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L18 block questions


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#41 Crashtd420

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Posted 30 November 2017 - 11:36 AM

Ya I went to that post... I don't have the imgur app so it wouldn't let me view....
Thanks for posting the pic.... that's definately a little different....

#42 G-Duax

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Posted 30 November 2017 - 12:50 PM

Maybe someone will buy you a real computer for Christmas  :)


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !


#43 wayno

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Posted 30 November 2017 - 02:37 PM

Ya I went to that post... I don't have the imgur app so it wouldn't let me view....
Thanks for posting the pic.... that's definately a little different....

I don't have the app either but I can see the photos, but I had to click on the blue "engine L18" to see them.


 

 


#44 docbainey

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Posted 30 November 2017 - 05:27 PM

Non USA 'Z' motor with an 'L' head?  Take a pic of the block serial #, it'll show the engine family.



#45 Giljr2

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Posted 01 December 2017 - 09:05 PM

Non USA 'Z' motor with an 'L' head?  Take a pic of the block serial #, it'll show the engine family.

the Serial # is

 

L18 490560 W

 

its on the passenger side of the block on the top on the rear on the engine on a flat piece almost below where the ID of the head is



#46 Giljr2

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Posted 01 December 2017 - 09:07 PM

 

He gave the link his whole album in post #7.

Just click on it, you will go right to them.

 

But here is said dip-stick, and the other side has the casting, but it's not drilled.

Simple to plug one, and drill the other.

 

Love those aluminum spring retainers on the head.

Had several sets that I sold on eScrew (eBay), then they dried up in Japan, so I ended up without any  :)

 

A3D4Wwh.jpg

 

thanx! I'm new to building datsun and i don't really know what material they are made or anything, but id love to know! I'm starting to love this truck more and more with all your guys input



#47 Giljr2

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Posted 01 December 2017 - 09:10 PM

You're right. One other thing I noticed (hadn't looked at the pics in the link until now), the crank isn't fully counter weighted like the early L18 cranks were. The fully counter weighted cranks are obviously a better crank.

 

If the motor's in good shape, use it, but drill a new dipstick hole and plug the old one. If you're planning on any type of exhaust header, you'll have to cut the angled boss off under the two center exhaust ports.

what do u mean by fully counter weighted? and it is! took it all apart and took it to an engine shop and they said its bored 40 over with 280z flat top pistons

and why move it? it has headers already and it was left in the same place



#48 Giljr2

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Posted 01 December 2017 - 09:17 PM

who cares  what its out of. Most likely a 610 if it had a 200mm flywheel

 

hope that stripped spark plug hole dont go bad again.

 

you got a nice head and look like a 272 duration cam.  hope the lash pads are correct for the set up  as it s best guess for the wipe pattern.

 

non turbo 280zx had flattop pistons and the W53 Head is a good match for it(best ported to 1.5 to a 15 incha manifold). to get best power I would run Mikunis sidedrafts.  Persoanlly I would do a L20 and the W53 if giving a chance again but all I had was L16/18 and I really can tell the difference between the 2 when equip with a weber 32/36 downdraft

so what i have found out is the block is boared 40 over with flat top pistons out of a 280zx? the head was decked and the cam has spacers to raise it up the amount that was decked?.. and it has headers

i want to paint the block and head also can you guys guid me in the right direction on if i should spay paint or powder coat it? the head is aluminum like you guys have said anyway to paint them? that won't fake and look bad? haha



#49 datzenmike

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Posted 01 December 2017 - 09:20 PM

L engines are usually ID'd behind the dipstick handle just below the head. The head ID is to the front between #1 and #2 spark plugs just above the block.


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#50 Giljr2

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Posted 01 December 2017 - 09:21 PM

I don't really know myself what perfect is, maybe the guy telling me what I need to do only sees perfectly set up as the only way.

Flat top pistons and closed chamber head appears to be 10.9 to 1 compression ratio, when I told my machinist that number he made a face, that cannot be good as everything he has ever told me was true, he used to do mostly racing engines, and he would squeeze in work for me when he had the time, now he is doing normal machining for the public and when he retires the shop will likely close.

There is another thread on here, here is a link below, look at post 35 specifically, the guy made list in that post that mentioned everything I needed to do, and I basically replied with I didn't understand half of what he wrote, un-shroud the valves, time the cam at 107/108, re-curve the distributor, also lighten the flywheel which I did understand, I also understood some of the other stuff but likely don't really understand the extent of the work needed.

http://community.rat...2985-z20-build/

The L18 has been said to be a revver, but the fact is unless your on a race track it is not likely that any of us would drive it like that on the road, therefore we would not use its true potential and the only reason to have it is for bragging rights.

I built mine just to see if I could get it to run, I had just about every part needed in my parts bins, I am only out time and a gasket set, plus I intended from the start to use this engine to mock up a frame/chassis for my work truck, I want everything ready so I can just transfer everything without having to modify anything as that part will already be done(motor mounts specifically), I have done this a few times so I know what is going to need to be done.

is lightning the flywheel a good idea? i want to make this build as best as it can, as its out of the car i want to do this build right

also i need bolt because i believe the head-bolts are torque to yield? and are one time use?



#51 Giljr2

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Posted 01 December 2017 - 09:23 PM

L engines are usually ID'd behind the dipstick handle just below the head. The head ID is to the front between #1 and #2 spark plugs just above the block.

yes i remember seeing it and i wrote it down and posted it but once again it is 

L18 490560 W

that is what is displayed 



#52 Giljr2

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Posted 01 December 2017 - 09:32 PM

i was wanting also to ask i i haves a rustomieum thing that i brushed on that killed rust and turned black when rust was killed 

wanted to see what you guys thought on that? or any ideas you guys have on killing rust



#53 datzenmike

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Posted 01 December 2017 - 09:34 PM

L18 is all you kneed to know really. The rest might tell what year or model vehicle it was used in but again L18 is an L18 for parts and such.

 

L18s are 85mm bore so 86mm would be 280z/zx piston size.

 

Flattop pistons would be non turbo use.


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#54 wayno

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Posted 01 December 2017 - 09:40 PM

is lightning the flywheel a good idea? i want to make this build as best as it can, as its out of the car i want to do this build right

also i need bolt because i believe the head-bolts are torque to yield? and are one time use?

The guy said lightening the flywheel will help the engine meet it's true potential, I am going to start by re-curving the distributor just to see if I can drive it without it knocking.

All L series head bolts are reusable, at least if in good condition, if badly rusted find replacements or buy an L series head stud kit.


 

 


#55 datzenmike

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Posted 01 December 2017 - 10:24 PM

The flywheel stores kinetic energy in the form of a spinning mass. This helps to get a heavy truck mass moving easier from a stop. I'm only saying that if you remove too much mass, you will have to rev the engine higher and slip the clutch more to get moving on every start. Pound for pound a smaller engine or one used in a heavier vehicle will have a heavier flywheel.

 

A lighter flywheel has less mass to absorb spinning energy from the engine and this energy can be used to move the vehicle.... but only if already in motion. I have weighed 200mm 225mm and 240mm flywheels some are 29 pounds some are 21 pounds. I've only seen these two weights used. Twenty one pound are six cylinder or light car 4 cylinder. Twenty nine are 4 cylinder truck flywheels.

 

Weigh it and see. If 21 pound I wouldn't go lower in a truck. I definitely wouldn't if only driven in stop and go, in town traffic. If you have the fully counter-weighted crank there's an extra 5 pounds of spinning weight. If 29 pounds I would go lower.

 

Look on the engine side of the flywheel. If flat  across they are 29 pound. If scalloped (below) they are 21 pound.

 

xxlTAPR.jpg

 

.


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#56 Giljr2

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Posted 01 December 2017 - 10:30 PM

The flywheel stores kinetic energy in the form of a spinning mass. This helps to get a heavy truck mass moving easier from a stop. I'm only saying that if you remove too much mass, you will have to rev the engine higher and slip the clutch more to get moving on every start. Pound for pound a smaller engine or one used in a heavier vehicle will have a heavier flywheel.

 

A lighter flywheel has less mass to absorb spinning energy from the engine and this energy can be used to move the vehicle.... but only if already in motion. I have weighed 200mm 225mm and 240mm flywheels some are 29 pounds some are 21 pounds. I've only seen these two weights used. Twenty one pound are six cylinder or light car 4 cylinder. Twenty nine are 4 cylinder truck flywheels.

 

Weigh it and see. If 21 pound I wouldn't go lower in a truck. I definitely wouldn't if only driven in stop and go, in town traffic. If you have the fully counter-weighted crank there's an extra 5 pounds of spinning weight. If 29 pounds I would go lower.

 

Look on the engine side of the flywheel. If flat  across they are 29 pound. If scalloped (below) they are 21 pound.

 

xxlTAPR.jpg

 

.

so if its 29 Lbs i can shave it to 21 Lbs? but if it'd 21 Lbs don't do anything? when i took it off it felt pretty heavy haha ill weigh it tomorrow! its 10:30Pm here so ill check it in the am when i go into my shop! 

idk how to check if i have a counter weighted crank?



#57 wayno

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Posted 01 December 2017 - 10:38 PM

WOW, I never noticed this before, I have a scalloped flywheel with a 240mm clutch cover/disc, I would have put that one on if I had noticed, I use 240mm flywheels on all my trucks.

I also have a really heavy flywheel with a 225mm clutch cover/disc, it even looks heavy, but all these flywheels have the clutch covers/discs installed on them so they don't get lost, so I cannot weigh them without taking them apart, and that really is not on my top 10 list right now.

DSCN7453.jpg

 

DSCN7454.jpg

 

DSCN7455.jpg

 

DSCN7456.jpg

 

DSCN7457.jpg


 

 


#58 datzenmike

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Posted 01 December 2017 - 10:47 PM

It's arguable. You could probably go lower than 21 pounds but once cut you can't put it back if you don't like it. Your 620 is at least 500 pounds heavier than a 510 car. Running a seriously lightened flywheel is for race cars that don't stop often. In fact you don't even need a flywheel other than for a clutch surface in a race car. Some NASCAR flywheels are 7 pounds!!!... basically a pie plate with a starter ring on it.


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#59 datzenmike

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Posted 01 December 2017 - 10:50 PM

DSCN7457.jpg

 

Yes! I also have a 21 and  29 pound 240mm flywheels. All Z24s and KA truck engines had 240mm wheels. Car KAs had 225mm. I have no idea what they are off of.


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#60 G-Duax

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Posted 02 December 2017 - 03:31 AM

I run an OS Giken 7-lb flywheel with a twin plate all metal clutch on my 620.

It's like an on/off switch.

I've leaned to drive it just fine, but few others can.

I call it theft prevention   :)

 

IMG_2649.jpg

 

The place that does my state inspections doesn't even try any longer, they just check the lights, and hand me the receipt. 

Back when I first started playing with L4s, I machined one down to 20-lbs, and even that was a big improvement.


"All of a sudden it started making noise, then started losing power. I limped the car home and tried to get it up the driveway, the engine just died."

 

Why do people do this?

A $100 tow bill is never as much as the extra damage you cause by trying to "limp the car home".

 

Don't be that person !