'74 and then some

[datzenmike]

The close ratio only came on the '80-'82 non turbo 280zx. If it has the speedometer retaining bolt in the 12 o'clock location like this...

 

... then it can't be a close ratio. Often with identifying a transmission you can easily tell what it ISN'T more easily than what it IS. Having the bolt in the 6 o'clock location does not guarantee it is a close ratio either.

[JNHEscher]

http://m.summitracing.com/parts/usw-844-7860p

[JNHEscher]

http://www.tirerack.com/tires/tires.jsp?tireMake=Kumho&tireModel=Ecsta+W710&partnum=645VR6EW710&vehicleSearch=false&fromCompare1=yes&tab=Specs

[KlassicMotion]

Yeah, I think those will look good.

 

I like the look of the tread pattern on th Kumho.  Just be informed, the brand new Kumho Ecsta's I had on my Mazda PR5, would always go "thump, thump, thump" down the road, until they warmed up.  Maybe that was just my set, but I haven't tried another set since.

[JNHEscher]

Yeah I had a lot of trouble with Ecsta's hydroplaning really bad. This is a different tread, though. I'm willing to give any tire a try. You get what you pay for when it comes to performance street tires. Those look like a dirt track tread.

 

I'll widen those wheels to work with the tires. Wanted to stuff the widest I could in back while keeping the overall diameter less than the stock 25.5". Love the look of wheels with studs or bolts. Would go 17", but you can't get that without a 4" front space. There's only 3.5" between the brake drum and fender. I have room for 6.5" backspace. Haven't measured for the fronts, yet.

[JNHEscher]

W710's would've been perfect, but they're discontinued. So, these are the runner up. http://m.summitracing.com/parts/bfg-44288

[KlassicMotion]

I like the G-Force.  I haven't tried them yet, but they are what I will try next.  BFG radial TA's are fine for what they are, but I don't plan to go back to them, unless I need that vintage look.

[JNHEscher]

Those only have 4/32" tread depth, which I find to be a waste of rubber for the street. These Potenza's look to be the ticket. Same size, about and inch shorter than stock tire and reasonable tread depth. Better price to boot! I'm placing the links here so I don't lose them.

http://www.tirerack.com/tires/tires.jsp?tireMake=Bridgestone&tireModel=Potenza+RE-11&partnum=445WR6RE11V2&vehicleSearch=false&fromCompare1=yes&tab=Specs

[KlassicMotion]

So, you started at a $50 tire, now your looking at a near $200 tire?....  I like the Potenza's  are those directional?

[JNHEscher]

I'd have a pair of those $50 Ecsta's right now, but they're gone. They were so cheap because they are discontinued and that was the last one available. Bummer.

 

Everything checks out on the Potenza. I'll get one mounted on the rim at 8" wide and see how it fits. Might be a a couple weeks or so before I have them. We just had 8" of snow and all the delivery drivers are too chicken shit to drive in it anymore.

[BlackBird620]

The arms are at pretty good angles considering I measured nothing.

 

What's the upper arm in this shot from

[JNHEscher]

Arms and knuckles are all from the '81 2wd 720 out back. Pondering beebani's upper arms. Planned to make my own, but I have enough to do on other projects already. The caster angle needs to be much more positive.

[JNHEscher]

Test drove yesterday. Man, its nice to have a fifth gear, but not one that consistently pops out of gear. It won't hold fifth upon accelerating, so a fixing' I go. The power band is up a bit high, but I think I can make the 720 rear end happen. We're almost out of dipping into the negative temps which will make tinkering fun again.

[JNHEscher]

This has been on the back burner, lately. Busy fxing so many other vehicles. I plan to do something about the upper control arms in the very near future. I would like to fix the cold idle issue, too, but that won't be a problem if the weather would ever warm up.

[JNHEscher]

Just found out the other day that my uncle used to have two B210's. Gradually discovering more and more that much of my family has rocked out a Datsun or two in their day and have fond memories of them. I'm going to make reminder to get loads of progress pics and descriptions on here as soon as I get back from Texas next week. Miss getting on here and conversing with you rats.

[JNHEscher]

Swapped my upper control arms for decent caster angle. Should drive in a relatively straight line, now. I welded on a new muffler and used a hanger off my wife's WRX. Had to torch a small section out of the way so the exhaust didnt knock around.

 

Went for a drive the other day and fifth gear wouldn't engage at all. Just felt like nothing was there. Pulled the trans tonight. Hosed the detents with penetrating oil and worked them around. No obstructions found. I'll see how it drives tomorrow.

 

 

Got a pic to compare the control arms. Swapping them left to right works really well. Hadnt seen anyone post a pic for those wondering.

[JNHEscher]

Pulled my axles out just enough to get the differential out. I was scrambling to torch the 720 free before the hail storm rolled in. Managed to get it all cut out, loaded onto the cart, and pushed back to the shop just in time. I'll have the 3.89 rear end in today.

 

 

Looked over the stock gears just for the hell of it. Perfect pattern wear and all the bearings are in excellent shape.

 

 

[JNHEscher]

My purty(rusty) new 3.89 rear end. When I pulled it out of the 720 housing, three of the ring gear teeth had some gnarly rust on them. Buzzed them over with a wire wheel and called it good. Ran through all five gears while on the lift and could see a good difference in wheel speed. I just might keep up with today's traffic.

 

 

Went with the one-piece driveshaft again. Instead of having it shortened an inch, I moved the drive train forward. Shaved a notch into the ends of the front side of the trans cross member and flipped it around. Lined up just right. Redrilled and added some plate to the motor mounts to make those work. The radiator fan ran out of room, so I'll probably run a hole saw through it and recenter it to set it back a bit.

 

 

The steering center link has just enough room. The forward shaft made removing the transmission a lot easier.

 

 

[JNHEscher]

There's been a terrible metal-on-metal noise while the engine idles. I suspected that it was the water pump, and indeed it was. The bearings sound like gravel. I just placed an order for a new pump, front cover gasket set, timing chain, and valve cover gasket. I planned to run the motor as is, but since I've freed up the room to do the maintenance, I might as well freshen things up. I'm ditching the stock fan for an electric. Hopefully this will help reach operating temp faster. It runs like complete ass until it hits the right temp.

 

 

 

 

What say ye to these Weber 32/36 dgev jet sizes for an L20? It runs rich and has an especially hard time running at any rpm until it warms up. Kenny and I noticed that the temp cycle is like clockwork. It takes about half an hour to reach temp and the second it does it runs like a champ. Its right at about the time the coolant is hot enough to open the thermostat. The vacuum valve on the thermostat housing being disconnected has me curious. I thought maybe it was used to control the evap valve.

 

 

 

 

 

[ggzilla]

Adjust your choke. It should only just - barely - close when cold. If you adjust it when kinda cold it won't be right.

[JNHEscher]

Unfortunately, it runs just the same with it propped open. It continues to run rich when warm and the choke has fully opened.

[KlassicMotion]

Im not sure this will help, but...

Have you run through Weber's setup process?

 

http://www.redlineweber.com/html/Tech/carburetor_set_up_and_lean_best_.htm

 

And in response to the jet size; towards the bottom of the instructions you will see this paragraph:

 

EXAMPLE     With the speed screw set at no more than (1 1/2) turns in after contact with the stop lever; and the best idle occurring with the mixture screw set at  3 turns from bottom, indicates the need for a larger Idle jet. Achieving the best idle at under 2 turns indicates the need for a smaller idle jet.

[JNHEscher]

I went through it last year just to read it. No adjustments were needed then. It started running like it is now when the fuel started to foul over the winter. Has new gas, filter, and plugs since it started this but hasn't improved. It runs great just as soon as its warm enough, like it all of a sudden snaps out if it. I've had it idling outside the shop door a few times and we always hear it go from a jumpy stumble straight to a smooth pur in that same time frame.

 

I wont mess with it until next week after I have the new parts on. The timing chain may not be all that necessary, but everything on the front cover looks original and I don't know the mileage on this motor. I'll check valve lash once the chain is on.

[ggzilla]

Don't fix what ain't broken

 

 

There is some crud in the carburetor fuel bowl. Drain it. Remove the sight glass cover.

[JNHEscher]

Don't fix what ain't broken.

True that. I needed to replace the cover gasket anyway because its an oily slobbery mess. Discovered that none of the bolts were torqued. The chain looks good. I just need to look up the timing specs and make sure the marks are where they need to be.

 

I'm thinking I'll tear the carb down to at least reseal it. The paper gaskets are soaked in fuel. Might be crud in it. Might be stuck parts. Dunno. Just odd how its like a switch gets flipped and it runs smooth with no transition from rough idle.