Raptor Auto Cam Chain Tensioner swap

[ddragon63]

Looks good. To answer your question of when do you know.... I'm not sire thefes an answer for that. When do you know its time to change the timing chain or belt in an over head cam auto engine? Have it inspected @ service intervals? But if your driving riding styles are different from others this mileage may differ. So I don't know how to answer that

[Schming]

Nicely done. That engine is clean!

Thanxs Cody but the bike hasn't seen the road since 2001 and that's fresh 2.5 year old Duplicolor DE1650 Cast Coat Aluminum 500* Engine Enamel w/ ceramic that is dying to get some bugs on it.

I'd like to thank Crazy Steve for bringing to my attention the decrease in pressure the shaft has on extension. I wanted to make sure the XVZ ACCT had at least close to equal pressure as the OEM CCT at full extension, to assure the ACCT would actually adjust, which was remedied as seen in the previous posts.

Also I'd like to thank ddragon63 for his thoughts on not only the limitations of shaft extension on the OEM CCT but the the idea of fabbing a stop to limit plunger travel depth to match the OEM CCT dimensions.

So, THANXS FELLERS

[ddragon63]

No problem buddy... I may take mine off and do the same as you did. As the raptor cct body is way long I think its only about 4 clicks out from fully depressed right now. So a stopper to insure I don't push the chain into oblivion may be a wise idea.

[crazy steve]

I think you guys are worrying too much....

I would expect that a timing chain should be good for well over 100K, particularly one with a tensioner arrangement; it's harmonics that's hard on chains. I had a early Pontiac tempest years ago, one of those '1/2 a V-8' four cylinders they sold. It had a much heavier-duty timing chain (and included a tensioner that the V-8 lacked) compared to the V-8 it was based on because they found that the harmonics produced by four cylinders was much harder on the chain. The tensioner damped those harmonics. Broken chains are almost always caused by being loose and trying to jump a tooth and by limiting the travel you're increasing the chances that the chain could get slack in it...

[ddragon63]

Another thought to ponder... Maybe someone with more experience inside an xs motor can answer this. Is there an internal movement limitation to the guide bar. I know in Modern sport bike inline 4 cylinders there's only so far the guide bar can travel inward before it stops. I would imagine this is to keep the acct from pushing the chain to failure. Do we know is there is a stopping point to the guide bar close to the limitations of the oem cct?

[Prothec]

I just installed the Raptor ACCT on my XJ last evening and was also surprised at the length of the body and the length of travel. I'm guessing the plunger extended only a couple of clicks compared to the position of the original CCT. My cam chain probably only has about 1k miles on it.

Thinking about it now, I didn't hear it click when I put the spring in so I probably should have pulled it back out and checked where it stopped. Oh well.

[Prothec]

Another thought to ponder... Maybe someone with more experience inside an xs motor can answer this. Is there an internal movement limitation to the guide bar. I know in Modern sport bike inline 4 cylinders there's only so far the guide bar can travel inward before it stops. I would imagine this is to keep the acct from pushing the chain to failure. Do we know is there is a stopping point to the guide bar close to the limitations of the oem cct?

If I remember from my rebuild, there isn't really anything to limit the travel, but what are you really going to contact, the other side of the chain? I would imagine you would have noticeable timing issues by the time it stretches that far. How far can a chain stretch without breaking, anyway?



I think at this point in the build, I realized I probably should have replaced the cam chain while the cases were split.. The chain I ordered didn't have a master link, so we said to hell with it, practice makes perfect, and tore it back down. Then at some point, SOMEONE (not me!) was trying to put the engine back on the lift with a hand truck and DROPPED the engine about 4-6 inches onto the concrete floor.. luckily, no damage.

[ddragon63]

If I remember from my rebuild, there isn't really anything to limit the travel, but what are you really going to contact, the other side of the chain? I would imagine you would have noticeable timing issues by the time it stretches that far. How far can a chain stretch without breaking, anyway?



I think at this point in the build, I realized I probably should have replaced the cam chain while the cases were split.. The chain I ordered didn't have a master link, so we said to hell with it, practice makes perfect, and tore it back down. Then at some point, SOMEONE (not me!) was trying to put the engine back on the lift with a hand truck and DROPPED the engine about 4-6 inches onto the concrete floor.. luckily, no damage.

well I know from my experience inside modern sport bike engines that the guide bar travel is limited. there is only so far it will fold in before its stops. @ this point the chain becomes very noisy and you know its time to do something. BUT these motors were also designed with the Auto CCT. So the question is... does the 1100 engine have a limited travel on the guide bar or is the travel preset in the factory CCT?

Like I've stated previously, when I pulled my factory CCT all the adjustment marks are towards the end of plunger and roughly 1/4 to 3/8 of an inch of the starting point. So there really is not much adjustment length to the factory CCT. A few of us have a theory that cam chains break more often from improper adjustment than stretch. If improperly adjusted the chain can: jump, skip, wad up @ the bottom, and or slap about and bang its broken.



I've got 47k on this bike. after this summer I plan on taking the motor out and doing a valve job, cam chain, rings and bearings, and back cutting the dogs on the gears in the tranny. I figure after 33 years and 50k she could use a freshen up. I'd rather do it while it still runs good than wait till something goes south and I'm hitting all you guys up for parts