Project: Ol' Sparky 620

[Crashtd420]

This was the tear down of my motor, yes that's rtv.... motor was nasty before the rebuild...

 

 

You can see the m2 and how the block vent is.....

Edited June 17, 2020 by Crashtd420

[Crashtd420]

Better pic...

[Crashtd420]

The only other feature I know of are 4 bolt holes around the oil filter.... I think that was for a bolt on oil filter relocation... not sure if that was year related too...

[EDM620]

16 minutes ago, Crashtd420 said:

I know of some difference but I'm not sure if was related to years....

There was something called M2 blocks, its cast into the side of the block..  I was told they were nissan replacement blocks... I have one of these...

Mine has the block vent tube that exits the top and routes to the back of the engine... most L16s I have seen the block vent came straight out between the exhaust....

I was told they are a little stronger, better casting or something... could be bullshit I dont know, just what I was told... 

There may be truth to that. The Z24 block has M3 cast on it and it was the next block design for Nissan

[EDM620]

Personally I hate RTV in engine builds, chunks you don't see break off inside and end up blocking oil passages.

Form-a-Gasket #1 or 2 is my personal preference.

[Crashtd420]

3 minutes ago, EDM620 said:

Personally I hate RTV in engine builds, chunks you don't see break off inside and end up blocking oil passages.

Form-a-Gasket #1 or 2 is my personal preference.

Ya that was pretty ugly, my engine was on its last leg when I tore it down.... the motor did not go back together with any rtv....

I did use the form a gasket for my oil pan though, that worked really good....

[EDM620]

18 minutes ago, Crashtd420 said:

The only other feature I know of are 4 bolt holes around the oil filter.... I think that was for a bolt on oil filter relocation... not sure if that was year related too...

And this was also on the Z24 block. I'm assuming it was for a factory oil filter relocation kit

[EDM620]

2 minutes ago, Crashtd420 said:

Ya that was pretty ugly, my engine was on its last leg when I tore it down.... the motor did not go back together with any rtv....

I did use the form a gasket for my oil pan though, that worked really good....

If the machined surfaces are clean and matched up, the sealant really is just an insurance against leaks. If the surfaces are pitted/gouged, then MAYBE using silicone might be warranted.

For many of the surfaces, I only use the sealant on 1 surface - generally not the block - for 2 reasons: 1) the iron surface is harder & less likely to be damaged, and 2) if I open it up again, the gasket will be stuck on the part I remove making it easier to clean off. For example, the valve cover gasket is only stuck to the cover. When/If it needs to be taken off, I don't run the risk of gasket bits falling inside the motor.

 

BTW, I also use anti-seize on the bolts, especially those attaching into aluminum. Dissimilar metal corrosion should be avoided.

[datzenmike]

L16 and L18s had the side block vent.

 

 M2....might be Z22? has block drain on this side and two dip stick choices. 5 bolt crank?????

 

 

[Crashtd420]

4 minutes ago, datzenmike said:

L16 and L18s had the side block vent.

 

 M2....might be Z22? has block drain on this side and two dip stick choices. 5 bolt crank?????

 

 

Mike that M2 block picture I posted is the L16 in my truck....

Edited June 17, 2020 by Crashtd420

[datzenmike]

It's marked L16 in my picture files but I didn't believe it. Good to know.

 

I'm pretty sure I have an L20B marked M3. I have a Z20 block and a Z22 I'll check.

[EDM620]

I'm not seeing the machined surface on the block that identifies the motor. The answer would be there.

[Negative Ghostrider]

Ok. Thanks guys. I'll have a look later. 

 

In the meantime, here is my extra carb. There's no "Japan" cast into it. That was the extra master cylinder I had. I knew something in the extra box of parts said it. Anyway, it's definitely a Weber, and it seems legit. The question is whether or not to use it, I guess. 

[EDM620]

With a bit of clean up it'll look good. 

[datzenmike]

4 hours ago, EDM620 said:

I'm not seeing the machined surface on the block that identifies the motor. The answer would be there.

 

L series are behind the dip stick handle.

 

Z series are on the left or drivers side between cylinder 2 and 3.

[Negative Ghostrider]

Entry 9 - Bad timing

 

So I took the valve cover off again, because being the amateur I am I think I had not done my valve adjustment correctly. Long story short, I was right. I scrubbed a bunch of varnish off and I found my timing mark and the notch is in front of it rather than behind (and position 3). I verified TDC with a straw in the #1 camshaft hole and at the top of the stroke I was at 0 on the crank indicator and the distributor was on plug 1.

 

That seems like a lot of shift, especially since there is no slack in the chain. I'm hoping when I do get it off I can actually get it timed correctly on one of the other 2 positions. Thoughts? 

 

I made a shim and tried to get the nut off the sprocket and re-index but I couldn't get it to budge. I'm guessing I'll need to source a larger impact wrench and some help and try to correct that later, then readjust the valves accordingly.

 

I got a cheap endoscope and got a shot of the pistons. Can anyone tell if those are flat or dished? 

 

I also took a look at the fake Weber. Looks like it's jetted at 170/160, which is higher than redline's baselines IIRC. Still not sure if it's worth it to try to rejet.

 

Lastly, just looking around the engine bay there are a lot of hoses without clamps on them so I need to address all of those. Most suspicious are the 2 small lines under the master cylinder, which also seem to connect into things that aren't connected to anything anymore elsewhere and are just vented to atmosphere. Are these issues?? In the photo there's no line on the big barb in the foreground nor the blue tube in the background. 

 

I also found one of my starter motor through bolts flopping around. 

 

Every time I think I'm going to make progress

on this thing I hit problems and waste a day. It's starting to get to me. 

Edited June 25, 2020 by Negative Ghostrider

[EDM620]

You're on the right track. Your pistons are dished tops which are normal.

The difference between the timing marks on the L series is designed to adjust cam timing, I understand that is to account for stretch in the chain, net difference is apparently = 1/2 link each mark.

I have often used a thin diameter rope (soft like clothesline not nylon, and really long) to crack the crank bolt loose. Here's how I do it:

1) verify #1 piston @ TDC and both valves are closed (remove valve cover), remove spark plug

2) using flex bar & socket (do NOT use an impact), turn engine FORWARD so intake valve is partly open & start feeding in the rope end. you'll be amazed at how much actually fits in there.

3) once you really can't get any more stuffed in the cylinder, turn the engine BACK and the piston will compress your SOFT rope until it binds, and you can crack the bolt loose. IF the engine turns too much and the exhaust starts to open, STOP - turn the engine back & continue stuffing more rope in the hole.

4) back the engine off, pull out the rope and return it to TDC 

The SOFT rope won't damage the internals but don't let the exhaust valve start to open or you'll bend a valve. BAD BAD thing to do.

 

I can't say about the Weber jetting, I'll guess that you'll need to re-jet.

The small hose lines are vacuum. I'm suspect that the larger tube in the foreground of the pic is from the EGR which is possibly deleted or otherwise disconnected, the blue tube is also part of the original emissions and would be a vent coming directly from the block. It would have connected to the stock air cleaner to suck any unburnt fuel vapors back in. It should be connected at least to the intake manifold.

I'm pretty sure that starter through-bolt would have gone into a loose nut (not captive) so you'll have to pull the starter off to re-attach it. I might be wrong and it is a captive nut, so try to just re-tighten it first.

The truck was obviously not given much love for a while, good thing it has you to bring it back!

[Negative Ghostrider]

3 hours ago, EDM620 said:

You're on the right track. Your pistons are dished tops which are normal.

 

OK. So I've got lower compression since I've got the w53 head. I was hoping to find flat tops in there for the performance boost, but oh well. 

Quote

The difference between the timing marks on the L series is designed to adjust cam timing, I understand that is to account for stretch in the chain, net difference is apparently = 1/2 link each mark.

 

Right. I watched a couple videos of people adjusting L series. In one of them the guy had some stretch and had to re-index. The increments between the 3 positions seemed pretty small, like a fraction of the ^ mark. Mine's got a fair gap. I wonder if I'm off a tooth or something. 

 

Quote

I have often used a thin diameter rope (soft like clothesline not nylon, and really long) to crack the crank bolt loose. Here's how I do it:

1) verify #1 piston @ TDC and both valves are closed (remove valve cover), remove spark plug

2) using flex bar & socket (do NOT use an impact), turn engine FORWARD so intake valve is partly open & start feeding in the rope end. you'll be amazed at how much actually fits in there.

3) once you really can't get any more stuffed in the cylinder, turn the engine BACK and the piston will compress your SOFT rope until it binds, and you can crack the bolt loose. IF the engine turns too much and the exhaust starts to open, STOP - turn the engine back & continue stuffing more rope in the hole.

4) back the engine off, pull out the rope and return it to TDC 

The SOFT rope won't damage the internals but don't let the exhaust valve start to open or you'll bend a valve. BAD BAD thing to do.

I've heard about this rope technique. Maybe I'll give it a shot.

 

Quote

I can't say about the Weber jetting, I'll guess that you'll need to re-jet.

The small hose lines are vacuum. I'm suspect that the larger tube in the foreground of the pic is from the EGR which is possibly deleted or otherwise disconnected, the blue tube is also part of the original emissions and would be a vent coming directly from the block. It would have connected to the stock air cleaner to suck any unburnt fuel vapors back in. It should be connected at least to the intake manifold.

 

All the emissions stuff has been deleted. Someone elsewhere said that blue hose should be connected to the PCV which is that flared fitting in the foreground? 

 

Quote

I'm pretty sure that starter through-bolt would have gone into a loose nut (not captive) so you'll have to pull the starter off to re-attach it. I might be wrong and it is a captive nut, so try to just re-tighten it first.

 

I looked at a cutaway diagram for that starter and I don't see a free nut on the back side so I'm guessing it was captured. At the time I tried to see if it would just thread back in and it just spun. I didn't pull it all the way out so see if the threads were stripped or sheared or anything. I'll have to revisit that. 

 

Quote

The truck was obviously not given much love for a while, good thing it has you to bring it back!

 

Thanks man. I feel like I'm in over my head a little more each time I dig into it, honestly. LOL

[Negative Ghostrider]

I noticed this segment in the middle of the cam with 2 squared lobes on it. Couldn't I put a wrench on that and rotate the cam back until the handle of the wrench wedges against the side of the head, then crack the bolt free with a breaker bar? Then use the wrench to rotate the cam back to TDC? The cam is still captured by the index pins with the bolt loose and everything should still move in unison, right? That way I wouldn't have to worry about bending a valve by stuffing things into the chamber. 

[EDM620]

Yes you absolutely can do that - I'd forgotten about that I was thinking about the crank bolt. Duh 😏

And do connect that crankcase vent into the PCV, you want to capture the blow-by gases and suck it back into the engine. It'll smell better if nothing else! Take the PVC valve out & give it a solvent bath, it should be free to move internally which I'd suspect right now it doesn't.

5 hours ago, Negative Ghostrider said:

The increments between the 3 positions seemed pretty small, like a fraction of the ^ mark. Mine's got a fair gap. I wonder if I'm off a tooth or something. 

I'm told the difference = 4 degrees of cam timing. Unless you're lucky, you'll probably need to pull the front cover off to see if the cam chain is out by a tooth.

Make up a small stick to jam down and keep the chain adjuster wedged tight before you take the cam gear off, or you'll be pulling the front cover off anyway.

 

I just took another look at the starter pic - is that yellow/black wire to the oil pressure sender just stuck through the terminal? LOL

[datzenmike]

 

 

 

Move the sprocket one tooth (9⁰) clockwise to get the V under the horizontal etch mark on the cam thrust plate. To be this far out it's most likely that the sprocket was moved one tooth by mistake when installing. When the cam is this advanced it drastically takes away from idle through mid range torque and power. Might not even start and run. If it is running expect a lot more power.

 

 

 

The block vent (blue pipe) needs a hose to the PCV valve (open pipe middle center with hex shape)  On L16/18s this is an S curled shape and of course it can't be easy. The ends are different diameters. Perhaps use a garden hose on the small end and fit it inside a larger hose on the block end?

 

The smaller hose on the block vent goes to the flow guide valve on the fender. The flow guide valve should have a host to the gas tank and to the stock air filter.

 

A picture from farther back would help.

[banzai510(hainz)]

to me look like your off a tooth on the cam sprocket. Moving the number higher is not enough to make a difference. Move the cam to the right or clockwise 1 tooth and should be ok.

Bes to get a timing chain wedge if you haven't don't this otherwise most people fuck this up.

 

If the later Cam center boss. I put a big adjustable wrench then rotate it till it hit the head bolt break the upper cam and lower crank bolt then put part to TDC then tear apart.

I do the lower crank bolt in case you drop the chain and have to pull the front cover.  You can always tighten later if not needed.

[Crashtd420]

15 hours ago, Negative Ghostrider said:

 

I got a cheap endoscope and got a shot of the pistons. Can anyone tell if those are flat or dished? 

 

 

 

I agree with edm620 about the pistons being dished, but My L16 pistons did not have valve pockets like yours do..  I

 

So you might have something better than stock L16 pistons..... hard to say more without pulling the head off and measuring..... 

 

 

 

 

[datzenmike]

Stock 7cc dished with clearance notches.

[Negative Ghostrider]

Thanks everyone. I had made a tensioner shim but I'm not sure I trust it. The Chilton's book only said 9 tall and 1.5 wide but nothing about how to taper it. I just ordered one of the blue plastic ones from Z car Depot. Should be here soon. 

 

I'll see about getting the vent pipe connected to the PCV. I can probably find a host that fits the PCV flare and then a double male reducer fitting to mate the other end to the breather. I have to go to the hardware store today anyway. This is probably a contributing factor to it running so rich, yeah?