Race Engine Forum UK

MODEL THREAD!

Marvellous photographs, tons of excellent technical info and innovation.

GC

Guy Croft wrote:MODEL THREAD!

Marvellous photographs, tons of excellent technical info and innovation.

GC

Thank you Guy.

This is a real live project and thus lots of technical issues are raised as they come up and resolutions often arrived at with valuable contribution from fellow forum members.

Just so that everybody understands:

This is the short story and the heart of the project !

It started with your original book - the new one is bible for anybody who thinks he knows something about DOHC engines and those who - like me - want to learn !
Than was my visit to your shop ! ( I could not sleep for two days !
Than was my GC engine build and shipped to me ...


And finally my GC engine in my car ; the heart of the project !


Thanks Guy !

Miro

hi Miro,

Good news! This was what I thought I had seen in your earlier pictures.
See the notes in this picture. I know it is not quite a proper engineering drawing :-)

The inner cable must be fitted into a hole in the middle of your axle (or hub). It even looks like there is already something there that can be used (Do I see a square hole? Someone made that with a reason.)
The outer cable must be fixed to the upright (hub carrier?) with something like the bracket on the Bagheera, or in the cap that was there in another picture (that too had a hole in the centre, maybe for accepting the outer cable?).
Your speedo cable will run at exactly the same revs as your front wheel. The speedo must be chosen and calibrated to work with that, because you have no gears to play with like when it is connected to the gearbox.

This can not work on a 124 like upright because there the stub is fixed to the upright and the hub/wheel rotates around it. However, in your assembly the axle/hub/wheel all turn as one inside the bearing while the outer bearing ring is fixed inside the upright.

I think your friend mr. Jan will be able to do this for you.

regards
Tom

Yes, I'm pretty sure we found the way Abarth did this originally.

regards
Tom

Gents ,


You have not only answered my question - but also solved the mystery.

I noticed this white metal piece in the back and the whole in the bearing stub of the hub but could not figure out what it was for.

Now it is all clear.

Congratulations and thanks very much !

Miro

It may be for the speedo cable but more likely for a Halda tripmeter.

That is what I would do anyway, run the speedo off the gearbox and the Halda off the front wheel. For those that don't know why it's so the navigator can measure distance with reasonable accuracy since the rear wheels are spinning a lot of the time.

G

Guy, you are probably right .

I have never seen a gr 4 with a speedo - meaning the cable off the hub must have been for Halda Trimpaster.

But this gives me an idea I can run speedo off the left wheel and Haldas off the right ?

Currently I run the Haldas from the speedo cable that runs from the gearbox . So it would be enough to run a speedo from the hub and both will be run from the hub. This would give me pretty accurate reading on both!

(Too bad I have just invested into X and Z wheels to accommodate two diffs , but this gave me 120 km/h on the speedo (on the first gear with 6,14 diff ) which rendered speedo most useless. )

Miro

hi guys,

Wheelspin.... of course. That would upset the Tripmasters greatly. Funny, I never realised that (oops).
As far as I know it is quite common to branch the Haldas off the regular speedo drive (be it from the gearbox or from a non-driven wheel) through a T-piece. Also that is a common cause of failure for a standard speedo cable, so you'd need a reinforced one. I would do 'wheel - heavy duty cable - T-piece - Haldas on the straight through - speedo on the T-branch'. The speedo itself does not put much load on the cable or T-piece. A couple of Trip/twinmasters and Speedpilots do. Of course routing the cable is very important; no tight bends etc, but you will know that.

Nice to have solved this one, coming from 3 different countries.

regards
Tom

..as the gearbox is connected to the rear wheels it would be absolutely pointless running the tripmeter off it..

G

Guy, Tom ,

Well taken!

Currently the Haldas are fed fro the same cable as speedo ( through a T- piece)

What I intend to do is ti run speedo of the left wheel and the Haldas from the right wheel

Miro

PS Some progress mad on the dash.

1/ I have found and bought the long (16 use ) fuse box. it was advertised as "Maserati Merak Lamborghini Fuse Block Box OEM" I paid a Maserati / Lamborghini / Ferrari premium price for it.
2/ I have found porcelain fuses for the box in a local electric supplies store (and bough all sock) for peanuts !
3/ I have found a gr 4 131 abarth original switch ( searching through some junk at friend's garage) Free !

Compare it to the original
All in all the average price for all these items was OK (LOL)

RE : 16 use fuse fuse-box ;

Reportedly the 16 fuse fuse-box of the old type were also used in Fiat X 19 serie 1 or Lancia Beta Montecarlo.

What I have found is almost but not exactly the same . It has two smaller fuses on one side.

See Lancia Montecarlo
and the lambo ( exactly like 123 abarth gr 4 )
and original gr 4 dash
Miro

What does that label say by the button?

FAR*

G

Guy,

of all people I thought you spoke (enough) Italian ... (LOL)

The control valve for the FAR* you have in mind is ( pardon my French ) in driver's unacceptable.

It says "FARI" ( literary "lights" ) Note: "I" not "T"

In fact this is high beam indicator light

The labels used in gr 4 are:
'Luci posizioni" - parking lights

"Luci supl." - supplementary lights ( additional driving lights - typically large sports halogen lights )

"Fendinebia" - fog lights

"Luci prof." - main lights ( low beam on )

"Fari" - high beam control light

"Int . Gener." -(interrompere generale) - kill switch

"Pompe benz". - fuel pump

"Frecce" or "Direzione" - indicator lights

"Avviam" or "Ritard Acc" starter switch

"Alternat." or "Batteria"- alternator control light

"Vent Aqua" or "Vent. Radiat" Radiator - radiator fan switch

"Ventilaz." - hot /cold air ventilator

Always happy to explain ! :)

Rgds

Miro

Thanks Miro, greatly relieved.

Are you going to run 24v starting? I would.

G

Guy,

I will be charged at least 750 KV !

M