V-8 8N, the weak link?

the reason I ask is because I am a machinist as well as a aircraft mechanic, and I own a 1949 8N and I would love to put a flathead in her, of course I would rather fix the weakest links all at once rather than finding out the hard (and expensive) way. and also, I DO plan on using her as intended, so if i want to utilize the power and I need to machine new parts, that’s ok with me, its the price of HP!!!!

-Leo-

Respectfully, S

That is in fact the weak link and I am not sure that it can be beefed up enough to fix it. Ifa big enough clamp could be fabricated and bolted across this pinion thrust bearing web and made to fit snugly against the shape of the casting and bolted to the upper and lower castings where the material is beefier then it might be possible to use the higher HP engines. Otherwise it is foolish to use these tractors for anthing other than a conversation piece with the added HP.

I have seen it tried time and time again to use them with the larger engines and that pinion web always shells out. Back when the housings were pretty much available it was pretty expensive to replace and now that they are a lot less available it is more foolish to risk breaking the housing by overpowering it.

That patched one Hobo shows in the picture will not stand even the stress that a standard four cylinder engine can produce because it will never be strong as it was to begin with. Brass is OK where there is no stress but in a place like that you may as well be whistling Dixie!

Zane

Since you are a machinest, I would like to suggest a different challenge to your talents. That is design and build a BETTER reducer, like the Howard, to go between the tranny and rear. You could even sell a bunch of them, if you wanted to have a "retirement job".

The problem you would have would be the space - add a spacer in between ? - the PTO dog clutch was redesigned for the Howard, so that would be an issue also. Then the sizing of the gears to handle the torque would need to be such that it would hold up. May thought there would to be make one, easy to replace, part the "weak link" that when it broke would not tear up anything else. Example the shear pin in a bush hog drive line. And of course, you would need some place that would heat treat your gears.

As far as the engine goes, you would need to start at the rear tires and work forward, which is what I am guessing the Ford engineers did. There is only so much force that the rear tires can put on the ground before it slips for some given weight on the rear tires. From that force, you then can work back through all the components to find the force they have to carry and then check to see if they have enough strength. For a gear, you are looking at what it takes to shear off a tooth, the force the the root thickness can apply.

What you want is to have everything hold together so that when the load on the rear tires - i. e. the pull of the implement - is too much it stalls the engine. The is what happened to me with my Uncle"s 8N (S# is my handle) that had a newly rebuilt engine. My friend wanted me to "deep plow" his garden. It turned out that about 8 to 10 inches down there was not clay but the next thing to shale! I started out and put the touch control lever all the way down. I went just far enough for the old double bottom plow to get into the shale. The engine lugged down, I gave it some more gas and made it a few more feet and was stopped dead! I got the garden plowed, but I had to not put the touch control lever all the way down.

Regards,
Larry

But if I can get this adapter figured out and make it profitable I am all for taking the next step and making a better reducer. Once I have the design figured out and the CNC programs written it wont take to much effort to produce if I use CNC... my only issues are keeping up with servicing my stuff after its in use, if I am a one man shop, and the fact I don’t have my own machines yet, I use the ones at work at the moment to make my parts after work or during lunch..

-Leo-

I wish I knew all that my Dad did about gears. He was a truck mechanic before his boss talked him into going to college in the late 20"s. He was born in 1900 so was in his late 20"s when he started college. He went to Iowa State and graduated in ME. In the late 40"s and early 50"s he worked for JICase in Rock Island. I have some pictures and notes that he had from when he was working on the redesign of the rear end of what I late found out was the Case VA series tractors.

I was in grade school at the time and remember him taking me thru the Case foundary while they were working. Noisy, dirty, dark, and quite impressive!!! I also got to go with him on a visit to a subcontractor that did heat treating of gears, etc. Some time later that building caught fire. All that oil made one big blaze and made the steel in the structure like taffy.

I can also remember my dad dressing up some cold chisels, then heat treating them. He used a plumbers torch to get the chisel end red hot then quenched it in oil (I think - may have been water) and them tempering it. He used a file to tell when he got it just hot enough and then requenched it.

I still have his old college books, but had to throw out a lot of papers, etc. that I wish I now had. But there was no room for them in the smaller house we moved my Mother in when Dad died. I do know that there was a LOT of math involved in gear design. :-) I also went to ISU and got my ME (as well as EE) degree, but have forgotten most all I learned from lack of use.

Regards,
Larry

It doesn’t take a rocket scientist to see the pinion mount in the case izz the weak link. heres one that has been repaired

The N rear end came from the commercial truck, some of which were using the flat v-8. They had no problems in the trucks because of their wheel/tire size.

The larger diameter tractor tire amplifies the torque from the 25hp flat-4, like adding a cheater-bar to your ratchet to turn a nut.

Jeff

• N-Newsletter

-Leo-

The frontmount N-Engine would make an "ideal" conversion exchanging the righthand genny for a smog-pump and adding small lefthand alternator 12v conversion. Use the lefthand NAA M/S carburator so the carb mouth faces the smog-pump outlet. Gitta K&N cone airfilter to fit. Brackets are your own fabrication. You can buy 454 Chevy V-8 smog-pumps from the junkyard for $25.

Read-up on superchargin' in some "hot-rod" books. The slow-revvin', low-rpms tractor engine could be eazily blown to 4-7psi with a big smog-pump.

Whatta concept!!! And think about the "braggin' rights"!!!..... ...Dell

speaking of small superchargers I did see a small roots supercharger for a Briggs & Stratton engine, now that would be quite the visual impact, seeing 2 of them suckers hanging of her!

but this is what I was thinking when I thought about supercharging, as far as boost goes, and I have looked into it, boost would be great for a flathead due to a flatheads poor ability to breath. however the cylinder walls on my 8n ford are only .040 thick, however they are steel and not cast, which makes me think it MIGHT be strong enough concidering its material, as cast iron bores in automotive are considered thin at .130, however ford's 8n cast cylinders are only .090 thick. this seams thin, but one must remember this is a low RPM low compression engine in its stock form.

With that in mind and if I were to stay with the 4 cylinder, I think I should search for another engine and machine some new cylinders with thicker walls and get custom pistons. I figure the decrease in displacement is worth it for the added durability..... then again if I just put a v8 in their I would start out with more power and not have to worry about cylinder walls, however I would not have any room for any type of boost without ruining the body lines of the tractor (I hate to move the fuel tank, I want it where ford intended).

Oh and another issue I have with almost all common early ford engines, the number of main bearings. Their are so few, and in my opinion that’s not good when you start cranking up the power. The bearings seam a bit wide to, but I guess they need to be when you use that many. They are a great engine in stock form though, its construction just makes me nervous if I plan to turn any rpm or make any HP.

-Leo-

Infact, the un-goverened N-Engine was used in 1941-42 in city delivery vans and pickups and Ford's early WW2 JEEP. Rated at 40hp? at 3600rpms?

Don't be fer blowin'off my supercharging with smog-pump suggestion..... ...Dell

With that in mind your right, supercharging does sound like a good idea. and no, I was not blowing off your idea about the smog pumps, I was just surprised to hear that some1 else was already doing it. like I said, when you get an idea like that it never seams long before you get word that some one else was one step ahead of you and already doing it :-(

as for the bearings, yeah Iknow that the v8 flatheads also on had 3 and i am very aware of what they can do short term. I have liked them little v-8's ever since i was little and i have always had my eyes on em, just something about their sound, the nostalgia, infact i always wanted one with sharp aluminum heads, hunt mag, and either 3 deuces or hilborn injection.... but back to the bearings, personally I think that if I want to use this engine to have a long reliable life WORKING HARD on the property here the block needs to remain rigid, and their should be more main bearings (not like I am going to change that).

This is my theory, the engine under heavy load in the flathead puts the load on the 3 main bearings, while a newer engine like a chevy places the load on 5 bearings and the main caps are held on with 4 or 6 bolts, with any hint of detonation which wouldn’t be unusual with an aggressive tuned supercharged engine it seams that a 3 main engine would have problems first due to more load placed on fewer bearings and the crank being less supported and thus more flexing, so in theory I would think that the mains would spin on the flathead first or just simply get pounded out. and yeah I know the bearings are wide on a flathead so the force is on a wider area, but I don’t think that helps much with a flexing crank. (and I have seen to many twisted and bent cranks from drag cars, different situation though) To aggravate the problem if you ever had low oil pressure and you couldn’t sustain an oil film on the bearings under that hard use your in trouble again, but that goes with any engine
I still want to use a flathead though, but in my opinion its not a very good basis to make hp. but I am not going to push the engine with to many RPM's in a tractor so i would think it should be "ok" but definitely not ideal, btw, I have yet to hear a supercharged 8n 4 cylinder motor, i wonder what it sounds like with the stock cam....

Another thing I haven’t thought much about yet would be weight. the v-8 weighs more I would think (not sure with that cast oil pan on the 4 cylinder), so that might slightly help reduce the tendancy to raise the front end of the ground.

Anyways guys I am not an engineer, I just love tinkering with old things and making things of my own creation and I am just thinking out loud, engineering does fascinate me though, if my train of thought is off I am happy to hear any comments.

would be interesting to have some dyno numbers of the stock engine itself, both torque and HP at the flywheel....

to me 100 hp don’t seam like much, even the 1950"s Chevy 3 unsychoed "crunch boxes" (with the 4 bolt side covers) could handle 100 hp, then again they probably don’t see the torque "used" like on a tractor.....

-Leo-

I'd see ring gear rivits popping.. splined coupler damage.. and pto shaft twisting.. not to mention gear stripping in the tranny..

Soundguy