[Twin cam head for the L6 from Derek at Datsunworks]

I am designing a DBW actuator for this DOHC now! 

[Twin cam head for the L6 from Derek at Datsunworks]

On 5/13/2025 at 7:38 PM, zboi said:

Don't worry PAMS is already testing a real DOHC head on cars and you will actually be able to buy it. I expect prices to be better and unlike this head it will install without a headache and an engineering team.

Its now my least favorite looking DOHC, but it's pretty darn cool technology. 

[DCOE ITBS wanted]

Used ITBS seem to be very rare.  HKS, 

 

I would stay away from the full chinese DCOE ones.  KMS takes the chinese bodies and retrofits them with better butterflies and such.  

 

https://en.kms.vankronenburg.nl/products/throttle-bodies/bodies/throttlebody-twin

 

Then there are 

Jenvy

EFI Hardware (probably the best designed out) Throttle blades open the opposite way, tapered bore, better throttle blade angles

Borla 

OER(I would stay away from these)

ETC.... 

 

A common issue with ITB is when the engine is hot on a hot day, they tend to stick slightly open and having them return to idle doesn't work.  I believe the bodies expand and cause pinching, but who knows.  

[1971 240z ITB install]

I got my Datsun Z Car Series Oil Sending Unit Relocation / Remote Block done! I have only one for sale now, but more are on order. I am pretty proud of this design.

Three outlet remote oil sending unit block. Metal 3D printed out of aluminum to look stock and mimics the 240z, 260z and 280z brake proportioning block design.

Block has 3 outlets, all are 1/8 NPT. Comes with a custom length -3AN hose and one 1/8 NPT -3AN fitting and either a 1/8 BSPT or 1/8 NPT for the engine block side of the hose.

Stock sending unit on a 240z is BSPT, this will require a NPT sending unit like this. [https://zcardepot.com/products/oil-pressure-gauge-sender-240z-260z-280z-70-77?variant=32184292737137](https://zcardepot.com/products/oil-pressure-gauge-sender-240z-260z-280z-70-77?variant=32184292737137)

No sending units come with this order. Pictures of sending units are just for reference.

Link: https://www.m2racing.com/shop/p/datsun-z-car-series-oil-sending-unit-relocation-remote-block

[3.2 Build EFI N42 / MN47]

15 hours ago, madkaw said:

Reducing vacuum line size seems to have helped the MAP reading. Looks like I might even get 60kpa at idle too! 

First drive was interesting for sure. Almost stalled pulling out in traffic and rich and lean mixtures all over the table-lol. The autotune was trying to correct but some of my settings were off. I didnt stay out long because it was Little 5 in Bloomington and too many crazy kids out . Monday when everyone is at work Ill do some more tuning, 

Idle seemed to increase as the engine got hotter. No heat shield yet so that is an issue  

Idle increase while hot is the same issue most of us ITB guys are dealing with, I hope a heat shield fixes it.  

[1971 240z ITB install]

Here is something fun/ silly I have been thinking of and finally made. It’s a remote oil pressure distribution block made to look like the stock 240z brake prop valve. I previously had a steel T In the block, that broke off and then when I was using an easy out I cracked my stock block bung. I said never again!

3D metal printing is neat stuff. I had it tumbled to look even more cast.

I run stock gauges and my ecu needs its own signal. This location allows stock wiring to also work.

[1971 240z ITB install]

On 4/15/2025 at 3:42 AM, Derek said:

Man that is so cool. Not as cool as a DOHC though. 😀  I'm for sure going to do this mod at some point especially after seeing how responsive it is. Great job!

I don't have DOHC type funds:) 

[1971 240z ITB install]

 

[1971 240z ITB install]

I love it when a plan comes together!

Fully operational below dcoe throttle body actuator for DBW ITB. Mostly hidden!

[R180 pinion shims]

Gonna have to use the internet for that one then.  

[R180 pinion shims]

6 hours ago, madkaw said:

Okay - you would think they are the same . Were you able to specify sizes ?

Yep, I bought a few.  

[R180 pinion shims]

I was told the subaru shims are identical, i bought from the local dealer.  

[1971 240z ITB install]

Well I decided to pick a new header. I wanted the header to give my room on port 5-6 for my lower mounted actuator and also get out of the way of the throttle bodies a little more. I decided on the Kameari drag 45mm. Which I purchased through Binh Nguyen.

The header design gives me plenty of clearance for my actuator and throttles! Pretty darn happy with it overall. Prior I had a now moth balled Fujitsubo header. Which had a terrible runner design for a lower actuator.

[Triple Blowthrough Turbo]

On 3/15/2025 at 8:01 AM, Dat73z said:

@DuffyMahoney the raised aspect of the manifold is for packaging. I think l posted these pics before, but here's what you're working with on high mount turbo setups and surge tank/induction boxes (ignore the cold side charge pipe wonky angles I will fabricate a new one later). Early on I referenced the dimensions between a few other manifolds I had (SK/FET/Mik). The form is really dictated by making everything fit and function properly, and as you can see space is at a premium. 

I was inspired by the FET as well! It gave almost the perfect injector angle.  

 

I am not a turbo guy, but very nicely done.  

[Triple Blowthrough Turbo]

44 minutes ago, Dat73z said:

@DuffyMahoney yes balance bar with takeoff ports in my case for BOV, timing control, brake booster, etc. The takeoff ports are separate from the 1/8 npt ports you can see on the runners which may be used later for direct port nitrous or other injection. Also modular rod holder. I'll do a proper photodump and full post later but it is a clean sheet design by Larry Asp at Revery Performance so you likely see some similarities to other manifolds he has designed including one I've seen on a SEMA Z. 

 

The concept here was the ultimate mid-runner high clearance manifold. The geometry is such that it clears even high mount turbo manifolds such as the ProtunerZ vband custom I am running along with providing adequate clearance to run a surge tank or air box. We went through several design iterations over 2 or 3 years (I took a ~1yr break from my Z to finish building and selling a couple of other cars before starting back on this build late last year 😂) and found the ideal packaging in the s30 chassis. 

 

Imo there are a lot of novel design features present here which are missing from any other offering on the market today such as the o-ringed balance bar, ability to isolate individual runners and sync check without pulling the airbox/surge tank, etc. I'll cover the aspects later when I get past paintshop crunch time. 

 

I can't say enough good things about Larry but he's an incredibly talented designer and incredible to work with. I'll be showcasing more of his work soon 😁. If anyone is interested in getting one of these manifolds or anything custom made reach out to him. 

Larry is a good guy and I consider him a friend.  He is very talented, we talk a lot about intake design.  The up and away aspect looks a lot like my design as well.  Super cool stuff! 

[Triple Blowthrough Turbo]

16 hours ago, Dat73z said:

Still going through prep work on the chassis but a quick turbo update. 

 

Got the custom cnc intake manifold in and couldn't resist unboxing. I'll dedicate a post to this later when I get it fully set up but I snapped a pic on the dining room table before it goes into storage for a while 😁

 

Next up will be the cnc fuel system components and there are a couple of concepts I have in mind from OEM performance blowthrough cars such as the Lotus Esprit Turbo I'd like to implement and have parts machined for as well. 

Very cool! Looks almost identical to my flange thicknesses.  What is the bar? Balance?  Then it's also a rod holder?  

 

For some reason the picture is too small to zoom in on.  

[3.2 Build EFI N42 / MN47]

Nice

[L28 Triple Webers Idle Hang Problem]

Come you can take better pictures then that! 

 

That intake is known to have very poor linkage.  

[L28 Triple Webers Idle Hang Problem]

35 minutes ago, SumRando said:

I do have a heat shield. I have external return springs attached to each carb that I got from pierce manifolds. Before that, I tried 2 return springs on the connecting rod itself and it didn’t fix the issue but only made the pedal too stiff so I don’t think it’s a spring problem. It doesn’t only do it when hot. Even when the car first starts

 Could be a poorly aligned throttle blade? Try to figure out which carb it is.  Picture of your setup please 

[L28 Triple Webers Idle Hang Problem]

It could be so many things

 

Does your linkage bind?  

 

Heat Shield? 

 

Return springs on the shaft and each carb?  You should have both.  I make and sell a return spring.  https://www.m2racing.com/shop/p/lounge-tunic-/-cream-4l2xd

 

Does it only do it when hot?  

 

One way to find out which carb it is.  Take the dog bones off, blip each, see which one stays higher idle

[1971 240z ITB install]

240z hidden drive by wire actuator for my ITB setup. This is design number 4.

This plan utilizes a Efi hardware actuator. The goal is the same length arm to the bell crank and distances from shafts and the rod. So the rod passes through the firewall evenly and doesn’t walk from left to right.

This will mount to the pedal plate and the steering box mounts. So behind the firewall

Prior designs walked too much in the hole and I don’t want that.

[Draw Through Turbo project for my 2.9 Stroker L series COMPLETE 5 MONTHS 20 DAYS]

I make and sell knock sensor studs, that need no drilling, if you ever do this again:)

[RB25DET AC Bracket + Vintage air Compressor?]

on a rb? 

[1971 240z ITB install]

I love it when a plan comes together.  This is custom titanium banjos, which will come off my balance bar and hold my heat shield on! 

[1971 240z ITB install]

Well I got my prototypes in for my passive cooling on my Efi hardware throttles! These will be between the heat shield and the throttle bodies. Also it will be a nice and clean way to run the return fuel.