g741.org

AAM's 11.5 is weak-sauce... well, at least compared to what I plan on eventually getting.

I'm eventually going to stick a Spicer FDS75 and Timken N175 in it. Thats 7500 lb Capacity front, and 17.5K rear...

Unlike rockwell toploaders, they are a sane width, and sane gear ratios: everything from 4.30:1 all the way to 9.5:1...

A guy on youtube has em in a 1966 IH that weighs 3 tons, has a 500 HP 502 BBC, and 49" swampers with chains. they hold up no problem.

Did I mention they have a 16.5" ring gear?

The music sucks, just mute it... you can see them compared to a D70 differential at 2:45:

http://www.youtube.com/watch?v=PONdJcZz ... re=related

As for power, if it doesnt make north of 700, I'll be really, really dissapointed...

oh, if you're wondering what a twincharged motor sounds like...

right click, save target as:

http://www.hilmersson-racing.com/bilder ... msning.mpg

It's worth the download. 2.5L makes almost 600 HP.

So you want your tires to stick out too? I know what you and I both have gone through to hook up Dana 60s...I wonder what engineering you will have to do to make those axles work?

no, I want them under the truck. I think with flat faced rims, they would be under it, but he has some pretty deep dished rims on his that cause the stance to be so wide. Part of it is his tire choice. tehy are so wide, he has to run that much dish just to keep them from smucking the frame when he turns.

Interesting...

Was a sharp looking IH untill the awful stainless fender flares.

Axles are interesting, but I question his driving style. We've got guys up here regularly running 1000hp and 1500lbs of torque through thier AAM rear diffs and not breaking them - Mostly towing mind you, but still.

Plus if any big block is run through dual transmissions then parts are surely going to fly. Nothing will standup to that much gear reduction, even the diffs he's got under there now won't take that type of abuse for too long.

I would still consider the 2.5 or 5 ton rockwell. After the Ouverson Engineering upgrades to the brakes, they are just as narrow, and just as strong with the spur gear setup. Put the 2" chromo inner shafts in it, and forget about it forever. You'll appreciate the 6.17 gears when running tires any larger than a 44. 6.17's and 44's would run at 3065-ish rpm at 60mph in 1:1. With a trans with a 30% overdrive it would roll around 2100rpm at 60mph. Thats almost perfect operating rpm for any Big Block.

Consider also the effect on offroad performance that those big diffs take away. On 49's his ground clearance at the bottom of the diff is only 2.5" more than what I have under my Toyota on 36" tires. He looks big, mean and dirty, but I think He'd have a difficult time keeping up cause he's too wide, and too low.

Plus his boat is way over the trucks GVW at 13000lbs. Regardless of whatever diffs are under it. If ever in an accident, an insurance company lawyer would have a field day with his towing setup. It would have been better off to just buy a used IH rig to tow with.

Its like the old saying - "sometimes less is more...."

Ok - rant over.... Sorry for the hijack Josh. I will give props for the guys engineering skills - the custom flywheel to mate that trans to the engine was pretty slick.

Ray,

no problem, all good points. I like constructive arguements.

The ouverson hub conversions are nice, but dang are they pricey. Do you know what the mouted width is on them, WMS to WMS?

The rocks have two HUGE draw points. 1, the diff clearance, especially cut down, and two, the toploader takes about 9" of drop out of your shafts for more friendly driveshaft angles.

HOLY SMOKES!

Ouverson is offering a bevel gear 4.9:1 kit for the rocks. With a 42" tire, that puts you right at 2350RPM @ 60. Perfect for a big block, while still giving you enough off road gearing.

https://store.oemaxle.com/product_info. ... 35c1b57bc4

Josh wrote:The ouverson hub conversions are nice, but dang are they pricey. Do you know what the mouted width is on them, WMS to WMS?

Off the top of my head, no, but I do know that its common to shorten the front axle housing about 7" and run two short side shafts. This shortening makes the front housing the same width as the SRW rear axles. Plus the wheel hubs can be installed backwards, thus narrowing it up even further.

IMS you're running an Nv4500 right? If so, then I wouldn't worry about the stock gearing. 5th gear on the Hwy. is going to run at a reasonable rpm so save a few bucks. Its not like a few rpm is going to make much difference, a twin turbo BBD isn't going to be much of a mileage star anyway...

Josh wrote:oh, if you're wondering what a twincharged motor sounds like...

right click, save target as:

http://www.hilmersson-racing.com/bilder ... msning.mpg

It's worth the download. 2.5L makes almost 600 HP.

I can't see the clip. When I try to open it, all I get is a blank white page that says "done" at the bottom.

Chuck, just right click on the link and select "Save Target As" and save to your hard drive
nice clip BTW, sounds more like a motor than an engine!!

Regards - MM

Master Yota wrote:

Josh wrote:The ouverson hub conversions are nice, but dang are they pricey. Do you know what the mouted width is on them, WMS to WMS?

Off the top of my head, no, but I do know that its common to shorten the front axle housing about 7" and run two short side shafts. This shortening makes the front housing the same width as the SRW rear axles. Plus the wheel hubs can be installed backwards, thus narrowing it up even further.

IMS you're running an Nv4500 right? If so, then I wouldn't worry about the stock gearing. 5th gear on the Hwy. is going to run at a reasonable rpm so save a few bucks. Its not like a few rpm is going to make much difference, a twin turbo BBD isn't going to be much of a mileage star anyway...

Problem with flipping the hubs in is hub brakes don't clear the spindles anymore. the hubs have to stay out, and when you cut out 7" on the long side, that 10" tall diff is now centered... right under the oilpan.

Im runing an NP445. ID love a 4500 but Im to cheap to pony up for one, and if I get one, it has to have the married 205 behind it, with a dodge input, which is a rather rare animal.

I hunted over on pirate, and the Ouverson hubs make it 75" wide WMS to WMS. They also still allow for dis brakes.


Unfortunately, at $400 for the hub, and $650 for the brake, Thats over $1K bucks a hub. Add in the cost of rebuilding the axles with lockers and new bearings, bushing, seals, atc and you are looking at an easy 6-7K bucks. for half that, I can build a set of Danas that will take one hell of a thumping.

Monkey Man wrote:Chuck, just right click on the link and select "Save Target As" and save to your hard drive
nice clip BTW, sounds more like a motor than an engine!!

Regards - MM

That's all blower whine... the growl in the background is the actual enigine, and the Whssssssss, is the turbo. I like watching the timing belt arc up in the middle between the cam gears when they put her under load.

Thanks for the guidance, MM. Don't know why I didn't follow the instructions in the first place.

Anyway, there's something "sinful" about that engine. Reciprocating, internal combustion engines just aint supposed to turn that many RPM. That exhaust header looked like it was about ready to melt, too! That thing just plain scares the crap outta me!

being an engineer, Im obsessed with efficiency, and nothing says efficiency like 600 HP out of a measy 2.5L!!!!

well, time for an update. The superchargers are, of course, driven off the crank. I calculated the belt loading and such for the pair of blowers, and need a 1.5:1 ratio to give me 5 PSI of blower boost over atmospheric, or, a pressure ratio of 1.35.

That may not sound like much, but, with compound boost, the ratios are multiplied not added, so, if I run 10 PSI off the turbos, or, a pressur ratio of 1.7, I dont end up with 15 PSI of boost, I end up with 19 PSI of boost. It's important to let the turbos do most of the work, as the blowers are not as efficient, and, the point of the blowers is more to scavenge the cylinders than provide high boost.

The good news in all this is a co-worker of mine has an 8 rib 4.75" pulley, wich will give me a 1.47:1 drive ratio with the pulleys that are on the fronts of the blowers now, so, I've got my serp pulley setup nailed down. The problem is the crank pulley, and the fact that the blowers are too short to reach out past the end of the waterpump, AND, my AC air pump is alsoin going to be in the way, so, to get past all that, I plan to run a jackshaft. I'll have the crank turn a cog belt belt, which will turn one end of the jackshaft. The other end will have the serp belt and the 4.75" pulley. To get the cog belt and cog pulleys, I went out to the junkyard I scrounge and found a smucked Ford contour with the 2.0 DOHC Zetec. I snagged both cam cogs for the timing belt, then took the factory front pulley off the 400 and made some solid models in solidworks. I cooked up this assembly:



Green pulley is the stock 400 pulley. The red ring is the 36-1 toothed ring I'm going to use for the EFI to keep track of RPM and crank position. Grey hub is the part I need to have made, and the blue ring is the outside of one of the Zetec pulleys. I'll have a local shop make the adapter, and then machine the Zetec pulley for a light press fit, same with the red 36-1 ring.





hub will me made from aluminum. The 6 large holes are just to remove weight, while the 6 smaller ones will bolt it to the crank. The large hole in the middle is both to remove weight, as well as clear the stock crank snout bolt. The inner diameter will pilot on the crank snout, keeping it all concentric. I did the mass calculations in soldworks and it will weigh about 2.3 lbs.

And, a few cutaways showing the assembly: