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Cardinal Grammeter

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About Cardinal Grammeter

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  • Gender
    Male
  • Location
    East of Pittsburgh PA
  • Cars
    1974 620

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  1. Chrysler had those wells in the manifolds that housed the bimetal spring. There was a rod that went to the choke shaft arm. Simple system. Studebaker had various tubing layouts that were inserted into the exhaust port that ran under the intake manifold. (Carters and Strombergs were used in the 50's and 60's) One end of the tube went to the top of the air horn to obtain air after the air cleaner, the other went to a fitting on the choke cap. The choke chamber had an internet port to manifold vacuum to draw in the hot air. The more I think about this, the more I think there may be a long forgotten consensus among mechanic friends that those electric chokes never worked right. But it is all a dense fog nowadays. I'm going to have to "break open" one of those 340 sealed chokes... ... you know, the issue isn't with the choke since it always starts the engine, it could be there is "too much" fast idle cam. I wonder what would happen if I adjusted the FI cam so that the next to the highest step was the starting step thereby reducing the range of the FI???
  2. So the Datsun choke cal was off in the "opposite direction" of American Iron? NOTE: Maybe my problem is that I've never dealt with American electric chokes - only the ones that used manifold vacuum to bring hot manifold air into the choke spring chamber. I could see transitioning from that "wimpy" system which always never produced enough correction, to the electric which was like a blast furnace and produced too much correction. Hey wait a minute, I had a 1972 510 and a 1974 (or 76?) 4-dr 1400 B210 and don't recall this problem. I drove them until 1983 when I moved from PA to FL. My dad drove the B210 until the frame broke in half from rust. We talked a lot and he never mentioned any problems with the car. I need to go through my other 340 parts carbs and see what springs I have but they are buried on a work bench and will take some time to unearth them...
  3. Since I might have the wrong choke spring in my carb, the question is, "Does anyone else have this problem - needing more choke in the summer / less in the winter?"
  4. I've been through everything - I even bushed the throttle plate shaft on the DCH340. (It has an electric heated choke with the proper inner fender relay that detects alternator charge to determine engine running. As far as centrifugal and vacuum advance, the engine has too much power and fuel economy for either to be a glaring issue - I get over 20 mpg around town and it's not even a full mile to town - 1/2 my runs the engine doesn't get fully warmed up. There is one glaring omission regarding the 620 (and not the 52x trucks), the BCDD. It was working OK but the last time I had the carb off, there is something wonky with it. (a quick "test" is to take the plug out and push on the adjusting screw, it should make the engine speed up.) RE: Timing - I keep the timing as far advanced as the fuel will allow.
  5. EDIT: Here is a better way to understand what is going on: Choke temperature correction has always been approximate and minimal. When you adjust a choke in hot weather, it's because you have too much choke. When you adjust a choke in cold weather, it's because you don't have enough choke. My situation is the opposite: too much temp correction resulting in too much choke in winter and not enough in summer. END-EDIT I know exactly what you are saying. What I'm saying is that what I have going on is something out of said envelope. I suspect wrong bimetal or heating element. As I said, carb was a basket case and frankly I don't know if the black choke cap was included or the proper one since I don't think there is a FSM test for it or a means of IDing it. .... or is there?
  6. Has anyone encountered this problem? I'm near Pittsburgh and yearly temps range conservatively from the "teens" to the 90's. The carb is a basket case: parts were "like new" and there was a metal tag with "74 MT" stamped on it. I checked all the jets and bleeds and they were correct. I also accumulated 2 other 340 carbs. I can't determine if I have the right electric heater choke cap. If I adjust my choke for summer, when winter comes, the choke is too rich and the fast idle is too high. If I adjust my choke for winter, when summer comes, the choke is too lean and the fast idle is too low - engine will actually "flame out" in 90* weather due to too low a fast idle. The reason for this is the bimetal spring is moving too much from its Start (ambient temp) to Run (heated temp.) SOLUTION: (maybe): Reduce the bimetal spring movement: 1) Reduce electric heater current: insert series resistor - this could also be a power rated rheostat that would be adjustable. 2) Cool the choke housing: introduce ambient air venting of the choke chamber. Obvious way would be to drill hole(s) in the plastic choke cover. 3) Find different bimetal - one with fewer tuns.
  7. Someone should make the faceplates so other tachs could be used. As a start, the tack could be photographed, scaled, and then printed with photo stable ink on premium photo or card stock. A professional print shop or sign shop might be able to make a high quality, more durable (UV) one. Then find a tach with a needle that is similar, install the faceplate, and no one would know the better.
  8. MORE MISTAKES ON MY PART > 620 wheel widths are 4.0" and 4.5", early and late, changeover date: Feb. 1973 https://www.carpartsmanual.com/datsun/pickup-1972-1979/axle/front-drum-road-wheel This begs the question: If only the 620 had the "3-ball" hub cap clips, where did the 5.0" slotted wheel w/"3-ball" come from? I discovered this when researching part numbers to determine if the bed part numbers were unchanged for the 620 run. They change. In fact there is a change in 1978.
  9. I can see there being changes with the redesign of the brakes to disc, however the more negative offset is in the direction of more interference with the calipers unless the hub flanges were moved outboard. Now while all that could be true, If nothing was changed in the rear, the 5.0 rims result in less clearance with the bed wheel well which is unexpected (unless they changed the distance between the axle flanges.) All confusing.
  10. Yes, I gathered that. With the availability of hubcap clips and mild steel balls, I figure it would be easy to get those caps on late model wheels. I'm just wondering why in the world there is so much offset difference in the 4.5 and 5.0 620 OE wheels. I have to believe the beds are the same - did they widen the track for the L20b w/ball joints???
  11. The recommended rim with on the 215/70r14's is 5.5 to 7 inches. This is a standard tire spec. They are wider than the 205/75r14's so would rub more on the bed w/5.0 OE wheels. I'm into handling so I want same tires on all 4 corners. If I'm running 185's (maybe 195's) they probably wouldn't rub w/5.0 rims in the front. I do like the tight turning circle of the 620 and do not want to give that up. I thought I had a easy and cheap way to put wider rubber on my truck but that isn't the case I'd either have to find a complete set of rims of some Brand X with the right offset. I'm going to stick with the 205/75r14's on the 4.5's - all I need now is to find one more 4.5 for my spare. If I get a deal on 185s or 195s, I can always run them. NOTE: I do wonder if the D21 wheels have a different offset. They'd probably be the easiest to find in the bone yard.
  12. I agree with custom or non-OE wheels you have to get the right offset. What totally shocked me was that there are issues going from a 4.5 OE 620 wheel to a 5.0 OE 620 wheel. I didn't see that one coming.
  13. Please read EDIT to initial posting regarding 14x5 rims and 205/75r14 tires. The guys are Walmart Auto discovered this offset problem. I think I'm done with this. While I would like wide low profile tires to lower and make handling better, rubbing appears to be problematic AND I don't need deeper "effective" final drive ratio. While I have 5-spd to put in (waiting for clutch to wear out), I'd be giving the OD back with low profile tires. I think the 205/75's are probably about as tall as I'd want to go. Some tall narrow low profile 17 or 18 might work, but what are the odds of Narrow?
  14. Thanks so much! I had no idea such a thing existed. Of course finding the right one will be the effort. However since still have to drill holes in wheel and the fact that mild steel balls are readily available, it might be a tossup as far as effort. (The balls could be drilled and held on with a screw and nut (stainless and Locktited) On the plus side with the clips, if one set doesn't work, it's not like you ruined the wheel even if you have to drill different holes for a different clip. I wonder how many 620ers out there want to keep the OD baby moons?
  15. EDIT UPDATE: Just discovered the 14x5 have different offset (more negative/inward - perhaps went with the ball joint models?) resulting in the following RUB problems with 205/75r14's: *) 205/75r14 on 14x5 mildly RUB the inner side on the bed side *) 205/75r14 on 14x4.5 RUB on the front inner fenders when turned to lock NEWLY REALIZED PROBLEM: *) 205/75r14 on 14x5 on the front are going to RUB significantly @ lock This trashes my whole concept of getting 14x5 rims and running bigger tires. If I want to run 205's I need to get another 4.5" rim for my spare! HOW are people running Titan wheels/tires??? I have a set of 14 x 4.5 stock wheels w/caps for my 1974 620. I also have (2) 14 x 5.0 late-620 stock wheels that have the "racetrack" slots ring. I want to keep the OE look. *) While I would settle for 2 more late-620 "slots", it may be easier to find a later model that would look OE. *) I don't care about the rim diameter but I'd like 5" wide or even 5.5 or 6.0 don't need more than that. *) Want to run the baby hubcaps. Obviously "3-ball" rims would be a slam dunk. However if 720's or latter models have a similar cap with no markings, logo, etc. (since the OE ones have none) that would also work. From what I can tell the 720 and D21 did not have hubcaps and obviously "no balls!' (Arf Arf) But hey, I'm a good welder and I found you can buy soft steel balls. So I don't see why I couldn't make a welding jig and mod any steel wheel I can find. Looks like the common D21 is only a 14x5 which is not cool. 14x6 would be better. They did make a 15x6 4x4 steel but I've got a deal on 14" 215/70's I am lusting over. There are a bazillion 6x5.5 bolt 14's out there from other makes. But man I hate walking through junk yards... too old, bad feet, too fat! Oh, and TOO CHEAP! LOL
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