacuun secondary, drop base air cleaner and the stock 68 hood. There is about 1/8" to spare under the hood, and I can see where the air cleaner has rubbed off the paint under the hood, presumambly on hard acceleration
You mentioned the large ports of the Brodix heads, the Air-Gap runners cover them just fine w/ a 1206 gasket
You mentioned the large ports of the Brodix heads, the Air-Gap runners cover them just fine w/ a 1206 gasket
Pro
Joined: May 2009
Posts: 569
Likes: 2
From: Clio Mi
I think the Rpm air gap manifold is to blame... i believe there is only one boss for manifold vacuum and it is found on that cylinder.... without going out to my barn in 1' of snow to check it out? at least that's the way my manifold is set up.... i wish i would have plugged it and drilled and tapped a new port under the carb to distribute the vacuum to all cylinders..... 
