Just bought a 521

[d.p]

Just now, mainer311 said:

Zerk on top of the steering idler, I believe. I have the 50 amp 510 alternator which is probably the same. Tight fit for sure. Too far in either direction and you hit something. 

 

Yeah that's it, I just went down into the garage and moved it back towards the block.  How much deflection should that alternator belt have? 

[mainer311]

3 minutes ago, d.p said:

 

Yeah that's it, I just went down into the garage and moved it back towards the block.  How much deflection should that alternator belt have? 

 

I don't know. I loosen the mount bolts at the bottom, pull as hard as I can by hand on the alternator case, and then tighten the upper slotted bracket bolt. Then I tighten the lower mounting bolts back down. 

 

On this L20b build, I'm going to buy a turnbuckle and replace the slotted bracket on top. 

[datzenmike]

Push firmly with thumb half way between pulleys. One belt width is ok. I pry out between alternator and block with a tire iron to get it tight.

[datzenmike]

On my 620 the belt went on the alternator pulley first, then the bottom mounting bolts, then the adjusting strap. Adjust tension then tighten mount bolts. It was the only way to use a short enough belt, get it tight and not hit the grease fitting on the idle arm. This was the larger car alternator.

[mainer311]

1 hour ago, datzenmike said:

On my 620 the belt went on the alternator pulley first, then the bottom mounting bolts, then the adjusting strap. Adjust tension then tighten mount bolts. It was the only way to use a short enough belt, get it tight and not hit the grease fitting on the idle arm. This was the larger car alternator.

 

This is my exact experience as well. The belt I used was a 15385.

[Stoffregen Motorsports]

2 hours ago, mainer311 said:

 

Yeah, I know, but then you run out of adjustment later if it's needed. I have no idea what my cam specs are (duration in particular) and I'm running flat tops, so I'm already concerned about piston/valve clearance.

 

 

Zerk on top of the steering idler, I believe. I have the 50 amp 510 alternator which is probably the same. Tight fit for sure. Too far in either direction and you hit something. 

I was trained to slot the holes in the curved guide to get the chain geometry perfect. You want as smooth a transition from the plunger to the curved guide as possible. Sometimes you can add a second rubber washer behind the plunger to help with this setup.

 

I also tap the guide holes in the block to 1/4-28. The grade 8 bolts in that size are stronger than the 6x1.0.

[mainer311]

1 hour ago, Stoffregen Motorsports said:

I was trained to slot the holes in the curved guide to get the chain geometry perfect. You want as smooth a transition from the plunger to the curved guide as possible. Sometimes you can add a second rubber washer behind the plunger to help with this setup.

 

I also tap the guide holes in the block to 1/4-28. The grade 8 bolts in that size are stronger than the 6x1.0.

 

I have a big ass order of grade 10.9's on the way. I keep all the original hardware, but I typically don't use it.

[mainer311]

Guys, I just got this from a dude on eBay. It was advertised for a Z car. Now I’m scratching my head if this will fit on an L20b block. I’d run out and check, but all my shit is at the machine shop.

 

Edited January 29, 2021 by mainer311

[john510]

It should fit as long as that Z car was an L series engine.

[Stoffregen Motorsports]

That kinda looks like it's tilted to the driver side, like a NAPS Z. I wonder if the guy got confused and said Z car, when he meant NAPS Z.

 

I'm probably wrong...

Edited January 29, 2021 by Stoffregen Motorsports

[d.p]

I just painted mine that came off my L20B and I don't remember it looking like that.  

[mainer311]

36 minutes ago, d.p said:

I just painted mine that came off my L20B and I don't remember it looking like that.  

 

There are a couple different flavors that Mike posted on your thread. This is a "full" plate w/o the inspection cover at the bottom. For some reason, the hole pattern threw me off. That, and I don't really get how it works if the block is 3/4" taller.

[Crashtd420]

11 minutes ago, mainer311 said:

 

There are a couple different flavors that Mike posted on your thread. This is a "full" plate w/o the inspection cover at the bottom. For some reason, the hole pattern threw me off. That, and I don't really get how it works if the block is 3/4" taller.

I dont think the transmission bolt location would change..... 

Should only really be the deck height that's increased..... 

[Crashtd420]

2 hours ago, mainer311 said:

Guys, I just got this from a dude on eBay. It was advertised for a Z car. Now I’m scratching my head if this will fit on an L20b block. I’d run out and check, but all my shit is at the machine shop.

 

This is a picture of mine... sorry best I could find.... the one you got looks like its correct....the starter location would be the biggest thing to look at....

Tried to orientate it to compare....

Edited January 29, 2021 by Crashtd420

[datzenmike]

The starter stays in the same relation to the block whether L or Z series. Only the bolt pattern for the starter and engine rotates clockwise to orient the Z series approximately 18⁰ from the L series position. Looks like an L series to me.

 

 

This one has to be an L series standard transmission.

 

 

The Z starter looks closer to the engine but it isn't. It's rotated 18 clockwise.... but so has the block. This is what 18⁰ does. I measures between the top starter bolt and the first bolt at the top and 4 5/16" on both. Looks can be deceiving.

 

...................................................................... L on Left and .............................................................................................Z on the Right

 

 

You could put a Z series engine plate on an L series engine and the block and starter bolt holes would line up but the holes along the bottom would not and the plate might stick out in places.

[mainer311]

38 minutes ago, Crashtd420 said:

I dont think the transmission bolt location would change..... 

Should only really be the deck height that's increased..... 

 

Yeah, I think I see it now. Only the part of the block above the dowel pin grows in height.

[Charlie69]

This is more of an idea for relocating your fuel door.   Wouldn't want anyone throwing up in their mouth a little over a relocation of a gas door!  LOL

 

 

Creativity is the key.

[Crashtd420]

1 hour ago, Charlie69 said:

This is more of an idea for relocating your fuel door.   Wouldn't want anyone throwing up in their mouth a little over a relocation of a gas door!  LOL

 

 

Creativity is the key.

You missed again Charlie....

I think that was ment for my thread....

I like that though, very creative....

[mainer311]

That would be a fun truck in the summer, but, I already have a topless roadster. 

[Charlie69]

You are correct it was for crashed thread.

[Stoffregen Motorsports]

16 hours ago, Charlie69 said:

This is more of an idea for relocating your fuel door.   Wouldn't want anyone throwing up in their mouth a little over a relocation of a gas door!  LOL

 

 

Creativity is the key.

Throwing up in your mouth a little? How about a lot?

 

[mainer311]

Looks like cam tower shims won’t be needed. Dude took .004” off the block and .002” off the head just to clean it up. Came out awesome.

 

 

 

[d.p]

Nice man, did you get a 5 speed yet?  

[mainer311]

7 minutes ago, d.p said:

Nice man, did you get a 5 speed yet?  

 

I wish.

[d.p]

I got lucky and found mine on FB like 20 miles away, same as my engine and both on craigslist.   It seems CL is place to find Datsun parts on this side of the country, very little luck on here or FB marketplace.