Well i'm in the middle of my engine rebuild on my 92 240sx with a ka24de engine. I just got thru scraping all the old gasket material off, and was set to start putting things back together when i looked at the lower timing chain and remembered that i did not mark the chain and the idler sprocket so i can align everything again. I feel so stupid!

Well i did a little research in the factory service manual and saw that the lower chain is supposed to have two silver links for mating marks. Well i do not have the front cover off and I have the 1-4 pistons set to top dead center via the crankshaft pulley marks. (I can also see the pistons) For as much of the chain that i can see, I do not see any silver links on my lower chain. I should be seeing atleast one at this point?? Well i also looked at my upper timing chain and i only see one silver link. Aren't there supposed to be two??

Well am i screwed?? Am i missing anything?? Any advice would be greatly appreciated.

Oh and the chains are still the orginals and i am not going to replace them. Car has only ~60,000 miles on it. So i don't see any reason.

If #1 is tdc and the head is on you need to check cam position. Int. should have the #1 lobe with the high part pointing almost to the flat porsion of the valve cover gasket surface and the same for the ex. on the ex. side. If this is not the case you need to carefully turn the crank backwards about 1 quarter turn so the valves will clear the pistons. Then turn the cams to the correct position and slowly turn the crank back to tdc and stopping if you feal any resistance, this could be valves contacting pistons. TURN THE CRANK BY HAND !!!! The bottom chain position is not to cridical as long as you are on #1 tdc. The only way to line up the lower chain is to pull the cover. Put the upper chain on and count the rollers in the links between int + ex. cams and there should be 14, 14 between ex. and idler gear,and 20 between idler and int. gear.This can be a trickey job and if unsure take the frt. cover off or toe it to a shop. If you do pull the cover you might just go ahead and replace the chain and related parts. Best of luck to you!!

Thanks for the help.

This might make me sound like a newbie, but can I assume that the first lobe is the one closest to the front of the engine??

I'm trying to follow what you’re saying but you loose me when you say "pointing almost to the flat porsion of the valve cover gasket surface"??

I currently have the head installed but have not put on the camshafts or idler sprocket. Could I not turn the crank so #1 piston is at tdc, then put the lower chain on the idler sprocket. I would then put the upper chain on the idler sprocket, count 14 rollers going counterclockwise to the exhaust sprocket, then count 14 rollers to the intake sprocket, then count 20 rollers to the idler sprocket to make sure I have everything correct?? I would then turn the crank slowly by hand to see if I get any resistance as a double check that everything is ok???

Would this work??

I'm totally screwed!!

I put on the head gasket, bolted down and torqued the head, bolted down and torqued the intake and exhuast manifolds. No problem.

Then i focused my attention on the idler sprocket. I put the chain on the sprocket and threaded the bolt into the hole on the head and started to hand tighten it down. Then i whipped out my trusty torque wrench and set it for 54 ft-lbs, the FSM recommends 48-61 ft-lbs. Well i go to tighten the bolt and its gets kinda tight but then all of a sudden starts to spin! I am so screwed.

I know there are Heli Coil repair kits but will they apply to my application?? How big will i have to go?? Will the helicoil hold up to the torque i have to apply?? I've only heard about heli coil, anyone know where to buy the kits??

Please help?

anyone?? any help??

This might help:http://doitbest.com/shop/vendo...=1081

The manuals are sometimes wrong; this might be one of those times. 48-61 is a lot of torque--unless the bolt had a 10 or 12mm shank, it might be way too much. Any idea how large the bolt diameter is? You'll need to know, since you'll have to size the helicoil based on the original diameter. When you're done, make sure you paint the new larger bolt head and the area around the coil a bright red or something to distinguish them for future disassembly.

Actually, hold on a minute. If the screw broke clean above the surface of the head, then you might be able to get the screw out with an extractor and not have to bother with a helicoil. You will need to remove everything in the way and drill a nice clean hole down the center of the stuck screw. Extractors work pretty well if you can get the hole drilled. When all is back together don't forget to do an oil change right away and I'd recommend another one within 500 miles. All that debris can really wear on your engine.