Alfa Romeo Owners Club of Australia Forum

Racing => Historic Group S Racing => Topic started by: Glenn Campbell on August 29, 2009, 09:03:48 AM

Title: Engine Mods for Group S
Post by: Glenn Campbell on August 29, 2009, 09:03:48 AM
It did not take long to realise that I need to do plenty of work (and $) on the engine.

Any help and suggestions for the following will be gratefully accepted:

- Electronic Ignition system
- Carbys - I have been told 48DCOE are OK to use - any specs
- Camshafts
- Cylinder Head mods
- Pistons

Anything else?

Regards
Glenn

Title: Re: Engine Mods for Group S
Post by: branko.gt on August 29, 2009, 01:52:23 PM
- best to confirm in the current cams manual but i do not believe you can use electronic ignition unless it was supplied on the model originally. This would make a no go for all alfas for group S.

- all engine internal modification are OK with a max bore out  +1.5mm and no stroke change allowed

- no addition of metal allowed for cylinder heads

- camshafts are free

- pistons are free

- carbies are a bit of a grey area with people using 48, but the strict reading of rules may make that illegal

other things where you may spend money on and stay within rules :

gearbox internals free as long as you retain the number of forward and a reverse gears

diff internals free

clutch free

flywheel

crank lightening

exhaust

radiator is free in size but cannot be made of aluminium unless original for the model

electric fan is OK

Title: Re: Engine Mods for Group S
Post by: alfagtv58 on August 31, 2009, 10:22:22 AM
Branko is correct in everything but the 48's (which are fine)....not sure how you come up with that one Branko, my spec sheet says "Carburettor bore size is free", further to that I can choose from Dellorto, Solex or Weber!!

As for specific spec's on head work/cams/pistons etc.  I suggest ring Vin Sharp at PACE (9844 0147), he is the guy that would be best to answer those questions (I would be just offereing 2nd hand knowledge!).

Oh yeah, Electronic ignition is a big no no....and this is something they are regularly looking for.......cos electronic ignition makes the car look modern  ::)
Title: Re: Engine Mods for Group S
Post by: branko.gt on August 31, 2009, 05:52:59 PM
the actual wording is:
"Carburettors or fuel injection systems must be of the same make, type and number originally fitted
to the vehicle. Carburettor bore size is free. Carburettor inlet manifolds are free except that they must be of a
type compatible with the period."

one could argue that DCOE40 and DCOE48 are same make and type but there is also possible argument that they are no. One could read the bore size freedom as such that you are permitted to use as large choke as you like that fits into DCOE40 that was standard on the car.

As I said, bit of a grey area ....
Title: Re: Engine Mods for Group S
Post by: Jekyll and Hyde on August 31, 2009, 07:10:14 PM
I understand where Branko is coming from, but to my mind that interpretation would seem to make the rest of the engine freedoms rather pointless, as well as free inlet manifolds.

My reading of the 'same make, type and number' rule would be:

Same make (so in this case obviously Weber/Dellorto).  Same type being twin throat sidedraughts, as opposed to single downdraughts or whatever else.  Number being the number of carby assemblys, in the case of Alfas being 2.

I suspect this rule is more aimed at preventing cars that came with crappy carby setups from upgrading to a better style, for example Datsun 240/260z's from converting their twin single throat SU copies for triple Webers.  After all, most cars running in this class didn't come out of the factory with a carby throat for each cylinder like an Alfa.
Title: Re: Engine Mods for Group S
Post by: branko.gt on August 31, 2009, 11:22:35 PM
talking about pointless, rules let you make your engine go as much as you can but you are not allowed to upgrade brakes  ::)  :o
Title: Re: Engine Mods for Group S
Post by: alfagtv58 on September 01, 2009, 09:12:35 AM
Quote from: Branko Turk on August 31, 2009, 11:22:35 PM
talking about pointless, rules let you make your engine go as much as you can but you are not allowed to upgrade brakes  ::)  :o

here, here.  particularly for an Alfetta
Title: Re: Engine Mods for Group S
Post by: Paul Gulliver on September 01, 2009, 11:05:05 AM
Phil,

Stopping at the end of Conrod Straight with brake pads half the size of a box of matches must get your attention every time.
Title: Re: Engine Mods for Group S
Post by: Gary Pearce on September 01, 2009, 01:12:41 PM
P.B. once said good drivers don't need brakes.
Title: Re: Engine Mods for Group S
Post by: Paul Gulliver on September 01, 2009, 01:34:45 PM
Just Big Balls
Title: Re: Engine Mods for Group S
Post by: alfagtv58 on September 01, 2009, 03:31:17 PM
Quote from: Gary Pearce on September 01, 2009, 01:12:41 PM
P.B. once said good drivers don't need brakes.

That must be Peter Brock.....'cos I sure as hell didn't say that!!

Quote from: Paul Gulliver on September 01, 2009, 11:05:05 AM
brake pads half the size of a box of matches

Shhh. I need to pretend to forget about that for my own sanity.
Title: Re: Engine Mods for Group S
Post by: Sheldon McIntosh on September 01, 2009, 04:12:10 PM
Get hard, ya big puffs. 

I thought Group S was supposed to be about recreating "period" racing.  Why should you have more braking than they did back then?  Besides, I thought your brakes were pretty good for an old car Phil (well, that's what I thought after I outbraked myself into Honda and had a spin, then remembered it was an old car ::)).
Title: Re: Engine Mods for Group S
Post by: Paul Gulliver on September 01, 2009, 06:20:34 PM
Sheldon,

It might be bad manners , but i have been meaning to ask what's going on inside your avatar ???.
It looks like the either the little bloke and or the car have just been given 240 volts in a damp area.

Or maybe he's warmimg up for some line dancing???
Title: Re: Engine Mods for Group S
Post by: Sheldon McIntosh on September 01, 2009, 07:03:35 PM
That little bloke is the one-and-only Gary Coleman doing a little tap dance in front of KITT, with hydraulics, while David Hasselhoff taps his foot (knowingly) and gives the thumbs up (if you look closely you can see David's thumb popping up).
Title: Re: Engine Mods for Group S
Post by: Paul Gulliver on September 01, 2009, 07:58:31 PM
Either i was away that day or my mum wouldn't let me watch that American rubbish.
Title: Re: Engine Mods for Group S
Post by: Glenn Campbell on September 02, 2009, 06:48:10 AM
Yeh...thanks guys for all the ....help..... - back to the question however.....

Re ignition system - my reading of the specs is that "Coil and Distributor" system is specified using Bosch or Marelli. What is to stop the points being substituted with an electronic spark system, hidden under the distributor, for that historic "look"?

Wouldn't this still meet the specs?

Regards Glenn
Title: Re: Engine Mods for Group S
Post by: branko.gt on September 02, 2009, 09:28:37 AM
you are not allowed to to replace points!
you can try but that is easy to spot and will not pass scrutiny!
Title: Re: Engine Mods for Group S
Post by: Paul Newby on September 02, 2009, 02:56:35 PM
The points have to trigger the ignition.

There are some systems out there which help give the points a healthier and more reliable spark (that is maintain the correct gap) than a totally standard system.

As long as the points are in there doing the job they were designed for I don't believe there is an issue.

Not that I would know, of course...  :D
Title: Re: Engine Mods for Group S
Post by: branko.gt on September 02, 2009, 03:11:32 PM
How hard is it to read the manual which is quite cleat on the subject :  ::)  ???

CAMS manual says this on the subject:
Electrical equipment: All electrical equipment must be unmodified from the original specifications, and fully
operative.
- The dynamo/generator may not be replaced by an alternator.
- Electronic ignition devices are not permitted, unless included in the original specification.
- Electronic revolution limiters are permitted.

further to that in :
5th Category - Historic Cars
3. Vehicle Eligibility
3.6 Equipment Standards and Guidelines
3.6.7 5th CATEGORY EQUIPMENT CHART

it specifically lists what is allowed and what is not. Breaker-less and transistorised ignition is specifically prohibited.

it should not be that hard, particularly with the manual available for download !
Title: Re: Engine Mods for Group S
Post by: alfagtv58 on September 02, 2009, 07:16:30 PM
New Avatar Glenn....car is looking good.

Yup, as far as I can work out, points it is.....whichever way you look at it.

And Paul I was thinking of your 'points' while reading this earlier  ;)
Title: Re: Engine Mods for Group S
Post by: Scott Farquharson on September 08, 2009, 04:57:56 PM
The only interpretation is the one used by the rule makers - that is that 48's are fine - the intent is to make you use the same "type" of carby ie "sidedraft twin throat etc" but allow the throat (and manifold) size to be free.  To be clear - 48's (any bore size for that matter) ARE allowed.

Electronic ignition is NOT allowed.

I'm still looking for a new car - as soon as i can find one I'll be building again!!
Title: Re: Engine Mods for Group S
Post by: Martyn on October 03, 2009, 09:02:11 PM
Quote from: Paul Newby on September 02, 2009, 02:56:35 PM
The points have to trigger the ignition.

There are some systems out there which help give the points a healthier and more reliable spark (that is maintain the correct gap) than a totally standard system.

As long as the points are in there doing the job they were designed for I don't believe there is an issue.

Not that I would know, of course...  :D
Can you share with us where we can find these more reliable points systems. Much appreciated
Regards Martyn
Title: Re: Engine Mods for Group S
Post by: Paul Newby on October 06, 2009, 11:43:52 AM
Quote from: Martyn on October 03, 2009, 09:02:11 PM
Can you share with us where we can find these more reliable points systems. Much appreciated
Regards Martyn

Everything on my Alfetta GT came from Pace Engineering, but this was several years ago. I suggest that you give Vin a call... :)