SR20det cam install questions and concerns - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Luvs2slide · 06-27-2010, 06:23 AM

So I am in the middle of installing some Tomei poncams and RAS

. I set the cams to TDC the best I could by making the intake at 10 o'clock position and exhaust at 12 o'clock position, b/c i couldn't see the 2nd timing mark. ALso I made sure the front lobes on each were pointing away from the center. Before I pulled the stock cams out, I noticed that the goldish colored link didnt line up to the dot on the exhaust sprocket. I ziptied the chain to each sprocket, installed both cams w/ RAS. So when I started really thinking about it, I am wondering if the chain was installed wrong from the beginning. So here comes the questions...

1. Will it matter that the chain links aren't how the FSM states as far as markings and shit being in certain places?

2. I havn't torqued the sprockets yet and currently the chain has no slack (took out tensioner & CAS).The FSM states to bolt the tensioner in and if it doesnt lock in place then slowly turn the crank until it takes up the slack. I tried installing the tensioner and it doesnt want to lock at all...DO I need to take up the slack some other way?

Sorry for the long as post... What you guys think???

Oh forgot to add that the car was running strong before and had perfect compression, no problems whatsoever even though the marks didn't line up at TDC.

*fliprayzin240sx* · 06-27-2010, 07:21 AM

I have yet to tear down an SR where the chain marks lined up. This is where counting chain links comes into play. As far as the tensioner goes, turn it and it should pop open. Once its open, itll push against the chain and take most of the slack out. It wont fully tighten up till the engine is running since it hydraulic and fed by the oil pressure.

Luvs2slide · 06-27-2010, 02:49 PM

Im going to call you later so you can come over and help lol.

240Zfunahollic · 06-28-2010, 10:01 PM

Unless your chain isn't factory the marks should line up. I've done several cam swaps and they have all lined up.

cotbu · 06-28-2010, 11:31 PM

fliprayzin240sx, is right! It take a multitude of manually cranking to make the links line up normally. Just set the engine to TDC on compression stroke, This is basically ZERO!
A good place to start when taking shit apart.

OP, if you installed the cams and everything is bolted down and the only problem you have is too much tension on the chain, you can manually crank the engine to find that missing slack, try a half crank counterclockwise or just crank clockwise the chain shouldn't jump time, but it's plausible...!

*fliprayzin240sx* · 06-29-2010, 02:33 AM

^^^We got it installed. He was freaking out about the excess slack on the chain and was worried the tensioner isnt doing its job. Basically, all he had to do is hand crank the engine a full rotation and put it back to TDC. Took the slack out.

Now just have to double check the timing with a gun to make sure it is set at 15 degrees. The CAS is stabbed properly but I always like to check to make sure its GTG.

Luvs2slide · 06-29-2010, 02:39 AM

Yep, thanks again Ray. I got it timed and just had to adjust it a tad. Everythings good to go now. Thanks for everyone who chimed in.

06-27-2010, 06:23 AM	#1
Luvs2slide Zilvia FREAK! Join Date: Oct 2006 Location: NW Florida Age: 43 Posts: 1,490 Trader Rating: (81) Feedback Score: 81 reviews	SR20det cam install questions and concerns So I am in the middle of installing some Tomei poncams and RAS . I set the cams to TDC the best I could by making the intake at 10 o'clock position and exhaust at 12 o'clock position, b/c i couldn't see the 2nd timing mark. ALso I made sure the front lobes on each were pointing away from the center. Before I pulled the stock cams out, I noticed that the goldish colored link didnt line up to the dot on the exhaust sprocket. I ziptied the chain to each sprocket, installed both cams w/ RAS. So when I started really thinking about it, I am wondering if the chain was installed wrong from the beginning. So here comes the questions... 1. Will it matter that the chain links aren't how the FSM states as far as markings and shit being in certain places? 2. I havn't torqued the sprockets yet and currently the chain has no slack (took out tensioner & CAS).The FSM states to bolt the tensioner in and if it doesnt lock in place then slowly turn the crank until it takes up the slack. I tried installing the tensioner and it doesnt want to lock at all...DO I need to take up the slack some other way? Sorry for the long as post... What you guys think??? Oh forgot to add that the car was running strong before and had perfect compression, no problems whatsoever even though the marks didn't line up at TDC.

06-27-2010, 07:21 AM	#2
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	I have yet to tear down an SR where the chain marks lined up. This is where counting chain links comes into play. As far as the tensioner goes, turn it and it should pop open. Once its open, itll push against the chain and take most of the slack out. It wont fully tighten up till the engine is running since it hydraulic and fed by the oil pressure. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

06-28-2010, 10:01 PM	#4
240Zfunahollic Zilvia Addict Join Date: Aug 2003 Location: South Carolina Age: 38 Posts: 621 Trader Rating: (35) Feedback Score: 35 reviews	Unless your chain isn't factory the marks should line up. I've done several cam swaps and they have all lined up. __________________ Visit My Trader rating page http://zilvia.net/f/traderratings.html?u=15347

06-28-2010, 11:31 PM	#5
cotbu Post Whore! Join Date: Sep 2005 Location: SWFL Age: 50 Posts: 3,318 Trader Rating: (3) Feedback Score: 3 reviews	fliprayzin240sx, is right! It take a multitude of manually cranking to make the links line up normally. Just set the engine to TDC on compression stroke, This is basically ZERO! A good place to start when taking shit apart. OP, if you installed the cams and everything is bolted down and the only problem you have is too much tension on the chain, you can manually crank the engine to find that missing slack, try a half crank counterclockwise or just crank clockwise the chain shouldn't jump time, but it's plausible...! __________________ LoverTechnologies "Half Broken Things!"

06-29-2010, 02:33 AM	#6
fliprayzin240sx Man w/ CTSV & a Car Seat Join Date: Aug 2002 Location: Tampa Posts: 17,998 Trader Rating: (19) Rides Gallery: fliprayzin240sx Feedback Score: 19 reviews	^^^We got it installed. He was freaking out about the excess slack on the chain and was worried the tensioner isnt doing its job. Basically, all he had to do is hand crank the engine a full rotation and put it back to TDC. Took the slack out. Now just have to double check the timing with a gun to make sure it is set at 15 degrees. The CAS is stabbed properly but I always like to check to make sure its GTG. __________________ If you think Zilvia has too many assholes... CLICK HERE!!!

06-27-2010, 02:49 PM	#3
Luvs2slide Zilvia FREAK! Join Date: Oct 2006 Location: NW Florida Age: 43 Posts: 1,490 Trader Rating: (81) Feedback Score: 81 reviews	Im going to call you later so you can come over and help lol.

06-29-2010, 02:39 AM	#7
Luvs2slide Zilvia FREAK! Join Date: Oct 2006 Location: NW Florida Age: 43 Posts: 1,490 Trader Rating: (81) Feedback Score: 81 reviews	Yep, thanks again Ray. I got it timed and just had to adjust it a tad. Everythings good to go now. Thanks for everyone who chimed in.