Over - carb'd?
 

Hi, I'm a new member and would just like to thank eveyone for all the info gained from this site in building my motor. I am in the process of having my motor built and curious is the 850 cfm Holley (mechanical secondaries) I have going to be too much carb? I have searched historical posts, but couldn't find a difinative answer. The motor is as follows:
454 Mag .030 over
Crane 139731 cam
World products 310 cc rectangular heads
World products dual plain intake
CMI exhaust.
Any setup I should us (Jets, etc) to get me on the right track for a trial run?
Also, has anyone on the board used a World products intake? Looks a lot like Holley's dual plain. Thanks for any advice in advance..

I was looking at a combination that was simular to this, but with a bit more cam. Bruce, who is not a fan of the 850, felt that while the carb would be a bit big for my application, that it would work. His main concern was in the dificulty of setting the 850 up. Apparently it's a tricky carb to work with.

Dyno's had good luck with his 850 carbs. 454's, .030 over hypereutectic pistons, .556/.578, 234/244(at.050) cam, 9.5:1 compression, dual-plane intakes, MSD ignitions. I think he's jetted at 84 primaries, 93 secondaries, no secondary power valve.

"If more is better, then too much is just right."

Seriously, I ran 850s on milder engines without problems, 82 jets all round with secondary power valves. One advantage of the 850 is the bigger primary size, which allows you to cruise at a higher speed on the primaries only. A smaller carb would need to open the secondaries a bit to flow as much air, and if you had the secondaries jetted a lot richer, there goes your fuel economy. As if you worried about that. ;)

I'm with you, Tomcat. Actually, Dyno gets very good fuel economy. He was surprised when he started running the boat, as the 330 engines he had before were real fuel hogs.

I'm jetted at 83 and 90 ....works great!

Sorry Dyno. My memory for the jet sizes isn't too good. I posted somewhere else today that I thought you had 85/93. My mistake. I need to pull SuperV's apart and rejet so you just saved me a phone call. You going to be available for the engine run-up Monday or Tuesday?

[ 01-18-2002: Message edited by: Crazyhorse ]