Slant Six Forum :: Reading plugs

: I recently got my '64 Valiant running after
: many years of storage with a previous owner.
:
: After a night of highway driving, I pulled the
: plugs to see what they looked like. 1 thru 5
: were various shades of tan with a reddish
: deposit on the electrode ceramic. In my
: opinion, they looked very normal, and I'm
: assuming the red color is from a fuel
: additive.
:
: Number 6 was nearly white with no evidence of
: red. Is this cylinder running lean?...and is
: that a slant trait because of the manifold
: configuration, or am I mis-reading it?
:
: I was very pleased to see absolutely no oily,
: or even dry carbon deposits on any of the
: plugs. Despite the clean burning, the car
: has a distinct roughness at idle. The idle
: mixture screw is adjusted properly, it's on
: the second tank of fresh fuel, the timing is
: steady at 5 degrees BTDC and it received a
: complete tuneup before I put it on the road.
: I also replaced all vacuum lines, and vacuum
: at the intake tap on the # 6 runner reads a
: steady 22 at idle. Could there be enough
: leakage at the tap fittings to lean out #6?
:
: At cruise, the engine is very smooth and except
: for the nuisance factor at idle, I'm totally
: pleased with the performance and condition
: of the engine. Maybe I'm asking too much
: from the 38 year old engine!

Author:	Gary [ Sun May 05, 2002 7:45 pm ]
Post subject:	Reading plugs
I recently got my '64 Valiant running after many years of storage with a previous owner. After a night of highway driving, I pulled the plugs to see what they looked like. 1 thru 5 were various shades of tan with a reddish deposit on the electrode ceramic. In my opinion, they looked very normal, and I'm assuming the red color is from a fuel additive. Number 6 was nearly white with no evidence of red. Is this cylinder running lean?...and is that a slant trait because of the manifold configuration, or am I mis-reading it? I was very pleased to see absolutely no oily, or even dry carbon deposits on any of the plugs. Despite the clean burning, the car has a distinct roughness at idle. The idle mixture screw is adjusted properly, it's on the second tank of fresh fuel, the timing is steady at 5 degrees BTDC and it received a complete tuneup before I put it on the road. I also replaced all vacuum lines, and vacuum at the intake tap on the # 6 runner reads a steady 22 at idle. Could there be enough leakage at the tap fittings to lean out #6? At cruise, the engine is very smooth and except for the nuisance factor at idle, I'm totally pleased with the performance and condition of the engine. Maybe I'm asking too much from the 38 year old engine! lancer_41@excite.com

Author:	Doc. [ Mon May 06, 2002 4:37 pm ]
Post subject:	Re: Adjust the valves and read plugs again
Quote: : I recently got my '64 Valiant running after : many years of storage with a previous owner. : : After a night of highway driving, I pulled the : plugs to see what they looked like. 1 thru 5 : were various shades of tan with a reddish : deposit on the electrode ceramic. In my : opinion, they looked very normal, and I'm : assuming the red color is from a fuel : additive. : : Number 6 was nearly white with no evidence of : red. Is this cylinder running lean?...and is : that a slant trait because of the manifold : configuration, or am I mis-reading it? : : I was very pleased to see absolutely no oily, : or even dry carbon deposits on any of the : plugs. Despite the clean burning, the car : has a distinct roughness at idle. The idle : mixture screw is adjusted properly, it's on : the second tank of fresh fuel, the timing is : steady at 5 degrees BTDC and it received a : complete tuneup before I put it on the road. : I also replaced all vacuum lines, and vacuum : at the intake tap on the # 6 runner reads a : steady 22 at idle. Could there be enough : leakage at the tap fittings to lean out #6? : : At cruise, the engine is very smooth and except : for the nuisance factor at idle, I'm totally : pleased with the performance and condition : of the engine. Maybe I'm asking too much : from the 38 year old engine! I would check the valve lash adjustment, swap-out that spark plug and plug wire and see if that helps. (Is there any vacuum accessory comming off the #6 runner tap, if so try plugging it as a test) DD

Author:	Gary [ Mon May 06, 2002 6:32 pm ]
Post subject:	Re: Adjust the valves and read plugs again
Doc, thanks for the suggestion to check the valve lash. I've got gaskets ordered, so will give that a try. There are no vacuum accessories except for my console mounted vacuum gauge, and it has been installed with all new fittings. I will double check those also, but the rough idle was there before I installed the gauge, so I don't think the lean condition is related to the idle. Since the car had been sitting for nearly 17 years, I'm guessing there is some junk in the carb and it's possible the idle circuit is affected. I think I'll order a carb kit too. If nothing else, I'll be getting alcohol resistant rubber parts so the upcoming alcohol additives in the gas won't cause a problem. From the looks of the carb, it hasn't been touched in many, many years, so doubt the parts are neoprene. Quote: : : I would check the valve lash adjustment, : swap-out that spark plug and plug wire and : see if that helps. (Is there any vacuum : accessory comming off the #6 runner tap, if : so try plugging it as a test) : DD lancer_41@excite.com

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