Help timing a shaved head L-16: What's off?

[fisch]

EDIT: I should add that this engine is still in assembly lube and has never been run. (Yes I will double check that the oil pump was primed!)

 

OK, so I have found out the head on my L16 that was totally rebuilt by the PO was shaved. So I thought I should check the timing, and something is off, but is it the result of the shaved head?

 

First a pic of the level of shave.

 

 

 

OK with that in mind the second thing that is confusing is that my timing marker on my crank pulley is on the opposite side of the shop manuals. Additionally the marks are on the pulley and not on the front cover. I am guessing that is because this is a double crank pulley? So which is the zero mark on the pulley? The one on the far left?

 

I will show this two ways, set by the far left mark on the crank pulley, and later set by the 'V' and '-' on the cam sprocket.

 

First, set by the crank pulley:

 

Pic 1: Crank pulley, set on the far left mark.

 

Pic 2: Bright link set to #2.

 

Pic 3: Dist close to 11:00 and :25

 

Pic 4: 'V' on cam sprocket way off dash on plate.

 

 

OK, now simply rotating the crank pulley back enough to line up the 'V' and '-' on the cam sprocket, this is what we see.

 

Pic 1: Crank Pulley mark now almost all the way to the right mark.

 

Pic 2: Bright Link still at the #2 position.

 

Pic 3: Cam lobes close to the 10 and 2 position

 

Pic 4: Dist a bit more 'off' of 11 and 25 but not quite 12:00 and :30

 

Pic 5: Showing the 'V' and '-' on the cam sprocket line up

 

 

 

So doing nothing other than rotating the crank you can see the results. Is this because the head was shaved? Is it timed? Or is the cam sprocket off a tooth?

 

If it is off a tooth, is the easiest way to fix it to put a block in the chain, take off the cam sprocket and move it? But if I do that won't the #2 bright link position be off?

 

Thanks gurus, I watched the Hainz video again, but not sure in the case of a shaved head.

[racerx]

I have an L16 pulley with L18 engine.  And the TDC is the one with a bigger indentation, on top of the first indentation on your pic #1.  Each mark is 5 degrees. Also is your timing tab crooked cuz if it's straigthened out it looks like it is very closed to TDC. You also mention your shop manual, is your shop manual for an L16, L18 or L20?

[fisch]

I wondered why the farthest Mark on the Pulley was not as deep. The timing point tab does come off at an angle, certainly not a 90 degree bend. But I assumed that was a factory bend as it doesn't seem twisted.

 

But boy of both of those were issues it might be at TDC.

 

I have the FSM shop manual that covers the l16 and L18 as well as the Haynes.

[racerx]

I just checked mine again and the pointer is straight up and down. Yours look crooked..maybe it's bent?  I can't paste it but check out olddatsuns...has pictures of different timing marks.

[Stoffregen Motorsports]

Probably sounds like I'm beating a dead horse, but finally we have a situation that shows why it's important to verify TDC. There are at least 3 different pointers I can think of and 3 different pulleys that go with them, so mixing and matching results in mass confusion.

 

It doesn't matter which pointer, pulley or notch in the pulley you use, as long as it's always the same. Verify TDC with a spark pug removed and then use some yellow or white paint to mark which notch is the right one. You can make your own notch with a file if none of them line up.

[racerx]

seems like he has the right pulley for L16 engine. His 1 and 2 and cam lobes are at 10 and 2 pm.  I think his tab is bent, it should be squared with the hold down bolt. His question was if the head was shaved will that affect his timing. Maybe its how the PO put back the head.

[fisch]

Probably sounds like I'm beating a dead horse, but finally we have a situation that shows why it's important to verify TDC. There are at least 3 different pointers I can think of and 3 different pulleys that go with them, so mixing and matching results in mass confusion.

 

It doesn't matter which pointer, pulley or notch in the pulley you use, as long as it's always the same. Verify TDC with a spark pug removed and then use some yellow or white paint to mark which notch is the right one. You can make your own notch with a file if none of them line up.

THanks man, So I should set the dash and V groove, check the cam lobes are 10 and 2, make sure dist is at 11:25, bright link on #2 sprocket, and then last, mark the pulley wherever the pointer is? So you think this is timed then?

[Draker]

Is that pointer bent? This is what my L16 looks like. It's stock:

 

[DanielC]

On a Datsun L-engine, TDC, cam timing, and distributor spindle position (timing) are independent.

First, you need to verify that pistons #1, and #4 are at TDC when the pointer on the crankshaft pulley indicates they are.

 

With the engine crankshaft at exactly TDC, then you can install the camshaft, and chain.  With the head shaved, you may need to put the camshaft sprocket in the #2., or #3 index hole.  If the camshaft is still showing it is retarded from the crankshaft, (too far counter clockwise) for the notch and slot on the cam thrust plate to line up, you can get some shims that fit under the camshaft towers, that raise the camshaft away from the head, and help make up the difference from the head being machined.

 

With the engine crankshaft at exactly TDC, and the camshaft and chain on the engine, you can then put the distributor drive spindle in the front cover.  The head being shaved should have NO influence on how the distributor spindle lines up.  The position of the camshaft has no control on how the distributor drive spindle lines up.  The distributor is driven by the crankshaft, not the camshaft.

[fisch]

LMFAO it was bent!!! I thought it had that angle from the factory for some strange reason. Well that makes all the difference! Looks way better now. Everything lines up, but the dist looks closer to 12 than it does 11 to my naked eye.  Close though. And I think Hainz mentioned :28 in his video, which seems about right. If the oil pump were off it be way more off, right?

 

I have to check that the oil pump was primed anyway, so I will check when I drop it.

 

I imagine it was, the PO was pretty thorough, but I don't have his contact any more to ask, so I will double check.

[Draker]

It would be very obvious if it was off a tooth. 

[datzenmike]

As the pulley turns clockwise the last or second last notch is TDC as shown by Draker.

 

Only when you are perfectly at TDC by turning clockwise only up to the mark can you check the cam timing. If you overshoot backing up to the timing mark is no good as you will have introduced slack to the dizzy side of the chain. Back the crank up about 1/2 turn and begin again, and as many times as needed to get it right. Clockwise only up to TDC and stop.

 

Now check the cam timing. The #1, #2 and #3 holes don't matter, what does matter is that the V notch in the sprocket is under the etch line on the cam thrust plate or very slightly to the left as viewed from the front. Normally the L16/18s are set at the #1 and L20Bs are on the #2 but wear, chain slack or shaving the head will advance the cam and it must be moved up to the next number and checked. If you cannot get the V under the mark on #3 hole, the sprockets and chain must be renewed. If the slack is strictly from shaving the head you can shim the cam towers to raise the cam and sprocket.

[fisch]

Another case solved by Ratsun detective agency. I am still laughing. I swear from straight on it looked like a factory angle they put in. But when I peeked underneath the pointer I saw the bend.

[racerx]

Exactly....i know my eyesite is getting bad, even had to look at mine 2x. I was going to tell u to take out the pointer but had u figured it out.

[fisch]

As the pulley turns clockwise the last or second last notch is TDC as shown by Draker.

 

Only when you are perfectly at TDC by turning clockwise only up to the mark can you check the cam timing. If you overshoot backing up to the timing mark is no good as you will have introduced slack to the dizzy side of the chain. Back the crank up about 1/2 turn and begin again, and as many times as needed to get it right. Clockwise only up to TDC and stop.

 

Now check the cam timing. The #1, #2 and #3 holes don't matter, what does matter is that the V notch in the sprocket is under the etch line on the cam thrust plate or very slightly to the left as viewed from the front. Normally the L16/18s are set at the #1 and L20Bs are on the #2 but wear, chain slack or shaving the head will advance the cam and it must be moved up to the next number and checked. If you cannot get the V under the mark on #3 hole, the sprockets and chain must be renewed. If the slack is strictly from shaving the head you can shim the cam towers to raise the cam and sprocket.

Crap I forgot about the counter clockwise thing. At this point I am thinking this engine is timed. Will check for sure.

[racerx]

Shouldn't he spindle's half moon, the other half towards the engine, be bigger than the other half, If its at 11.25 oclock position.

[Doctor510]

Shouldn't he spindle's half moon, the other half towards the engine, be bigger than the other half, If its at 11.25 oclock position.

Best way to remember is  "11:25 / fat back".  You'll never go wrong.

[banzai510(hainz)]

saw that right off the bat the pointer is bent!!!!!!!!!!!

[Stoffregen Motorsports]

The best way to verify TDC after the head has been installed is by removing a spark plug. Use a long handled screwdriver and rest it on the top of the piston as you're bringing the engine to TDC. You'll feel it when it passes TDC so you may need to bring it back around and try it a few times before you get there. Once you're at TDC you can rock it back and forth a couple of degrees and you'll feel it crowning.

 

You can also estimate TDC with the oil pan off by squaring up the rod caps with the level surface of the bottom of the block.

 

Note: If the cam timing is in question, be careful not to hit a valve on a piston.