Thread: Cam Sprockets

I finished rebuilding my U12 DET this weekend. Got it installed and running, however it seems that I may have timed the cams 1 tooth off. My question is regarding the difference between US market DE sprockets vs JDM DET sprockets. I have the B13/NX FSM which shows two sets of timing marks on the the sprockets. 1 set lines up the marked links on the chain, and the other smaller marks (dimples) are supposed to face each other on the two sprockets. The problem seems to be that the DET does not have the smaller dimples for lining up the cams with each other. So, I just lined up the marks on the chain with the mating marks on the sprockets and counted the links between the two, which was 20 links. Somehow I was a little bit off. Now it runs with 12inHg @ idle and has slow throttle response coming off idle. Any suggestions or tips for getting better results? Any experience with this? thanks

No takers huh? Anyway, I realized the only way this could have happened is the chain had to have moved one tooth on the crank when installing the timing cover/oil pump. Just gonna pull the VC and try again.

Keep at it, you will get it fixed. I had a timing issue this last time I changed cams. I fixed it by pulling the valve cover and setting the timing to TDC on the crank pulley. Then I set the cam timing.

thanks man. It was one tooth out on both cams. got it straight yesterday. It ran great, except at idle. 12"Hg.( Vacuum leak maybe, MAF?) IDK yet. Cranked it up to go to lunch today and it was tapping like hell. wtf. It seems to have spit the shim and guide off the top of the #4 exhaust valves, and the lash adjuster doesn't seem to be collapsed. I cant find the shims in the head, so now I gotta pull the oil pans and hope for the best. It's just wearing me out at this point! Icing on the cake is that im a full time technician, so I have to do it in between everybody else s' POS and after hours. I sometimes wonder if would just be happier flippin burgers and riding a bike! Ha!

Aw that sucks, hope you get to working soon.



I know my coworkers ask all the time why I'm not working as a mechanic, truth be told I don't want to work on other people's dailys... Lamesauce.

I figured out why it spit the shims. I put them on the wrong valves on the exhaust side. The FSM shows the flat shim on the valve closest to the front of the motor....on the intake cam. the exhaust cam is OPPOSITE! I didnt realize the difference, and installed the shims and guides on the exhaust cam in the same orientation as the intake. It now seems like common sense to me because it is the same p/n rocker arm, turned around; on the other side of the head. So, now I need replacements for the exhaust cam shims because when you make that mistake it breaks the ears off of the guides. At least I found all the little pieces! Hard Knocks for sure

now if you can just get the trans shop to fix what they were already paid to fix you might be getting somewhere...

ha! yeah. fix muh tranny fools! Thanks for the pic josh. That is my engine

stealthy

Thanks. ya like that huh? I really dig the BBQ black on that cheese ball GReddy RS. I got it all together again and drove it home last night. All seems well...sort of. I replaced the broken rocker arm guides and shims with the ones out the original DE motor, seems to be good. Still having an issue at idle. I was too tired at the point that i got it going last night to really bother with it much. But I did notice that when you pull the oil cap off while running it immediately straightens out and idles around 19-20inHg instead of the 12-15inHg with the cap on. So obviously I have some sort of blow-by or PCV issue. It is a freshly rebuilt engine with 300 miles on it. im hoping the rings will seat in and all this mess will chill out. Probably not that lucky though...