Just ordered my Rebello 3.0, now what

[Chickenman]

Dave dyno'd this engine with that dizzy in place, so he's probably going by what they used on the bench. I havnt taken it apart to see if he elongated the slots or not. I run 91 and 94, and I think I once heard a ping, but really it behaves pretty good. The engine is running a little over 10:1 but he's got a colder plug in it, possibly that may be avoiding said detonation. It's beyond my knowledge. Engine runs like a vtec.

Got you and kurby confused as to who is running what. If Dave dynoed that engine with the current Dizzy in place then he knows what the curve is.. so that's why he said just set at at 10 BTDC at idle. Hadn't realized you bought a complete dynoed engine with Dizzy and Carbs? in place. If Dave set up the carbs he also would have set the fuel curve. You can richen the mixture a bit at the top end to decrease the chance of detonation. Fuel calibration makes a big difference.

 

For comparison, my L28 with Fuel Injection has an N47 head with flat tops. 280 degree cam, headers, 2.5" exhaust and Big Bore TB. Timing is set to +12 BTDC at idle with 33 degrees total advance. With 91 Octane fuel ( no Ethanol ) I get some pinging between 4,500 rpm and 5,500 rpm. 94 Octane gets rid of  " most " of the pinging.

 

I'm pretty sure i have a lean spot in the Fuel curve at those RPM's. Wide Band installation this winter will tell me what's really going on. May have to go stand alone EFI like Megasquirt or Haltech. Or the injectors may just need a good Ultrasonic cleaning. Bottom line is I can't run more than 33 degrees total advance safely, especially if I cruise into the Western USA with their Goat P**S fuel...

Edited July 12, 2015 by Chickenman

[Kurbycar32]

Quick note on octane. Here in the People's Republic of Kalifornia we have at LEAST 10% ethanol and there's a movement to get that number up to 20%. It's hell on small motors..

The highest octane fuel available to me is 91, which is all I use in the Z and dirt bikes. There's a place in town with race fuel for $9/gal up to 110 octane but you have to pump it into a container, they shut you down if you put it in a car on the road.

Sent from my SM-G900T using Tapatalk

[oranngetang]

Chickenman, he had my carbs on it as well, but the engine ran poorly when I got it in my hands. The needles were all ratty looking and filed down on one side, but not in a uniform or otherwise sciencentific looking way. Ran way rich, 10:1 afr throughout most of the range or even richer at WOT. Oil contamination and plug fouling was prominent with those needles. I'm really curious what kirby finds to be the sweet spot for his as the engines are both 3L, same cam, same carbs, different dizzy, not dyno'd.

[oranngetang]

And kirby, the engine runs well with 30-35 total advance above 5000 for me but has absolutely no bottom end with the base timing set low enough to achieve that. I'll get the light on it again tonight and play around a bit. I have a pertronix ignitor in that dizzy, no points.

Keep us posted.

[oranngetang]

This chat about the dyno and whatnot has brought me full circle to digging up the data from the computer just now and all I see on the sheet is 36 degrees BTDC, which is likely why the dyno only charts 3500 - 7000.

 

With that said, I can't recall where my -10 degrees starting mark came in as I see I posted -15 degrees elsewhere closer to the date of talking with Dave.

 

So to avoid any misinformation... My engine dyno'd at 36 total advance, which is printed on my slip. Perhaps ignore the idle numbers as that was by word of mouth and clearly I'm having troubles remembering, or something. I'm dunno!

[oranngetang]

As a follow up, I posted in my own thread. Remeasuring with my light, I see a maximum deflection of 31 degrees from the dizzy by mechanical advance. A 5 degree idle setting is what's required to achieve this for my engine.

[oranngetang]

Rebello says to set the timing at 33 degrees at 5500RPM.

Blue I'm sure I've never lubricated my distributor which means it's likely never been lubed. I bet my vacuum advance is stuck. I did notice on my last motor the vacuum advance didn't seem to work and this is the same distributor. I'd love to get one of those 123 ignition units..

Sent from my SM-G900T using Tapatalk

Kurby, if rev the engine to about 1500 rpm and suck on a 1/4" line attached to the vacuum advance, I can get it to start rotating.

I don't notice it moving if it's connected to the manifold, as if either there is insufficient manifold vacuum or sticky mechanism.

Maybe see if you can get it moving on your own. Pull the rotor off and see if you can swing it.

[Kurbycar32]

I disassembled my stock 260z distributor and found that it was pretty much wasted.  The vacuum advance was frozen solid, the weights were stiff to move around and the Armature was mangled (not sure how that happened).  Rather than deal with that I called Rebello about a distributor replacement.  Dave said the 123 ignition thing was cool but really expensive (i agree) and he runs the 280zx dizzy on his race cars.  I happened to have one of those distributors in my blue Z so i went ahead and did the conversion.  The car runs amazing now!  I have some cleanup wiring to do post-conversion (temp sensor, tach hookup, relocate the fuel pump power) but this is otherwise a working car.  I drove it around the block and put some gas in it, i wasn't stranded so I'm declaring victory.  Right now its running 33* timing at 5500 RPM and close to 10* at idle.  Heres a glamour shot of my tuning session, its pretty awesome to have RPM, voltage and both carb sync tools working together.

[oranngetang]

Very nice! Who makes those carb sync tools and do you prefer them to the unisyn style?

Sent from my iPad using Tapatalk

[Kurbycar32]

My car was previously running Weber DVG carbs, and these were sold on the Weber website with a rubber square mouth adapter.  I have also used the mercury column balance tool on motorcycles, i really hate those things.  I have not used the uni-syn but I am very happy with these meters and i think these are more universal because you can buy rubber adapters for lots of different style carbs.

[oranngetang]

It looks like a great setup, as you're able to run the engine while drawing through them. The unisyn is an adjust and place, adjust and place trial and error setup back and forth. I'm seriously on the fence about ordering. 123 dizzy.... That cad dollar though...

Sent from my iPad using Tapatalk

[Kurbycar32]

Guess and check sucks, I'd recommend getting a set of these if thats how you tune your carbs now.  You cant run these at high RPM but they more than handle idle speed and yes you can tune while the motor is running.

 

im not sure how much better the 123 dizzy could be than this ZX unit.  I saw the propaganda video and its clearly better but the electronic unit just before the 123 unit looked pretty darn good too.  Its probably better at doing things like cold starts and ultra fine tuning, for the money though i can have this ZX dizzy and 700 (american) bucks to put into another system..

Edited August 10, 2015 by Kurbycar32