Re: Aluminum Head?

Posted by DavidPackard On 2021/5/6 18:15:23

54packpac;

It looks like you have a 327 carburetor on a 359 engine . . . maybe, you surely have a 2103S tag, and perhaps all of the rest of the internal parts too.

It should work just fine, but some areas to keep an eye out for are:

Idle adjustments that don’t match the Carter recommendations. At idle your 359 will have about 10% more air flow and the idle stop and idle mixture will need to accommodate this air flow change. My bet is once you adjust the idle speed the mixture screw adjustment will be close to what Carter expected, but these adjustments are dependent on one and other, meaning change one and the other will need rechecking.

The idle port opening is different, and there may be (emphasis of the word ‘may’) transition roughness during the idle to main circuit transition.

The vacuum port size appears to be the same, but you might want to keep an eye on it next time you have a timing light on the engine.

My greatest concern if the potential of 6% lower secondary fuel flow, which will alter the air fuel ratio by about ½ a ratio unit. It’s not clear to me if the aluminum head needed some extra fuel to stay out of detonation jail (those with more experience may fill in the gaps in my education), but if it did your iron head may be quite tolerant to going a bit in the lean direction. Read the sparkplugs to determine if this is a potential problem.

The good news is the correct secondary jet size for the 2112S parts list is the same as a #47 drill. Keep your eye out for a ‘junk’ 2112S, because the parts you might need are quite tolerant to corrosion damage.

With respect to your posting #54: I’ve been looking for a ‘ballpark’ figure for the CFM of a WCFB. What I found was 350 – 500 CFM depending on the specific WCFB. I concluded, based on main venturi sizes, the Packard carburetors would be at the lower side of the range. I found a few Holley four barrels that are rated at 350 CFM, and equipped with either electric or manual chokes. The smallest AFB I found was rated at 600 CFM, therefore your carburetor selection may be a bit large.

dp