Siciliano15

iTrader: (7)

hey everyone i have a general question about JP adjustable timing chains. i have one on my dakota r/t and plan to get one for the t/a when i do the cam swap. great quality piece. they have multiple keyways on the crank gear from +8 to -8 in incriments of 2 degrees. the cam gear can only be installed one way. my question is about the adjustments. the first cam i had someone install for me but the second one i did myself.

noticed that the crank gear was installed on the +2 keyway and the dot on the cam gear was lined up with the outer +2 marking on the crank gear tooth which is about an inch or so to the left of the +2 keyway.

now people would assume that this means the cam was advanced 2 degrees from whatever advancement was already built into it. however, if i were to take the crank gear off the crank without rotating the crank or cam at all and re-install it but on the 0 keyway, the 0 on the tooth then lines up with the dot on the cam gear showing that the cam is not being advanced or retarded at all.

NOTHING moved but somehow the people at JP are telling me that the way it was originally installed meant it was advanced two degrees and the directions seem to indicate that as well. How can this be possible if i made no movement to anything and just simply took the gear off and re-installed it in a different position?

if i wanted to advance it, I would think I would have to install the gear on the 0 keyway but line up the outter +2 marking with the cam gear dot right?? if this is the case then the JP directions and the guy that works at JP must both be wrong right?? sorry for the long post it just doesnt make any sense....

ebk06

iTrader: (5)

They are probably assuming you rotated the crank to TDC also. If you simply move the gear it shouldnt change the timing. But why would you do this? It would only cause confusion later is someone installed a new cam/timing chain and didnt bother to check everything properly.

Siciliano15

iTrader: (7)

thats my reasoning. the JP instructions must be wrong because i would think i can install that crank gear on any keyway i want and as long as nothing moved, the cam would still be installed with no additional advance or retard.

Sales2@Texas-speed

iTrader: (5)

For an LS1 engine, to advance the JP set, you have to put the crank keyway at the +2 mark on the inside of the gear. The roll the engine over slightly until the +2 on the outside teeth is at 12 o'clock. The keyway on the crank will now be at about 2 o'clock or so, the +2º mark on the crank gear is at 12 o'clock, and the cam gear dot will be at 6 o'clock.

That help any?

Siciliano15

iTrader: (7)

hey Matt, i get that part. the confusion comes when lets say i take the crank gear back off the crank without moving anything and re-install it on the 0 keyway. Now the 0 on the crank teeth will be at 12:00 and lined up with the cam gear which is still at 6:00 making it seem like the cam is no longer advanced at all. this is whats confusing me. seems like id have to have the keyway at 0 with the +2 on the outside teeth at 12:00 in order for there to be any advance.

Sales2@Texas-speed

iTrader: (5)

No sir, for no advance/retard it has to be 0 on the keyway and 0 on the outer teeth.

ebk06

iTrader: (5)

I had to read the first post a few times Matt. I think what he is asking is that, as long as the motor is set to TDC you technically can place the crank gear on whatever reading you want and not necessarily advance or retard the timing.....as long as everything is on TDC already. Moving the crank gear alone wont move the timing unless you adjust the cams centerline, basically.

Siciliano15

iTrader: (7)

yes if that was confusing you guys im talking about when i get the #6 piston to TDC so that the crankshaft key is at approx 2:00 or so & the cam gear dot will be at 6:00. in this situation if i install the crank gear at the zero keyway, the 0 on the outside teeth is at 12:00 and lined up with the cam gear dot at 6:00. however if i decide to install the crank gear in the +2 keyway, now the +2 on the outside teeth will be at 12:00 and lined up with the cam gear dot at 6:00. so because of this, the JP instructions and the guy i was talking to that works there must be wrong.

im thinking if i want to advance the cam i have to get the motor to #6 TDC and then install the crank gear at the 0 keyway and then rotate the crank until the +2 on the outside teeth is at 12:00 and lined up with the 6:00 cam gear dot.

if this is wrong someone please chime in lol otherwise i think i may have to email JP Performance to tell them their directions are wrong.

Sales2@Texas-speed

iTrader: (5)

AWWW, I see what you're asking now. BUT, when you go from having the keyway on the 0º and the 0 on the teeth at 12....take it off, put the +2º on the keyway, your +2º tooth is not perfectly at 12 o'clock now and you have to roll the engine slightly. That's all it takes...remember, you're only talking a VERY minute amount here and it's not going to be a full tooth off or anything! I just checked a set and the instructions are correct.

ebk06

iTrader: (5)

Yea, as I said I just installed that exact timing set this weekend. The instructions were correct. Dont forget you need to degree the camshaft when installing a double roller chain.

Siciliano15

iTrader: (7)

oh wow i didnt see that at all. guess its kinda hard to tell just by looking at it. so i guess 5 years ago my mechanic installed my 210/220 performance cam advanced by two degrees even though it already had 4 degrees in it so thats 6 degrees. i just got done with my new 224/230 cam install and did it myself this time but left everything where it was since my mechanic had degreed it last time and it was running great. both cams had the same 4 degree advance built in so im in the same situation. not gonna take it apart now though ill just hope that with the 25k miles that are on that JP chain that it stretched just enough to make up for the extra 2 degree advance on it. i read that over time chain stretch retards the cam timing by 1 to 3 degrees.

Go5.3tt06

iTrader: (1)

I have problem here same where you been through. I haven't install yet. I was planning to do on Jan to do this. Why do I need for advance or retard. I thought I can just stay with dot line up. As Cam spocket have dot going be line down. The Crank keyway with spocket should be on 0 and outer teeth 0 like up to cam spocket 0

Does it make sense? I hope you can help me correct before I able install it. Plan to swap cam on my Silverado 5.3 hope hear from you.

BlackFish

Not to burst your bubble but throw that jp POS chain away. Had one of the bars in the chain snap on me in my motor. Bent 3 exhaust valves and 1 intake valve. Plus it jammed the chain in between the gear and the block. I swapped to a c5r chain and had to throw the gear away...