Prototype Adjustable timing chain set

[KMcCullah]

I like it! From the looks of the machined finishes I'd say those sprockets are pretty hard. Since this is a new deal, how about adding an eccentric stud for gnats-ass adjusting? Turn the hole next to the timing dot into an up and down slot. Add a hole to the hub. Make a drop in eccentric stud with a 3/16 broach for a 3/16 allen wrench. Or start with 3/4 hex steel maybe... Pull the stud out after adjusting. Or make it integral maybe...

Tried moving the cam with an eccentric on a Chevy hex-a-djust.  Not real smooth or easy on an assembled engine, although it works without the valvetrain installed.  On the other hand you just loosen the six fasteners a touch on an assembled engine and use the damper bolt to rock the engine - the cam stays in position and it happens almost embarrassingly easy.

I see what your saying now. Kinda like the tail wagging the dog. The cam is a bugger to move with everything assembled. Much easier to leave it alone and move the crank.

[BB-63]

Is Cloyes 9-3108A-10 not applicable here?  Sorry if that is a dumb question. - Garrett

http://www.summitracing.com/parts/clo-9-3108a-10/overview/make/ford

[jayb]

The problem with the hex-adjust set, as I understand it, is that they don't stay in position very well.  Plus they only offer a +/- 6 degrees of adjustability.  I agree with Barry that with the six screws around the outside of the top gear, they should hold indefinitely.  Put Loctite on them and no worries...

[Barry_R]

I know it is work, but what would be the possibility of drilling a set screw hole for each of the timing marks around the perimeter of the gear.  If the holes were spaced around the perimeter, the balance would not be affected, and no two holes would line up with a degree mark. Just an added safety by the set screw going through both halves and locking the gear halves in position.  Joe-JDC

Interesting idea.  Might have to give that one a shot....

[cjshaker]

The problem with the hex-adjust set, as I understand it, is that they don't stay in position very well.  Plus they only offer a +/- 6 degrees of adjustability.  I agree with Barry that with the six screws around the outside of the top gear, they should hold indefinitely.  Put Loctite on them and no worries...

The problem with using Loctite is that when/if they are loosened, the Loctite can break up and form little shards of glass that love to chew up bearings if they aren't removed completely. I've tried the blue and red on worn original interference fit rocker adjusters, and when I had to adjust them again the Loctite splintered into little rock hard shards. I never trusted the stuff again on anything inside an engine that wasn't going to stay put until a complete tear-down.

[rockittsled]

Drill the nuts for safety wire and wire three nuts together and wire the other three together using method three, not method eight.  I would not trust method eight (single wire) on a part that rotates at 3 or 4 thousand RPM

[jayb]

The problem with using Loctite is that when/if they are loosened, the Loctite can break up and form little shards of glass that love to chew up bearings if they aren't removed completely. I've tried the blue and red on worn original interference fit rocker adjusters, and when I had to adjust them again the Loctite splintered into little rock hard shards. I never trusted the stuff again on anything inside an engine that wasn't going to stay put until a complete tear-down.

Boy, I don't know about that, Doug.  I've been using blue and red loctite inside engines forever, especially on SOHCs, and have never seen a problem.  I know the little shards that you are talking about, but it seems to me that they just aren't hard enough to do any damage.  Have you ever seen any evidence that they cause a problem?

[cjshaker]

The problem with using Loctite is that when/if they are loosened, the Loctite can break up and form little shards of glass that love to chew up bearings if they aren't removed completely. I've tried the blue and red on worn original interference fit rocker adjusters, and when I had to adjust them again the Loctite splintered into little rock hard shards. I never trusted the stuff again on anything inside an engine that wasn't going to stay put until a complete tear-down.

Boy, I don't know about that, Doug.  I've been using blue and red loctite inside engines forever, especially on SOHCs, and have never seen a problem.  I know the little shards that you are talking about, but it seems to me that they just aren't hard enough to do any damage.  Have you ever seen any evidence that they cause a problem?

When it happened to me on the adjusters, I removed the rocker systems and thoroughly cleaned them, so I didn't have any problems. But feeling them in my hands, they were very hard, just as Loctite is designed to get. So, while I'm assuming, I can't help but think they would cause serious bearing damage if they went through the bypass on a filter. Did you use the Loctite in areas that were loosened and then retightened, Jay? I've used it inside engines also, but only on something that will stay together while the engine is assembled. I doubt there's any problem using it that way. Or, maybe it dissolves in the oil and I'm just wrong, but I never felt like testing that theory.

[bartlett]

I had thought about this alot when I was building racing atv engines. My idea was to build two sections one slotted and the other with a pin that went into the slot. Then I would make offset slugs that would fill the entire slot. The slugs would have a overlap on top so the slugs could be retained with a small screw. So a guy would need a selection of slugs for each adjustment.       this would make for a positive lock.

[jayb]

When it happened to me on the adjusters, I removed the rocker systems and thoroughly cleaned them, so I didn't have any problems. But feeling them in my hands, they were very hard, just as Loctite is designed to get. So, while I'm assuming, I can't help but think they would cause serious bearing damage if they went through the bypass on a filter. Did you use the Loctite in areas that were loosened and then retightened, Jay? I've used it inside engines also, but only on something that will stay together while the engine is assembled. I doubt there's any problem using it that way. Or, maybe it dissolves in the oil and I'm just wrong, but I never felt like testing that theory.

Why test the theory if you don't have to LOL!  I use Blue Loctite on the 4 bolts that hold the timing gear onto the SOHC cams.  Every time you change cam timing, or change cams, you have to loosen or remove those bolts.  Probably loosening them a 1/2 turn wouldn't cause an issue; I like the Loctite because the bolts stay tight even after you've loosened and retightened them a few times.  I'm sure I've dropped some of that stuff in the motor before when I've had to remove the gears completely from the cam, but of course I try to prevent that.  But again, I've never seen a problem (knock on wood).

[plovett]

Why test the theory if you don't have to LOL!  I use Blue Loctite on the 4 bolts that hold the timing gear onto the SOHC cams.  Every time you change cam timing, or change cams, you have to loosen or remove those bolts.  Probably loosening them a 1/2 turn wouldn't cause an issue; I like the Loctite because the bolts stay tight even after you've loosened and retightened them a few times.  I'm sure I've dropped some of that stuff in the motor before when I've had to remove the gears completely from the cam, but of course I try to prevent that.  But again, I've never seen a problem (knock on wood).

Loctite is right up there with JB-Weld, zip-ties, and duck tape.   My whole life has been so much better because of these things.

JMO,

paulie

[cjshaker]

Loctite is right up there with JB-Weld, zip-ties, and duck tape.   My whole life has been so much better because of these things.

JMO,

paulie

4 things you have to have on your list if you're going to conquer the world.

[Qikbbstang]

Jay with your with a CNC equipped shop, wondering if machining two gears to produce one adjustable one is actually the most efficient/economical?  ..... Not sure how machining one cast cast gear down compares to machining a billet piece, but a billet drive side piece could perhaps be aluminum or some other easier to machine metal.
    For decades I've seen a shop produce adjustable timing belt pulleys for 4cyls:


http://www.ebay.com/sch/i.html?_odkw=2.3++adjustable+cam+gear&_from=R40&_osacat=0&_from=R40&_trksid=p2045573.m570.l1313.TR0.TRC0.H0.X++adjustable+cam+gear.TRS0&_nkw=++adjustable+cam+gear&ghostText=&_sacat=0

The fact that retarding timing (the direction that load naturally forces timing to go) makes for better top end.  Anytime there is adjustable timing including the option to make it automatic seems natural. Don't forget one of the EMC contestants did so last challenge.

[TorinoBP88]

Nice!

[Barry_R]

One of the two adjustable sets we've prototyped is on its way to Jay - he does not know that yet but will any second now

The other one will be on its way to Cloyes today once I transcribe the drawing from "bar napkin" to a clean sheet of paper with greasy fingerprints and spilled Diet Coke...