.......Finally got my friends boat up and running and in the water and am wondering what I should shoot for as far as SAFE A/F ratios...
The boat is a 27' Carrera with a bravo drive.. Sooo not exactly light and it gets run pretty hard..
The engine is a 509 cid with JE "flat top" pistons, cast iron rectangle port heads with Inconnel exhaust valves, and a Weind 256 blower with twin Holley 750's on it.
Not sure about the cam specs but it has a fair amount of lope at idle..
Timing is currently set at 25° at idle with 32° total in by 3000 rpm.
We have an AEM air fuel meter running in just one collector...
We took it out for a short run just to see where everything is currently....
(BTW it's running on 93 octane with "up to" 10 % ethenal fuel )
Running on just the primary circuit It'll pull up to 3500 rpm with the A/F ratio was running right around 11.5:1
Once the secondaries opened up the A/F ratio was running about 12.5:1
It made a total of 6 pound of boost at WOT (not sure about rpm, I didn't get to look at the tach)
Correct me if I'm wrong, but it seems to me I need to get those numbers switched around...
.. but then again this is the first blower engine I've ever tuned..
(glad it's my buddies and not mine )