WARNING: Deep philosophical discussion brewing!
> Reply-To: Simon Favre <favres@engmail.ulinear.com>
>
> Jim, you got me all confused. If you are running well prepped factory
> crank and rods, where's the modernization that lets you run 3000+ miles
> on a race motor? Other than the synthetic oil, what's modern? <CLIP> Is
> it just the oil that gets you bearing longevity?
90% of the improvements are in oil, part in blueprinting and balancing to
reduce vibration and part in what we know about dealing with metal - like
nitriding cranks and micropolishing journals. On Alfas, there are mods to
the oil and cooling passages that provide better lubrication and cooling
that Don Black and others found out with GTA devellopment.
>
> One should also note that for the 1950's, the Alfa DOHC 4 was years
> ahead of its time. <CLIP> In an Alfa motor, it would seem all
> the secrets for power and reliability are in preparation, not parts. (I
> do know of an Alfa race motor with Cosworth pistons, but again, the rest
> is just very well prepped factory parts.)
Alfa 1300 rods are fragile and fatigue, so it is highly recommended to
upgrade to aftermarket rods (with Carillo perhaps being the only source) if
you want to build a hot engine (>125 HP and 8000 RPM). 1600 rods require
magnafluxing, shot peening and polishing (standard Veloce stuff) and are
safe to 8000 RPM and about 170 HP. The problem becomes metal fatigue and a
limited number of good rods to prep. There ain't no more new 1300 or 1600
rods unless it's NOS or aftermarket.
Pistons have always been free (as long as we have raced) because even in the
60s, raising compression was OK. Today's high silicon aluminum expands much
less so they run very small clearances, as opposed to the aluminum ones we
used 30 years ago that slapped like mad after a few races and had massive
blowby. Ring material seems better too.
>
> Maybe it was hot pistons that started this discussion, but it broadened
> to include Carillo or Titanium rods, billet cranks, Titanium valves,
> etc. What would you consider too modern for vintage racing?
Bill Ruger has a Dusenberg engine developed by Callaway for 400 HP at 4000
RPM from 400 cu in, and uses titanium rods (and about a 5 inch stroke!)
which it probably needs!
But aftermarket steel or aluminum rods to replace old used rods seems to
make good sense to me. If you can get or afford a billet crank to replace
the cast ones in a Mini or Sprite with 3 mains (and too small ones at
that!), go to it, with my blessings. I'd bet a Mini with all modern guts
would be much more reliable and fun to race (working is less fun than
driving, I think) and if you get a few more HP with that head, that's cool!
A point I can make here, and not purely opinion, is that the HP we got in
the 60s was almost what you can get now. For example, 1300 Alfas got 130-135
HP in the 60s and "grenades" today get only a few HP more now. Ferraris are
comparable in HP/L today but engine management makes them more driveable.
Back in the 60s, we ran Porsches to 8000 and the power was comparable to
what you can do today with 2V heads. Even the British iron isn't much more
than Huffaker, Tullius, etc. got 25-30 years ago.
Gains in HP can only come with major head changes. If you use a 60s head
(even with bigger valves like me), the head design and 2 valves limits what
you can do with stock carbs.
Remember this:
HP comes from the head.
The rest of the engine is purely there to transmit that power to the
drivetrain and eventually the road! Low friction and reliability are the
design guidelines.
Even wilder cams cannot make the same effect if the head won't flow. Alfa
heads look great, but the high included angle of the valves (90 deg) limits
combustion chamber design to a big hemi, relatively poor for combustion
compared to 4V squish designs we have today.
I could care less what you put in the rest of the engine, as it makes little
change in output, only reliablity.
SCCA in the 60s became liberal and allowed mods to most everything but valve
size, carbs, brakes and wheels. A very practical desision!
Vintage racing should look at the current rules of the cutoff dates of the
race organizer.
On my '62 1600 Alfa, I have followed 60's GCR modifications: upgraded from
1300 normal (single carb) to 1600 Veloce (dual webers, but only the legal
40DCOEs, not 45s as some racers run - usually with 40 cover plates and IDs!)
and disk brakes (pad and lining material was always free, so I run a carbon
fiber composite, not vintage but would have been legal if it existed then!).
I run a close ratio gearbox from factory stock of the era, also legal in the
60s. And narrow wheels and tires, with a little finessing of the wheel
wells, totally worked steel. It is what you could have done in the late 60s
with a car you had been racing for a few years and wanted to go faster
(exactly the case, remember, as it IS my car from the 60s!) Oh yeah, I use
bigger valves than stock and radiused valve seats - that would have been
illegal in the 60s.
Hell, the idea is to have fun. I am just continuing the development of a car
that my brother and I raced in the 60s! We couldn't beat 356s then and can't
now. We were competitive with the same cars then as now. I'm satisfied. And
having lots of fun!
jeh@fotec.com http://www.fotec.com/jim.htm
veni, vidi, veloce
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