The beater 620 is back on the road!

[datsunaholic]

Well, after 13 months of procrastination, machine shop work, and carburetor issues the beater '74 620 is back on the road.

 

As some of you may remember in October last year it blew the head gasket after overheating on the freeway. I mean really blew it out- had a jet of steam out the side. I considered calling it dead and parting what little was usable (it IS a beater, after all) but I decided, what the heck, I need practice changing heads out since I haven't done it in a while. Plus I wanted to see how the nifty factory chain tool works (end result- it works very well, much better than the wooden wedge).

 

Well, I didn't get the head removed until June or July. Just didn't want to work in the rain. That's as far as I got, as I didn't have a good straightedge to check the rest of my W58 heads (roundport exhaust, didn't feel like modifying the exhaust again). In July or so a friend who also volunteers down at the Hydroplane museum and owns an automotive repair shop in Bellevue had a customer who has a '78 620 and cracked the head. He wondered if I had any reconditionable W58 heads he could buy. Well... How 'bout a trade? I'd give him 2 W58 heads that weren't cracked, he'd take both to the machine shop and if both were useable I'd get one back. So, the trade was on. I ended up giving him the head off the '74 and a head that I got from Bleach 7 or 8 years ago that supposedly had a bent valve. I figured my buddy could use valves out of the cracked head (he was going to use the cam and rockers out of it anyway, I had stripped those from the head). I got back my old '74 head as it turned out both heads were in need of only light milling and the "bent valves" turned out to just be stuck open (needed the guides reamed a bit). So I got back a nice freshly milled head.

 

I installed it in August, but when I tried to start it it would kind of run but not idle, and just bogged out under any load. When I tried running around teh block I had to used the accelerator pump just to make it back. I had an old Weber 32/34DFT on it, and apparently the main jets plugged up. Not having a DFT kit (dunno if you can even get those anymore) I didn't work on it the rest of the summer.

 

Well, I got sick of looking at it this weekend. It's been uncharacteristically warm so I pulled off the old DFT and stuck a 38DGAS and adapter plate setup on it. I'd had the DGAS for some time but it didn't work on the 4X4 so I shelved it.

 

Same problem. It'd run on the secondary but sputter and bog out on the primary. Well, it did that on the last car I tried using it on so I bet the damn jets are clogged up. Pull the lid and sure enough the bowl is full of varnish and the primary jet is gummed up. Not solid, but pretty plugged. Cleaned it out, scrubbed out the bowl, checked the secondary jet (it was OK) and lit it off again.

 

Still a little boggy but it doesn't die. Still no idle. Pull the idle jets- secondary is clear but the primary was plugged up solid. Cleaned 'em all out and now I have idle, a nice smooth acceleration. Test drove it and it does have a slight hesitation if I get into it too fast- probably due to it being a non-progressive carb. It's a lot of carb for a otherwise stock L20B.

 

The patient:

 

 

 

Nice shiny head. Yes, I know there's one blue plug wire. I'm a cheapskate and I broke one of the black ones when I did the disassembly so I grabbed one from the pile of old plug wires

 

 

 

The carb. The overlength fuel line is because the DFT had the fuel inlet in the back (I had it installed backwards due to the throttle pull being the wrong way if installed the other way). I do need to figure out what to do with that vent fitting- it goes straight to the fuel bowl. Cap it?

 

 

 

The nice part about this L16 manifold is I have the throttle bracket. You can see the non-progressive "gear" linkage unique to the DGAS. The stock Hitachi cable pull fits here perfectly. It doesn't work if you use the tall adapter. In this case I have one of the 2-piece Redline adapters, the work really well on an L20B for hood clearance.

 

 

 

And yes, I replaced the root cause of this whole exercise. The radiator had sprung a leak at the bottom of the core. I had a brand-new OEM '74 radiator, so in it went. Nothing too good for the old beater. Well, except maybe matching spark plug wires.

 

 

 

 

I do think I'm going to need to rejet this carb. It's really rich under load. I got the idle mixture to a somewhat tolerable level, but open the throttle and it's pretty smoky. Pulls pretty good though. The main jets are both 140s, I don't know tuning that much but it seems pretty big. The carb had been tuned for a 4.0L Jeep, twice the displacement.

[Pacific coast Datsun]

Doug thats not a beater it's a cruiser ;) ?...do you still have the blue KC you got from Ted awhile back?

[crabbyone]

Old datsuns never die....after a suitable amount of procrastination, they are pulled out of mothballs and recommisioned.

[Llittle_Llama]

wow, first i have seen of this thing, but glad its back on the road :)

[datsunaholic]

What, the Rustbucket KC? Actually I sold it to Ted and then traded back for it (so I've owned it twice). That's the one I stuck the ZX 5-speed in and the best-lean Weber on. It's my commuter (it gets 32MPG average). But it is really rusting apart- the only thing holding the cab on is the front 2 mounts, the steering column, and gravity. I've been looking for a replacement cab, or maybe a whole truck with a blown engine I can find cheap. But haven't been looking hard.

 

As far as this not being a beater... that's its GOOD side. I bought it at an abandoned vehicle (tow) auction; it had been impounded after the driver was caught driving with a suspended license. The front was bashed in from rear-ending a bus, and the back end was pounded flat from God knows what. On the plus side, it has the L20B and 5-speed from a 200SX which is which I bought it and not the longbed that was at the same auction.