Heavy Fuel - Page 13

somewhereinusa · 07-10-2016, 06:41 PM

Many truck tire sites give a rolling circumference dimension which is more important for the calculation you are doing.

Brad_SwiftFur · 07-10-2016, 06:59 PM

Quote:

Originally Posted by M1031A1

Ok, one *perhaps* stupid question, anyone know what the height of an 11R22.5 tire and a 12R22.5 tire should be and what the differences in height are?

I'm trying to see if I can bump up the top end while keeping the engine turning @ 2K rpm. Preferably getting Heavy to get up to 65 mph by changing tire size. So far with the help of Tango's calculator I have figured going from 11R22.5 to 12R22.5 gets me close to 60 mph from 48 mph. Yes, a big jump, but not quite big enough. The question is am I using the right calculations such as tire height and (I believe) the 643 tranny having a 1:1 final ratio going to the drive shaft. I do know I have a 5.29 gear ratio in the rear axle, but the rest I can use a little bit of help on to be sure I can get 65 mph @ 2K rpm with 12R22.5 tires. Just trying to save some $$$$ before spending any........

Thanks all!!!!

M1031

The 11R22.5 tires are very common and easy to find. The 12R's, not so much. Personally, instead of spending well over $1000 on new tires (and still not getting much over 60 MPH), I think you'd be better served by changing the rear-gear ratio. If you plan to put a lot of miles on it, you'll likely save that much in fuel over time. I looked into this for mine; removing and replacing the axle "chunk" myself, having the gears professionally changed (and warrantied) will set me back around $900 ... plus gaskets (I forgot to ask if the swap would include them), and of course a gallon or 2 of gear oil.

My Volvo runs something like 3.53 gears, Lo-Profile 22.5 tires, ISX Cummins and 10-speed trans; it has a top speed well over 80. It turns around 1600 RPM at 70 or so.

M1031A1 · 07-11-2016, 10:04 AM

Yeah, I did some number crunching and I'll get a better bang for the buck by swapping out the gears for 4.11s. Thanks for all the feedback!

M1031

cadillackid · 07-11-2016, 10:51 AM

the other thing to rtememberr is driveability changes the bigger the tires you go on the same size rims.. taller tires are usually wider so you'll have a little more feet on the street... plus there is more flexible material between the road and your steering wheel.. so you may have the tendency to get the bus in a sway motiomn a bit as the steering responses become slightly dampened with each tire height increase...

getting new gears has the advantage that you have a fresh set of gears in the rear... plus when the driveshaftys are down id have the U-joints changed in those too...

-Christopher

juliol · 07-11-2016, 04:51 PM

Quote:

Originally Posted by M1031A1

Yeah, I did some number crunching and I'll get a better bang for the buck by swapping out the gears for 4.11s. Thanks for all the feedback!

M1031

Hey M1031A1, I have the same set up as you, did you eve find out where to get the gears?

J

M1031A1 · 07-11-2016, 09:52 PM

Quote:

Originally Posted by juliol

Hey M1031A1, I have the same set up as you, did you eve find out where to get the gears?

J

J,

I'm STILL looking! I'm calling Eaton tomorrow as well as Spicer to see IF they have ANYTHING I can use to get the 4.11 conversion done. Short of that I'm now starting to seriously consider an axle swap from a semi-truck. That may be the way I finally go. Have some more calling to do tomorrow. Will have results from my search tomorrow evening. On a more positive note Blumenthal's has my sheet metal work ready for the windows I'm blanking out! Pics to follow when the blanks are up and secured!

Oh yeah, before I forget (again) Brian called me about his problems breaking drill tips. I got the message, but without a phone number, it's kinda hard to call back......... So, Brian, PM me when you read this.........

milkmania · 07-11-2016, 11:00 PM

No worries... I had someone else bring me some more bits! They were closer than Texas!

Quote:

Originally Posted by M1031A1

J,

I'm STILL looking! I'm calling Eaton tomorrow as well as Spicer to see IF they have ANYTHING I can use to get the 4.11 conversion done. Short of that I'm now starting to seriously consider an axle swap from a semi-truck. That may be the way I finally go. Have some more calling to do tomorrow. Will have results from my search tomorrow evening. On a more positive note Blumenthal's has my sheet metal work ready for the windows I'm blanking out! Pics to follow when the blanks are up and secured!

Oh yeah, before I forget (again) Brian called me about his problems breaking drill tips. I got the message, but without a phone number, it's kinda hard to call back......... So, Brian, PM me when you read this.........

Brad_SwiftFur · 07-11-2016, 11:19 PM

Quote:

Originally Posted by M1031A1

J,

I'm STILL looking! I'm calling Eaton tomorrow as well as Spicer to see IF they have ANYTHING I can use to get the 4.11 conversion done. Short of that I'm now starting to seriously consider an axle swap from a semi-truck. That may be the way I finally go. Have some more calling to do tomorrow. Will have results from my search tomorrow evening. ...

I simply called Atlanta Gear (I think that's the name of them); they are a heavy truck axle/transmission shop in Atlanta. I'd look for something similar in a major city near you. Doing the actual gear swap yourself is *NOT* recommended unless you really know what you're doing, something about adjusting the spacing on the ring gear, adjusting something on the pinion, adjust, adjust, adjust. Bah! Let the experts do all that, I'll just unbolt the "chunk" and bolt in the new one (plus they warranty it if they do the work). Yeah. I can manage that.

M1031A1 · 07-18-2016, 05:43 PM

Well, I've been trying to update my thread. Got my locking cargo bay door handles Friday. Third time trying to post the pic... So here it goes.....

crazyinga · 07-29-2016, 09:41 PM

I'm a newbie and was reading another conversion that had a rear end problem. He has a source that you can exchange pumpkins. Hope it helps. Louis

http://www.skoolie.net/forums/f11/the-wait-is-over-5819-13.html

M1031A1 · 07-31-2016, 06:44 AM

Crazy,

Thanks for the info. However, I believe I have found the solution. It's not cheap - due to the fact this Eaton axle is not produced anymore AND it's not common either..... However, I can get the 4.11 ratio I'm after. More to come after I get this HAM radio antenna array finished at a dear friend's home. He's got FCC approval for experimental/prototype antenna R&D for certain frequencies and I'm the first to be hired if this comes to fruition. New tires are being put on this week and the rear end will be worked on shortly thereafter. Lots to post in August.

M

Tango · 07-31-2016, 09:58 AM

Hoiwdy M --- Glad to hear you have a gearing solution. Should make quite a difference on the highway. And...can't wait to hear more about the Ham array. I believe any serious boondockers should have radio capabilities.

M1031A1 · 08-01-2016, 08:17 AM

Missed the UPS delivery of our Webasto Friday by 90 seconds. Wife will be here all day today to get the UPS delivery. Pics to follow!!!!!

M1031A1 · 08-01-2016, 08:44 PM

Webasto arrived today WOHOO!!!!!!

Right now I'm too tired to do anything since I've been drilling holes in a hard clay/iron ore ground all day long to get this antenna array up by the weekend..... It's going to be SO worth the effort!

Pics will be coming soon I PROMISE!!!!!!

milkmania · 08-01-2016, 08:52 PM

Quote:

Originally Posted by M1031A1

Webasto arrived today WOHOO!!!!!!

Right now I'm too tired to do anything since I've been drilling holes in a hard clay/iron ore ground all day long to get this antenna array up by the weekend..... It's going to be SO worth the effort!

Pics will be coming soon I PROMISE!!!!!!

M1031A1 · 08-04-2016, 08:05 AM

Well, here's what $2500 looks like. Now that I have some safe tires it's onto the gearing in about two to three weeks...... 4.11s here I come!!!!!!

Those are Kelly Springfield 11R 22.5 tires. Now I gotta continue the antenna array. Pouring concrete today! WoHOO

!!!!! Next is standing up 20 feet of tower and concreting that, leveling the towers then putting up an additional 10 feet per tower, with one section getting 30 extra feet. Made my own gin pole too!

M

Justin McCormick · 08-04-2016, 08:11 AM

Nice. Nothing like a fresh pair of new tires!

FlyboyHPD · 08-04-2016, 08:28 AM

Quote:

Originally Posted by M1031A1

Well, here's what $2500 looks like. Those are Kelly Springfield 11R 22.5 tires.

M

Very nice. Is that about the going price for those or did you shop around and get a good deal?

M1031A1 · 08-04-2016, 09:10 AM

Quote:

Originally Posted by FlyboyHPD

Very nice. Is that about the going price for those or did you shop around and get a good deal?

I shopped around. D.H. Tire on McCarty had the best price in town. Six new KS for $2488. The fronts are balanced, and it also includes the disposal fee.

dan-fox · 08-04-2016, 10:06 AM

Quote:

Originally Posted by M1031A1

I shopped around. D.H. Tire on McCarty had the best price in town. Six new KS for $2488. The fronts are balanced, and it also includes the disposal fee.

I had wondered about balancing on bus tires. This is the first I've heard it mentioned around here. Gotta-have or nice-to-have?

You may also like: