Abarth engine upgrades

[MrJD]

http://www.sfconline.org.uk/models/124/ ... ticles.asp

"From 1974 an Abarth kit was available, comprising camshafts carburettors and manifiold, to raise the road going 124 Abarth's output to 150bhp"

150 hp out of an early 1.8? With nothing but added cams, carb, and manifold on top of a 9.8:1 compression block and likely ported head?

So my questions are as follows: The "civilian" market Euro 124 abarth (not the rally car per-se) had about ~130 hp. Thats probably an easy 30 over the US spec car. I know the compression was different, but what else was there? I assume cams, I predict the "Abarth" cars had some fancy head work from the factory... But does anyone know for sure?

And has anyone ever heard of one of these Abarth "kits" out there? I wonder what the cam profiles were and what carb was supplied.

[MrJD]

Some cam data

http://avs.spot-mate.com/cam.html

[wmausbach]

The euorpean 1756 cc TC produced 118 hp with a single 34mm weber. It had 9.8 compression with a mild camshaft with 9.9mm lift (Vs 9.4 USA) with 15/55 intake and 55/15 exhaust timing( 5/53 intake-53/5 Exhaust (USA)). The Abarth used this with a special exhaust manifold Header (Auto-Ricambi has a replica) and 44mm IDF Webers to produce 128 hp. It had standard size valves.
I would think that with a similar compression ratio 9.8 to 10, a 40/80 cam with 9.9 mm lift, Oversize intake valve(43.5 mm), the fore mentioned header, 44mm IDF Webers, and a mild port job should do the trick. I looked in Guy Crofts books for a similar setup but all I found were data on the two liter which produces about 180hp. I think 150hp with the 1756cc would be an easily achieveable with this combination.
Wayne

[westy64]

These figures seem very high to me.
In the early 80s, fiat produced a few models with abarth engines.
Ritmo 105, 1600 cc and one double barrel weber carb, with 105 HP
Ritmo 125, 2000 cc and one double barre weber 34 carb, with 125 HP
Ritmo 130, 2000 cc and two double weber IDF (40 or 44 ?), with 130 HP.
I do not know of a civilian car sold with 150 HP at that time...

[djape1977]

ritmo 105 is not an abarth

ritmo 130 had dual webers or solex 40

[MrJD]

These figures seem very high to me.
In the early 80s, fiat produced a few models with abarth engines.
Ritmo 105, 1600 cc and one double barrel weber carb, with 105 HP
Ritmo 125, 2000 cc and one double barre weber 34 carb, with 125 HP
Ritmo 130, 2000 cc and two double weber IDF (40 or 44 ?), with 130 HP.
I do not know of a civilian car sold with 150 HP at that time...

Considering the Alfa Romeo spider 2.0 of that time came stock from the factory with 130hp, it doesn't seem that far out for me.

[divace73]

ritmo 105 is not an abarth

ritmo 130 had dual webers or solex 40

Also did'nt the 130TC have DCOE's side draught (thanks for the correction dj ) style??

[djape1977]

yes, side draught

[Jimb]

1985 Volumex in stock format is 135hp.

Jim

[wmausbach]

Gentlemen,
You are missing the point. All the production engines that was quoted were based on production tolerances that were in effect during those years with very mild cams. Even the Abarth's were based on production engines with slight modifications.
I have modified and raced several 124 engines and believe me , just matching the mismatch between manifolds and the head offer a lot.
"Blue Printing" an engine of that vintage is good for about 15% in hp with no other changes. Today's engines are built with CNC machined heads with injection molded intakes that are as good as the ported heads of long ago. "Blue printing" and porting correct all the features to the design intent to achieve increased performance.

The 1756 Abarth spider was rated 128 hp for the Stradale version( street) and 170hp for the Rally version (Competition). The differences were cams, compression, and ported heads. My suggestion is that 150 hp was midway between the two.

150 HP Achievable ; yes. The only question is what it will take in hardware and the select massaging of the head. I gave my suggestion which I believe still offer streetable engine with good drivability and power.
Ciao
Wayne

[fiatfactory]

.

[MrJD]

So this begs the question: For a fun "canyon road/around town" car... in the spec you outlined... modded 1.6, 1.8, or 2.0?

[wmausbach]

I think the original post was about an 1756cc producing 150 hp but the items will work on all sizes. However my estimate for the other sizes would be 140hp for the 1608 and 170hp for the 2 liter.
Wayne

[MrJD]

170hp for the 2 liter.
Wayne

I think that would require serious cams, head work, and non-pumpgas compatible compression.

Although, I see no reason 150hp at the crank would be impossible with a MUCH prettier torque number in 2.0 form... just wouldn't be near as revvy as the 1.8

[wmausbach]

SportCpe on this form and a local has almost this setup (2 liter, 44 Webers and cam) on his 72 Coup and it dyno's about 180 hp. It is fully streetable and has 10.5 Cr if my memory serves right.
wayne