1977 Silverado Crew Cab.

[y5mgisi]

Ordered up all my door and window seals Hope to have the buff job and window seals and such all in by the end of Thanksgiving weekend.

 

[76zimmer]

Turning out very nice!
What is your method(s) for cutting and buffing?

 

[y5mgisi]

1000, 1500, 2000 grit sandpaper and then meguiars 105 on a wool pad on the buffer.

 

[jekquistk5]

Buff job coming along nicely. Still need to order new seals and see what trim pieces I need.

Looks great!

 

[GWeakland620]

Mmmm looks like you could just look at it, and then say "would you look at that"!

 

[y5mgisi]

Hello again everybody! Still been working slowly on the buffing, window seals, etc. It's to the point where I'm going to start driving it a little here and there again. I knew the carb kept leaking it's fuel out of the casting plugs over night so the other day I rebuilt the carb and sealed the plugs up. One thing I noticed was that one of these tubes had fallen out of the air horn and was resting in the bottom of the carb. Near as I can tell it's a secondary air bleed tube. Don't really know what it does... Either way, I put it back in place and peened it into place a bit. Seems tight now.

Sorry I got it running again today. Definitely runs a better! Was able to turn the idle down about a full turn from where it was before! Still not smooth at idle. Mostly smooth but not quite.

So I checked the header temperatures at each port and each was between 550-650 at idle. Seems a bit warm no?

I haven't messed with the idle mixture screws yet. When I put the carb back together I just ran them all the way in and then turned them each three turns out.

Either way, one of the header ports was at only 300 degrees as opposed to the 550-650 of the other ones. So I pulled that plug (number 5) and the number 3 plug just for fun as a comparison.

I broke the number 5 plug taking it out. I think. So the broken one is the colder running cylinder, and the not broken one is a cylinder running as hot as the others. What, if anything, is there to make of all this?

 

[prolinews]

I would check compression on that hole.

 

[prolinews]

Could be a few things plug wire etc but a compression check would 1st on my list

 

[y5mgisi]

Borrowing a compression gauge from a friend tomorrow.

 

[jekquistk5]

Are the gaps equal? Could be the angle of the picture but it looks like the hot one has a larger gap. Larger the gap hotter the spark

 

[y5mgisi]

Are the gaps equal? Could be the angle of the picture but it looks like the hot one has a larger gap. Larger the gap hotter the spark

Can't find my dang gap tool! But just visually they do look equal but maybe a bit big.

 

[y5mgisi]

Today after work I picked up a set of plugs and wires. I had a brand new cap and rotor laying around still so I put that on also.

First off, that is the last net of off the shelf plug wires I will ever buy... Second, every time I get up under the hood I realize I'm getting fatter and older... Either way, I essentially gave it a tune up.

Runs pretty decent but I'm still convinced something is off. It just feel like the part throttle is out of whack either in the carb or dist. But at least it runs good enough to burn them off nicely in the rain! Lol

 

[y5mgisi]

Oh and also I wasn't able to check the compression because the tester I borrowed doesn't have the end I need to work with these heads.

 

[GWeakland620]

What gap did you run on your plugs?

 

[y5mgisi]

The new ones I did 35 on. The old ones were 45.

 

[GWeakland620]

Hmmm, that's what I was going to suggest.

 

[prolinews]

Have you heat scanned it since you changed the plugs?

 

[y5mgisi]

Scanned what?

 

[prolinews]

Scanned what?

Header temperature at each port again .

 

[y5mgisi]

Ah. No I haven't. I checked them after I got back from my test drive and had already shut the truck off and that cylinder was colder than the rest.