Datsun Roadster Forum-311s.org

Slow but sure progress. Car started getting hot and temp fluctuating. Pulled thermostat and it was bad. In an effort to solve the stumbling which occurs between 3500 and 4500 rpm checked valve clearance cold and hot. Timed car to 18 btdc. 16 btdc is where the stumbling occurs. Still misses and sputters through the power curve with a slight power loss as compared to before although the stumbling is partially gone. Temp still fluctuates a bit but has also stabilized. Have also determined that it has a 2 core radiator which I will remedy, but I doubt it the root cause of the temp fluctuations. Pulling the plugs to check for mixture, nr. 4 plug hole was cross threaded which cost me time but able to fix. Also determined that my manifold has the (gulp valve?) mentioned in other threads. Still not sure what to do with it. Disconnect? The motor has the smog equip removed.

Also found one of the pipettes on the inside of the air filter frame is broken. Are these overflow pipettes necessary or are they only part of the (evaporative) smog controls found only on 70 model cars. (Like the "gulp valve")? Will post pics as soon as I figure out how.

Hey Glenn

Sorry i cant help with the 1600 stuff as I have zero experience with them...

All I can say is post some pics! haha

-Simon

Couple of pics for Simon et.al.

Stumbling sounds more like an air/fuel ratio issue, lean or rich (likely lean as rich is usually just sluggish). Run the engine with new plugs where it stumbles out on the highway for a time, then shut the motor off and pull over immediately, then pull the plugs on 1 and 3 to see how they are burning. Being gloves, they'll be hot. Check for intake leaks with carb cleaner.

I've been watching the plugs carefully. After changing to new, they are still burning tan color. My first inclination was mixture. Now I have no idea. Also see mystery gulp valve between carbs mounted to manifold.
How would I check for intake leaks w/ carb cleaner?

pic

Silver is such a good color on these!... Car looks good Glenn

augsburger wrote: Wed Oct 24, 2018 12:58 pm Couple of pics for Simon et.al.
d9-1530206079.jpgd8-1530206078.jpgd4-1530206079.jpg

The thing between the carbs is a fuel return valve. Don't remove it because if you do, the fuel will just go directly back to the tank and miss the carbs completely (path of least resistance.) Did you try running lighter oil in the carb dashpots?

Will

Thanks Simon. A lot I don't like on the car. The rubber bumper guards. Wish it was still the original color (#665 yellow). The PO told me he had the moulding which he didn't. He only had two sets of badging, none of the rear or hood badging, and none of the moulding. Expensive replacements which helped negotiate price although I wish I had them. Seats bolted to the floor on top of carpeting (seats wouldn't move). That and the fact I can't really drive it yet which is killing me.

were all the holes shaved for the badging or is it all just missing and lots small holes everywhere?

The side trim alone is a pretty penny from what Ive seen. Mine is there but not mint, but I dont mind

It's been shaved and filled. rrrrr...
Will. First thing I did after our conversation. Topped off w/ Marvel. Fuel return valve... hmmmmm.......

Can I put in Mobil 1 with a KN filter? If so, what weight is recommended in synthetic?

I notice 70 driver side rear fender with 68 front driver fender.

Probably and it wouldn't surprise me. The fit and finish leaves something to be desired, but it will make a good driver.