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L series Datsun help !


bvrley.running

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Hi, although I am not new to these forums, this is my first time making a post let alone making an account; a quick thanks, for that I don't think I would be where I am without these forums!

 

That being said, I have a 1980 Dastun EH 720 (factory dually) that I daily drove until it started knocking. I pulled the motor for a full rebuild, ordered an L20b rebuild kit for the motor, though after fully tearing it down to bare block, I was cleaning it and found an L16 stamp on the block. Frustrating, now funny to me though, that somebody swapped that in. 

 

My question is, what will I have to buy (if anything) to replace any of the l20b parts? I have already rebuilt the head before even realizing that I had an l16, and the valve seals seem to seat perfectly but am not sure if I should use them; and to my understanding from @datzenmike, I can use the l20's head gasket. Furthermore am I able to use the piston rings for the l20 and just grind them way down? or do I need new ones? I am for sure going to need new bearings to my understanding, Though not 100% sure, along with the rest of the gaskets?

 

Thanks.

 

 

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Yes the L20B head gasket will work but the cylinder bores are 2mm larger on the L20B and so are the rings. It's critical that the correct ring is used so no, the L20B rings can't be fitted to the L16

 

Valve seals are the same.

Front and rear crankshaft seals are the same.

Water pump gaskets are same.

Oil pan gasket is the same.

Oil strainer or pick up tube gasket is the same.

Oil pump gaskets are the same.

Distributor gasket to timing cover are the same.

Valve cover gasket is the same.

Rod bearings are the same but.......

 

The main bearings are not the same. L20B are larger diameter 

Exhaust/intake gasket is different. L16 exhaust is square, W58 (head) L20B exhaust is round.

Timing cover side gaskets are different. L20B are taller by 3/4"

 

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On 12/20/2024 at 5:01 PM, bvrley.running said:

Hi, although I am not new to these forums, this is my first time making a post let alone making an account; a quick thanks, for that I don't think I would be where I am without these forums!

 

That being said, I have a 1980 Dastun EH 720 (factory dually) that I daily drove until it started knocking. I pulled the motor for a full rebuild, ordered an L20b rebuild kit for the motor, though after fully tearing it down to bare block, I was cleaning it and found an L16 stamp on the block. Frustrating, now funny to me though, that somebody swapped that in. 

 

My question is, what will I have to buy (if anything) to replace any of the l20b parts? I have already rebuilt the head before even realizing that I had an l16, and the valve seals seem to seat perfectly but am not sure if I should use them; and to my understanding from @datzenmike, I can use the l20's head gasket. Furthermore am I able to use the piston rings for the l20 and just grind them way down? or do I need new ones? I am for sure going to need new bearings to my understanding, Though not 100% sure, along with the rest of the gaskets?

 

Thanks.

 

 

I got a set of L16 pistons and rings bro. I'm going to message you with information

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On 12/20/2024 at 4:54 PM, datzenmike said:

Yes the L20B head gasket will work but the cylinder bores are 2mm larger on the L20B and so are the rings. It's critical that the correct ring is used so no, the L20B rings can't be fitted to the L16

 

Valve seals are the same.

Front and rear crankshaft seals are the same.

Water pump gaskets are same.

Oil pan gasket is the same.

Oil strainer or pick up tube gasket is the same.

Oil pump gaskets are the same.

Distributor gasket to timing cover are the same.

Valve cover gasket is the same.

Rod bearings are the same but.......

 

The main bearings are not the same. L20B are larger diameter 

Exhaust/intake gasket is different. L16 exhaust is square, W58 (head) L20B exhaust is round.

Timing cover side gaskets are different. L20B are taller by 3/4"

 

After checking my engine out, (which took so long since I haven't had the money to do much) I believe that I have a w58 head paired to the L16 block. The L20b exhaust gasket I have lines up perfectly to it. Is there any benefits to this Frankenstein engine? Or L16/L20b in its own better? 

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No benefit whatever. The W58 head is an open chamber, meaning a larger 45.2cc displacement. The stock L16 head is more like 38.5cc so running a W58 drops your compression ratio from about 8.6 all the way down to 7.69 which will drop power.

 

Look along the bottom edge of the head just to the rear of the fuel pump between #1 and #2 spark plugs for the head ID...

 

yp5uytu.jpg

 

It's the only L head with ROUND exhaust ports.

 

 

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AR

8 minutes ago, datzenmike said:

No benefit whatever. The W58 head is an open chamber, meaning a larger 45.2cc displacement. The stock L16 head is more like 38.5cc so running a W58 drops your compression ratio from about 8.6 all the way down to 7.69 which will drop power.

 

Look along the bottom edge of the head just to the rear of the fuel pump between #1 and #2 spark plugs for the head ID...

 

yp5uytu.jpg

 

It's the only L head with ROUND exhaust ports.

 

 

Are you sure? as mentioned the L20B exhaust manifold I have lines up perfectly; though after checking my head is stamped, (A87).

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I can only comment on the information you supply...

 

29 minutes ago, bvrley.running said:

After checking my engine out, (which took so long since I haven't had the money to do much) I believe that I have a w58 head paired to the L16 block. The L20b exhaust gasket I have lines up perfectly to it. Is there any benefits to this Frankenstein engine? Or L16/L20b in its own better? 

 

Now it's an A87? Well they are also open chamber so still 7.69 but they do have square exhaust ports. There are some rare closed chamber A87 heads out there. No way to tell with the head on. IF and I say IF it was a closed chamber the compression ratio would still be lower than stock at 8.38. All these heads will work but the stock head would be best for compression.

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