240260280z

Day 1 Hammonds Plains packing. Beautiful Nova Scotia 45 degrees Latitude (crossed it again the next day) What a view. Could not stop anywhere w/o meeting nice people A hard rain's a gonna fall Who'll stop the rain? I can see clearly now Opps Day 2 6AM photo

Good news Jim, you were spot on! I put ~1000km on the cam with a new rocker and both look fine. Even the discoloration is gone from the cam and only 2 fine scratches remain. The new rocker looks perfect. Now with ~600km and enjoying ZCON here in NH (wish you were here!!!!) I'll take a photo and post later.

The body does not look too bad!

Found this: Planetisuzoo.com ? View topic - egr backpressure transducer Seems like it has a similar purpose to the manifold vacuum line to the FPR in fuel injected cars.

If you tow with the rear wheels off the ground, lock the steering and use seat belts or other restraint wrapped around the steering wheel to keep it straight. Make sure any chin spoiler will not hit. If you tow with the front wheels off the ground, make sure the drive shaft is disconnected from the differential (I guess it is with the motor and transmission out.). Also lock the steering and use seat belts or other restraint wrapped around the steering wheel. I would tow backwards because the front of the car will be lighter and will tow better .... and less chance to damage the differential. Don't forget the parking brake and secure any loose parts. Stop and check the straps after a mile to make sure nothing loosened. Then check at 10 miles into your 20mi trip for safety.

That is sad... MBA's and Hipsters are ruining the world

I guess if the EGR opens when the exhaust has less pressure than the intake manifold (low "rleative" back pressure) then the intake charge may flow into the exhaust rather than into the head. It probably has to do with pressure waves and pulses. It may also be a fail safe feature if the exhaust is crushed or clogged when there is way too much back pressure and it would over fill the manifold with exhaust gasses.

Yup.... got 30mpg (Imperial Gallons) cruising at ~ 3,000 to 3,500 rpm on a 240z. Idle jets significantly impact cruise fuel efficiency. I was experimenting and used two sets of idle jets: 1) 55F11 2) 55F9 with air drilled from original 1.0mm to 1.5mm (picked up some metric bits in Lisbon) I installed bolts in place of the spill jets to rule out accelerator pump leaks clouding the results...btw it is not so bad driving w/o acc. circuit. The 30mpg was attained with 18.5 a/f at idle and 14.7 to 15.5 at 3,000 rpm over flat road. The idle was rough and difficult to maintain at ~ 800rpm and 2 turns out on the mixture screws. I drove ~ 300km and eventually developed some methods for quickly collecting data: 1. Capture Idle A/F 2. Capture flat road at 3,000 rpm in 4th 3. I found that the mains came in on a gentle hill at 3500 rpm. I found that the cruise A/F down a gentle hill at 3,500 rpm was similar to the flat road A/F @ 3000 rpm (mains not in) I can now plot idle against cruise for various turns on the mixture screws to see where A/F and idle and cruise are optimized. It was interesting to note there were inversions where idle was richer than cruise then idle was leaner than cruise when plotted. It was also interesting to plot flat road 3,000 rpm in 2nd, 3rd and 4th. For one lean 55F11 @ 1.75 turns out test I got: 3000 in 2nd: 16.5 3000 in 3rd: 15.5 3000 in 4th 14.5 btw mains are 120 fuel with 170air and F11 Etube....nice A/F of 12 to 13 from 3500 to 6500rpm.

With respect to the orifice diameter, if the early needle's tip just protrudes through, then a thinner later needle will protrude further. I am guessing that later DCOE's have smaller orifices to match the narrower needles to prevent the tip from poking out into the throat or the casting is thicker and the orifice starts higher above the roof of the throat...... there are a few more variables here to be explored.

I am starting to look deeper into the claim that later DCOE's Idle Enrichment Screws are typically turned-out further. The details in the screw interface to the carb body distill to: 1. For the same flow: A narrow tapered needle needs to be tuned out further than a wider tapered needle if the orifice size is the same. It is proportionate to 1/tan 2. For the same fuel flow, a needle with the same taper needs to be turned out more from a smaller orifice than for a larger orifice. So to compare an early carb's Idle Enrichment Screw turn-out to a later, one must know the taper of the needle and the orifice size. In another post I measured the threads on early and later DCOE Enrichment screws and it was 0.8 for both. The part number for 40DCOE151 Enrichment screws is 64750.003 The DCOE151's I am tuning have this needle: 64750.004 64750.001 is stated to be "38 degrees" and for "early DCOE carbs" 64750.002 is the air bypass screw From the above, the 003 and 004 do seem narrower than the early 001.

Carburatori Weber

For the record the 40DCOE151's thread is also 0.8mm. I'll measure the taper.

I tried 55F9 but too rich.

That is interesting. The first cam seemed to go that route. On that one I checked the valves a 0mi cold then hot, 50, 500 and 1000mi with only two needing a minor adjustment at 500mi.

Thanks Kenny, Yes the rockers were Delta regrinds. btw the car has the same cam as yours but with schneider springs and retainers.

Follow up. Thanks Stephen, the 120's did the trick. I tried 115's with 170 and 180 air. They just seem to have a little less torque in the 4.0k to 6.5k rpm range. The 120's seem to be the sweet spot. Just trying the different airs to see the effect on high rpms. A/F is ~13.5 in the upper rpm's with the 115's and ~12.0 with the 120's. btw I am cruising at 12 A/F on the highway and 12 A/F at best lean idle so the 55F11 idle jest's are too rich. I need 50F11 or 45F11's for this one. I can turn the idle mixture in 1/2 a turn to get 14.7 at idle but I still get 12 A/F at cruise. After the experimentation to date I think the idle jet should be selected and optimized for cruise then the idle mixture's final set up shold happen AFTER the best idle jet for cruising is found. The idle jet should not be selected at idle as the mixture screw can pay havoc.

The throttle arm connected to the main shaft was wallowed causing rotational slop and delayed throttle valve actuation. I brazed the hole in the arm then drilled out and filed to fit the main shaft better.

Thanks Jim, I checked and all cam lobes are flowing a lot. I could actually see the oil flow start in the middle then move out to the ends. Each lobe behaves the same. I also ran a wire in through the first few lobe holes to see if it stuck or came out with debris....it just had clean oil. I agree with you that it looks like the rocker is the problem.

Yes I was thinking that however there is good flow, just delayed flow. The head and block were cleaned by the shop and oil plugs removed in the block to get the main galley. I am guessing that when the motor is off, oil in the cam and in the head drain back into the pan through the main bearings and oilers in the block.

Yup the cam is plugged at the end.

Thanks, I am 14 at idle with no choke. I did not measure A/F with choke but I see symptoms of too rich (instant bog) and no fast idle. Is 12 A/F a good choke target at 60 degrees F or 11?

New rocker is in. Let's see what happens. Yeah, I prime the pump like an IV and pour lots of oil over the valve train when first cranking (starter only) until I see oil coming out of the oil holes in the cam/oil bar....then I fire it up. btw on this car, after sitting over night, it takes 51 turns of the cam (starter driven only) before significant oil comes out of the holes. Is this normal?

They look like webers but I bet the metal will fail in a year. That is the problem with chinese copies...junk metal.

Fajs Carburetor - Buy Weber Dcoe,45dcoe Engine,Dcoe Carburetor Product on Alibaba.com