1973 Chrysler New Yorker 440 Motor Build

I looked up the Porter muffler site. Sorry not spending $200 for Cherry bombs. Last in the salt? Your New Yorker won't last in the salt. Check this muffler builder out. Classic Chambered Exhaust Inc. - Home Page
Jeezes. My last set of Cherrybombs were this price

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My desire was to get some "new tech" in combustion chamber design, which the Edelbrocks appear to have. By the same token, using "quench dome" pistons might work just as well, effectively making an open chamber design into a more-desirable closed chamber design with plenty of "quench/squish" orientations.

One other possibility is using 1.6 ratio roller-tip rocker arms, but keeping the total valve lift below about .450" at the same time. Reason is that the 1.6 ratio will move the valve off-seat faster than a 1.5 rocker will. Not sure if there might be a crossover point as to which one is best for peak power or if it might really matter on a more-stock motor at 2500rpm?

I ran across a POWERNATION segment where they dyno'd a "motor home 440", to see what it would do before they started doing their "stuff" to it. It was amazing how much torque it produced below 3500rpm. We were all surprised! In spite of its 8.2CR "worn" condition. Which can tend to support my orientation that the existing cam is pretty good, as is the head port flow, as Chrysler built them all to work together (seemingly better than other OEMS did back then).

Enjoy!
CBODY67
Even more impressive when you factor in that when actually measured, that 8.2:1 advertised CR is closer to 7.5:1.

If you are "tight" on funds, a hone, re-ring and bearings with a new timing chain and valve job, can get you almost as good as new for not a lot. Using a good double roller timing set with the extra keyways will allow you to advance the cam 4 degrees which will make a noticeable difference in bottom end power and it's pretty much free. That 4 degrees really wakes up a smogger.

Kevin
 
Even more impressive when you factor in that when actually measured, that 8.2:1 advertised CR is closer to 7.5:1.

If you are "tight" on funds, a hone, re-ring and bearings with a new timing chain and valve job, can get you almost as good as new for not a lot. Using a good double roller timing set with the extra keyways will allow you to advance the cam 4 degrees which will make a noticeable difference in bottom end power and it's pretty much free. That 4 degrees really wakes up a smogger.

Kevin
I like the way you think !
 
i have used a roller timing chain set with the advance key way in multiple B/RB engines over the almost 60 years i have been playing with this brand, that were factory stock in all other ways, and advancing the stock cam 4 degrees really wakes them up, especially the 73-78 engines.
also, playing with the factory distributor, welding up the mechanical weight slots and limiting the mechanical advance allows much more initial timing. this also makes a big difference in performance.
don't forget to play with the adjustment of the vacuum can by inserting a 3/32" allen key in the hose nipple. this will allow you to tailor the rate the vacuum advance comes in, faster or slower, eliminating pinging, surging, or hesitation.
however, this isn't a 10 minute once and done, way to tune. you have to try it, drive it, and try again if you don't like the results. the only way to know for sure, is to play with things until you have tried enough times and the car responds as good as it can get.
just my personal life experience with these cars over a long time period.
your mileage will vary.
:thumbsup:
 
i have used a roller timing chain set with the advance key way in multiple B/RB engines over the almost 60 years i have been playing with this brand, that were factory stock in all other ways, and advancing the stock cam 4 degrees really wakes them up, especially the 73-78 engines.
also, playing with the factory distributor, welding up the mechanical weight slots and limiting the mechanical advance allows much more initial timing. this also makes a big difference in performance.
don't forget to play with the adjustment of the vacuum can by inserting a 3/32" allen key in the hose nipple. this will allow you to tailor the rate the vacuum advance comes in, faster or slower, eliminating pinging, surging, or hesitation.
however, this isn't a 10 minute once and done, way to tune. you have to try it, drive it, and try again if you don't like the results. the only way to know for sure, is to play with things until you have tried enough times and the car responds as good as it can get.
just my personal life experience with these cars over a long time period.
your mileage will vary.
:thumbsup:
Yep, the hot rod magazines of the later 1960s were full of the "braze up the slot for the mechanical advance weights" and increase the initial timing, while also eliminating the vac advance. That was the trick way to do things, according to many magazines back then. Obviously it worked, but noboey was worried about "fuel mileage" back then! Lower mpg was the price to pay for a hot rod?

When I first looked at the advance curve specs for the lowly 1966 383 2bbl, running a factory 12.5 degrees BTDC initial timing, I was amazed to discover that the factory curve and initial yielded about 36 degrees BTDC total! Which meant that going to 15 degrees initial base timing would be in the allegedly desired 38-40 degrees total situation! Who would've thunk? So I advanced the initial timing on our '66 Newport Town Sedan 383 2bbl to 15 degrees and it worked well, but we'd been having to use premium fuel on that 9.2CR motor from day one as it clattered on regular-spec fuels.

So, much easier to emulate that 383 2bbl advance curve, possibly quickening it with lighter springs (although the max advance was spec'd to about 4200rpm or so anyway) would be less expensive and labor-intensive to do. You can bend the tab holding the lighter spring on the mech advance to let things happen quicker, or just delete it all together (as the old Direct Connection Race Manual mentions doing).

Similarly, the vac advance on the 383 2bbl dist starts at about 9"Hg and is all-in by about 14"Hg. But I also suspect that most replacement vac adv units, at this point in time, are universal AND adjustable. The amount of advance might be indicated by a number stamped on the part of the housing that is screwed-down to the distributor? Adjust to start the vac adv at about 7"Hg and let things happen from there. Vac adv is not operative at WOT, so it just affects part-throttle and fuel economy.

Just my experiences and observations,
CBODY67
 
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