My '76 710 Goon

[datzenmike]

Bought some Fell pro gasket material and made them today. Thermostat and fuel pump mounted. But Christ it took all damn day to clean and do it right. Took the Z24i CAS apart. Recovered the spline that fits the splined spindle. Compared it to the regular L and Z series spline and distributor and woah, it's sloppy loose. I don't doubt the timing jumps about at high revs. The spline has ZERO twist slop.

 

Have to figure out a way to fit this spline to an EI distriibutor.

 

This is the Z24i spindle.

[datzenmike]

Pulled out some PP, clutch discs and a flywheel. Gotta keep looking I'm sure there were half a dozen wheels. Found a 21 pound Z24 240mm wheel, clutch disc and PP. Cleaned it up and sprayed with WD-40 to preserve the 'finish' till next year when I need it. Spent the day throwing shit out and making room. Found 2 or 3 Z series clutch fans/water pumps. I need to cut the clutch off one because I have electric fans, then I can mount this on the L24B I'm making.

 

Also working on an aluminum windage tray to keep the oil splash away from the (slightly longer) Z24 crank throws. The L20B oil pan fits just fine and in my junk pile, while cleaning up, I found another oil pick up tube. It's identical to the 710 L20B one but dips down into the pan an extra 1/4" or so.

[datzenmike]

From c/l of crank to the bottom of the counterweight on the Z24 crank is just over 3.5". I measured a spare L20B crank and it's 3" so the Z24 crank is definitely dipping lower into the oil pan. I put 4 qts of water in my spare 710 oil pan, and it quite fills it. Can easily imagine hard cornering and sudden stops it would climb out of the pan and hit the spinning crank. Maybe all engines do, a little bit. Too much to be a problem? who knows. I'm going to make a 'windage tray' /' splash baffle' out of some spare aluminum I have.

 

........

 

It's only roughed in at the moment. Needs oil pump pick up tube clearance and the dip stick hole added. I'll drill and tap some mounting holes and the tray will sit inside the oil pan gasket. Still have to 'ventilate it' to let the cast off oil get back into the pan.

[datsunfreak]

14 hours ago, datzenmike said:

Can easily imagine hard cornering and sudden stops it would climb out of the pan and hit the spinning crank. Maybe all engines do, a little bit. Too much to be a problem? who knows.

 

I know. The answer is no. ?

 

Are you trying to win your class at the SCCA Nationals in Topeka, or trying to have a fun street car? 

 

Your car does not corner hard enough to make this a problem. And it doesn't matter if it hits on hard stops, as you are not trying to make maximum horsepower at that moment. 

 

Is this cool? Yes. Will you see a benefit from it? No. 

 

[datzenmike]

Not really thinking HP gains. Can't see the oil fog and droplets spinning around with the crank getting in the way. Centrifugal force would fling it outward. I was thinking the crank might whip the oil splash up and overload the rings or the excessive spray/fog might get sucked out the block vent by the PCV.

 

I tried carrying a car oil pan around and not slop any... impossible... and that's just walking. The slightest rocking motion sets up waves. I tried carrying a large oven pan with an oil change in it in the company van to recycle it and even driving normally it went all over and made a fucking mess. It's not just stopping and cornering, there's bumps too.    

 

I looked around and the average car and driver can safely brake at about 0.5 g, expert at 0.6g and maxed out 0.8g. (specialized performance cars can top 1.0g. ) 0.5 g would be the same as having the car facing down a 45 degree slope. Add to this, braking while driving down hill. I don't think you can tilt a full oil pan 45 degrees without spilling.  So my take away is that most cars must experience oil slopping up on the crank. I imagine the rings are just squeegees and can handle small amounts, most of the time, but I've seen accidentally overfilled engines puking oil smoke out the exhaust.

 

Having the crank throws and rod caps closer to the oil by 1/2" might be a concern.

[datsunfreak]

19 minutes ago, datzenmike said:

 

Having the crank throws and rod caps closer to the oil by 1/2" might be a concern.

 

Well, it is certainly not going to hurt anything to have it, so...  ?

[datzenmike]

 

 

 

Final design. Block vent can only use air from below the windage tray. Oil pick up clears and dip stick hole added. Has lots of oil return holes and the bottom 'louvers ' are almost crank scrapers. By mistake I got SS fasteners which are too soft. Will get something better. Oil pan now fits properly with some trimming at the bottom. 

[datzenmike]

I can't believe I rebuilt a few L series back in the mid '70s. It was in a weekend and on the kitchen table!!! Christ I must have thrown parts at it and not even cleaned the old gasket off. How was it possible???? Thought it was near finished but.... I want to have the engine as complete and ready to drop in as I can. I don't want to rob things off my L20B engine to make this swap work.

 

Found another oil pressure sender to 'plug the hole' in the block. I took it's 4x4 sender out to put on my current L20B. (forgot)

 

The L head and the Z series blocks both have the heater outlet elbow on the side. The one on the head was rusty thin so I removed it and found a pipe plug from a KA intake to seal it up.

 

Bought new steel fasteners with lock washers and washers and bolted the windage/splash tray on.

 

Installed the oil pan using two of those flat L shaped things that spread the tightening pressure on the rear of the pan. Apparently only one side uses them (left) so I trimmed the other and now have support all the way around the rear of the pan. The longer oil pick up won't work. Must be for a Z series engine it's actually tilted slightly. Better to use the 710 L20B one I have.

 

Found three high volume clutch fans I could use. The loosest one, (most of the silicone oil leaked out) I cut the clutch off and trimmed it. I have electric fans and the clutch would be in the way. Will install tomorrow.

 

Rather than fuck with the distributor I'll install the spindle and oil pump tomorrow. The EI dizzy WILL have to come off the L20B when I do the swap.

 

The pilot bushing has maybe three tank fulls of running so will leave it.

 

Alternator bracket from the L20B will be used... it was modified to use the 2002 Altima 100 amp alternator so it has to be swapped on.

 

I have a set of 710 L20B engine brackets and will put them on tomorrow. Again the less I have to take off the current L20B the better.

 

 

 

[datzenmike]

 Forgot the rear crank seal (no biggie but have to remember it, and engine brackets but water and oil pumps are on. All open ports on the head thermostat and rad return are 'sealed' up. Dip stick is in but only to keep hibernating bugs out. It's on the left side and will need to be graduated... it is a Z24 block with car L series oil pan so....? The three exhaust studs need replacing. Engine vent tube needs putting on. Have half a dozen L20B ones kicking around.

 

So I'm going to call this an L24B engine. There is precedence for this. The L20 six cylinder came first and when the L4 2 liter came out they couldn't use that, so it was named the L20B. Technically the L20 6 cylinder is now the L20A. So if I have an L2.4 and there already is a six cylinder by that name, this can be an L24B.

 

 

 

[datsunfreak]

On 11/18/2018 at 5:47 PM, datzenmike said:

There is precedence for this. The L20 six cylinder came first and when the L4 2 liter came out they couldn't use that, so it was named the L20B. Technically the L20 6 cylinder is now the L20A. So if I have an L2.4 and there already is a six cylinder by that name, this can be an L24B.

 

Well, there's the L20, a six cylinder used in the late 60s Skyline...

 

 

Then the L20A (based off the L16) that was used in the Fairlady and post '70 Skyline (and a few other JDM only models)...

 

Then came the L20b, the ubiquitous late 70s 4 cylinder variant...

 

 

 

So by that rational, this could be the L24A?  ?

 

Although there is the early 70s L24, and the later 70s L24E to further confuse things...

[datsunfreak]

Somehow it just now occurred to me how much the L20 looks like a stretched out U20...  ?

[datzenmike]

The L20 had a weird looking valve cover.

 

The L20 came first and was replaced by the improved L20A. At this time there was no 2 liter L series 4 cylinder so everything was fine, but when there was, the L20 and L20A were already spoken for so the L20B became.

 

The E as in the 200sx Z22E  is to denote EFI. An S as in the 720 Z22S denotes carb.

 

If there was a 2 liter L series V8 maybe an L20C????

 

L24A yeah I guess so but that would infer an improved L24 six cylinder? I'm going with the L24B because at a glance it looks exactly like an L20B 4 cylinder. Shit IDK

 

 

 

 

 

[datsunfreak]

13 minutes ago, datzenmike said:

I'm going with the L24B because at a glance it looks exactly like an L20B 4 cylinder. Shit IDK

 

As long as you don't call it LZ24, you'll be fine.  ?

[datzenmike]

Well I suppose it is a mixture of L and Z parts. Block crank, rods and pistons, timing cover and pulley are all Z everything else is L.

[datsunfreak]

On 11/20/2018 at 10:47 PM, datzenmike said:

Well I suppose it is a mixture of L and Z parts. Block crank, rods and pistons, timing cover and pulley are all Z everything else is L.

 

Yes, but the issue is that the LZ engine is already a thing that exists...  ?

 

[datzenmike]

Oh yeah. The head definitely makes it. However many people call an L head on a Z22 an LZ22 I'll stay away for LZ

[datzenmike]

Rain last w/e. Today I replaced the exhaust studs with ones that have more threads and go deeper into the aluminum. Anti-seize and nuts on for the winter. I got an engine hoist years ago because someone with a 'problem' needed $50 if you know what I mean. Didn't even want it. I used it to get the L20B out of the parts goon and the Z24 out of my 620 but storing it outside never expecting it to be used again it wouldn't pump up this summer. Oil was milky, filled with ATF that was handy, could not bleed it. Amazon $48 delivered!!! New ram installed today and bagged for the winter.

 

 

[datzenmike]

Next spring when I swap engines I want to use the intake on the L20B. It was heavily modified to rid it of the EGR but keep the PCV and looks rather nice like the stock L16 intake. I might try the L20B carb but with 400extra cc's why not the Z24 carb. 

 

............. Primary.... Secondary

L20B.... 34.4mm X 33.6mm*

Z24...... 33.6mm* X 38mm

 

Looks like the primary on the Z24 carburetor is as large as the secondary on the L20B!!! So I'll get it running on this first befor I start messing with my R-1carb and intake.

 

Now the problem is the two primary side studs in the intake fit the Z24 carb but the two by the secondary are spread farther apart. This amount...

 

I removed the throttle plate and filed the holes larger...

 

 

 Still have to grind away some of the case so the nuts will fit but getting there.

 

Noticed the secondary does not open fully and there is a tap that hits a stop on the diaphragm casting. This thing...

 

 

Stops the throttle here...

 

 

When properly filed down....

 

the secondary can fully open to vertical...

 

 

Small things eh? I noticed the primary was also slightly less that vertical. That is easy for anyone to figure out and use vice-grips to fix, and I did.

 

As this was a truck carburetor with cable throttle I put a car linkage  on it..

 

[datsunfreak]

On 12/16/2018 at 1:09 AM, datzenmike said:

Next spring when I swap engines I want to use the intake on the L20B. It was heavily modified to rid it of the EGR but keep the PCV and looks rather nice like the stock L16 intake. I might try the L20B carb but with 400extra cc's why not the Z24 carb. 

 

So why not just use something like a 38/38 Weber? I know it's not low budget, but it works...

[datzenmike]

I'm just making do with what I have on hand. The end goal is this...

 

 

And I have an Isky 280?  .480 lift cam laying around somewhere.

[tr8er]

And the 38/38 is pretty unfriendly for daily.  

 

Looking great mike!  

[datzenmike]

I want to be able to drive this to the new Canby show, maybe.... so will do the R1 and cam later. It should go alright with the stock Z24 down draft. Docility and mileage will be important.

[datzenmike]

 

OK. Ground away enough of the casting for a 'shoulder nut to fit. Not very neat but it will work. This way I can keep the intake stock and an L20B carb will also fit.

[datzenmike]

Spent a couple of hours taking the Z24 carburetor apart and cleaning it. This is the Carburetor that was originally on the '84 engine that later turned out to be an '87 D21 Z24i converted to Carb and put in the 720 that was rolled. The engine ran beautifully, no smoke, quiet.

 

I have dozens of spare carburetor parts and maybe 8 or more carburetors.   Blew out all the orifices with carb cleaner. Replaced the inlet valve (solid metal so maybe was replaced before?) with a neoprene one. Set the float drop, checked the vacuum break setting, and fast idle.  The primary is a 109 jet I have a 112 on my L20B carburetor and can swap it on if I need it. I'm at sea level and richer is better. Replaced stripped screw heads and cotter pins... made it nice again.

 

Trying to find an accelerator pump. I got 4 or 5 years ago at Canby with the leather seal but they don't want to fit. The Z series were all blue neoprene? I heard once that the leather ones were made from kangaroo hide. 

 

The high speed enrichment (power valve) was sticky. With the top air horn off I could work it back and forth to loosen. My 710 Carb had been apart before and the hollow screw in the base was switched for a solid one. The hollow screw feeds intake vacuum up to the power valve. Made a big difference after when into the secondary. The Z24 carburetor doesn't use a hollow screw.

 

The primary and secondary throats had sharp edges and casting flash so I ground them down and smoothed with the carbide burr and sandpaper.

 

Need to make a gasket from material that I have. And modify the L20B intake holes to fit the slightly larger 34/38 carburetor.

[datzenmike]

Well March. Horn just clicked so put charger on over night. Fired it up yesterday and warmed her up in the driveway. Smells like spring.