I THINK I MADE A BIG HUMAN ERROR

[L0$]

Here is the story, I am almost completely done with my swap, got new wiring and finished up on other miscellanous things when I started the car the car cranked over and back fired but didnt start. Me and my friend realized we didnt reset the CAS to its proper position. We started reading the manual and it told us to remove the "chain tensioner"...this is where we made the error. We werent suppose to remove that werent we? Now we tried putting it back and nothing good came out of it. We started to manually turn over the crank pulley and the chain popped out of place.

Now its out of timing completely and I am been told that I need to take out all the pulleys and belts, drain out the oil to properly set the chain were it goes. But another person has told me all we have to do is give it slack on the passenger side of the chain and align the top with the crank pulley and we are set. I am wondering what is the fastest but without cutting any corners and not damaging anything in the process way on doing this????

please help my car was suppose to start 6 months ago, even tonight but it hasnt..I feel like I went two steps back. I almost shed a tear today

[SpeedRacer1]

If you know the chain skipped a tooth then you were pretty well screwed. Risking putting it back to where you "think" is right is dangerous. Basically you have hours if not days of work to do to finish the swap short of just getting a new long block.

If mechanical timing is off you need to basically do the work described in the FSM for doing a timing chain.

If you want to chance it you can put the crank key at 12 o clock, put the cam sprockets to where they "should" be and then put the timing chain links to where you think they should be. But the risk is damage to the engine on startup.

Sorry to hear your misfortune.

[URAS]

yeah line up the crank to top dead (second mark) line up the crank gears and count 11 links between the two dots. to get the tensioner back on you will need to compress it and use the little clip on the side to hold it in. put it in and rock the cranshaft back wards and forwards gently to unlock the tensioner. i can post up some pics if some-one hosts them.

[Coolwhip]

what happen was the ignition timing was off and wouldn't start hence the back firing. So instead of adjusting the ignition timing from the CAS, they pulled the tensioner to mess with the mechanical timing of the engine. However, when they thought they had the motor on timing they didn't and they didn't set the slack of the chain to the tensioner side to take the slack. Thus jumping chain. Now they have 2 problems. Ignition timing is off as well as mechanical timing.

What needs to be done as i explained over the phone is for the front of the motor needs to be cleared for a proper timing job. After that set up the CAS properly. I explained to him as well that the motor is an interference motor and will bend valves if the engine is turned out of timing.

I will get over there to see what exactly happen and what exactly needs to be done... Lo$ I'll call you tomorrow.

[notslow]

that really sucks... I hope you get to see your sr run!

[FAST-DATSUN]

I need more info to help, Call me

[Gspec]

I was under the impression that the timing chain couldnt "slip" on the lower gear because of a guide holding it snug...or something to that nature...you should be able to simply reset your cam timing and stab the cas and fire it up.

[spider_slayer]

thats just the thing. unless the front cover is competey off the chain really can't. as long as you had the cams set to tdc and everything before disaembly you should be good to go setting it up again.

sucky thing it is an interference engine. you only really got one shot at it

[Rican_Nick]

from rs-enthalpy.com

SR20DET Camshaft Installation Procedure

1. Set crank to top dead center (TDC)…2nd mark from the left on the pulley. With the #1 cam lobes facing away from each other.2. Remove tensioner.3. Look at the front of the exhaust cam. You will see that there is a pin that locks the cam to the gear. You will also see a dot stamped into the cam gear at approximately 1 O’clock. This dot is used to mark tooth #1.4. Starting from exhaust cam tooth #1 count (clockwise) the number of teeth until the top surface of the head. The head should be between 8 and 9 teeth.5. Adjust cam position as necessary.6. Find the DOT on intake cam. Once again this is tooth #1. Count COUNTER-clockwise to the top of the head. You should find that the top of the head should be between 4½ and 5½ teeth. Adjust as necessary.7. Count the number of chain pins between the 2 dots across the top. You should count 20 pins.8. Install tensioner. Rotate engine 2 full turns and slowly bring it back to TDC ( #1 lobes out) 9. Re-inspect cam position as listed above. Repeat if necessary.10. Install CAS according to FSM procedure.