Restoring Rusty

[Gregski]

Good morning you'all thank you all for following along, the plan for this rainy morning is to weld in some O2 (Oxygen) sensor bungs into the LMC Truck dual exhaust and see what the Air Fuel Ratios look like (AFR)

this will serve as a baseline for tuning the carb before we put our dreaded Hooker competition long tube headers back on

and I got another exhaust surprise for you all

so here we go

[Gregski]

so rather than taking the perfectly good non leaking exhaust manifolds off I decided to weld in some O2 sensors and weld up these LMC Truck exhaust pipes cause it don't even sound half bad, so lets see how it breathes

[Gregski]

X marks the spot

the passenger side first...

this Harbor Freight step drill bit aint half bad

it ain't pretty but it will hold

[Gregski]

and passenger side all weldered up and ready to go on

[Gregski]

and on to the driver side, rinse, lather, repeat

[Gregski]

and driver side all weldered up and ready to go on

keep in mind this is the LMC Truck 2 1/4 exhaust system that normally would go over the axle and out the back, but not on this bad boy, we just turn it down out right quick after the mufflers

[Gregski]

So after allowing the truck to warm up and taking it down my test circuit here are the AFR numbers

Idle: 11/12 (that is too rich but easily adjusted with the two idle mixture screws)

WOT: 13/11 (this is what drives me crazy why are these not even? I thought we fixed the bad rings on the cylinders)

Cruise: 16/15 (So a bit lean)

and it backfires and chokes on acceleration in 2nd gear, so some carb tuning is in order

however when I blimp the throttle it revs up nice and even, no hesitation or spit and spatter there, so the accelerator pump seems dialed in

still running the 63/67 jet combos, may try 64/69

[Wide Open]

How does it sound? Any droning?
Posted via Mobile Device

[Gregski]

Originally Posted by Wide Open

How does it sound? Any droning?
Posted via Mobile Device

Great question, sounds good, like a baby 60's muscle car, ha ha

Comparison: not as loud as the Flowmaster Series 40 mufflers but louder than the Magnaflows

Yes there is a little bit of drone at idle for me thats at 750 RPM but even above 1000 RPM its very smooth

Silent at speed on a highway

For the money this LMC Truck dual exhaust is a very good choice for a do it yourselfer, easy install, Mike did a great job building it 40 plus years ago

[harley87ta]

good to hear rusty is still going

[Gregski]

Originally Posted by SkinnyG

Sounds like the distributor is out a tooth. Just pull it, turn it a tooth, turn the oil drive about the same amount with a LARGE flat-blade screwdriver, and plunk it back down.

OK, finally got around to doing exactly that. This allowed me to set the Initial Advance Timing to 12° instead of the 10° that I had, and I must say the truck runs much much better now, it now has some gitty up again

Note To Self: some day do a study of timing advance and the correlation to truck gitty up

[Gregski]

So more of Truck Doing Truck Things, picked up ALL this hot rolled steel at S&K Steel today for only $10 bucks (unlike the home improvement stores those prices I can live with - I'm looking at you Home Depot)

[Gregski]

so believe it or not we got enuff raw material here (ha ha) for not one but two projects

first we will build ourselves a Pipe Weldermatic Jig, so instead of clamping pipes to our patio table with C clamps and welding crooked exhaust we will jig them up in the angle iron on top of the two sliding plates to allow for weld beed rotation as such and we should end up with less crooked exhaust

[Gregski]

Alright, time for a mathematical word problem, (remember those from sixth grade math)

Here we go, Greg drove his green truck to S&K Steel to buy 5 pieces of steel. He used 3 pieces for his welding jig project. He still has another project to do. What color is Greg's truck? ha ha

[Wide Open]

Sunset orange. Aka rusty 😉

I get what the angle iron is for but what are the two pieces of flat stock used for with the welding jig?
Posted via Mobile Device

[79sierra]

Originally Posted by Wide Open

Sunset orange. Aka rusty 😉

I get what the angle iron is for but what are the two pieces of flat stock used for with the welding jig?
Posted via Mobile Device

I am guessing it is for the weld so the pipe can lay flat.

[Wide Open]

Originally Posted by 79sierra

I am guessing it is for the weld so the pipe can lay flat.

Ahh, I see. Makes perfect sense now. Thanks.

[Gregski]

Originally Posted by Wide Open

Sunset orange. Aka rusty ��

I get what the angle iron is for but what are the two pieces of flat stock used for with the welding jig?
Posted via Mobile Device

some exhaust pipes have a flange on them allowing you to slide one pipe inside the other, the flat stock is to raise the pipe enough so that it still stays aligned with the other pipe

I may have not made it obvious with just the two long pieces until today I realized the vertical wall will need spacer too, so I divided them by 2

[Gregski]

Originally Posted by 79sierra

I am guessing it is for the weld so the pipe can lay flat.

yep, the spacers allow for full 360° rotation of the pipe whilst welding, so the bead doesn't touch the wall and make things crooked

note the offset spacers to the right, in other words they ain't in the middle of the angle iron, that's to allow for the pipe to be welded to the muffler

[Gregski]

so I am having to add 1.5 quarts of water to the radiator after a week of driving, roughly 200 miles, I aint too happy and I don't know where the water be going

one more observation, last time I topped off the radiator on Saturday and on Thursday I noticed it was just over 1/2 a quart low (20 oz) this is peculiar since I did not even drive the truck for those 5 days this week

things that make you wanna go "Hmmmm"

[Gregski]

time to go to our Thinking Chair

(some of you with no kids may not get this)

[Gregski]

so went and visited Nichols and Sons Machine Shop in Sacramento and the only person nicer than the guy I talked to was his dan Glenn and the only nicer person than him was his dad, Mr. Nichols I presume, these guys are wonderful

so got some quotes

$20 bucks to magnaflux cylinder heads (brought in assembled minus the rockers)

$80 bucks to pressure test them (this does not include the magnaflux and if they decide to pressure test them they do not magnaflux them)

I assume that's per set, and not per head

but that got me to a thinking, what will the Greg a learn if he just drops off the heads and the Nichols tell him they is cracked or leaking... nothing

but if he do it himself, he will be that much smarter

so far our materials are:

$10 bucks for the steel plate

$10 bucks for three pieces of 1/4 inch thick 3 inches wide by 20 inches long black rubber in the pic on the far left (safety first) ha ha

[Gregski]

alright so first we gotta make some metal shavings

[Gregski]

man that plate looks nice, I would totally tap that

[Gregski]

so let's try it on for size