Builds An Accidental Frame Off.................. (2 Viewers)

[rkymtnflyfisher]

So I put a tank of fuel through it over the last week or two, all with the front hubs locked in, some of ot with the t case in 4 hi.


8 mpg


I should probably investigate this. It's never been that low, even in 4hi running up to the ski hill. Anything under 10 mpg is a huge red flag for me.

 

[rkymtnflyfisher]

Valves all looked good. I'm impressed with how clean it looks under the valve cover also.

 

[Green Bean]

Wow, that is super clean. I wonder what the explanation is for the "low" mpg. Maybe just a anomaly and your next tank will return to normal?

 

[rkymtnflyfisher]

Right to left, front to rear.

 

[rkymtnflyfisher]

Valves were all pretty good, nothing that was obviously wrong, or much more than maybe a fuzz off. Plugs all looked decent, #6 looks like it just came out of the box, #5 no so much. The timing was right where I set it a few months ago, the BB just visible at the bottom of the window.

Vacuum was about what it always is.

I didn't adjust anything on the carb, sprayed it with carb cleaner a little.

Hopefully tomorrow I can get time to put the front up on stands and look for something amiss with the front driveline.

 

[rkymtnflyfisher]

Wow, that is super clean. I wonder what the explanation is for the "low" mpg. Maybe just a anomaly and your next tank will return to normal?

I'm hoping it was just because I had it in 4hi for almost the whole tank of fuel. I did have a crazy vibration at around 45mph one evening, I stopped to check it out but didn't find anything wrong. Maybe it was just snow stuck to a tire or something, I'm not sure.

 

[middlecalf]

Curious as to what spark gap you‘re using. You are turning a bit more hardware in 4wd.

 

[rkymtnflyfisher]

Curious as to what spark gap you‘re using. You are turning a bit more hardware in 4wd.

Whatever the OEM spec plugs are, I checked them when I put them in over the summer, I didn't see any reason to check today.

 

[rkymtnflyfisher]

Pics from back in April

 

[thatcabledude]

“Winter formula” gas playing a part?

 

[Green Bean]

Pics from back in April

View attachment 3174034View attachment 3174035

Careful here. It is a slippery slope from pulling plugs to a compete engine tear down. I think that you've been down that road.

 

[Grayscale]

Maybe you need cardboard in front of the radiator? I'm considering exhaust wrap on the arm of the intake manifold going to cylinders one and two because it happens to me too.

Pressure x Volume = n x R(constant) x Temperature - lower temp of air at the carb means that n (# of moles of atmosphere) has to go up just from the temp drop in the volume of the intake side. The air pressure in my tires has dropped without letting any out...
'Open Loop' in the carburetor world = running with the power valve open. It corrects for the above and would be a means to get more gasoline thru the system without having mechanical issues like overflowing float bowl, etc. My choke open, warm temp carb in summer has a really low idle at the red lights. In winter I can hear the engine above the radio, and idle is way up.

Your plugs suggest to me that fuel mix looks a bit lean - tan, not white is normal, but, I don't know that plug heat range? I use NGK BPR5ES, and Denso. My worst gas mileage was 8mpg. My best was 15mpg.

Coasting down the hill, other rig, the other day. Just idling down the mountain caused my aftermarket radiator to source my motor with serious cold coolant, and my block got so cold, that I had to choke it after I eventually had some landscape to ascend. The thermostat might be worth testing. Desmoged air intake, and removal of the original hood insulator is going to make for quite a bit more space to move air around there, and I have trouble keeping the aftermarket carb warm.

 

[rkymtnflyfisher]

“Winter formula” gas playing a part?

That's a legitimate question, I do know they use a diesel blend that sucks ass in the winter, but I'm not sure about the gasoline. Maybe I'll check out the placard at the pumps next time.

Although if they did use a winter gasoline blend all of other vehicles in the household would show it also. My wife's Tahoe got super s***ty milage on the last couple of tanks.

All in 4wd auto on that one.

 

[middlecalf]

Not implying this has anything to do with your mileage drop, and it might just be the picture, but I asked about the gaps because your’s look more than the 0.031-0.035” the F-manual specs out. Not sure what 2F specs are if that’s what you have. Winter blend thought is interesting, didn’t know they did this in gasoline, know about the diesel winter blend. I run non-ethanol in my old cruisers to avoid alcohol issues and aging out issues.

 

[120mm]

That's a legitimate question, I do know they use a diesel blend that sucks ass in the winter, but I'm not sure about the gasoline. Maybe I'll check out the placard at the pumps next time.

Although if they did use a winter gasoline blend all of other vehicles in the household would show it also. My wife's Tahoe got super s***ty milage on the last couple of tanks.

All in 4wd auto on that one.

Back when we lived in Iowa, we simply ignored mpg when temps dropped to 10 degrees F or so.

Cold weather is hard on mileage.

Though the observations about putting cardboard in front of the radiator are sound. For engine health it's imperative to get temps up as quick as possible (without overheating, of course).

 

[rkymtnflyfisher]

I run a direct drive fan also.

 

[rkymtnflyfisher]

Not implying this has anything to do with your mileage drop, and it might just be the picture, but I asked about the gaps because your’s look more than the 0.031-0.035” the F-manual specs out. Not sure what 2F specs are if that’s what you have. Winter blend thought is interesting, didn’t know they did this in gasoline, know about the diesel winter blend. I run non-ethanol in my old cruisers to avoid alcohol issues and aging out issues.

Those plugs were installed in April of this year, I didn't see anything alarming with them when I had them out yesterday. The mileage drop was with the last tank, subzero temps, snow covered roads, and 4 hi almost the whole tank.

I'm guessing it's more of environmental factors than anything mechanical.

I still need to double check the front driveline.

 

[rkymtnflyfisher]

Valves all looked good. I'm impressed with how clean it looks under the valve cover also.

View attachment 3173864

That's 20K on the engine after the rebuild.

 

[pb4ugo]

They do have winter blended gas. I know it doesn't burn as clean, and you probably have been burning it for a while. The Govt doesn't know how much us peasants use our beaters, so the have to sell it months or weeks in advance of winter temps. Summer diesel will gel up somewhere around 15* and will not flow.

 

[1911]

Right to left, front to rear.
View attachment 3173908View attachment 3173909

Those all look really good!