Fiat Spyder 1438 eng-project to build for max pwr/Bonneville

[KenCemo]

I am starting this project with a 1970 Fiat 124 Sport Spyder that I have owned since 1973. With the original engine and original paint still intact it is a little overdue for a makeover.

Here are the engine regulations for a Bonneville class record with this car:

-1523 cc max.
-choice of camshafts, inductions and ignition are unlimited
-cyl heads are limited to orig number of valves and port configurations
-any exhaust system capable of being closed off may be used
-gasoline for fuel

The rules are very open compared to the "Fiat 124 AC Race Engine Prep" thread where his engine was setup for Historic Races. This was a project very similar to mine in that we are both using the 1438 engine as a powerplant. That was a good discusion with great results.

My questions are as follows:

How far can this engine be bored over 80mm?
What compression pistons are availalbe for this application?
Does any one have first hand experince with Empi Carbs? I have a handle on a pair of 40 twin down drafts with a Pierce manifold.

My goal is a 8000 rpm max hp engine with 8500 redline. Many more questons to follow!

Ken Cemo
Orangevale, California

P.S. I will post pictures when I can get the image to shrink. Everytime I attached an image it was huge.

[Guy Croft]

Ken, hi

this 1438 project by Director of CKL Developments is worth reading for starters:

http://guy-croft.com/viewtopic.php?t=54 ... ght=melvin

The car competes in the Historic Road Sports Championship run by the UK's Historic Sports Car Club (HSCC), and it is up against some formidable competition. Melvin Floyd has achieved an amazing 2nd= in class and 6th= overall in the first year already. I'm not harping on here, I know from now over 17 years experience of TC race engine prep just how difficult it is to do that, and it speaks volumes for the capability of that tiny engine - the particular unit being, of course, the best part of 40 years old.

Placings see:
http://www.hscc.org.uk/PDF%20Forms%20&% ... Points.pdf


That 124 AC engine, 81mm bore (that's the max really) std stroke, is only on a single Formula Ford type Weber twin-choke and the power is just simply one for the record books. I am certain it would top 150 bhp comfortably on twin 40s. The cams are quite a mild GC IIB profile (because of the carb) and a more radical inlet cam would work well on twin carbs. Naturally the unit is on GC race rods and pistons, relatively modest - but survivable - CR of 10/1; not the limit by any means.

I figure you can maybe begin to work out a spec from all that..

GC