Timing Gear Drive

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Here's what I have so far on the oiler. Drilled intersecting holes on the back and side of the plate and simple length of 3/16" brake tubing. Its not secured yet. The end going into the plate for the gallery feed I will laser weld in place once I've got everything finalized. I happen to own a laser, its fun! The great thing about it is there is virtually no heat transmitted to the piece, can hold it in your hand while you weld...no heat will get to the bearing, no oxidation. And no tapping. I'll drill a few holes at the bottom of the tube aimed at the gear to spray onto the bearing/teeth and cap it off after shortening. I still need to devise a clamp of sorts for the free end of the tube and blend the intersecting holes. I'm thinking a removable clamp in case I ever have to pull that bearing or change the tube for whatever reason

The bottom side of the plate where you see the black marker needs to be clearanced against the aluminum Moon front cover, its not alot, a MM maybe. Opinions on whether to grind the plate or the cover would be appreciated. On the one hand grinding the plate may increase the possibility of debris getting in the bearing, one the other hand grinding the cover may weaken it and lead to cracking, now or after use. Also need to figure out a seal on the back side of the plate, around the gallery feed. I was wondering about an O ring in a groove or a compression washer of some sort.

I wanted to run all that passed you guys in case I missed something on my first venture into this kind of work.

Thanks in advance

PICT0045.jpg
 
ne57 said:
Here's what I have so far on the oiler. Drilled intersecting holes on the back and side of the plate and simple length of 3/16" brake tubing. Its not secured yet. The end going into the plate for the gallery feed I will laser weld in place once I've got everything finalized. I happen to own a laser, its fun! The great thing about it is there is virtually no heat transmitted to the piece, can hold it in your hand while you weld...no heat will get to the bearing, no oxidation. And no tapping. I'll drill a few holes at the bottom of the tube aimed at the gear to spray onto the bearing/teeth and cap it off after shortening. I still need to devise a clamp of sorts for the free end of the tube and blend the intersecting holes. I'm thinking a removable clamp in case I ever have to pull that bearing or change the tube for whatever reason

The bottom side of the plate where you see the black marker needs to be clearanced against the aluminum Moon front cover, its not alot, a MM maybe. Opinions on whether to grind the plate or the cover would be appreciated. On the one hand grinding the plate may increase the possibility of debris getting in the bearing, one the other hand grinding the cover may weaken it and lead to cracking, now or after use. Also need to figure out a seal on the back side of the plate, around the gallery feed. I was wondering about an O ring in a groove or a compression washer of some sort.

I wanted to run all that passed you guys in case I missed something on my first venture into this kind of work.

Thanks in advance
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We'll you are obviously think about things a lot! I think it looks pretty good the way you have it. 1 Thing you don't want to to is rob too much oil from the lifter galley. Is there an oil slinger on theses engines?
 
Yes on the slinger. Before I finalize things i need to install the slinger and damper just to make sure there's no problems.

I agree on the oil robbing. Someone mentioned that the hole in the gallery plug should be about .025 if I remember right. The way I envisioned it, and I might need to change that, is to maybe have NO plug but positively seal that area so no pressure drop there. The restriction would be at the bottom of the tube at what would be the nozzle(s). I think i need to figure out how many of what size holes would be good enough to oil without a measurable pressure drop upstream. If I go too small on the holes there's the chance they might get clogged with something. Too big and may have pressure problems.

Yeah I do think alot, sometimes that annoys people. Think twice, cut once, as they say.
 
Oh, another thought. If CAT made the cam gear with the holes just a little bit more outboard, then you'd be able to assemble the unit loosely, do the newsprint thing and THEN tighten the bolts hopefully getting a much more accurate lash. The way it is now you have to loosely assemble, do the newsprint, then disassemble in order to tighten the bolts which could let things slip. Or if you could find allen head bolts that used a smaller wrench but I dunno if such a thing exists.
 
ne57 said:
Yes on the slinger. Before I finalize things i need to install the slinger and damper just to make sure there's no problems.

I agree on the oil robbing. Someone mentioned that the hole in the gallery plug should be about .025 if I remember right. The way I envisioned it, and I might need to change that, is to maybe have NO plug but positively seal that area so no pressure drop there. The restriction would be at the bottom of the tube at what would be the nozzle(s). I think i need to figure out how many of what size holes would be good enough to oil without a measurable pressure drop upstream. If I go too small on the holes there's the chance they might get clogged with something. Too big and may have pressure problems.

Yeah I do think alot, sometimes that annoys people. Think twice, cut once, as they say.
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See Page 3 Post 59 this thread
 
So much for my memory. But it spurred me to think about this...I mentioned having no plug and the nozzle would provide the restriction. But suppose there ever was a problem downstream from the non existant plug, as in a busted line or something, might be good to have that restriction at the plug afterall.

I can see i have to do a test. Will there be enough flow with .016 at the plug, considering the oil would have to travel something like ten inches thru the small tube beyond the plug hole.
 
I think drilling the oil galley plug and then drilling the Timing plate would do what you want. If the oil hits the back of the Cam Timing Gear the oil will fly everywhere for sure and cover all the rotating parts with oil. You could even do both sides using both galley plugs for DUAL oiling. JMO
 
Yeah, that's the way its usually done, spitting out of the plugs. My feeling is that since the bearing is recessed, positive oiling might add a little insurance.
 
Badart said:
I was able to get my 106 degree centerline without any keys. It does take some time and I had to move it a few times to find the right combination. I now have almost 2,000 miles on mine and have no issues. This has been a great thread.
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You remember which keyway? or which one relative to the marked one?
There is a little cat logo thingy on the one I think is straight up. But I could be wrong.

reason I ask is that the gear is a tight fit on the crank.
I dont want to have to keep pressing it on and pulling it off.
 
POS Dakota said:
You remember which keyway? or which one relative to the marked one?
There is a little cat logo thingy on the one I think is straight up. But I could be wrong.

reason I ask is that the gear is a tight fit on the crank.
I dont want to have to keep pressing it on and pulling it off.
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I'm sorry I don't remember which one it was. I just had to pull it back off until I got it right. Good luck.
 
>reason I ask is that the gear is a tight fit on the crank.
I dont want to have to keep pressing it on and pulling it off.

On mine the first couple tries the gear was very tight going on/off. I pulled the key and filed just a little bit on the flats and corners and reinstalled it. Went much easier, but my key is about 53 years old and who knows many times it has been apart. That made things easier what with many trial fittings. I will use a new key on final assembly.
 
i've been thinkin about a gear drive in the 360 i'm putting in the scamp , won't be a huge power maker, i'm hopin for something like 350-400 hp but i love the sound and realiability compared to a chain. does anyone have the link to these CAT gear drives?? i can't seem to find them. don't really have the $$$ to dish out for a milodon
 
Mad Dart said:
What fuel pump is quiet? BG? I don't like to hear it either. Are you going to run one big enough for some squeeze also?
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Well holley pumps can be quiet if they are mounted correctly.
The important thing is to find a place that is solid and not sheet metal, or the pump noise becomes amplified. Kind of like farting on a 50 gallon drum.:-D

I am not sure if I am going to run any nitrous on this one.
I know I will on my r3 though.
 
74scamp360 said:
i've been thinkin about a gear drive in the 360 i'm putting in the scamp , won't be a huge power maker, i'm hopin for something like 350-400 hp but i love the sound and realiability compared to a chain. does anyone have the link to these CAT gear drives?? i can't seem to find them. don't really have the $$$ to dish out for a milodon
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ebay.
 
If its not 400 bucks, its a CAT> (mad dog, thunder chicken, insert distributor name here) I ran a CAT on a 451 and the whine was like a blower, but it was a dual idler Pete Jackson style. Not very good design if you ask me as the floating idler actually rocked between power and coast and there was no room for a line bored motor, If the gears were too close they would turn blue. I got a Milodon myself, have not installed it yet but liked the noise of a gear enough to buy another one for a small block (got it used, a week before I was going to buy a CAT before I shelled out the same for a decent chain and tensioner) its going on a 402 stroker.
 
I hope someone can answer this....

I have mine on my motor now sitting on the stand.
The crank gear is not mating flush with the flat shoulder of the crank. There's about .030 of clearance between the back of the gear and the flat crank shoulder which means it's sitting possibly on the chamfer transition into the crank snout. Maybe the chamfer on the back of the gear is not adequate?


Is this what you guys have too? It is in line with the other gears. But like I said, I can get a .030 feeler in between the back of the gear and the crank.

Acceptable? Or no?

Also, it did not just slide on. I did not beat it though or force it. I heated it to 250 degrees in the oven, greased the snout and slid it on until it stopped.

Talk to me!

If anyone has a side view of how it sits on their crank, please share! or at a minimum, look at yours and tell me what you see.
 
I know its frustrating to wait for an answer. I can't give you one, sorry. On my 392(which interchanges with sbm timing parts) I just tapped the crank gear on all the way aftre deburring the key, didn't think to check the clearance on the back, but since you brought it up i will. But the gear teeth line up nice. If its seated and the lined up, I dunno what more you could ask for. I wonder if its possible you have the gear on backwards or a bur on the snout? No offense, I had to trial and error to find the right orientation.

Maybe this weekend i can finally get around to finishing up my drive. I had to pull the shortblock apart when i spotted a tiny chip of metal resting on the girdle. Did I not clean the block well enough or was it some lost chip that got knocked off the bench or something? Dunno but can't take chances.

I had to have the recess on the plate deepend because it was just not made to the right spec. The one good thing about that is that it allowed the machinist to measure the cam washer and machine to a specified clearance rather than going with whatever it might have been had it been machined right in the first place. I realize that while the timing parts are supposed to interchange, this set was labeled for a 392 so there might be some differences with the 318 so take whatever i am learning with a grain of salt.

I'll measure the backside clearance if any and post some pics including side view. Hope you get yours figured out.
 
Here's what i got...

geardrive2-1.jpg


And here's the "issue" is it's really an issue at all. Eff it...I'm just gonna run it like that.
I can't see why it would be a problem since all the force imparted is on the woody key and not the snout. Any comments on this? There's .030 clearance in there all the way around. I guess if there is a "problem" with the balancer, I'll take .030 off it and call it a motor!

crankgear.jpg


And if anyone was curious...my shortblock with the legendary POS Dakota looming in the background. I'm really happy so far. This is not going to be the truck to mess with. ;)

shortblock.jpg
 
POS Dakota said:
Here's what i got...

geardrive2-1.jpg


And here's the "issue" is it's really an issue at all. Eff it...I'm just gonna run it like that.
I can't see why it would be a problem since all the force imparted is on the woody key and not the snout. Any comments on this? There's .030 clearance in there all the way around. I guess if there is a "problem" with the balancer, I'll take .030 off it and call it a motor!

crankgear.jpg


And if anyone was curious...my shortblock with the legendary POS Dakota looming in the background. I'm really happy so far. This is not going to be the truck to mess with. ;)

shortblock.jpg
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Mine ended up the same way with that little gap!
 
Gear drives are no more accurate than a good timing chain. The crank and cam sprokets will stay in sync and in phase as long as the chain does not skip a tooth. PERIOD Because of the design of the chain and the nature of how the engine runs, it's impossible for the cam timing to vary from the crankshaft. While the engine is running, even of there's slack in the chain, which there is, even on a new one, the chain is always tight on the driver's side of the engine, because the crankshaft is pulling the chain and cam gear right along. There's no slop on the drive side of the chain. Want proof? Fire that pup up without the timing cover and see for yourself. I've done it quite a bit in diagnosis. Gear drives have only one advantage over a chain. They last longer. And with a high end chain and gearset, even that becomes arguable. A chain will eventually fail, although a good high quality billet double roller will probably not fail in your lifetime. Also, another known problem with gear drives is that they set up some freaky harmonics back through the entire valvetrain and can cause havoc with some forms of electronic ignition up through the distributor gear. They have even been known to cause some frequency interference with valvesprings at high RPM. THAT is something you don't wanna play around with. Can you say dropped valve @ 7K? Even computerized engines cannot run them because of this phenomena. They will slap booger up the knock sensor. What do the big boys run? Pro Stock, Funny Car and Top Fuel all run belts and chains. Ask around even the smaller classes. Nobody seriously into racing runs a gear drive, because the serious racers all know. Gear drives are nothing more than a gimmick fad to get into your wallet. I'll take a good chain anyday. Simple as that. Thank you. Drive through.
 
Mad Dart said:
Mine ended up the same way with that little gap!
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Excellent, then all of my questions as far as this thing goes are answered.:cheers:

I dont need any grief! Yesterday morning I realized I had installed the second rings on all the pistons upside down. I am glad I backtracked and caught that.

It's stuff like this that whirls around in my head forever until I am positive about it. Now I can dismiss it and find something else to worry about. haha!

I worry about ths simplest things sometimes. Check this out...
Do you know this engine works PERFECT with a stock length 6.92 inch magnum pushrod between the head milling the block decking, the head gasket thickness and the rocker shimming? lol

I couldnt believe that ****! But it's true. And I mean they fit PERFECT with only 2 threads of adjuster sticking out the bottom of the rocker!!!

I dont drink, but I think tonight I'm getting drunk:cheers:
 
StrokerScamp said:
Gear drives are no more accurate than a good timing chain. The crank and cam sprokets will stay in sync and in phase as long as the chain does not skip a tooth. PERIOD Because of the design of the chain and the nature of how the engine runs, it's impossible for the cam timing to vary from the crankshaft. While the engine is running, even of there's slack in the chain, which there is, even on a new one, the chain is always tight on the driver's side of the engine, because the crankshaft is pulling the chain and cam gear right along. There's no slop on the drive side of the chain. Want proof? Fire that pup up without the timing cover and see for yourself. I've done it quite a bit in diagnosis. Gear drives have only one advantage over a chain. They last longer. And with a high end chain and gearset, even that becomes arguable. A chain will eventually fail, although a good high quality billet double roller will probably not fail in your lifetime. Also, another known problem with gear drives is that they set up some freaky harmonics back through the entire valvetrain and can cause havoc with some forms of electronic ignition up through the distributor gear. They have even been known to cause some frequency interference with valvesprings at high RPM. THAT is something you don't wanna play around with. Can you say dropped valve @ 7K? Even computerized engines cannot run them because of this phenomena. They will slap booger up the knock sensor. What do the big boys run? Pro Stock, Funny Car and Top Fuel all run belts and chains. Ask around even the smaller classes. Nobody seriously into racing runs a gear drive, because the serious racers all know. Gear drives are nothing more than a gimmick fad to get into your wallet. I'll take a good chain anyday. Simple as that. Thank you. Drive through.
Click to expand...

With all due respect brother, this "gimmick fad" only cost me 110 bucks, and men have penises, women have vaginas. Sometimes both penises and vaginas have problems, even though "god" intended them not to. For the record, my junk works as intended. If I ever have a problem, I'll just play golf. Know what I'm sayin? LOL!!!

Motor will be rev limited to 6200. It's a daily driver. I have no worries. But thanks.8)
 
Guitar Jones said:
John is right. The gear drive is just not necessary. In fact it may even impart detrimental harmonics into the camshaft from the crank causing more valvtrain harmonics that may influence timing events more than any measured chain stretch. This is why all the Pro Stock and Comp Eliminator engines have gone to a belt drive.

My engine is critically close on valve to piston clearance, .058 int/.076 exh and after nearly 6 years of racing it and twisting it to 7200-7500 rpm's I've yet to bang a valve.

Personally I think you get what you pay for and I wouldn't put a $100 gear drive in my engine. YMMV.
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What he said...I agree.
 
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