440 Source MELONIZED intermediate shaft gear

[lewtot184]

The design helix on the cam gear and intermediate shaft are designed for downward thrust. Any vertical thrust would damage the distributor. To verify this all one has to do is look at the thrust surface on the bushing. I fell for the vertcal thrust thing years ago and did the collar on the distributor shaft. If by chance the intermediate shaft is climbing it's probably a bad bushing. The oil pump does create a wobble on the shaft because of the gerotor design. Unfortunaetly the little bushing has to carry that wobbling force which gets worse as oil pressure is increased.

 

[andrewwoz]

The shaft/gear will move up, the problem when it moves up is what happens to the cam gear riding along side it

Would the distributor be out of time once it moves up as well?

 

[mopardemon]

The design helix on the cam gear and intermediate shaft are designed for downward thrust. Any vertical thrust would damage the distributor. To verify this all one has to do is look at the thrust surface on the bushing. I fell for the vertcal thrust thing years ago and did the collar on the distributor shaft. If by chance the intermediate shaft is climbing it's probably a bad bushing. The oil pump does create a wobble on the shaft because of the gerotor design. Unfortunaetly the little bushing has to carry that wobbling force which gets worse as oil pressure is increased.

Would the distributor be out of time once it moves up as well?

distributor wont be able to move held in by bracket

 

[andrewwoz]

distributor wont be able to move held in by bracket

I was thinking if the gear was able to move up and still be meshed with the gear on the cam it would not be timed the same due to the gear being helical. Like when you drop the gear in and it rotates as it meshes with the cam gear

 

[lewtot184]

I was thinking if the gear was able to move up and still be meshed with the gear on the cam it would not be timed the same due to the gear being helical. Like when you drop the gear in and it rotates as it meshes with the cam

i believe you are correct. the timing should retard if the gear is moving up; been thru this before.

 

[andrewwoz]

Using this rudimentary method with cheap calipers, here are some dimensions:
Melonized gear: 1.548"(Gear height) - .170"(depth) = 1.378"
Bronze Gear: 1.548"(Gear Height) - .168"(depth) = 1.38"
This is the best I can do with what I have in easy reach.

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Copying this method with the Hughes shaft/gear

Hughes melonized 1.540" (gear height) - .140" (depth to top of slot) = 1.400"

Also measured the depth from the top of the gear to the bottom of the slot which came to .439"

 

[mopardemon]

is yours angled inside where the slot is

 

[andrewwoz]

is yours angled inside where the slot is

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The gear has a small chamfer, the shaft/slot does not.

 

[mopardemon]

do you see the difference between the two, still waiting for 440 source

 

[andrewwoz]

do you see the difference between the two, still waiting for 440 source

Yeah, you are talking about the chamfer on the shaft at the top of the slot correct? Is the gear height and shaft depth roughly the same?

 

[mopardemon]

Yeah, you are talking about the chamfer on the shaft at the top of the slot correct? Is the gear height and shaft depth roughly the same?

when seated properly just barley engages the gear

 

[andrewwoz]

when seated properly just barley engages the gear

I feel like it would be useful (maybe for members considering this gear in the future) if you could post the dimensions of your gear. I understand it won't work for you but it would nice to know how it compares. It seems like the 440source gear vertex_jeff has would work.

 

[mopardemon]

I feel like it would be useful (maybe for members considering this gear in the future) if you could post the dimensions of your gear. I understand it won't work for you but it would nice to know how it compares. It seems like the 440source gear vertex_jeff has would work.

dimensions are the same as vertex jeff, the problem is the chamfer it has, if it was straight like the hughs it would work.
Been on the phone with Mike from 440 source all week he's telling me to put washers to raise the gear or to raise the bushing, told him machine shop would not do that, they refuse to.
Machine shop said you have 15 grand in this motor are you crazy

 

[andrewwoz]

dimensions are the same as vertex jeff, the problem is the chamfer it has, if it was straight like the hughs it would work.
Been on the phone with Mike from 440 source all week he's telling me to put washers to raise the gear or to raise the bushing, told him machine shop would not do that, they refuse to.
Machine shop said you have 15 grand in this motor are you crazy

That makes sense. Yeah washers seem like a less than ideal solution, especially on a spendy build.

 

[Brewzer67]

I was just looking at this thread today and decided to weigh in and hopefully am helpful. Years ago I was involved in the development of a some skateboard trucks so had to do tons of analysis on metallurgical stress loads. It is insane how much stress a 90 pound 10 year old can put on a skateboard truck. That said, the load that the tang on the distributor to the intermediate shaft contact patch will be insignificant for the grade of metal that both are made of. The biggest stress point will be the shear line on the tang on the distributor shaft itself. The short engagement will not increase the likelihood of shear occurring as the load it sees is minimal due to the sealed bearing supports of the shaft in the distributor itself. Additionally, the rotational load points on the shaft are largely from the weight of the rotor which has minimal mass located offset from the centerline of rotation. Where the lack of additional tang depth would bite you would be in the event of a timing chain related issue (skipped gear with valve to piston contact, or oil pump failure causing sudden lockup of the gerotor). If either of those occur, you have bigger issues anyways. As long as you have positive engagement between the two (intermediate shaft and distributor shaft) and it isn't so shallow as to cause binding and tangential distributor shaft support-bearing load when the distributor is cinched down, you should be good to go. If it does bind in that scenario, then you will be side loading the bearings and cause premature failure.

As an extra tip, to keep your timing from bouncing around due to the minor intermediate shaft movement that may occur, you can put a piece of 3/8" fuel line that is cut a smidge longer (1/8"-1/4" depending on the quality of your hose) than the distributor shaft. Slip it over the shaft, reinstall the distributor, and it will provide enough tension to prevent the upward movement. Viola, problem solved, zero risk, and almost everyone has a spare piece laying around that would work. I learned this from Alan Kulwicki's father when he built a motor for me back in the 80's. Been using it on every build since.