Timing chain

[Stoffregen Motorsports]

It's pretty common in the west to need a three row radiator. Any radiator shop can build it for you. Cost about $300.

[datzenmike]

Good for a needle width on the gauge.

[Stoffregen Motorsports]

It's funny how many people overheat Datsuns. In all the years I owned Datsuns, I never once had one overheat. Even the 210 hp 2200 I had in my 510 with a 3 row radiator and a stock plastic fan never overheated.

[wayno]

Shit happens

[Duncan]

On 8/3/2020 at 11:12 AM, Stoffregen Motorsports said:

Take this opportunity to set your TDC pointer. Slip the timing cover back on, with the TDC pointer and pulley. Bring the piston to TDC and verify it against the pointer. They are notorious for being slightly off.

 

Thanks for the tip.  I did just that today, and noted the mark on the pulley shows around -1 or -2 degrees BTDC against the pointer.

 

I should get a little notepad and write down these little idiosyncrasies for the next owner in case something happens to me...

 

 

[Duncan]

Well, it's been a while but here's a brief rundown of what I've been through.  It took a few weeks to rustle up parts.  I had some stuff polished and powder-coated clear, and a few days to slap it all back together.  I'm old, and it's been really hot..

 

Started the car up, and it ran like death on a stick.  Clearly a dead cylinder, maybe even two cylinders.  Took me a few days to round up a compression check tool.  Used to have one, but no longer, so I bought a Harbor Freight cheapie.  Not the best by any means, but it worked. 

 

Cylinders 1-3 were all at 145-ish give or take a few pounds.  Number 4 was zero.  Nada. Nicht. Nothing.  Not even a twerk of the needle.  DOA..

Okay, looked for a leak down tester and HF had a cheapie on clearance, but I was too late, so they were all gone.  I didn't want to pay $80 at HF for the next one up, so I actually made my own.  It worked well enough to tell me cylinder 4 intake valve was highly suspect.

 

So today, I pulled it al back apart and it's kind of a good news/bad news.  The good news is my motor is probably just fine.  The bad news is, the machine shop I used totally screwed the pooch on me.  I should have looked closer at this, but I've never had a problem like this with any machine shop in the past..

 

Here's number 4 on the compression stroke from the topside.. For some reason my photo editing software randomly rotates pictures.  I can't complaint too much because it's free, but it's still weird..

 

 

And here's looking at it from the underside.  This is as far as the intake valve closes at any position..

 

 

I get to go back on Tuesday and see what they have to say.  I'm going to be polite, but not entirely sure I want the same shop to fix this..

 

I actually want to do another motor for this car, but I want to get this one running and use it and enjoy it while the new motor is underway.  It's my first OHC engine I've ever had and a good learning experience and all, but holy shit, what a pain..

 

I have to order all new gaskets again, too...

 

 

 

 

 

 

 

 

 

 

 

 

Edited September 5, 2020 by Duncan

[datzenmike]

Lash adjusted?

 

Did you bend a valve? This can be from placing or dropping a head valve side down on a table. This should never be done. Or having the an intake valve at full lift while the piston is at TDC when installing. Look on the #4 piston for a strike mark from the valve.

 

 

Also that exhaust valve looks kind of sunken into the head. Could be the camera angle.

[Duncan]

5 minutes ago, datzenmike said:

Lash adjusted?

 

Did you bend a valve? This can be from placing or dropping a head valve side down on a table. This should never be done. Or having the an intake valve at full lift while the piston is at TDC when installing. Look on the #4 piston for a strike mark from the valve.

 

Lash is good.  I was very careful when the head was not on the car.  I did not think about the valve hitting the piston and will check that, but I'm a bit skeptical of that.  I'm expecting the machine shop to give me grief and claim this is my fault.  I appreciate the info!

 

 

[Duncan]

BTW, here's my $5.00 leak down tester.  I hollowed out the base of an old plug, then found some tubing that was just a bit large.  Used my friend's lathe to turn it down for a snug fit and pressed it into the plug base.  Tack welded it, then tapped the threads out for an air fitting to screw onto it.

 

I enjoy making stuff like this..

 

[wayno]

If that valve got bent it might not close all the way, you cannot rest an L head on it's face for any reason, you could hit a bump in the road and have the head come up and then hit the valve hard coming down, heads are not light objects, also if it rests on the valve for a long period...............................

[datzenmike]

Pop it out and see. Twirl it with your fingers, if the head wobbles it's bent. Get new valve. Give a quick lap

[Duncan]

Yep, it was WVS.  (Wobbly Valve Syndrome)  Probably caused by me, but now I know...

 

https://www.dropbox.com/s/z2hhu6w0wrhdc0y/valve.MOV?dl=0

 

 

[datzenmike]

Easy fix. Pup another in and give a quick lap with compound.