djwarner

A friend of mine had a normally open switch spliced into the starter wire going from the lock to the fire wall. He had the type of emergency brake where you pushed the pedal to engage and pull a knob to release. He set the switch so that you had to pull the brake release lever to close the switch and engage the starter. His thought was that most car thieves want to be gone in under a minute. Even if the perp pulled out the ignition lock, it wouldn't crank. After two or three twists with a screwdriver and no results, the perp would seek another vehicle to lift.

Since my car has downdraft Webers and since the owner of my local Z shop has retired, I am faced with trying to balance my carbs after I diddled with the linkage. I know there are flow meters and adapters available for the Webers, but it occurred to me that there might be a way to locally fabricate something. My son and I used to balance the four carbs on his Suzuki using manometers, but he had one carb per cylinder and no balance tube to deal with. I realized that pressure measurements were a poor substitute for what we really needed, an air mass sensor ahead of the carbs. Then it occurred to me that cheap air mass sensors should be available from the salvage yards. Since we are looking for balance rather than absolute measurement, circuitry should be an absolute minimum and calibration not a problem. Has anyone tried this? Any suggestions on which air mass sensor would be the best candidate for the experiment?

Christian, From what I've learned you should definitely be checking the timing with the vacuum hose disconnected and plugged to get to the 10 BTDC setting you are reading about. I've started another thread in Engine and Drivetrain (S30) discussing timing. The remaining issue you may have is your 7000 ft altitude. I have Weber carbs and don't have experience with SUs but you elevation may require a jet change.

Here is what I've learned so far. Using what Leon said about distributor specs given in Distributor RPM rather than Crankshaft RPM, my spreadsheet made a lot more sense. Re-reading Chilton and Haynes it appears the dual point ignition systems were used on AT z's to reduce noxious compounds. The question remains whether timing was retarded for a cold engine and advanced for a warm engine or vice versa. Complicating things is that I have a transistorized distributor from a 79 280ZX automatic. Looking at the response curves of my distributor vs the stock distributor, I found they were very close but the vacuum advance on mine had a smaller range. Both Chilton and Haynes gave the timing as 10 BTDC which is the spec for the retarded timing. However, when I compared the calculated timing with vacuum advance include ( as in normal operating conditions ) I found the automatic was 5 to 7 degrees retarded compared to the MT Distributor. This oddly compares to the additional 6 degrees specified for the advanced timing spec for AT distributor. This would indicate that the advanced set is used for a warm engine and the retarded set is used for a cold engine. Comparing the vacuum advance curve differences, my distributor could allow an additional advance when developing less manifold vacuum (something less than 3 degrees). When opening the throttle, the vacuum advance actually decreases thereby retarding the timing. This took a few minutes to sink in. Aircraft instruments measure manifold pressure rather than manifold vacuum. A stopped engine will read 29.92 inches of Hg. At idle, the throttle plate restricts airflow and a partial vacuum is created (perhaps 14 inches of Hg). As the throttle is opened, more air flows in and the partial vacuum is eased. At full power, a normally aspirated aircraft engine will have a manifold pressure in the 23-28 inch range. In our ignition systems we measure the vacuum, not the absolute pressure. So as we open the throttle, the vacuum reading falls. As the vacuum falls, the vacuum advance applied to the distributor decreases, retarding the ignition. If I were to re-time the engine to run at the advance setting spec and had the additional advance contribution from the different vacuum curve, I wondered if it could lead to detonation. This is where the non emission controlled distributor specs helped. Even with my 79 280zx distributor at the advanced setting, the timing would never be more advanced than the non emission controlled one. So I advanced the timing to 16 degrees BTDC and went for a spin to fully warm the engine. The difference in performance was remarkable. When I got back in the garage, the temperature switch for the timing relay was 25 ohms compared to the 220 ohms I found at room temperature. Concerned that the system may have doubled the 6 degree advance, I hurriedly took another timing check only to find the timing still at 16 degrees. I then stopped the engine and pulled the lead off the temperature switch and found the timing still at 16 degrees! So either the transistorized ignition systems is broken or it was not wired in properly when it was installed. In either case, I'm happy with the significantly improved performance. According to Chilton, a 6 degree advance in timing would only supply about a 2.5% increase in power but dramatically increase spark plug temperature. Since my plugs have been sooting up, I would expect some better cleaning with the higher temperature. I will have to see. As for the 2.5% power increase, that may have been compared to a properly timed engine. If I had only seen a 2.5% increase, I doubt that I would have noticed it. So I suspect my previous timing setting based on the 10 BTDC was causing a significant power loss.

Leon, that makes sense. I'll adjust my formulas. Zed, the vacuum port comes off the balance tube per FSM. Chilton says for models through 1979 to leave the vacuum connected which should be incorrect as I figure it. Haines sets the point distributor with a test light and uses a strobe for transistorized ignitions with the vacuum disconnected. No one has answered whether the centrifugal and vacuum advances are mechanically limited at the upper limit. Anyone?

Haines provides specs for the various distributors used on our cars. Specs include Idle degrees/RPM, upper and lower centrifugal advance specs, and upper and lower vacuum advance specs. In a recent thread it became apparent timing setting taken with a strobe varies considerably depending on whether the vacuum port was connected. Timing can be set with a strobe with the engine running or with a test light with the engine stopped. Since some of the distributors listed have a centrifugal advance effective at idle speed, I began to wonder just what is the appropriate method for setting timing. The factory service manual is less than explicit on the matter. I constructed a spreadsheet to calculate the advance for varies RPMs and Manifold Vacuum based on the following assumptions. The calculated timing is the sum of the static timing, centrifugal advance, and vacuum advance. The minimum advance for centrifugal and vacuum is zero and the max advance is that given at the upper limit. Static timing is adjusted for any centrifugal advance in effect at idle. For a stock distributor on a 240 or 260 Haines says the Centrifugal Advance is 0 at 550 Rpm and 9 degrees at 1200 Rpm. Vacuum advance at the upper limit is given as 7.5 degrees. The question is whether 9 degrees is a mechanical limit or just a point on a curve? Same thing for the Vacuum Advance. Members of the forum are reporting numbers above 30 degrees with the vacuum line connected. This is far above the 26.5 degrees I calculated when applying the upper limits as a hard limit. I ran my unloaded engine at various speeds and recorded the manifold vacuum with a digital manometer. I then computed the expected advance per my spread sheet for the stock distributor, the non-emission controlled distributor, and for the solid state distributor from a 79 280ZX I actually have installed in my L24. Applying the upper limits as described above, the various distributors should have maxed out between 1000 and 1200 RPM. So I am assuming the upper limit given by Haines is just a point on a curve and not a limit. Can anyone confirm the proper method for setting the timing and what timing should be expected?

Is your car an automatic by any chance? Are you checking the timing with the vacuum advance disconnected? I just checked my AT Series I and it measured 30.2 degrees BTDC at 840 RPM with the vacuum line connected and 10 degrees BTDC at 1000 RPM with the vacuum disconnected. I know that Chilton says to set the timing with the vacuum connected for these models. But now I'm confused. The 1970 factory service manual does not give any specs for A/T cars since they were introduced mid year. They say to set the timing using a strobe light and to set timing to 5 degrees at 750 RPM for SU carbs with emission control and 17 degrees at 750 RPM for SU carbs without emission control. But they give no instructions about whether the vacuum line should be dis-connected. The 1972 manual gives no additional instructions regarding the vacuum line but gives emission control timings of 5 degrees at 750 RPM for MT and 0 degrees at 780 RPM in neutral for AT. Chilton agrees for the 1972 model year. Haines says the static timing should be 10 degrees at 550 RPM MT (16 degrees at 650 RPM AT) with centrifugal advance of 0 degrees at 550RPM and maxing at 9 degrees at 1200 RPM. Vacuum advance starts 3.94" Hg and maxing at 7.5 degrees at 13.0" Hg. for A D609-56A Distributor. Just what is the proper procedure for checking timing for our cars?

Increasing octane from a pump beyond what's needed will only lighten your wallet. I used acetone as an additive in my 2002 Q45 with no ill effects. Added 5 ounces at each 17 gallon fill up. Adding more than this percentage does not increase octane.

Found this vendor doing business on the internet for classic Japanese connectors. Found him very easy to do business with, with super fast delivery. I would not hesitate to recommend him. OEM-Type Bullet & Spade Electrical Connectors for 1960's through 1970's Japanese Vehicles... Bridgestone, Datsun, Hodaka, Honda, Kawasaki, Landcruiser, Suzuki, Tohatsu, VW, & Yamaha

Let's not confuse the two issues of Ethanol and Octane. Ethanol actually has an octane rating well over 100. However, ethanol delivers less energy per gallon than gasoline. This is because there is already one oxygen atom in each molecule. This adds weight and volume while eliminating a carbon/hydrogen bond during the burn. Octane rating does not indicate power available but rather the resistance to detonation (read explode). Modern engines can advance the timing until knock is detected and then back off a tad. This optimizes performance for whatever fuel is used. For our cars with timing that was not dynamically advanced, things are a little problematical. If you set the timing to the book, a particular fuel either knocks or it doesn't. If you set your timing for optimal performance with a certain fuel, you are probably making the best of a suboptimal situation. If you really want a cheap way to raise octane to get the last bit of timing advance, add 4.5 - 5.0 ounces of acetone to each tank full. This will raise octane about 4 or 5 points for less than a buck. BTW, as been said on this forum many times, the 95 octane rating specified in the owner's manual was calculated in a different way than the way it is done today. Today's 91 octane should do just fine in cars set to factory spec. As to how much energy is lost with ethanol being added? I used to commute between the west and east coasts of Florida weekly where one coast had little ethanol while the other had almost none. As far as I could figure, ethanol dropped mileage 3-5% or about 1 MPG at highway speeds. This was with a modern, timing adaptive engine.

Here are a few pictures of the build. These compare the GEN II Mini and shows the vent/door configuration. In order to align the fan with the vent, I inverted the fan and added an air box made from a Radio Shack Project Box. I cannibalized a lever from the OEM heater control to construct the fresh air - recirculate control. One point I should make, modifying the air handler probably voided the warranty. If I were doing it again, I would have used a woodworking dust exhaust gate and built an air box that moved with the gate leaving the air handler stock.

Free market means the seller is free to ask whatever he wants and the buyer is free to offer whatever he is willing to pay. If the two numbers overlap, a deal occurs. Otherwise everyone waits for someone else to come along. Negotiation starting points may rarely overlap except for commodities where products are uniform and markets exist with many buyers and many sellers competing simultaneously. NOS Datsun parts meet none of the above conditions.

I'm assuming you are looking for the sheet metal nuts that fit inside the black funnels that hold the chrome vents in place. More importantly, they hold the funnels against the inside of the hatch preventing fumes from entering the cargo area. Mine are also missing. As a work around, I used some half inch closed cell foam insulation between the funnel and bottom of the inner hatch to hold the funnel in place. To secure the chrome vents in place I used some clear plastic glue.

If you remove the passenger rear wheel, you should be able to get a good look at the breather.

Strange how things work out. I remembered that a Paul Newman racing suit had shown up on Pawn Stars a while back and if I remember correctly, there was a question about authenticity of the signature. I wondered if it was the same suit. A quick search on the History Channel website confirmed it was the January 30, 2012 episode. Better yet is will be rerun November 14th at noon eastern time.

I just replaced the headgasket and if I remember correctly, #1 and #6 Cylinders at top dead center when the timing mark is set to zero. The #3 intake valve was open. Have you removed the front cover or jammed a plug to hold the timing chain?

I replace the air handler, modified the center control panel to accept the modern control, mounted the condenser coil and ran the electrics and the heater hoses. Went to a local Z expert for the compressor mount plate, compressor installation and to fabricate the hoses. I went to the trouble to modify the air handler fan location to fit under the fresh air vent and fabricated a vent mechanism that dropped down onto the fan for fresh air and with an internal door that closed when the mechanism was raised for the recirculation function. If I were to do it again, I would use the stock air handler and purchase a gate valve used in sawdust capture systems from a woodworking supply store. VintageAir air handlers do not have fresh air venting built in. I was able to use all the existing air/defrost vents and yielded a clean installation. I did pull the dash to facilitate fabricating the fresh air vent mechanism. I understand you can pull the heater box without pulling the dash. Routing the heater hoses proved problematic because I bought bulkhead fittings with 90 degree elbows. Doing it again, I would use the existing grommets through the firewall.

I replaced the factory heater core in my Series I with a VintageAir Mini GenII. Fit neatly in the space without crimping the passenger leg room. Mounted the compressor in the air pump location and used its v-groove for the belt. Works well in our Florida summer heat. Figure to spend about $3K if you aren't doing the work yourself.

Since you are in the land of fruits and nuts, do you still have your air pump? Part of the early smog systems was an anti backfire valve that injected fresh air into the intake manifold on deceleration. Seems the overly rich mixture with the throttle closed could be ignited due to the OEM valve timing. Since you have a non standard cam, this might point you in the right place to look.

Is your automatic still on the road as a driver? You might be interested in this thread about other A/Ts: http://www.classiczcars.com/forums/open-s30-z-discussions/50748-series-1-71-blue-blue-automatic-purist-debate.html

Well Automatic SN 9110 has shown up on the forum. http://www.classiczcars.com/forums/open-s30-z-discussions/50861-has-anyone-seen.html

The dual point distributor work in conjunction with a relay and a temperature switch mounted near the thermostat. The two sets of points have one set advance and one set retarded. When the engine coolant is at low temperature, the switch controls the relay and only the advance set of points receives current. As coolant temperature increases, the relay also passes current through the retarded points. When the advanced points open, no spark is created because current is still flowing through the retarded points. When the retarded points open, the advanced points are still open so a spark is created. The references I have vary. Both Chilton's and Haynes give the dwell angle for both points at 35 to 41 degrees (a gap of .4 to .5 mm). Chilton's says the retarded timing will be TDC for temperatures above 30 degrees F and the advanced timing 10 BDC @ 600 RPM for temperatures below 30 degrees F. I suspect this to be in error as there is supposed to be a 6 degree timing difference for the two sets of points. Haynes says to set the timing with the vacuum line disconnected and the retarded timing set to 10 BTDC and the advance timing set to 16 BTDC. For you mechanic, Haynes says Centrifugal advance starts at 550 RPM and max's out at 9 degrees at 1200 RPM. Vacuum advance starts at 3.94" Hg and max's out at 7.5 degrees at 13.0" Hg. From what I've learned, you should normally see timing at 10 BTDC at 650 RPM warm. If you have a miss at timing I'd look elsewhere. I have an electronic ignition distributor from a 1979 280ZX mounted in my 1970 A/T and it works fine though I don't have emissions testing in Florida. The distributor part number is D6K80-031103 and the Nissan part number is 22100-P7901.

You can get the lead replacement just about anywhere, even Wally World. As for gas, the octane ratings back then used a different method. Today's 89 octane fuels should run just fine. Here is a source for non-ethanol fuels: Ethanol-free gas stations in the U.S. and Canada

If you are going to look a lot, drive a little, non-ethanol regular will serve you well. Can usually be found at marinas at a 60-70 cent per gallon more than premium. Do you know if the head was rebuilt for non-leaded gas? If not, there are supplements for that as well.

OK I have HLS30 09310, 12441(later converted to 5 Speed Manual), 12746, 17574(mine), and 17595. This makes 10. Carl, do you know if all these are still on the road?