Didn't block timing chain...

[choke artist]

So I'm replacing my head gasket and I didn't put a block in the timing chain...

 

I did keep tension on the chain the whole time though...first I zip tied it to the camshaft sprocket to see if it would fit through the head...but after it didn't, I kept tension on the chain while a friend lifted the head off.

 

I've got the chain tied to something (keeping tension, until I put the head back on tomorrow.) It just felt like it was going to be hard to get the sprocket back on the end of the shaft. Can I get a bit of slack in the chain or do I just need to pull up harder to get it on?

[datzenmike]

Best to wait until tomorrow and see if can be put on or not. If the tensioner is out.... this is the best way to learn to wedge the tensioner in place.

[choke artist]

thanks datzenmike

 

how will I know if the tensioner has fallen out?

[datzenmike]

You won't be able to get the cam sprocket on the cam with the chain on it. If the tensioner has just slid out slightly you may be able to reach down between the two chain guides and press it back to gain some chain slack to get the sprocket on. IF you kept a lot of tension on the chain while removing the head. This is highly unlikely.

 

Here is likely what has happened....

 

A friend did manage to do this using bungee cords to the roof truss in his garage. I have never heard of it ever being done since.

[flatcat19]

Did you know you needed a wedge prior to doing the head job?

[skyblue]

you're fuct.

seriously tho you might get lucky. but like mike said, if you can't put the sprocket back on the cam it's time to pull the timing cover. All it takes is one time for this to happen and you'll never let it happen again. trust me, i've been there. and i think it's safe to say it's happened to a lot of guys here. live and learn.

 

for future reference this tool is great, cheap and made just for that.

buy it here: http://www.amazon.com/Alltrade-648831-Nissan-Timing-Holding/dp/B0002Q8TV4/ref=sr_1_fkmr0_2?ie=UTF8&qid=1347517727&sr=8-2-fkmr0&keywords=datsun+timing+chain+tool

[BRE510]

...You can also use a wooden dowel (cut off the end of a broom stick) and shove it down between the chains. Just remember to pull it back out when you’re done. The last time I did this I used a short dowel so it would be easier to remove/replace the cam sprocket. The dowel sat far enough down that when I was finished, I forgot to pull the dowel out and drove about 5,000 miles with the dowel riding between the chains. End result => no harm done. I found it when I went to replace a leaky valve cover gasket. I felt so stupid when I finally pulled it out :w00t:

[datzenmike]

Someone on here suggester a folded length of garden hose also. As long as there is something between the two chain guides so the tensioner can't push out.

[doomdatsun]

if I were you I would check if I didn't ruin the tensioner spring (I did the same as you and rotated the crank a little and *_*" had to replace it), try to use a light to see if the tensioner is out or not and if you can put the wooden dowel in (put some electrical tape on it) you don't want fragments of wood in your block, the other problem is that you might be able to regain tension but the timing mark on the chain and crank might have been mismatched.

[80daterpillar]

Someone on here suggester a folded length of garden hose also. As long as there is something between the two chain guides so the tensioner can't push out.

 

 

Thanks for the advice, worked like a charm!

 

Any advice for removing/fixing that broken headbolt you can see in the middle on the right side??? I was thinking drill and helicoil?

 

Thanks again

[Jayden71]

I hate broken BOLTS!!! :angry: . That sucks

[datzenmike]

That's easy, weld a nut onto the stub and torque it out. The nut doesn't have to thread onto the bolt but weld it up good.

[banzai510(hainz)]

Ray Stonehocker told me about the Garden hose. But I think the tensioner tool is cheaper unless you take the neiboors gardern hose.

 

as for the chain to give it soem slack rotate the cam in the direstion you need to go. its usaully turing it clockwise(right) and youll still be able to put the sprocket on the chain link you marked. then put it on the dowl with out hammering it on as it will move the cam backwards.

 

http://vimeo.com/19077890

 

 

what were you thinking not blocking the chain????????????

[80daterpillar]

That's easy, weld a nut onto the stub and torque it out. The nut doesn't have to thread onto the bolt but weld it up good.

 

There's only about an 1/8" sticking out ofthe block...

[izzo]

doesnt matter. put a nut on there the diameter of the stud sticking out so that the stub sits nicely inside the nut, run a bead all the way around it on the inside, it will stick to that stub. then take it out....

[80daterpillar]

doesnt matter. put a nut on there the diameter of the stud sticking out so that the stub sits nicely inside the nut, run a bead all the way around it on the inside, it will stick to that stub. then take it out....

 

And if that doesn't work?

[flatcat19]

Then you're right back to where you started.

 

The bolt broke because it was stretched.

Meaning the middle of the bolt was weak.

Not the threaded part.

 

 

[Dat Lurka]

Curse it out.

Sacrifice a goat or something.

 

Don't fergut the pb blaster

[Z-train]

[Stoffregen Motorsports]

I know this doesn't help the current situation, but you can cut the tensioner spring in half so it doesn't push the plunger out. Oil pressure is what tensions the chain, not spring pressure.

 

Just thought I'd share a trick.

[Stoffregen Motorsports]

I don't know if you guys are old enough to remember Kurt Farry (Farry Bros Racing), but I found one of his screwdrivers down a timing cover of a motor I tore apart once. It had his name on the handle and it looked like it had been there a while!

[banzai510(hainz)]

they had ads in the UFO news letters(Farris Bros Racing)

[datzenmike]

I know this doesn't help the current situation, but you can cut the tensioner spring in half so it doesn't push the plunger out. Oil pressure is what tensions the chain, not spring pressure.

 

Just thought I'd share a trick.

 

I.... don't agree totally with this. If that's the case why did Nissan make the spring so stiff? and it is really stiff. They could have done the same thing or left it out. The plunger is barely 0.575" across or 0.259 sq. in. so my L20B idle oil pressure is 29 PSI and the plunger is then pushing only 7.52 pounds. At 50 PSI that's only just under 13 pounds. I would leave the spring full strength.

[68Datsun510]

I.... don't agree totally with this. If that's the case why did Nissan make the spring so stiff? and it is really stiff. They could have done the same thing or left it out. The plunger is barely 0.575" across or 0.259 sq. in. so my L20B idle oil pressure is 29 PSI and the plunger is then pushing only 7.52 pounds. At 50 PSI that's only just under 13 pounds. I would leave the spring full strength.

 

Stoffregen Motorsports for the most part built my engine. I was merely the parts supplier and cleaning boy. I have well over 15000 miles on my engine thus far, two trips to canby, lots of high rpm driving, (its a variation of an L18....) and its been my daily driver. He did this trick on it, no chain slap, no abnormal wear, runs like a top.

 

Just my 2 cents.

[Z-train]

If this was a good idea,it would be more prevalent.