Reply to "dyno of 351"

I actually don't know if the a/f is too rich.

You don't tune Webers that way, i.e., like fuel injection. You keep feeding it fuel until you don't get more power.



There is no intermediate circuit. The idle circuit hangs around until the mains come on line around 3,000 rpm, then they both run together.

You can see the black smoke kick out of the exhaust of a car in front of you when they hit the throttle.

Reading the plugs with them can be a challenge but Shelby established a jet size on the dyno on the 289 Cobra engines.



The idle circuit was/is very heavy. Much like a Holley 4179, 750cfm "double-pumper" carb is.

Basically, smarting your eyes at idle.



You can lean them out now due to more idle air holders/correctors being available but they will never be know as "environmentally friendly".

If that's the kind of engine you want then computer controlled electronic fuel injection is the only way to achieve that but frankly from what I have seen, these carbs seem to make more power but their big deal is the throttle response particularly coming out of corners. It's a little difficult to explain. You need to drive the car to understand entirely.

You can not compare carburetors to electronic fuel injection. One is analog and one is digital. A carb can not be tuned for every 100 rpm differences. FI can and is.



Fun to drive? Sure. Any car with over 500hp and almost 450lb-ft of torque is fun. That's really big block territory.

It's a real 12 second 1/4 mile car too.



I just posted this to show everyone a plus 500hp stock block, iron head Cleveland.

Something some say doesn't exist, only does in someone's fantasy world or isn't streetable? This engine and car are very streetable.


I know this car and it is down on power from what it was originally at because of the cam change to a "Weber cam".



Of course to seriously go racing in "vintage" and be competitive you still need to find about another 100hp.

This engine would run at best in the middle of the pack at this point in time.

The front runners are making 620 to 650 BUT at 8,000rpm.


So you'd have to tune this engine to that, 8,000rpm on the dyno. Of course then you'd kill the durability and life expectancy would probably become nil?

Clevelands can keep making power up the rpm band but it would need more cam and the carbs tend to get restrictive around 6,700rpm or so in that bore size. Probably a "NASCAR" type cam with lifts in the .700-.750 range to gain the upper rpm power band?


As it is, this engine is PROBABLY pretty much what you should have found in a Group 4 Pantera but these dyno numbers are much better then the previous dyno numbers from one of the original vintage Detomaso factory race cars I posted previously.


That one topped out at around 450hp and 380lb-ft of torque.

I don't know why but maybe they needed someone from New York to go tune the thing for them? That is where this engine is from.



That Detomaso engine came from the Bud Moore shop too? So much for North Carolina know how? Beats me?

Maybe Bud Moore didn't want to supply them "I-talians" with a competitive engine? Those guys can be funny like that?

On the surface, it would seem that they didn't know what to do with an American engine in Europe I suppose back then? That logically shouldn't be the answer though?



There certainly isn't any black magic in this engine. It's as basic as it gets with the exception of the Weber carbs and it is making around 100 more hp and torque then the factory and Moore could get out of it, AND they were using 180 degree headers to boot.

Something was not right in Modena for sure back then? Maybe just way to early in the engines racing development timeline history?