Aaron Neubauer

Mech advance in the distributor is locked! It’s slow progress but thats better than no progress. Next is wiring the megasquirt! I can’t wait to test the launch control feature and see if I can’t blow up the exhaust.... Share the vid if you know someone who might benefit from it.

Mmmm those carbs! What model of DCOE are you using?

I don’t know if you are testing the piston with the needle. I found a good verification method was to test fit the piston without the needle. I found I had a teeny bit of sticking but was able to determine it was the needle/nozzle alignment not the piston and spring.

Gav if its any comfort I have not used Loctite on any threads and have not had a problem. I am also not running the last chance filters in the banjo. I’ve put a good quaility in line filter just upstream of the carbs instead as its far easier to inspect and maintain. Any washers that tha ZT kit didn’t supply I recycled. I made sure I had something between each steel fixture and the alloy. I did the fitting for the fuel bowl up without anything and I was amazed at how soft that allow it. The plastic O rings in the ZT kit are to locate and space the banjo in the sleeve. I’ve installed them on my SUs. When I didn’t I found the banjo bolt too loose after grounding out at the bottom of the thread. According to an article on ZParts.com a standard SU needle for the 240Z is a BCE (https://zparts.com/index.php/resources/su-carburetors-explained/) . Chucking that into Teglerizer’s finder shows it is similar to N27 but not exact. I would think N27 needles would be available from a supplier in the states. SUmidel may also be able to advise an equivilent, I found them very helpful and knowledgeable. I dunno if that will help.

I found some interesting parameters in the Tunerstudio software about launch control and flat shifting which got me thinking and consequently the megasquirt case hasn’t stayed assembled for long! I’ve build a protective circuit on the prototyping area to ground a 5v signal from JS11 leg of the CPU. This will be used to trigger launch control and flat shifting functions. I don’t know how this will function with the SU carbs as the MS1 is only controlling ignition. I suspect backfiring will ensue! I’ll have to build a clutch switch if launch control passes testing. I want the car to be about function not form. If the launch control doesn’t prove useful, I’ll bin it. Oh and the wiring loom of less than ten wires is also complete……

Same here! They look good Sean.

Slowing chipping away little by little. I mucked with the Megasquirt 1 this week. Got the V3.0 board sorted from where I left it two years ago from a full EFI build. Flashed MS/Extra and plugged it in to the PC with the stim board (after I installed the USB to RS232 driver for the cable ) and low and behold it worked first time! I'm pretty stoked that it worked. I don't have any special hardware built other than the standard configuration. It is literally taking the signal from the Pertronix unit and manifold pressure from the vacuum advance pickup and determining ignition advance from the ignition table. I will have to zero fill all the other tables. next step is get the wiring loom in order although I won't need a lot of wires for what I'm doing....

Many thanks Gav!

Following on from the SB needle install I decided to adjust the float level to factory. Previously I had the float level a little higher as a band aid fix to richen the top end mixture of the SM needles. The rear float bowl gave me grief. I think I had the lid off 20 times before the geometry of the float was massaged so it wouldn’t stick in the bowl not closing the jet properly. I got there in the end. When you bending little metal tabs minute amounts you need a good swag of patience. Using the float sync tool and a trusty bit of clear pine dressed down to 9/16” thick the floats are set to the same level. The Nissan workshop manual suggests making one float higher than the other, presumably for G forces under acceleration, but I’ve never done this. Working on the 240Z is not the highest priority in my life (although I wish it could be!) so road testing and datalogging with the Innovate LM2 wideband will have to wait. Video below.

Cheers Gav!

I turned my attention to optimising the needles in the Hitachi SUs. I took the function stations from the SM, RV and RU needles I’ve trialed previously and went searching for a best match. I went to use the Mintylamb.co.uk resource but found that had closed down some time ago. Ended up using Teglerizer’s resource http://www.teglerizer.com/suneedledb/ to find SB needles were the closest. Ended up sticking the needles in without lowering the fuel floats down from the band aid fix to riches top end with the SM needles. The SB needles worked a treat and the AFRs are offset by the amount that raising the float changed. Overall very happy. Next port of call is to lower the floats to factory and I reckon I will have 99% convergence to the best mixture I can achieve without making custom needles.

Wait a second! What’s going on here?! No weberage?

Not a worry! What colour is that you’ve used on the rocker cover? looks snazzy!

I’ve decided to use the part built MS1 v3.0 megasquirt with MSExtra code as a programmable ignition. I will retain the MSD 6AL and pertronix igniter 1. I did look at 123ignition, MSD 6AL programmable, etc. and these were all good products but I went with the megasquirt as I already had it. There are also other peripherals the MS1 can control and I hope to knock together a means on the proto area of the V3.0 board to output a signal for the temp gauge to use. The original temp sender is cactus. Another task is locking the distributor. I think I may have found a copyright free STL file for a lock out block on the net. If it is what I think it is I’ll get something printed up in ABS...problem is I don’t think there are any local printers so this may take some time.... There is a video on my YouTube channel but its me waffling on so I haven’t embedded it in the post.

Agreed! That is an awesome colour combination!

The first of many pieces of the puzzle for the road to 200whp on round top Hitachis has been completed. The old POS bit of exhaust I recycled from the system that came with the car 10 years ago is out and replaced with a Zstory centre pipe. The car now has a full Zstory offering: Race sport header centre pipe with silencer JDM style muffler I could not be more impressed with the sound! The new silencer is leagues ahead of what was in there. I think the change from aluminised steel to full stainless steel has contributed. The note sounds ‘clean’ and not as ‘cheap’ as it used to sound. The system was also extremely easy to fit and all I had to do was bend up a ‘z’ bracket out of thin flat plate to help align one exhaust mounting point with the point on the body. I wanted teh rubber isolator mounts to be vertical. Anyway, I put the install and a sound check in a video if anyone is interested.

I run a K&N style filter from the breather with Zstory headers. Daily driven for a few years and not a problem with the filter. The system is a legacy from when I had triple DCOEs but I now run round top hitachis on the stroker motor. I also run a road draft pipe from the rocker cover down next to the gearbox to stop crankcase vapour pooling in the filter and dripping out. It’s tech from the 50s but its doing the job until I can force myself to get a proper catch can system.

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Phew! What a hiatus! Since the last post only small changes have been made. The car survived the 4.5 hour drive from Toowoomba to Bundy in one continuous run back in April 2017. It used about 10l/100k which I thought was odd but put further investigation on the low priority pile. Upon checking with the LM2 the cruise to WOT section of the needle was indeed running very lean. I promptly ordered RU and RV needles to see if that would fix the problem. The RV needles got near perfect AFR at top end but cruise sat at about 10:1. Humph! I settled on a half baked band aid measure of lifting the floats up a few mm and sticking the SM needles back in. This made things a little richer (13.5:1 approx at WOT) but is not the long term solution I desire. If you plan to maintain the Hitachi SUs on your car yourself I can not recommend enough getting a ‘Float-sync’ tool. I’m not sure if they are still manufactured but they are bloody helpful when setting the floats! I got mine from here: https://zcardepot.com/carburetor-float-sync-tool-su-240z.html That was around October 2017. Fast forward to now, I am able to ‘donate’ more of my time the ol’ girl. I have set a goal to aim for 200RWHP on the SUs without opening the engine. I have a spiel on the plan on my YouTube channel which can be seen here. The three areas to focus efforts are: - Removing the recycled section between the Zstory headers and muffler and putting something better flowing in - New or custom needles for the carbs to get the AFRs where they should be - Muck with the advance profile in the dizzy. Currently the ‘all in’ advance is far to low. I’m thinking MSD 6AL-2 with locked dizzy or repurpose the MS1 I have on the shelves with a CAS. After all this is done it’ll be off to the dyno. If I don’t get 200 aitch pees I can always bust open the motor and port the head to the buggery, swap in a new cam or just admit defeat and put triples or EFI on it!

I got mine on eBay. I think my kit was Pertronix reference 1761.

It could be your points if they are out of adjustment or are worn particularly if your feeding full 12v through them. I get rid of points as fast as I can. I use Pertronix modules and have found them very stable and ‘set and forgot’ in comparison to points. I normally check the following when I am diagnosing ignition problems: initial timing and behaviour of timing advance ignition coil ignition leads spark plug condition, gap and heat range Your cam may be limiting performance also. I run a hotter-than-mild cam, Pertronix, MSD 6AL and plenty of fuel delivery verified by my WBO2 and experience the ‘hard wall’ just over 6500rpm....but that is intentional by design.

PM sent RE slab. I typically design 100mm slabs for dealership services areas unless ground conditions are poor or they have a specific jack generating a point load.

Video of dyno run.

170hp @ 5600. Not bad for a home built $5k stroker on stock carbs! Video to follow.