She's got the shakes, need help locating the cause.

[DoubleDingo]

I've heard many things on octane and don't run the high octane fuel in a run of the mill engine. I used to drive back and forth for visitation all the time. To get out of here is a mountain you have to climb. 87 octane the transmission would kick down into drive sooner than when running 91 octane, and it pulled hills much better running the 91. Got better mileage with 91 as well. That is in my '91 Jeep Cherokee. It has cruise control and a tachometer so replicating the conditions it can get fairly close, by setting the cruise at specific rpm. When I still lived in my hometown I had access to 100LL at the airport. I'd put 5 gallons in each tank and top off with 91. Manual transmission trucks so passing was just mash the throttle and go, and with the high octane each truck ran way better. Heck I even ran 100LL in my little 3.5HP Briggs & Stratton lawn mower and it cut grass better with the high octane fuel in there.

 

[Rusty Nail]

Wonder what else i can find in the diffs and case.
It's like a treasure hunt.
But instead of treasure,
It's trash, and ****, and booby traps.

That was really funny!
The little plastic part that came out? What color was it? The speedometer gear is in there, does your speedo work?

 

[Bextreme04]

Science says one thing, but I beg to differ.
If the motor runs better and uses less gas then with e-gas, or anything lower, then why wouldn't run high octane.
Burns cleaner to, don't it?
I can tell a difference on my non high performance motor, it does give benefits as far as I can tell, to everything I've owned.

My old school bmw seemed to be the same, I never ever put low octane unless I had to, and would drive around on e to find non ethanol. E85= oh 200 miles on a tank at most,91 clear I could get 400-450 miles out of a tank. And ran way better. But that's what she was tuned on from stock so..
I haven't crunched the numbers yet for the truck but when I do ill post results.
Data is key and I can tell difference between octane. And different gas stations too sometimes if they have lower quality or watered down gas then they post.
Any lower octane has always diminished mpg as well as ethanol(more contributing then the octane rating) in any of my vehicles I've ever owned, talk in 1990s and before.
If it didn't give any benefit to my non high performance ****, I wouldn't care what gas.
Be that as it may, we can disagree, I'm not saying your wrong I'm just saying what I have felt and seen and logged in my experience is different.
Dumb question:
if it has more octane (measurement of the power potential in the fuel, right? )And no ethanol, (which density wise alone causes problems as far as mixing air gas and ethanol into the right mix per area) then couldn't you lean out your mix, get the same power with less fuel?

That's kind of the problem though, science can explain exactly what is going on there. Correlation is not necessarily causation.

I'll try to address all of these at once without going to in depth. The octane rating does not have anything to do with power potential of the engine. An octane rating is a measure of the stability of a fuel. It also does not have anything to do with how clean the fuel burns. The octane rating is a reference number between Octane(Rating of 100) which is a hydrocarbon that is very resistant to auto-ignition, and Heptane(rating of 0) which is super unstable. Here is a link to a more in-depth description of what octane is. https://www.eia.gov/energyexplained/gasoline/octane-in-depth.php


Now, as to having more power and better mileage. If you are using 87 Octane almost anywhere in the US, it has at least 10% ethanol. Gasoline(of every octane level) will have an average energy density(the actual measure of a fuels power potential) of about 33,867 MJ/m^3. Octane has almost the exact same energy density but unfortunately the fuel manufacturers are not adding octane to the fuel to get the fuel octane rating up. They get the rating up by adding fuel stabilizers that are cheap and don't burn as clean. In a lot of places, you can't get non-ethanol fuel. In Oregon, we can get ethanol free 93 octane, but it is almost double the cost of standard 87 octane. Ethanol has an energy density of 23,278 MJ/m^3, which means that right off the bat it takes 1/3 more fuel to get the same power output. Most modern fuel injected cars can automatically detect the amount of ethanol in a fuel and adjust the fueling tables accordingly. It is really not that big of a difference though.

Ethanol actually burns MUCH cleaner than hydrocarbons, but it has a lot of downsides in certain situations. Lots of high performance applications use methanol and ethanol either supplementally or as the main fuel. Forced induction especially likes it because it cools the intake charge and quenches the combustion chamber while resisting detonation. The downsides generally come from old applications or lack of use. Namely if you don't drive it regularly, or let the fuel sit for any amount of time, it will pull water in and start to break down the fuel very quickly. Also, older and cheaper fuel system components aren't made to handle ethanol and will break down quickly.

In a carburetor application, it has no way to know what is being run. The carb puts the same amount of fuel in for a specific air charge regardless of octane rating and the timing is the same no matter what. If you are getting a big bump in power and mileage on a carbureted engine, you have the engine tuned for premium and it is probably detonating on 87 octane. If you have it tuned fro 87 octane, you should see no difference putting 93 octane in.

For fuel injection, you shouldn't see any difference. The engine will automatically adjust timing and fueling tables to keep the engine from detonating and keep it running at peak efficiency.

 

[Goldie Driver]

Your right.
Now the leaks have been plugged, I feel more comfortable with changing fluids.
Water, dirt, well used oil...who knows how much is in there. been on the to do list for a bit.
T case needs atf needs changed to,plus it's low. . It spit out this little plastic piece when I pulled the drain plug checking it the other day. Wonder what else i can find in the diffs and case.
It's like a treasure hunt.
But instead of treasure,
It's trash, and ****, and booby traps.

Them dam thangs will trap and suck away all your money.

Leastways that is what I hear Rusty tell ...

 

[Turt13]

Speedo is hooked up and worked, but the meddle was only half there and made it hard to tell where it was pointing. So when I took off the dash cover to get to it and try a needle from the scrap yard my lady got, and touched the one that was still on there, it decentagrated. Or how ever you spell"fell into pieces" all fancy like. So it worked, but no telling atm if it still does.

Thanks for more info on octane n such, clarifying some thoughts I previously had on it, n such.
I did know how ever that methanol was used in high performance and fi set ups, and that it kept **** cool, did not however believe ethanol was used to much in high out put set ups really,. unless it had a nitro set up, from what I heard the nitro and ethanol mix in an amazing way.
There is 87 and 91 clear here, I'll log some data n such on both kinds. Then tune for each and do it agian. Shouldn't take to long seeing I'm only getting about ~8mpg atm anyways.
Thanks for your awesome input.
Found some interesting things under the valve cover.
Even have pictures, ahem, rusty.
More on that later.
As for now, I'm going to go sit and stare at this hunk of thirsty metal and see what I can get accomplished, if any thing.

 

[Turt13]

That was really funny!
The little plastic part that came out? What color was it? The speedometer gear is in there, does your speedo work?

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

 

[gotyourgoat]

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

That's the plastic thing you found? Looks more like part of a dead bug than an automotive part.
There is improper use of a glove box in those pics. More importantly what is up with that driver vent window? Diamond plate with wiring?

 

[Turt13]

Like I said, the longer you look at these pics the worse it gets.
It's for sure not a bug, thinking it looks that way from being ground down from the chain, iirc the spaceing on the chain and linkage kinda looks similar to the unidentified t case object( uto for now on).
Yes steel diamond plate, welded tf on, prolly 1/4 in thick. With a duramax mirror monted crooked, and only the driver side, and wires ran in but hooked to nothing. Don't get me started on the doors.
Would have it all primer by now, at least it'd be one color, but I have new decent doors from a donor I'm going to go get.
The glove box didn't want to open when I got the truck, and when I finally got it open it fell out. It's back home or that'd be another project. But I have come to like the foot rest.
What I'm trying to say is I got 'okie-doked' from the p.o.
Everything looked ok ish, not even, but was enough to fool me into buying it. Shoulda looked closer, but how do you learn.?
But that's who im getting the doors from, the p.o. he had a set for me when I bought it but with moving i didnt have room to take them or time to **** with them. Being back down here I asked him if he still had the doors. He said he sold all the square body parts he had, and then I think he felt guilty for the price he got out of me and 'okie-dokeing' the truck. Cuz now he's all of a sudden got another 81, exactly the same but a c20, not k20, for a few parts for his 88 3+3.
Said I could have what one needed.
Hell yeah.
So, Rusty, this is for you. Iirc this was maybe the first suggestion to my post: grabbed a check valve for the brakes at the yard right?
Blew through it like a dui test, functioned perfect.
Pulled one off my truck yesterday and tried to do the same thing, basically no air went through, either way.
Put the scrap yard one on.
It helped.
Could that be why my master was leaking? Blocked check valve?

 

[Rusty Nail]

that's a good lookin horn button you got there.

 

[Turt13]

that's a good lookin horn button you got there.

it's Just a little horny.
But it's cracked too.

 

[Turt13]

Look at this stud. Rocker was way to loose. Found the little train noise I was having.

You must be registered for see images attach

and here, look closely and you will see a small chip on where the rocker sits on the valve spring

You must be registered for see images attach

Theses two push rods seemed straight. Only two I pulled out, seeing I dont know how to set these valves right.
Which brings me to a question.
How do you set your valves?
I could easily do valve adjustment on my cars, but they were not hydraulic.
What is the the clearance? Or do you even use a feeler gauge? Last time I did them
I found tdc on 1, did half of the vavles, rotated the motor one turn for tdc on 6, did the other half. I dont remember which vavles were done with each position. Have it written down some where. And did it by feeling for resistance while I was spinning the push rod.
But had a friend help who said he knew what he was doing. Obviously he didnt, or made a mistake somewhere.,
Not how I would have liked to do em.
Bout to do u joints this weekend.
At least on the rear driveshaft.
Anything I should know about doing them?
What is the correct size for the two joints?
The one I was looking at, Spicer, has one that says it fits the rear one on a one piece shaft, and says it would fit on the front if it was two piece.
Are the two the same size? Or is the front ujoint different?


Took the face off the gauge cluster, kept digging till I found the bulbs. Only one was working. Realized, the face of the cluster and lens and etc didnt have to be removed to replace the lights, you can get to them by reaching up behind the dash and twisting them a half turn and pulling them out. Got it all put back together now a turn signal light stopped working. Doesn't seem like you can get to those without taking the face off. Of course. Here's a pic. Its fkn lit.

You must be registered for see images attach

Way better, now just need to fix the speedometer needle. I hope.
Oh installed vavle cover load clamps on psg side finally. And here is how far my dizzy is twisted. Is this normal? This is where my vacuum gauge read the most steady at 20, really steady. Has a slight drop every once in a while. Remember I'm at 6,500 ft. So 20 here is more like what, 15?

You must be registered for see images attach

 

[Turt13]

Well, a long weekend and a couple projects later, shes back.
No more shakes, and shes got power back.
I replaced U joints on the rear shaft, changed t case fluid, changed rear diff fluid, and put in some cheap autolite spark plugs.

Thanks for everyone's help. Still have a grip of projects, but we will get to that.
For now I'm going to take a break from even touching the truck for a couple days. Been doing something to her every day for a couple weeks now. And I'm fkn sore.

I'll post some pics of this weekends shenanigans in a bit.

 

[DoubleDingo]

How did that elephant taste? A little less of it to eat now.

Looks like you got the valves adjusted. The distributor looks about right, maybe one tooth off to get it straight with the firewall, but I'd leave it as-is because the final orientation of the distributor once the everything is timed correctly has nothing to with how the thing performs. If it is not in-line with the firewall and it runs good, it doesn't matter, yes it looks better when it is in-line with the firewall. But to do so you would have to remove the distributor, turn the oil pump shaft a smidge clockwise and reinstall the distributor, and then re-time it again. Not worth it when it is that close and you have it pulling 20 vacuum, 20 is excellent.

 

[Rusty Nail]

I agree. If your pullin 20 inches quit touchin it.

 

[Turt13]

The vacuum had a slight drop everyone in a while, but I can't remember if that was before or after i found the loose rocker.
I was going to hook it up again to detune/lean her out a bit.
Shes got power back, and my ladys lead foot is back as well. To much gas $. plus shes got a mean backfire decelerateling, pretty much only on hill or after you get on it. the exhaust leak at the header flange and collector inst helping that either I'm sure.
But what I found should get me an award for this treasure hunt. I for damn sure didnt find any treasure. Well, maybe the Spicer shaft and yokes were. Idk. I dont think these u joints had been done since 99, from the date marking on the shaft. Here's a little taste of what I found:

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

And this is the old gasket, new one is blown out on the same cylinder. Which is the spark plug on the far right, first pic.

You must be registered for see images attach