L16/18/20B street build need advice

[datzenmike]

Beats me.

 

There is an outlet on the intake down in front of the carburetor. This must be linked to the bypass hose coming out of the thermostat housing that goes down the front of the engine to the lower return radiator hose 

[Gp620Rat]

[Gp620Rat]

[Gp620Rat]

Took me a while, but I figured out how to post pictures; it really wasn’t that hard LOL...

[iceman510]

No, it's not.  Congratulations.  Sounds like a good adventure upon which you are embarking.  

 

I might be interested in the A87 if you will not be using it. 😁

[datzenmike]

On 1/22/2022 at 12:57 PM, datzenmike said:

Beats me.

 

There is an outlet on the intake down in front of the carburetor. This must be linked to the bypass hose coming out of the thermostat housing that goes down the front of the engine to the lower return radiator hose 

 

All water cooled intakes have an outlet in front and below the carburetor. This has to connected to the line exiting the thermostat housing so the water has somewhere to go. It's the rusty pipe with the rubber hose on it.

 

[Gp620Rat]

sure, no problem; but first let me put together all my various combinations... you see, I have a number of these engines, mostly L20B, and I have a number of heads, intakes and exhaust, and I would like to sell them as complete units; as much as possible;

 

I will be taking the blocks to the machine shop, And having them vatted, magna-fluxed, and either honed or bored... at least that is the initial plan

 

I would like to end up with two good ones for me and my son, and everything else will go

[Gp620Rat]

[Gp620Rat]

[Gp620Rat]

As far as I can tell, these are very similar intake manifolds, and the ones that I am showing have a small plug in the same spot that your rubber hose combo is coming out of

[datzenmike]

All the manifolds in your pictures are pre EGR so before '74. From L16 maybe L18. These all had water cooled intakes.

 

8 hours ago, Gp620Rat said:

As far as I can tell, these are very similar intake manifolds, and the ones that I am showing have a small plug in the same spot that your rubber hose combo is coming out of

 

If the water outlet was plugged then someone plugged it. Can't imagine why. They are not L20B intakes, they would have an EGR valve on them. That said they are ok intakes and would work on an L20B but they do have slightly smaller runner diameters.

 

[Stoffregen Motorsports]

The A46 intake in the last pic is the best one to use. Not only does it flow better, but it also looks nicer due to the lack of junk on the outside.

[d.p]

Not for nothing but I did just this with a built L20b (cam'd bored 1 over), dual mikunis and a 5 speed in my 521.  Night and day over the stock L16/4 speed and a lot faster but still slow compared to todays standards.  Would I do it over again?  Probably not as I would most likely go KA or something more modern after having done the legacy path. 

[Stoffregen Motorsports]

You can get huge HP from an L4, but it's a completely custom motor and you'll spend $10K all in.

 

A KA24 single cam with dual Mikunis will net the same HP for half the price.

 

A KA24DE with turbo will net 100 more HP at about the same price.

 

Yeah, legacy style is for us old farts.

[Gp620Rat]

I am really enjoying, and learning a lot from all of the good input on this topic.

 

As you can tell, I am fairly new to this subject of the L20B, and the Datsun 510 world. So please, tell me what is still going on with the 510?
 

Are they still using it in road rallies, or from Paris to Dakar or Barstow to Vegas? classic categories? I do not know all of the rules for these various races as it relates to keeping your car stock, or using the L 16, L 18, or L20B-modified...and so on.

 

i’m definitely going to build up two of these L20B motors, in  a stout and street fun fashion;

 

but for all of the other blocks and heads (parts and pieces) that I have, are there things that I should or should not do when it comes to selling these things off to the “purist”, or the road rally folks... are there things that they prefer, or are there things that I should definitely stay away from doing?

Mostly, I was just going to vat/clean, magna flux, hone or bore, and then put all of the remaining parts that I have for better or worse into the package, and sell them off... or just sell off  good quality parts and pieces that are ready for someone else to put their personal touch on?
 

What do you think?

[datzenmike]

On 2/5/2022 at 10:17 AM, Stoffregen Motorsports said:

The A46 intake in the last pic is the best one to use. Not only does it flow better, but it also looks nicer due to the lack of junk on the outside.

 

I compared the L16/18 intakes and the L20B are larger diameter runners. Yes they look way better but with a grinder and a little JB you can do this to the '78-'80 intakes... The '75-'77 are the co joined to the exhaust manifold and are also not water cooled.

 

 

 

Ten times better looking than redneck diamond plate block off plate

[iceman510]

2 hours ago, Gp620Rat said:

I am really enjoying, and learning a lot from all of the good input on this topic.

 

As you can tell, I am fairly new to this subject of the L20B, and the Datsun 510 world. So please, tell me what is still going on with the 510?
 

Are they still using it in road rallies, or from Paris to Dakar or Barstow to Vegas? classic categories? I do not know all of the rules for these various races as it relates to keeping your car stock, or using the L 16, L 18, or L20B-modified...and so on.

 

i’m definitely going to build up two of these L20B motors, in  a stout and street fun fashion;

 

but for all of the other blocks and heads (parts and pieces) that I have, are there things that I should or should not do when it comes to selling these things off to the “purist”, or the road rally folks... are there things that they prefer, or are there things that I should definitely stay away from doing?

Mostly, I was just going to vat/clean, magna flux, hone or bore, and then put all of the remaining parts that I have for better or worse into the package, and sell them off... or just sell off  good quality parts and pieces that are ready for someone else to put their personal touch on?
 

What do you think?

 

I am not saying this is a definitive answer or the only answer, but I see three scenarios:

 

Street builds trend towards one of two- L series old school for those who like that (I am building an L18 SSS style build- period correct- 510).  Seems fairly desirable on Bring a Trailer for those looking for that driving experience. 

 

Otherwise, modern fuel injected Ka or SR (turbo or not depending on your preference) for high performance street builds.

 

Vintage racing (at least road racing, since I am not so familiar with rally activities)- still requiring period SCCA GCR rules, so L-series still King of the Hill there.  Not too many run L16 in their B sedan cars (but some do), but L18 is still wanted there.  L20B too if you want to accept the weight penalty.  I am getting a vintage B sedan car next month with Rebello L18 and a spare L20B as well.  (Not too mention the other 32 L series cylinders I have in the garage...)

[Gp620Rat]

“Vintage racing”! 
That was the term I was looking for with the “Period SCCA GCR” rules...you nailed it.

 

I believe that this is the group that would be most interested in the stuff that I have to offer; I just don’t want  mess it up, or get it outside of the rules or regulations by boring it out or doing something outside their category of rules... in my effort to clean them up and do something really good, I don’t want to end up screwing anything up for the vintage group.
 

Just remember:

“No good deed, goes unpunished“

 

[Gp620Rat]

I am out of town again, and away from my shop and FSM’s,

 

but does anyone know off the top of their head (don’t go digging for) dimensions/interchangeability of valves used in the L20B motor.

 

You see, I bought an enormous amount of old Datsun  parts and pieces, and I was going through some boxes the other day, and came across huge numbers of good condition valves,

 

the guy that I bought all the stuff from was into the 240 Z, 260 Z, 280 Z, 280 ZX, and the 510... so I have a lot of parts for all these various cars, and motors; I have heard that the 280 has slightly longer valves and that a lot of this stuff is the same size and is interchangeable.

 

[Stoffregen Motorsports]

14 hours ago, Gp620Rat said:

“Vintage racing”! 
That was the term I was looking for with the “Period SCCA GCR” rules...you nailed it.

 

I believe that this is the group that would be most interested in the stuff that I have to offer; I just don’t want  mess it up, or get it outside of the rules or regulations by boring it out or doing something outside their category of rules... in my effort to clean them up and do something really good, I don’t want to end up screwing anything up for the vintage group.
 

Just remember:

“No good deed, goes unpunished“

 

Vintage racing Datsuns use a good amount of non-standard performance parts. I mean a lot. The only original parts on an L race motor are the block, cylinder head, crank shaft, front cover and valve cover, the distributor drive spindle and some timing components. All of the rotating and reciprocating assembly is either custom or highly modified. Cylinder heads for race cars are so modified that they wouldn't even run on a street car. None of the original intake or exhaust parts are used, ever.

 

So unless you have a massive stash of desirable head castings or virgin engine blocks, aftermarket dual carb intakes or race parts, your parts are good for using on a street engine, but not a racer.

[Gp620Rat]

When you say “virgin block”, do you mean it has never been used, or it has never been bored 20 over or 40 over (only honed), or do you mean that it is just a good quality block (bored or honed) that is ready for the next big step in the race car set up? Same question for the various heads that I have...?

[Stoffregen Motorsports]

I mean blocks that haven't been bored. Race motors have offset bores cut into them so even a .020" over block is not as useful to a racer as a standard bore block.

 

Head thickness is crucial, at least on the top of the head. If the top has been cut, most guys will steer away from using it. The desirable heads for a racer are closed chamber heads. A87, 219, V912. The pistons are machined to fit into the combustion chamber and then hand finished to fit even further. This is how they get the 12:1 or 13:1 compression ratios.

[datzenmike]

Good used stock blocks are also well seasoned or aged. Been through countless thousands of heat cycles, they are survivors. Flawed ones will have failed long before now.

[Gp620Rat]

More great info... ‘splains a lot!

[Stoffregen Motorsports]

17 hours ago, datzenmike said:

Good used stock blocks are also well seasoned or aged. Been through countless thousands of heat cycles, they are survivors. Flawed ones will have failed long before now.

Cryo treating and/or vibratory stress relief (Metal-lax) can achieve the same results.