246 engine tuning

The best guy to speak with is Ron at Superformance. He has rebuilt many, many of these engines & has seen it all. He would be a good guy to start with.

 

I had an engine for my Dino 246 uprated at Autosport in Biella, Italy. The dyno said 252hp. Used 44 carbs, CPS pistons at 10.5, swiss cheese flywheel with AP twin disc clutch and different cam grind. Looks stock on the outside except is is sitting on a Stratos Gr4 close-ratio gearbox with changeable drop gears They work on a lot of Stratos' at this shop. They built my 24-valve Stratos motor. I highly recommend them.

 

Tom - I received the starter - mille grazie...

Snowy - your question, while of academic interest, raises a more pragmatic question. If larger valves or greater compression contribute to increased performance while not compromising reliability, do you not believe that Ferrari would have designed their production engine to these specifications? After all, they do, and did, have significant experience on tweaking output from small displacement power plants, and they were in a heated marketing war with Porsche 912 / 911. The extra horsepower would not have gone unnoticed by the automotive press.

One might argue that driveability might be compromised, or reliability, or cost, but none of these factors seemed to hold Ferrari back from producing a street car. Witness the tremendously reliable, low cost (of its day) Dino....NOT. The car was expensive, unreliable, albeit driveable.

As an academic exercise, sounds like fun. As a practical modification to an existing Dino engine, better that you purchase a Fiat 124 and do the same thing. More fun, lower cost, less frustration when you break something beyond repair. And if it is performance that you really seek, spend far less than these modications will cost and by a Corvette, or better yet, a Testarossa or 550 Maranello.

Jim S.

 

Thank you all for your quick responses.

The reason I asked was because i was looking at a uk car for sale which had high compression pistons and had asked myself, is this what 'everyone does' in a restoration. Then did my reading and discovered how lancia had upgraded the engine for rally work yet still as a two valve unit. I figured that a dino with 240hp would very, very much compete at ordinary road speeds with a 365gtb, as pwr to weight ratio would have been very close so why bother to improve it. My aston db5 was bored out to 4.2l and had higher comp and ran really well, albeit never much above 5500 rpm.

Boring out the liners is the cheap way to restore that engine and you get a little more power and torque. Sounds like the dino i was looking at was saying - i have been driven within an inch of my life - and will drop 20k of your money very soon.

As a total aside at the weekend I saw the Flying Legends show at RAF Duxford with my dad for his birthday. On proud display in one of the resto hangars was a spitfire and 275 gtb. Both said "if you have to ask how much to look after me, you can't..."

I will post a photo later.

Snowy

 

My Stratos engine uses 48 IDF carbs, large valves (45mm & 39mm) shimmed under the cups, ported head and inlet manifold, Group 4 exhaust, special cams with 11mm lift, 11,4:1 compression C.P.S. custom pistons, custom titanium rods (not original, had to deviate somewhere), lightweight flywheel with dual plate rigid clutch. Of course Group 4 gearbox and interchangeable cascade gear ratios.
Outputs 270bhp on the flywheel and a whopping 28.4kgm of torque. Super driveable from 1000RPM in 5th all the way to the 8400RPM redline.

The engine was built by Alberto Donati in Switzerland a great specialist of the Dino who uses his own research and parts unlike many others copying existing ones without understanding why...

Alberto's Dino engines can output up to a reliable 310bhp from the 2V depending on spec.

 

OP: In all honesty, why? Get a FIAT and mod them...why mess with resale on a Dino?

 

First these are race engines and I wouldn't see one of those on a street car. On a normal Dino the power output is, as usual, hugely overrated by Ferrari. The maximum output is an anemic 170bhp.
Some people like to use their cars rather than watch them. In these cases having an engine that sounds and goes as well as the car looks and handles is an asset. A mildly tuned and rebuilt engine adds a huge amount of satisfaction to the experience.

 

Ok.....in that case: GREAT.

Do anything else to the body, make it even more lightened? How about suspension.....honestly, it sounds very exciting to get it track ready.

 

+1 I would think an extra 50bhp+ makes all the difference in the world with these light little cars.

 

Some people see these as piles of money, others as fan machines, each to his own...
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AWWWSOME!!!!

 

I think these engines can handle a fair amount of tweaking without seriously handling reliability. They proved themselves in the Stratos and rallying has to be brutal punishment on an engine. If you are going for the max, then engine rebuild will come up sooner and more attention to tuning and cam/tappet clearances will be needed. It is all a trade-off. More fun=more work. A 3/4 race engine should hold up fairly well especially on a street car. I think if you are into the Dino 246 you must have a little hotrodder in you .

 

That's exactly it!
The Dino engine has been blessed with HUGE bores and short piston travel. A wonderful playground and the absolute top package to obtain serious power with no adverse effects.

 

Maybe one little experience I can add soon.
My engine is original and has around 60 000km since rebuild to oriinal specifications by pre owner.
If I would have the need to rebuild it I would for sure try some improvements in performance if with no
loss in durability and driveability. What I try now is to change the carbs against bigger ones.
To find out the truth about the original 195 HP I will go to a test bench next week and after this
I will replace the Weber 40 DCNF against Weber 44 DCNF and will re-measure again after adjustment.
I know that this really makes sense together with bigger valves and annother cams but it is a try and
we will see what the outcome is..

 

I think you will find less performance if you fit the 44's, as the 40's are plenty big enough for the standard engine. Please publish the dyno figures!

 

Great reading. For what it is worth I had my Dino on the rolling road and it gave 160 bhp. With an ecu fitted (I modified it all from ford components) and mapped ignition it gave 177bhp and returned 28 miles to the gallon. It also had 30% more torque at 3000 revs. I suspect there is no easier way to get the power and reliability up, I have driven the car on track and all over europe without drama. I have also fitted an electric water pump and controller for peace of mind. For me a dino is for driving and I currently have the engine in bits awaiting Dino parts high comp pistons and cams etc. I hope I have gone the right way - anyone got experience of this mod?
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It would be great to know more details about your conversion to an ecu fitted, and all from Ford components!
Regards, Alberto

 

You can call Vincent Latino at auto elite in fort lee new jersey. 201 947 2371 He has done it or an opinion on why not to do it.

Good luck!!!!!

 

I assume you mean you fitted ecu & throttle body injection?

I think this would be the single most effective engine mod on a Dino. Apart from the torque gain & fuel economy improvement you mention, it will eliminate the fuel surge/engine cut on cornering which plagues this car. I haven't tried it yet but will be doing so when my current Dino project comes together.

It can be done without stripping the engine and using off the shelf throttle bodies which bolt straight on to the manifold.

Also your standard 160bhp at wheels is impressive (assuming this is a corrected figure), and would suggest the engine really was giving around 190bhp at the flywheel.

Going a stage further with better cams & pistons will also work fine. I always wondered if the loss of low down torque would be a problem until I got my Group 4 Stratos going (cams, hc pistons, big inlet, std exhaust diameter valves, 48 IDFs) and am stunned by the driveability of it.

I don't know of anyone's experience with the Dinoparts cams and look forward to seeing your Dyno results. Are you building youir own engines?

 

One reason for a dissapointing dyno result could be that propably that there is no ventilator adjusted to the air intake on the left side.
I believe that this "ram air" effect into the closed carb box makes the main difference to the Fiat Dinos power together with the better exhaust.
At high speed there is a lot of air pressure from outside which is missing if it runs without the vent on the dyno.

As engines are my real hobby and I started my engineering work the first five years in engine development,
I thought a lot about the Dino engine with max. modern modifications. What would the ouptput be if someone would use
current technology? No question that 195 HP from 2,4L is still today a pole setter figure and now they have direct fuel injection,
moveable cams and so on.. A friend who worked at Bosch and ownes a 246 since more than 20 years started his own vision.
He replaced the carbs against an injection system, with throttles from a BMW motorbike.
These throttles fitts on the original intake manifold and airbox on the other side and look even quite original from a distance.
The injectors are in the original intake manifold. The throttles have a poti (don´t know if this is the same word in english?)
which give the opening angle as load signal to the ECU. In this ECU was at the beginning only the original ignition curve over Rev.
to be no longer depending on the weak distributor with its mechanical components.
The distributor housing was used to contain a hall effect given signal without any contacts.
Further development was a temperature influence to the injetor timing with a cooling water sensor who makes cold starts
with enrichment perfect and eliminates hot start problems by giving less fuel.
Lambda sensores were fittes in each exhaus manifold to adjust the maps on a test bench.
One idea was to include the choice to switch between severall maps depending on the drivers purposes:
Mapp 1 is the original standard one.
Mapp 2 is for fuel saving, if you have to do long distance runs or mostly running in city traffic. etc.
Mapp 3 is performance with earlier ignition timing and 100 octane fuel required..
and so on..
The throttle has a full load switch which dissables the lambda sensor and let the engine running at lambda 0,85-0,9 which is best for max. power.
At idle there is annother switch which starts idle control and keep it under all conditions stabile by influencing ignition.
The electrical water pump is annother nice idea, it can be controlled by the ECU and runs in just that revolution which is needed by engine
temperature. Even standing with no air in the traffic it can speed up and vice versa.
Best futher improvenment in my eyes would be having knock sensors, but finding the correct positions on the block which ensures
receiving real knocking under all vibrations and circumstances is the hardest thing to do.

 

God was kind with the Dino engine and gave it everything needed to easily achieve high specific power outputs very reliably.
I think you are removing the soul of the engine by going fuel injection. Carburetors produce very high power while retaining the amazing scream of the engine.
Again 195bhp is in dream territory. No standard spec Dino engine can even come close to that figure. More like 160-170. These were "mass produced" engines by the standards of the time and covered by usual manufacturer's warranty hence nobody would spec them as they were supposed to be specced. However little work is involved to produce amazing results for any street Dino engine. No need to go for fuel injection.

 

The ecu simply replaces the distributor and gets its signal from a toothed wheel on the crankshaft - I still have the carbs - but one of them has a load sensor fitted to it as throttle bodies would have. I looked into injecting it with Jenvey throttle bodies but concluded that amongst other reasons I would loose too much of the original character of the car. The system uses the wasted spark princple and so has a triple coil pack from a V6 ford fitted. All the bits are hidden with the Ht leads even routed through the old distributor to look original. The figures are at the flywheel. Another unexpected improvement was easy starting from hot.

 

I assume you mean throttle position sensor not load sensor?

Nice job getting those results with the carbs. Basically achieved from better ignition control.

 

I know what you mean about carbs but:

1. Ferrari was well into injection by the time the Dino was produced, and used it on the Dino race engines too. Admittedly no ecu & usually slide throttles...

2. Sound shouldn't be affected if using individual throttle bodies, why should it? Perhaps you're thinking of the single or twin TBI/plenum systems used on the road cars.

3. I'll only really know how I feel about it when I get the car going. I don't think so but you may prove right after all!