Breadbox's 720 Thread

[breadbox]

Still sticks and possible causes are primary and secondary can be sticking.

Also the butterflies sometimes bind on the carb adapter, so I will check this too.

For the meantime I am using a spring from the throttle to the air filter to close it, my gas pedal is so freakin heavy right now its annoying.

[breadbox]

Yay Rain... found leaks. :/

On the other hand radio got wired up today.

[breadbox]

Interior

Plans for interior:
1)Different radio
2)4 speakers and a sub
3)Comfortable seats
4)Clean up and respray all faded interior pieces
5)Clean carpet
6)Fix leaks
7)Vacuum it and put a road kit behind the drivers seat.

Exterior

Plans for exterior:
1)Drill out broken screws for the fuel door and replace
2)Install a new antenna
3) Complete and reinstall tailgate
4) Clean up hood and cowl and paint them white
5) take off front fenders clean up and paint white
6)Clean up doors and paint white and black where necessary
7) full off frame bed restoration and clean up frame and paint where needed

Engine bay

Plans for engine bay:
1)Get gasket paper and make a new exhaust collector gasket
2)Get a new radiator or fix old one
3)Get it tuned perfect and drive the piss out it some more.

[synack7350]

if you end up doing the blow through carb setup lemmie know how you deal with ignition timing on the fly. that's the tricky part. i thought about this for a while when I started looking at cold air intake designs. It'd be hella cool but the project died for me when I started tallying up the costs.

I figured I'd have to fab a carb enclosure which wouldn't be that pricey. (it'd beat trying to seal up the webber at all the places it can blow fuel from. )
the piping would be hella cheap no problems there
the turbo cost depends on where you find it it.
but then the ignition timing, you'd have to be able to retard the timing in conjunction with boost otherwise detonation would occur (right?) looking at msd kits for mapping ignition timing proved to be the cost killer. (either run 2 boxes or do away with the exhaust coil.)
fuel delivery wouldn't be an issue the way I figure. its just the nature of the boost / functioning of a carb. you would have to settle with a rich jet so you wouldn't lean out under high boost.

It'd be hella awesome I was thinking you'd see a 50 to 100 hp gain depending on boost. The technical issues are just too much to overcome. The TBFI would be the optimal way to go. with something like mega squirt running the engine management.
Just my 2 cents.

[breadbox]

Forgive me if I type some weird s***... I am definitely drunk off the beer I got from the brewery I've been helping out at but...

Yeah, I haven't looked into all the trouble that may come with turboing a carb. That being said, the current ignition would rely on vacuum and the turbo retard would probably be based on extra equipment aka the timing ring on the crank for the megasquirt.

It'd be combining the simplicity of carb but having to timing off the crank just as if it were efi. I am guessing the full efi setup would be easier, but luckily a computer can compensate for whatever you give it. So in theory as long as the comp as all the info it needs it can do what is needed.


I figure if I give it fuel based on throttle then the O2 can read what it needs for timing. I could be only drunk and dreaming but It could work.

Feel free to say what you will and when I am sober I will look at my logic.

I plan on playing with turbos a lot in my future. mostly big turbo aka holset hx35's and gt 40's because I'd really like to try to get a perfect twin scroll setup going and piss all over smaller t3/t4 setups with similar but limiting HP?tq numbers.

[breadbox]

Short answeer would be EFI is way simpler to turbo and really not that hard to find as long as your have a decent source. I have an amazing datto yard near me. I don't go there much because my main things are nissan SOHC 240's.

[synack7350]

drunk or not sounds solid. would you do away with the exhaust plugs? or how would that work with megasquirt (or something similar) running the ignition.

[synack7350]

does it even matter when the exhaust plugs fire? as long as its after ignition? would it be that bad to fire them both simultaneously on ignition? I can't see there being anything wrong with that. I might parallel my exhaust coil with ignition and see what happens.

[breadbox]

So I am here to correct previous Ideas and shoot holes in them. It should be either megasquirt efi or carb blow thru but not both.

I would say getting the parts and setting up a blow through would be easier... but then probably more work to tune it. meaning you would have to tune using jet size and what not, lots of guess and test.

EFI / megasquirt would take more effort to setup, but then tuning is way easier and you could data log etc.


As far as the dual spark. I'd imagine just use the exhaust plugs as primary firing so it'd be easier to get to for maintenance and just close up the other side. make it more KA24e like. Or just go KA24de/e and turbo that. There is a ton of turbo support online for KA's. The Z24 head just isn't ideal for turbo.

--->Crazy thought "how hard would direct injection be on this motor if you replaced intake side spark plugs with injectors?" I need to read more on direct inject.

[synack7350]

yeah I follow I took what you said for efi vs. blow through. blow through is always going to be a compromise. It'll have to run rich under no boost to avoid running lean under boost. Better to foul plugs then the results of running lean under high boost! He I never considered injectors at the intake or exhaust ports. That's a hell of an idea but aren't the injectors still usually behind the intake valve to keep from bad things happening? no I guess they aren't are they hmmm. I don't really know crap about cars past like 85....

[breadbox]

Yeah as far as the whole using the extra spark plug ports as direct injection... even if I built the motor to take the heat and high compression, I still would have no computer system that could control it. Seems that Direct injection has its problems mostly injector timing and carbon buildup on the intake valves.

With certain styles of motor the direct injection carbon build up problem seems to not be a major issue, but its there regardless.

[84Datsun720]

Does this make anyone else smile?

Do you know if this turbod Z24 is running a stock fuel delivery (i.e. standard or weber carburetor) without blowing through...just wondering if it was possible to turbo a Z24 without any major fuel delivery modifications?

[breadbox]

well lets just sat EFI would be WAAAAAAY easier to tune. But if you were running a small amount of boost then you might get away with jetting, if not getting a bigger carb right off the back. my current one would not enjoy turbo that much. Could it in theory? sure it could. but I'd go with a different motor altogether if I wanted "more power".

[breadbox]

Truck started getting hot lately. found my overflow tank has been pissing on my engne bay which can only mean other cooling system issues at play here.

I hope to flush the system starting with the heater core and then hopefully ending by throwing in a better rad.

[breadbox]

Drained "coolant" and ran a garden hose through the heater core and pissed rust for a couple minutes, then I ran it through the radiator and it pissed rust for a lot longer. I filled it back up with fresh coolant and am about to go drive a good distance so I hope this helps alot.

[breadbox]

Hey er'body. Zombro still runs like a champ.

I still haven't done anything to him or the 240's since I last updated.

The truck has a fresh inspection and I am going to slowly replace a few things and clean up some stuff. I need to pick up a dye and tap set and some extration bits.

I am about to get a tons of cabinets so the garage is about to get a much needed make over and organizing.

Hopefully everything will be setup nice to have a productive work winter. I have a couple friends who really want to do some work this winter. Updates to come.

[breadbox]

Still haven't done anything major. But I now have cabinets in the garage, which is better than I could have imagined.

So to update here a couple pics from leaving work last night. I work at a brewery in Norfolk called O'Connor Brewing Co.