Green Machine

[Getter-Done]

What plugs are you using?

Have you tried a (Cooler)lower heat range plug?

I like Autolite plugs in an older engine with some miles on it.

They burn oil better .IMHO

[fatbass]

I'm late to the party but I love this truck. I had a '71 K10 shortie the same color scheme and always wanted a 3/4 ton to make a pair.

Is there a chance someone did something to increase cylinder pressure/ compression ratio? Wrong head gasket, pistons, poorly machined heads, etc...
In the old days of points ignition (poorly maintained) and poor gas/air filtration, carbon buildup on pistons and head surfaces was a problem to the point of causing preignition.
I would do a baseline compression check. If wildly high or erratic readings are seen, scope your cylinders to check for carbon buildup.

[cariboumarkt]

Originally Posted by fatbass

I'm late to the party but I love this truck. I had a '71 K10 shortie the same color scheme and always wanted a 3/4 ton to make a pair.

Is there a chance someone did something to increase cylinder pressure/ compression ratio? Wrong head gasket, pistons, poorly machined heads, etc...
In the old days of points ignition (poorly maintained) and poor gas/air filtration, carbon buildup on pistons and head surfaces was a problem to the point of causing preignition.
I would do a baseline compression check. If wildly high or erratic readings are seen, scope your cylinders to check for carbon buildup.

I suppose there is that chance. This was my father-in-law's truck but he did sell it off for awhile. Knowing a bit of how it was used/abused for that decade I doubt there was even an oil change done on the thing much less an engine rebuild. I have been meaning to do a simple compression test, I'll put that on the list for cooler weather.

[cariboumarkt]

Originally Posted by Getter-Done

What plugs are you using?

Have you tried a (Cooler)lower heat range plug?

I like Autolite plugs in an older engine with some miles on it.

They burn oil better .IMHO

Yes, they are NKG V-Power XR5, which I believe is right in the middle of the heat range scale. Which plug would you reccomend?

[Getter-Done]

Originally Posted by cariboumarkt

Yes, they are NKG V-Power XR5, which I believe is right in the middle of the heat range scale. Which plug would you recommend?

Here is a good read.

Link: https://www.onallcylinders.com/2018/...ug-heat-range/

Which cylinder heads do you have?

Tapered seat plugs or the one that has the compression washer?

[cariboumarkt]

Originally Posted by Getter-Done

Here is a good read.

Link: https://www.onallcylinders.com/2018/...ug-heat-range/

Which cylinder heads do you have?

Tapered seat plugs or the one that has the compression washer?

Well, there's no washer so tapered seat I guess? Thank you for the article, very informative! I think a plug change to a step or two cooler might be a cheapish experiment. Going to try non-ethanol premium on my next fill up to see if that helps as well.

[Getter-Done]

Originally Posted by cariboumarkt

Well, there's no washer so tapered seat I guess? Thank you for the article, very informative! I think a plug change to a step or two cooler might be a cheapish experiment. Going to try non-ethanol premium on my next fill up to see if that helps as well.

I am old enough to say back in the day.

I used to go to the Local Airport and get 101 octane low lead air plane fuel when I had a race.

I would . Tell them it was for a Ultra Light.

104 Octane Booster was Great additive also.

I dont know if {104} is as Great as it was Now a Days.