Hey guys. I have a 57 tbird with a 312. It has a new Holley 4160 465 cfm carb on it. I seem to get significantly more carbon coming out of the left side than the right. I have the mixture screws turned out 1 1 / 2 turns out equally on both sides. Should the screws be turned out the same amount?



What is optimal temperature for these engines to run at? My car generally runs at about 175 - 180 degrees (right in the middle of the temp gauge). I find that when I get into stop and go traffic and the temp starts to creep up the car seems to run cleaner - the acceleration from a stop seems crisper and not as boggy.



Thanks

The mixture screws should be turned out for best idle. This involves turning them in, one at a time, until the engine stumbles a little bit, then turned out til it again stumbles a little bit. Turn back in about a half turn or so until it runs smooth. They may or may not be in the same position.



The running temp is about right. The temp always creeps up a bit in stop and go traffic.



Do you have a bog? Try advancing the initial timing a bit. 10 degrees is not unusual.

54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

Are you seeing more smoke from the left side because the heat riser valve is forcing more exhaust out the left side?  But, a clean running engine should not produce noticeable smoke.

John - "The Hoosier Hurricane"

Hey Hoosier. The car doesn’t smoke at all. Except for the condensation that burns off. It just emits a bit more carbon deposit on the ground on the left side. I do not actually see any smoke coming out of the pipe.

I will look closer on next start up. The heat riser moves freely. Does that open when the car gets up to operating temp. Any advantage to affixing it so it is open all the time?



Thanks

Hello Nat,

My 57 Fairlane with 292 engine has exactly the same "habit" on warm-up.  The engine has 3000 miles on a complete rebuild and runs great and burns no oil.  My theory is that the normal condensation during the warm-up period is directed out the left exhaust due to the heat riser being closed at start-up.  The moisture being pushed through the tail pipe and muffler causes the carbon to be washed out of the left pipe until the heat riser is open.  If you blocked the heat riser open, I think you would still get the carbon "wash" but it would come out of both pipes rather than just the left.  I think it just might be one of the things we have to live with with the old cars (not a real problem except for cleaning up the spot on the driveway occasionally).

Regards,

Dave

Nat - try wiring the heat regulator valve on the right bank open for a trial - it won't hurt the engine ......could be just what the doctor ordered.

The one on my car worked - but when I removed it and replaced it with an open spacer -  things were instantly better all around. And goosing the throttle in the driveway caused all sorts of ugly stuff to blow out the RH tailpipe. Spiders and stuff - even though the heat regulator would operate - it wasnt exactly "free flowing" for everyday low throttle driving. 

 
 Steve Metzger       Tucson, Arizona

Hey Steve.

Thanks for the idea. I pulled the lever fully open on the heat riser and took a screw and wedged it in tightly so it is fully wedged in an open position. Maybe its all in my head, but the car seems to have a bit more zip when pulling away from a light. Is it possible it is idling a bit smoother? Also the carbon being emitted out of tailpipes is equal on both sides and less of a deposit.

Thanks I hope this does it.

Nat, I have an extra unit that bolts in without any valve pieces that is still in it's packaging. shoot me a pm if you want. I won't be needing it.

       A  L  A  N   F  R  A  K  E  S   ~  Tulsa, OK