Info / advice on L20B rebuild

Engine, Transmission and related drivetrain.
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SteveEdmonton
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Info / advice on L20B rebuild

Post by SteveEdmonton » 02 Apr 2015 17:49

I've got an L20B block & U67 head all ready for rebuild. I'm finding myself a bit short on info though before commissioning the work.

I realize this is a hard question to answer, but any idea what a "reasonable" cost would be for a full rebuild with stock parts? I know it all depends on what quality of parts are used, how much machining is needed, how meticulous the shop is, how many unexpected problems arise, etc.... But is anybody willing to give me a ballpark figure, IF everything goes pretty much normally? :?

OR: Anybody in western Canada got a fresh or very good-condition L20B for sale? I wouldn't need induction, exhaust, or any peripherals-- just the long block.
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okayfine
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Re: Info / advice on L20B rebuild

Post by okayfine » 02 Apr 2015 20:31

Less than $2500USD:
http://www.ebay.com/itm/Datsun-510-521- ... 9f&vxp=mtr

If you're reusing hard parts (pistons, rods, crank, valves, etc.) and just getting new consumables (bearings, guides, gaskets, etc.) then perhaps a shop might get $1500 for the job these days. I rebuild an L20B 20-some years ago and did the whole thing for $800 out of pocket, reusing the hard parts. Parts prices may well have declined in the interim, but labor has gone up.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson

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Bike papa
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Re: Info / advice on L20B rebuild

Post by Bike papa » 03 Apr 2015 08:59

My L20 rebuild ran about $1,600.00. It included new oversized pistons and replacing the valve seats in the jdm
Peanut head with hardened steel seats.

BP
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Byron510
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Re: Info / advice on L20B rebuild

Post by Byron510 » 03 Apr 2015 23:09

I just did a friends L20B, found the right Hastings ring set (have two extra pistons worth as they were a Z set), used Michigan bearings, new ARP bolts including text head stud kit and all gaskets (Felpro) with a valve job and a hot tank for the block for under $1000 in parts and machine work. I did hone the block as I had the tools. I used the project as an excuse to buy a bearing ball mic because I have always wanted one. Cfank journals and block were dimensionally within spec -I also own through mics and a dial bore gauge which helps. However you local machine shop will measure everything for a reasonable sum if you ask.

An L-Series rebuild can be done very reasonably still. And all the parts are still available.

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SteveEdmonton
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Re: Info / advice on L20B rebuild

Post by SteveEdmonton » 04 Apr 2015 18:17

Helpful advice so far. Thanks for the replies!

Been looking at my L20B block and accompanying parts stash, figuring out what I'd need to get in order to rebuild it (now that my previous plan of buying a completed motor seems to be falling through). Three questions come to mind.

1. This double-dipstick setup seems totally goofy (see photo below). I presume it's because this block was from an HL510 which, if memory serves, has the lower section of the sump toward the front of the motor, not the back as on our 510s. (I switched this one over, some time ago.) So the rearmost "dipstick tube" seems to function here mostly as a place to anchor the clamp that supports the heater hose.... Anyway, I've got a spare dipstick tube (& dipstick) of the right length to fit where it normally goes on our 510-ready motors, namely the rearmost of the two places on this motor. But how can I properly "get rid of" that forward-most dipstick location, which doesn't work at all in my application?
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2. I want to run EI on this motor but don't seem to have a complete setup. What I've got is below (2 pictures)-- namely, a non-matchbox EI dizzy (series D4-F6-04) that seems to be lacking a module-- unless this EI module (E12-27, third picture below) is the right one to power it. But if it is, I haven't got the wiring to link them. Help?
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I've also got an old single-point dizzy (D411.88, which I think = a type used 1968-70). Would I be in equally good shape just cleaning it up and treating it to a Pertronix, as hunting down whatever I need to make the D4-F6-04 model work?
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3. Finally, I've got a couple of waterpumps with the clutch-type fans, but would prefer the older-style four-bladed plastic fan. Can't seem to find one for sale on Ebay though, nor at RockAuto. I'm guessing they're scarce. Suggestions for finding one?
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Bike papa
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Re: Info / advice on L20B rebuild

Post by Bike papa » 04 Apr 2015 19:36

I ordered a direct style water pump from my local carquest parts store a couple of months ago It was made in japan with the cast impeller.

Looked like a quality piece

BP
1971 Datsun 510 2 door
08 VW R32
69 BSA 650 Firebird Scrambler
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Byron510
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Re: Info / advice on L20B rebuild

Post by Byron510 » 05 Apr 2015 00:27

Your fwd dip stick removal is as simple as drilling it out with a hand drill to a pipe plug size, 1/4" if I remember correctly, and tap it out. Use a socket style pipe plug with a bit of loktite sealant and you're done. This mod requires no rocket science. I've done this many times, but usually because I have used rear some 4X4 L20B blocks where the dip stick is on the other side of the block at the rear.

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Re: Info / advice on L20B rebuild

Post by okayfine » 05 Apr 2015 07:34

That style EI used the remote box, which you have. You can use the normal black box module on that distributor as well, I did it before. Does your module have a specific plug? It should be just the same two-wire setup.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson

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SteveEdmonton
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Re: Info / advice on L20B rebuild

Post by SteveEdmonton » 05 Apr 2015 12:48

I ordered a direct style water pump from my local carquest parts store a couple of months ago It was made in japan with the cast impeller.
Didn't word it very clearly I suppose. You're right, Joel, both styles of water pump are pretty readily available. It's more the fan than the water pump it goes on, that I'm wondering about. I suppose I'll have to post a "WTB" ad for the four-bladed plastic fan...?
Your fwd dip stick removal is as simple as drilling it out with a hand drill to a pipe plug size, 1/4" if I remember correctly, and tap it out. Use a socket style pipe plug with a bit of loktite sealant and you're done.
I appreciate the tip on deleting the forward dipstick, Byron. Sounds simple and do-able, thanks.
That style EI used the remote box, which you have. You can use the normal black box module on that distributor as well, I did it before. Does your module have a specific plug? It should be just the same two-wire setup.
Julian, thanks for confirming that this is indeed the right remote module-- that was part of my question. I'll have to figure out the wiring I guess; here's a photo of the plug-connection on the module, showing 5 wires. I assume 2 are input and 2 are output. Maybe the 5th is a ground?
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'74 MGB-GT
'04 Miata

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Re: Info / advice on L20B rebuild

Post by 510rob » 05 Apr 2015 14:34

I'm not endorsing the absolute suitability of any of these images, but they might contain some helpful data...
Attachments
datsun 5-wire electronic ignition 1.JPG
datsun 5-wire electronic ignition 1.JPG (40.77 KiB) Viewed 2627 times
datsun 5-wire electronic ignition 2.JPG
datsun 5-wire electronic ignition 2.JPG (42.72 KiB) Viewed 2627 times
datsun electronic ignition HEI mod.JPG
datsun electronic ignition HEI mod.JPG (26.4 KiB) Viewed 2627 times

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Re: Info / advice on L20B rebuild

Post by datzenmike » 05 Apr 2015 14:43

Image

This is a low mileage (usually under 60K) import engine. They were cheaper to import than to rebuild here back in the 80s and 90s.


Image

22100-N5907 is a remote igniter EI dizzy used in the S10 (200sx) or the A10 (HL510)

It was only used on the '78 vehicles or the '76 and up California engines. The remote box was reduced in size and mounted on the dizzy for all '79 vehicles and is known as the matchbox. They are a bother to wire up but there is a simple and clean way to wire a General Motors HEI module to it using the red and the green wires from the dizzy pick up.

Image

You can mount the HEI unit anywhere under the hood you like, just make sure it is securely grounded.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

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Bike papa
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Re: Info / advice on L20B rebuild

Post by Bike papa » 05 Apr 2015 15:55

Get ahold of Yenpit here on the Realm. He might have a clean used four blade fan that he might sell you
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08 VW R32
69 BSA 650 Firebird Scrambler
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Re: Info / advice on L20B rebuild

Post by bertvorgon » 05 Apr 2015 16:14

I found those fans on a 2 litre really noisy when the RPM got up.

Now, just throw some boost at it and walla....300HP...
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okayfine
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Re: Info / advice on L20B rebuild

Post by okayfine » 05 Apr 2015 20:42

I liked the later L20B fan versus the four-blade stock 510 fan. Better design, moved more air.

As to the dizzy module, you could also just wire in the black box, mounted remotely (inner fender?) and grounded properly. I also did this for a while. Ground was REALLY important, though. I imagine a fair few of your 510 neighbors would have spare black box modules.
Because when you spend a silly amount of money on a silly, trivial thing that will help you not one jot, you are demonstrating that you have a soul and a heart and that you are the sort of person who has no time for Which? magazine. – Jeremy Clarkson

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Re: Info / advice on L20B rebuild

Post by datzenmike » 05 Apr 2015 21:42

The wrecking yards are full of old chevs. The HEI modules are so cheap they aren't worth stealing.
"Nissan 'shit the bed' when they made these, plain and simple." McShagger510 on flattop SUs

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