Big Block Gear Drive On A Slant?

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RustyRatRod said:
Yeah. Here's why. Guys I need some opinions here please. What do yall think at this slop? Too much?
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Looks like the idler and cam gears are too far apart. The idler gear appears to have more tooth engagement with the crank gear, than with the cam gear. Is there any way to adjust the idler up and in just a hair to remedy that?
 
Can you pop the cam gear off and wiggle the idler by hand to see how much backlash there actually is? I agree though - looks like there isn't much tooth engagement on the crank gear. It may just be the camera angle though?
 
Maybe it’s my poor eyesight, but the mesh on those gears doesn’t look just right to me. Gear contact looks a little shallow. I’m by far no expert, it just doesn’t look like I think it should.
 
Docmcg said:
Maybe it’s my poor eyesight, but the mesh on those gears doesn’t look just right to me. Gear contact looks a little shallow. I’m by far no expert, it just doesn’t look like I think it should.
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It's pretty much impossible to get them to mesh deeper. Look how the teeth are made. They get really wide quick. If I get them any closer, they'll start interfering.
 
Is it possible to take the cam gear off to check the backlash between the idler and the crank gear, then take the crank gear off and check the backlash between the idler and the cam gear? That second video looks good.
 
RustyRatRod said:
It's pretty much impossible to get them to mesh deeper. Look how the teeth are made. They get really wide quick. If I get them any closer, they'll start interfering.
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And with the chamfers on the teeth, they always "look" uneven in photos/video. Based on how you set the clearance, I bet they're pretty darned even.
 
Docmcg said:
Maybe it’s my poor eyesight, but the mesh on those gears doesn’t look just right to me. Gear contact looks a little shallow. I’m by far no expert, it just doesn’t look like I think it should.
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The thrust surface of an involute gear tooth is pretty far from the tip, so it's not uncommon for the depth at the tip to look uneven. Checking backlash of each separate like @mopowers suggested is a good idea though, because that makes it apples to apples.
 
Maybe the answer's obvious—I'm not a gear expert—but why doesn't anyone make a helical-gear cam drive? Seems to me it'd be a whole lot quieter and maybe less backlashy than straight-tooth gears.
 
slantsixdan said:
Maybe the answer's obvious—I'm not a gear expert—but why doesn't anyone make a helical-gear cam drive? Seems to me it'd be a whole lot quieter and maybe less backlashy than straight-tooth gears.
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That's a good question, BUT.....the Milodon fixed single idler gear drives are quiet. They are straight cut. Don't ask me. I cannot explain it. lol
 
RustyRatRod said:
Yeah. Here's why. Guys I need some opinions here please. What do yall think at this slop? Too much?
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I see your concern , looks to be too little gear engagement on the cam gear too , doesnt look like it would last very long . jmho<LOL
 
I think you're on to something big guy... I wouldn't rush it I would take my time and do my R&D and don't let anybody get into your head...True hot rodding my friend!!!
 
Mtrhead said:
I think you're on to something big guy... I wouldn't rush it I would take my time and do my R&D and don't let anybody get into your head...True hot rodding my friend!!!
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I think it's going to work, now. It's got TWO sources of pressurized oil, so it's going to be well lubricated and cooled.
 
In a (4)gear gear drive like this originally was, one of the smaller gears is designed to transmit the load between the crank gear and cam gear, the other one is simply an idler gear as its name implies. Did you take the correct gear out of the equation...? They are different diameters and the idler may not engage to the correct depth to be used as the drive gear if you swap them.....
 
CNC-Dude said:
In a (4)gear gear drive like this originally was, one of the smaller gears is designed to transmit the load between the crank gear and cam gear, the other one is simply an idler gear as its name implies. Did you take the correct gear out of the equation...? They are different diameters and the idler may not engage to the correct depth to be used as the drive gear if you swap them.....
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Chit if I know. LOL It's too late now! LMAO. I'll go look. This may be what'll make me go back to the Rollmaster set.
 
I used the larger of the two gears. For whatever that's worth.
 
Ok, that's good! I was just thinking that could have explained the excessive backlash you thought you had. You should be fine then...
 
CNC-Dude said:
Ok, that's good! I was just thinking that could have explained the excessive backlash you thought you had. You should be fine then...
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Did you see the last video where I adjusted most of it out? I think it's good to go now. I guess with the gears, I lucked up instead of f%&ed up. lol
 
RustyRatRod said:
Did you see the last video where I adjusted most of it out? I think it's good to go now. I guess with the gears, I lucked up instead of f%&ed up. lol
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I usually get the lucked up thing backwards > ^^^^^^
Stiil looked like too little cam gear mesh to me ...
no doubt you`ve put some thot into all this , what could you do to get a little more mesh on it ??
If you have much valve spring pressure , it might not hold very long ---???
 
I would cut strips of paper or foil and run it through the gears while turning them with the wrench. This is a check to see if the gears are parallel with one and another, this would be indicated by the meshing of the paper folds. Also you can tell if there is equal clearance, such as one strip use for crank gear and idler gear versus maybe two or more for the idler gear and timing gear.
 
The idler gear does appear to mesh better with the cam gear than the crank gear. Since idler is bolted to the block, I don't think you can move it closer without some major redo....
 
Well I blew up the picture, and I don't think this will work. the crank gear and idler gear must have the same amount of gear teeth. Crank gear has 24 and the idler gear has 23, so it may start but will not run long afterwards. But the picture leaves little to desire, I could be wrong on the count, hope I am......

Screenshot (130).png
 
It should not make a difference (the number of teeth on the idler) as long as the tooth pitch is the same. As long as the ratio is 2 to 1 on the crank and cam, the number of teeth on the idler is not relevant.
 
CNC-Dude said:
Put a degree wheel on it and see what you get....
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That's the plan.....when I get the cam I am going to use. Make no mistake. If there's any question at all, my JP/Rollmaster set is going on.
 
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