540HP NA 7L V12 3 seater

[F1natic]

Good tip I will have to remember when I get some of the material in to trial, thanks.

Lots of background things happening since the clutch locked things in place designwise, have printed out the first pinion housing pattern, pair of castings will follow on soon.



Bought a Melling M68 oil pump and measured on the CMM to confirm dimensions that will be machined into the billet dry sump housings. Once I have proven the parts work I will be happy to share the CAD files.

[RandomTask007]

Any reason for the two engines? Seems like a lot of extra effort/expense in lieu of making it simpler. . .

[F1natic]

Basically boils down to living with the final results long term. The Honda V6 engines are understressed, compact and easily sourced. Could not find a suitable V12 locally to use or package. The corvette transaxle is a superb unit and underutilised in mid engine builds. The BMW V10 engine is a jewel and would be my "no limits" budget preference, but the twin engine method of attaining 7L of NA engine in a reasonable state of tune will be ample for a roadcar - IF reliability is achieved. Always have the fallback layout of a conventional twin turbo V6 layout if the Tbox doesn't work out. If I build a second one as a racecar then that convention would have to be followed, but for an experimental roadcar it's a more interesting engineering challenge for me to skin the cat in a different way.

Edited by F1natic on Thursday 29th June 23:25

[PAUL.S.]

RandomTask007 said:

Any reason for the two engines? Seems like a lot of extra effort/expense in lieu of making it simpler. . .

Over the years people have asked me the same when I tackle a certain project.

My answer is always the same, it is "because I just simply want to, it intrigues me, and I can, it affects no one else, so why not"

Like the OP the central seat, 3 seat layout has always fascinated me, I was drawing it out in my teens, and I am now in my fifties, so long before the F1 appeared.

I have finally acquired a suitable existing aluminium chassis that can accept conversion to such, and a suitable v8 donor for most of the running gear, as much as I love the look of the F1 the plan is to make this bespoke though with elements of all the cars I admire, hopefully it does not become a curates egg as a result.

Given I have way to many projects already waiting their turn, and had to snap this up it or lose it, then it will not commence until the OPs car has many miles under its belt, so look forward to all the updates in the meantime,

Edited by PAUL.S. on Friday 30th June 11:11

[RandomTask007]

^^ Understood. I'm just curious how important it would be to "sync" the engines together to avoid any harmonic issues. You're certainly welcome to tackle the problem any way you see fit. Def reminds me of the Cizeta V16T.

[Brother D]

Such a great thread!

OP did you ever consider modifying an existing chassis for this project (like an Ultima or similar)? Or was this way too much of a unique of a project and just easier to build from scratch?

[Penguinracer]

Did you consider the Mercedes M120 or M275?

They can be picked up at reasonable cost outside of the NZ...but you'd need a helpful vendor who could make the freight costs feasible by finding space in an existing container load or with a vehicle on its way to Kiwiland.

[F1natic]

RandomTask007 said:

^^ Understood. I'm just curious how important it would be to "sync" the engines together to avoid any harmonic issues. You're certainly welcome to tackle the problem any way you see fit. Def reminds me of the Cizeta V16T.

Harmonic issues between the 2 engines should be negated by the +/- 10 degrees of crank "slop" the springs and dampers in the OEM dual mass flywheel allow, and given the output load is between the 2 engines they do not directly "communicate" with each other. The biggest drawback is the exhaust note will be a mixed bag, unless I can get both ECU's to synchronize, then it will be indistinguishable from a "real V12" - but that can only occur when the clutch is disengaged.

Brother D said:

Such a great thread!
Did you ever consider modifying an existing chassis for this project (like an Ultima or similar)? Or was this way too much of a unique of a project and just easier to build from scratch?

Thanks! No, I didn't want to modify an existing frame since my layout is so far from normal and the parts are so disparate that from scratch seemed the only logical way for me, however it is taking a lot longer than I hoped.

Penguinracer said:

Did you consider the Mercedes M120 or M275?
They can be picked up at reasonable cost outside of the NZ...but you'd need a helpful vendor who could make the freight costs feasible by finding space in an existing container load or with a vehicle on its way to Kiwiland.

Great engines, can't argue with Horacio Pagani's choice, but my budget is a little more modest and therefore locally available Honda it is! The J35 engines can live happily up to 7500rpm when the OEM ECU is removed, also the stock ECU blunts the engine response to make the standard Accord benign for general consumption. However a human controlled engine has quite a different character and with a bit of headwork they can breathe properly above stock RPM limits. This whole project is quite experimental so really only one way to find out.

This link is an interesting one, but I have not seen an update for a long time, was hoping to see this one finished;
https://www.drivelife.co.nz/2018/06/project-fz12-f...

Edited by F1natic on Wednesday 12th July 02:24 as I Spelled Horacio's name wrong! The shame.

Edited by F1natic on Wednesday 12th July 02:24

[F1natic]

Have been refining the plenum chamber design and measured the volume of the standard J35 plenum and upper runners, which is 6.5 litres. What would life be without duct tape...



It will be fabricated aluminium runners and bellmouths bonded to a carbon fibre box - after all there has to be some bling visible through the engine covers.

Edited by F1natic on Thursday 20th July 08:22

[Penguinracer]

What these guys do is interesting...

https://www.gooichimotors.com/m120-v12-parts

[F1natic]

Thanks for the link Penguinracer.

Last week I picked up (chuckle) a NZ new 2008 Accord with 100,000 Kms on the clock from the salvage yard. Sad how a minor scrape down one side can write off a fully driveable car, but it was cheaper than a bare long block engine from the specialist Honda dismantler so a complete no brainer. It now has a new purpose as the project donor. It's great fun stripping cars down to uncover the clever high volume manufacturing tricks, plus now have lots of spares for my daily driver and most importantly all 12 cylinders!

[F1natic]

Have cycled through another iteration of detail on the intake system, honing in on the final forms that will get fabricated. The intake air passes through a coarse mesh at the scoop entry to filter out the leaves and any other large road debris (birds, cephalopods, malicious discards etc.)

In extremes of cold or wet weather an air deflector is operated to close and block the air flow through the scoop and instead air is drawn from the top of the engine bay. The air deflector is the full scoop width, whereas the intake snorkel is only 2/3 the scoop width. Under normal conditions the air deflector is open and the bypassing air goes directly into the top of the rear cover to help cool engine bay temperatures.

The roof scoop is fixed to the chassis whereas the plenum and throttle body assemblies are fixed to the engines. To absorb the side to side engine rocking movement the standard Accord J35 rubber bellows have been reused. Not shown is the rear section of the airbox that is removable to allow access for servicing the 2 long rectangular K&N air filters that are inside the airbox.

For anyone wanting to make their own throttle body I can confirm that the butterfly shaft axis is co-incident with the throttle body bore.

Finally bought a pair of corrado wing mirrors to help finish of the door frame detailing.

Edited to add wing mirror source

Edited by F1natic on Saturday 2nd September 11:03

[Pflanzgarten]

Very clever.

[marine boy]

It's been a few years ago but I'm sure the original McLaren F1 used VW Corrado mirrors, yours look very similar

I had moulds taken off a VW part and then designed lightweight carbon mirror bodies with an extend plinth for the 97 long-tail car

Other parts raided from parts bins that I can remember are push button door locks were from the boot of an Audi 80 cabriolet, Lotus Elan front indicators, Citroën AX interior lights and for a one off cigarette lighter/ash tray upgrade from a Merecedes SL500.

Rear lights I think we're Hella units commonly used on German HGV trailers commonly

[dom9]

Awesome work!

[F1natic]

marine boy said:

Other parts raided from parts bins that I can remember are push button door locks were from the boot of an Audi 80 cabriolet, Lotus Elan front indicators, Citroën AX interior lights

Superb info, thanks!

[RandomTask007]

Front turn signals from Lotus M100. I've been hunting for these and they've been a PITA to find, notably the housings. That and since they're not produced any more, sellers want ~$200+ for a set of just the lenses that are cracked in half and glued back together.

Rear lights also came on buses; manufacturer was COBO. PNs'

COBO 02.282 - https://www.retroptic-auto.com/en/taillights-and-i...
COBO 02.279 - https://www.retroptic-auto.com/en/taillights-and-i...

I ordered the holders as well. Company took a bit to ship, but they got here perfectly fine. . .

Edited by RandomTask007 on Sunday 3rd September 04:59

[F1natic]

Thanks RT007, very helpful link.

[JaredVannett]

You magnificent bd ... bookmarked!

[F1natic]

Pinion housings cast up beautifully in 4130, very happy with them. Still need a heat treat then machining.