VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc Carter W-1 calibration

Just received a PM from a member concerning using a 1946~48 W-1 on a 1932 engine, and wondering about calibration changes. Thought there might be interest from others, so started this thread.

In 1946, Carter released W-1 number 569s as a service replacement for all Chevrolet passenger carbs 1932~1936.

For all practical purposes, Carter took a production 574s (1946~1948 Chevrolet 216 passenger), and grafted onto this carburetor a flat throttle arm like was used on the 1932~1936 carbs. The calibrations are the same.

So if an enthusiast has a junk 1932~1936 W-1, the enthusiast could acquire a rebuildable 574s, and while the carb was apart for rebuilding, affix the throttle arm from the junk 1932~1936 carb; and have arguably the finest available carburetor for a 1932~1936 DRIVER (not a numbers-matching show car).

Jon.

Hello Jon. Thanks for your post and for all the information that you publish at your website.

I confess that your article:
https://www.thecarburetorshop.com/CarterChevroletW1.htm
and the discussions published in this forum, led me to buy a NOS Carter 569s that recently appeared on eBay. It was quite expensive, but I suppose that these carburetors are hard to find in NOS condition.

Although I have a matching-numbers 1935 Chevrolet Standard with a recently rebuilt Carter 284s (with the Chevrolet tag 837341), I bought the 569s in case the 284s will give me problems in the future.
I have noticed that in the 569s the vacuum line is connected in a different position than in the 284s. I don't want to modify the current vacuum line used for the 284s, so installing the 569s might require adding some brass fittings.

I have a couple of questions.
1) Will the engine run better when using the 569s?
2) Can you install a NOS carburetor right out of the box, or do you recommend changing gaskets and/or other parts?

Thank you very much!

Ariel

Ariel - my GUESS is that the 569s will run better than the 284s for a couple of reasons: (1) the technology was significantly more advanced with the 569s, and (2) no offense meant to the rebuilder, but the 284s generally requires machine work to get back to its best state.

As to installing a new old stock carburetor?

Carter used velumoid gasket material (which shrinks over time) for the bowl cover gaskets.

Also, while I am not familiar with the arachnid population in Israel, here in Missouri USA we have lots of small spiders that just love to crawl into small places (like carburetor passages) and make nests. Compressed air through the passages is a good idea. When we sell a new old stock carburetor, we include a set of gaskets in case the customer should need them.

Jon.

The problem is that carburetor is jetted for use on a 1941-1948 engine. The later engnes had a higher compression ratio and could get by wth the leaner mixture which causes the mixture to be too lean for older models. Rejetting or different metering rods can easily correct that problem.
A whilE back there was a thread on thAT SUBJET.

Hi Gene

I was waiting for you to show up here. 🙂
I remembered what you've said before regarding different requirements for engines 1940 and earlier as opposed to 1941 and later.
Not that it would necessarily make a difference, but wasn't there also a valve timing change somewhere in there? Also in 1941 maybe?

I had to raise the float level in my '46 to make the idle circuit work, even with the proper rod, jet, idle jet etc in an actual 574s body (verified by number on the base).
So... could a 569s be made to run properly on a '32 engine by simply raising the float level a reasonable amount?
Maybe not, but just asking.

Ariel

So you are the one who bought that!
I was watching it and the other one along side of it, but had no need for it myself.
I had already caught an NOS 574s in the original box myself.
Better yet, I've got one of Jon's carburetors carefully packed away as well!
Having seen the carburetor you bought, nice catch! It was a bit expensive, but I would have bought it myself if I owned something it fit. 👍

i NEVER TRIED THAT BUT SHOULD HELP.
There were cam timing changes made for a 216 in 1940 and again in 1948.
They were for more power at higher engine speeds and would result is-n some power loss at lower engine speeds.
Also effected top speed.

Also consider thAT THE 1941 AND UP HAD A LARGER THROTTLE BORE AND THROTTLE PLATE.
iN 1941 INCREASR FROM 1 7/16" TO 1 1/2'.

That makes sense.
Larger throttle bore (and probably larger venturi) equals lower velocity air flow.
Plus lower displacement in the 194's and 207's means even lower air flow.
As per Jon's post on the recent 1932 carburetor thread, that should result in a leaner mixture at any given engine RPM.

Sound right?

That is another way of looking at it,
Also the atiitude of normal operation.

Just for information, I tried a 569s on my 1934 Master to check for smoother operation. I drive it quite a bit in nice weather.I noticed that even at normal idle the distributor advance {automatic} went to full advance. I switched back to the 284s and the advance operated as it should. This was with an old advance unit, then a rebuilt one.Timing was set with a light the same way to specifications for both carburetors. I also used a new bowl cover and pump arm on the 284 s. {problem areas}. The car runs smooth, I did have a miss with 569s at certain rpm’s. I think the 32 has a manual spark advance, from the 33 up it is automatic from engine vacuum. Not sure why this happened, just my experience.

As discussed in another thread I have a 569S on my 32. It has always seemed to run slightly on the lean side-particularly at idle and high RPM and I compensate by pulling the choke slightly. I have recently had a 584S rebuilt with the throttle arm changed to a straight one. I had wanted the metering rod changed to one that was slightly richer but the builder was unable to locate one so it still has the original metering rod. My plans are to try it as is to see if is better that the 569S that I currently have but if not I do have different larger jets to use with the current standard metering rod. Not sure when I will get to it but i will post the results when it does happen. My goal is to not have to fiddle with the choke to achieve smooth performance and eliminate the surging when starting and at higher RPM's.

Thanks for your comment! I am glad you think it was a good buy in spite of the price.
Meanwhile, I will keep the 569s as a spare. I have also bought a NOS bowl cover for the 284s, since this seems to be a weak point.
Kind regards,
Ariel