Wild Bill's Hot Rod

[Wild Bill 633 846]

In July, 2021 I meet Achto at the show in Portage, WI and we talked about lowered Rat/Hot Rod Wheel Horse tractors which spurred my interest. Two weeks later a 633 was purchased and this project started. After 9 months of design, engineering and solid modeling, the fabrication started. The first part to be fabricated is a custom 4-1/2" drop front axle based on the 520H swept forward axle with 1" spindles. The custom drop axle eliminates the camber issues when turning a stock axle upside down.

[Wild Bill 633 846]

The tractor is going to be powered with a Kohler Command engine, which is longer than the original engine, and to eliminate the LH tire turned left to blower housing interference a custom longer frame has to be fabricated.

[Wild Bill 633 846]

I want to improve on the Wheel Horse steering design, so a 90 degree gearbox takes the place of the original steering pinion and sector gears.

Edited August 26, 2022 by Wild Bill 633

[Pullstart 62,902]

What a creation!  

[953 nut 55,262]

2 hours ago, Wild Bill 633 said:

fabrication started. The first part to be fabricated is a custom 4-1/2" drop front axle based on the 520H swept forward axle with 1" spindles. The custom drop axle eliminates the camber issues when turning a stock axle upside down

Outstanding job, not too many of us do the thinking before the building.       I will be watching this thread with great interest.

[ebinmaine 67,538]

3 hours ago, 953 nut said:

Outstanding job, not too many of us do the thinking before the building.       I will be watching this thread with great interest.

Absolutely agreed!

 

 

5 hours ago, Wild Bill 633 said:

a 90 degree gearbox

What's the source of this? 

[Wild Bill 633 846]

2 hours ago, ebinmaine said:

Absolutely agreed!

 

 

What's the source of this? 

Boston Gear.

[wallfish 17,000]

Looks good ! I remember you posting pics of that front axle a while back.

Is there any gear reduction ratio for that gearbox? I think the original fan gear steering is about 12:1 reduction for approximately 3 turns of the steering wheel lock to lock.

[ebinmaine 67,538]

2 minutes ago, Wild Bill 633 said:

Boston Gear.

Can you please PM me or quote me here with a link? 

[Jayzauto 89]

4 hours ago, Wild Bill 633 said:

Boston Gear.

 

 

Yes, I'd be interested in one of those gear boxes too....  That is a fantastic design, very well thought out.    

 

Thanx, Jay

[Pullstart 62,902]

https://www.bostongear.com/products/enclosed-gear-drives-and-motors/right-angle-cast-iron-gear-drives/bevel-gear

[Wheelhorse#1 1,666]

Very cool project. Beefy gear box there.Looking forward to this one ! 

[Tractorhead 9,064]

looks radical Bill 👍

Great work 

[Wild Bill 633 846]

On 8/26/2022 at 1:07 PM, wallfish said:

Is there any gear reduction ratio for that gearbox? I think the original fan gear steering is about 12:1 reduction for approximately 3 turns of the steering wheel lock to lock.

If the 633 steering sector gear was a full 360 degrees it would have 72 teeth. The steering gear pinion has 10 teeth. Therefore the 633 steering gear ratio is 72T/10T = 7.2:1. It would be interesting to know what the 520H reduction steering gear ratio is.

The rack and pinion to be used has a ratio of 12:1. I think the 12:1 ratio will be satisfactory. I ordered the 90 degree gearbox in 1:1 ratio. If not, the gearbox is also available in 1.3, 1.5, 2 and 3:1 ratios.

Edited August 28, 2022 by Wild Bill 633

[Wild Bill 633 846]

On 8/26/2022 at 1:07 PM, ebinmaine said:

Can you please PM me or quote me here with a link? 

I am using the Boston Gear R1200-1-F, Item Code 06111. Use @Pullstartlink above.

[19richie66 17,508]

Very nice 👍 

[kpinnc 12,065]

Looks like a great build! 

[Wild Bill 633 846]

Since my last post I started working on building the engine which is a Kohler Command CH740-25HP. The engine will have billet aluminum connecting rods and forged pistons. The stock 2618 cast piston to cylinder wall clearance is 0.002". The 4032 forged piston requires 0.004" clearance. So the block went to the engine machine shop for honing.

The OEM pistons have a 12cc dish whereas the forged pistons are flat top, raising the compression ratio. The engine came with 23.2cc closed chamber cylinder heads. The resulting static compression ratio being 11.92:1. Machining a 2.2cc dish in the forged pistons, using a 0.062" thick head gaskets and 26.2cc open chamber cylinder heads reduced the static compression ratio to 10.08:1.

 

[Wild Bill 633 846]

The engine will have a roller camshaft and lifters. The block requires machining clearance for the lifter tie-bar.

[Wild Bill 633 846]

The engine will have roller rockers which require machining to remove the stock rocker pedestals and machining surfaces for the cylinder head insert to support the roller rocker studs.

Edited December 6, 2022 by Wild Bill 633

[Wild Bill 633 846]

The as-purchased roller rocker trunnions interfere so machining the end of the trunnions was required.

[Wild Bill 633 846]

I mentioned earlier a rack & pinion will be used for the steering. Had to machine the tie-rod mounting bracket.

[Oldskool 6,644]

Interesting looking rack.

Is that produced for something particular or is it a universal unit.?

[Wild Bill 633 846]

@Oldskool,

During the design & engineering phase of this project, it took 6 months to find a rack & pinion that would work with a center pivoting front axle so the tie rod ends would not bind. The rack & pinion is manufactured by Joes Racing Products for micro sprint cars.

Edited December 6, 2022 by Wild Bill 633

[19richie66 17,508]

You’re not kidding around with this one. Very nice