Need Help Deciding on what to use to build up a L20b or L16

[Suspect]

I just bought a cam off ebay. Its a Comp Cams.... Lift .480/.480, RPM Range 2500-6500, duration is 292 Deg. and the lobe angle is 110 Deg. At the moment I have a choice of a L20b which is in the truck I drive and a L16. I have a U53 head and a A87 both stock and need to be resurfaced. I also have stock carbs. What should I use for pistons, carborator, crank, rods, etc? The guy I got it from said it "was too much camshaft for my application" which was a stock motor.

 

I plan on putting that motor I build in a 1973 Datsun 620 Pickup. There is a local road course I'd like to mess with and there is always the drag strip.

[datzenmike]

He's right, that's WAY too much cam. Stock is .413 lift and 248 duration. Generally for every 10 degrees increase in duration the power band moves up the RPM range by approximately 500 RPMs. This will move your power range up over 2,200 higher resulting in very poor performance at idle and mid range where you do most of your driving.

 

With a cam like that you will need stiffer springs, larger carb or more carbs freer flowing exhaust system and maybe some head work in order to use the cam's potential. All of these extras will add to the poor low and mid range driving.

[Bleach]

something tells me its a 480/280 cam, not 480 duration

 

L20b would be the engine to build. Up the compression with either a closed chamber head, slightly surfaced OR some L18 pistons which have a smaller dish in them. You'll be running mid or prem gas for good power.

 

Throw on the cam, new timing chain set, #2 position on the top sprocket. Then electronic ignition and whatever carb setup you want.

[banzai510(hainz)]

its a little long on the duration but maybe set the timming to #2 on the L20.

 

My opinion youll be fine using that cam. Best with sidedraft Mikunis

 

if you have a L20 I would build that.with clutch set up as the L20 is a 6bolt crank trucks use a 225mm flyheel as L20 cars like the 610/710/200sx use a 200mm flywheel(info)

 

use the L16 as a daily driver motor(L16/18 is a 5 bolt crank)

 

use the head that has a closed chamber. Most W53s are closed chamber. Its a W53 yes W53

[Guest DatsuNoob]

its a little long on the duration but maybe set the timming to #2 on the L20.

 

My opinion youll be fine using that cam. Best with sidedraft Mikunis

 

if you have a L20 I would build that.with clutch set up as the L20 is a 6bolt crank trucks use a 225mm flyheel as L20 cars like the 610/710/200sx use a 200mm flywheel(info)

 

use the L16 as a daily driver motor(L16/18 is a 5 bolt crank)

 

use the head that has a closed chamber. Most W53s are closed chamber. Its a W53 yes W53

 

I was at Pull a Part in parkland last weekend and found a truck with a W53 (Not W58) head on it. Thought I'd struck gold for a while. So I took it off the easy way, removed the head bolts and disconnected the 3 bots on the exhaust flange and pulled the whole top of the motor off(highly reccomend this way for those who havent tried it), much easier to get those intake mani bolts out). Anyway, I flipped it over and saw it was an open chamber, sucks... (but atleast I scored some nice fenders that day :D) Long story short, W53's are not always closed chamber

[Suspect]

I just read something on ebay again. A guy on there is selling a Z22 Crankshaft claiming that it will make the L20 a stroker. Here is the auction http://cgi.ebay.com/ebaymotors/datsun-510-Z22-stroker-crankshaft-crank-L20B-M90_W0QQcmdZViewItemQQcategoryZ33616QQihZ005QQitemZ150251247837QQrdZ1QQsspagenameZWDVW

[datzenmike]

That's right, two possibilities at least:

 

2.3 liter motor

Z22 crank

L20B block +4mm over bore to 89mm (this is a bit extreme)

L20B rods 145.9mm

KA24 pistons

9.9 compression with open chamber head or 8.9 using Z24 pistons and closed chamber head.

 

2.19 liter motor OR (2.237 liters)

Z22 crank

L20B block +2mm over bore to 87mm OR (+3mm over bore to 88mm)

Z20E rods 152.5mm

Stock Vg30E pistons with 2.7mm trimmed off the tops. OR (+imm oversize 88mm VG30E pistons)

[Suspect]

I think I have one of the Z22 motors. Its in a 69 Datsun 521 Pickup. The guy said the motor came out of a 1986 Nissan Pickup.

[datzenmike]

'86 could have been a either a Z24, Z24i or Z20 motor. Course it could have had a Z22 swapped in.

 

If it still has the 8 spark plug head on it you can look between the exhaust pipes on the head, just below and to the rear of the #2 plug. On the block, easily seen it will say Z 20/22 or 24.

[Suspect]

I just went back and looked and its a Z22.

[datzenmike]

Cool little motor. In it's stock Z22 form should have better low mid torque than an L20B. Not so good a top end.

 

Hmmm... Put the cam in the L head and the L head and everything forward of the L20B block onto the Z22 bock. This will in effect give you an L22 motor. Thats 10% more displacement and longer stroke for more mid range torque. One of the guys on 'the realm' has an LZ22 with cam and side drafts, and puts out just over 130 at the wheels!

 

You will have to change to L20B motor mounts and use an L series tranny but it would be a real mover. Might be best to re-build THAT motor

[Suspect]

If I was to rebuild it, that gives me a bunch more options. As far as I know its stock. Hmm, so basicially I could just leave my running L20B alone and swap everything from a L16 motor and get the same thing?

[datzenmike]

The L16 timing cover is not tall enough and the head has smaller valves. For best results use an L20B head and timing gears/chain/cover.

[Suspect]

Wow, I didn't know there was that much difference in L16 to the L20b. I never really messed with the L20b, I just bought the 77 Datsun I drive. What heads came on the L20b? The L16 I have in the garage has the A87 head. I have 3 other heads around here. I'd have to look to see what they are.

[datzenmike]

On the '75-'77 620 I think the U67 was used. Square exhaust ports and the intake and exhaust is bolyed together for intake warming. "78and on used the W58 head with round exhaust ports with steel anti-pollution liners. The intake was not bolted to the exhaust and had a coolant passage below each runner for intake heat.

 

The L16/18 has a 5 bolt crank/flywheel and the L20B has a 6 bolt. The L20B block is also 2cm taller. Rod bearings are interchangable but mains are not.

[Suspect]

My motor in my 77 has the W58 head. How do you tell the difference on what head is open chambered and which head is closed chambered?

[datzenmike]

You remove it and turn it over.

 

I have a W-58 on my '78 620 also, and know it's open, I think all trucks were. I did have a closed and found it was from a '79 200sx L20B. This makes sense that it was off a 'sporty car'.

 

The W-58, at least the ones I've seen, had the steel exhaust liners. The P-nut head, I removed them, did some porting and sold it to a guy from Edmonton who used to be on here or NWDE. One of the Z car sites said the liners didn't affect performance on the six cylinders.

[Suspect]

Thanks for all the help and information. These Datsun's are older than I am. I bought my first Datsun when I was 15 in year 2000. It was a 73 Datsun 620 I bought for $50. I teached myself how to drive in it too.

[jose]

Cool little motor. In it's stock Z22 form should have better low mid torque than an L20B. Not so good a top end.

 

Hmmm... Put the cam in the L head and the L head and everything forward of the L20B block onto the Z22 bock. This will in effect give you an L22 motor. Thats 10% more displacement and longer stroke for more mid range torque. One of the guys on 'the realm' has an LZ22 with cam and side drafts, and puts out just over 130 at the wheels!

 

You will have to change to L20B motor mounts and use an L series tranny but it would be a real mover. Might be best to re-build THAT motor

 

What exactly do I have to do to get a LZ22? I put a z22 in my 620 but I can

[datzenmike]

First get it going! In order to have an LZ you need a running Z to begin with.

 

FUEL:

 

Look at the glass bull's eye on the front of the carb. The fuel level should be at or very near the dot.

NO GAS: find out why... clogged filter, stuck carb float/needle, pump electric or mechanical not working? kinked rubber fuel line, clogged line, empty tank.

GOT GAS: Pump the gas and look down the carb, you should see a strong squirt of gas from the accelerator pump. Check that the idle cut solenoid is connected and working by turning the ignition on/off/on/off... you should hear a click sound at the back of the carb if working. Check carb mounting bolts are tight and no hoses off or missing from the intake manifold causing a vacuum leak. Don't forget the vacuum line to the brake booster.

 

SPARK

 

If it cranks over, take both plug wires off the number one cylinder, that's the carb side and the exhaust side, and put some old plugs in the ends and lay on a good grounded surface like the valve cover. Crank it again and see if you have spark on both plugs.

 

YES THERE IS SPARK... Check the wires go to the proper plugs and aren't mixed up, be sure the distributor is timed properly.

NO SPARK: do the same with the coil wires on the cap...

 

YES SPARK check cap, rotor and wires.

NO SPARK check for 12 volts on + terminal of coils with ignition ON.

 

YES 12 VOLTS check the distributor module wires are plugged in. Black wire to ground, Black/White wire 12 volts in on position, Brown wire to exhaust coil, and White/Yellow wire to Intake coil.

NO VOLTAGE connect to a switched ignition source.

 

You should now have fuel and spark and if the timing is right, plugs wires right it should start.

Edited October 19, 2008 by datzenmike

[jose]

YES 12 VOLTS check the distributor module wires are plugged in. Black wire to ground, Black/White wire 12 volts in on position, Brown wire to exhaust coil, and White/Yellow wire to Intake coil.

NO VOLTAGE connect to a switched ignition source.

 

You wouldn’t have a diagram I need to see it. i think that were i have it wrong How do I time the distributor? It turns over I have fuel, and spark it just wont start

Edited October 19, 2008 by jose

[Suspect]

I found this head on the internet for sale. Its a Closed Chambered SSS A87 Peanut Head. He says its a "High compression race head". How can you tell? And approximately, How much is it worth?

 

Edited November 1, 2008 by Suspect

[RandyinRenton]

YES 12 VOLTS check the distributor module wires are plugged in. Black wire to ground, Black/White wire 12 volts in on position, Brown wire to exhaust coil, and White/Yellow wire to Intake coil.

NO VOLTAGE connect to a switched ignition source.

 

You wouldn

[datzenmike]

 

L heads are usually 'open' or 'closed' type. The open chamber type have a circular combustion chamber that fits over the whole cylinder bore and are about 45.2cc in volume. A closed chamber head is generally 41cc and is not round but kidney bean or peanut shape. The smaller closed, or 'P-nut' head gives a higher compression than the open chamber head. You have a P-nut head in the picture.

 

Stock L20B compression

Open chamber head .... 8.40 to 1

Closed chamber head .. 8.90 to 1

__________________

 

 

Because the A-87 has smallish intake ports it's ok for a stock L20B that isn't going to be improved or an L18 motor. If performance is the goal, the intake ports can be enlarged for better flow.

 

 

Unfortunately the (L20B?)cam is rusty so someone didn't store it properly. A good point to bring up when haggling about price. Also the head surface is pitted at contact points with the water jacket. The owner has attempted to polish it up and has hit and shined the #2 intake as well.

 

Still all in all an .... ok head. Not worth top price though.

Edited November 1, 2008 by datzenmike

[Suspect]

So far it would cost me $290 to get it to my house including $40 for shipping. The cam isn't a problem because I already have a good race cam.