Stepdown distributors

GrimGreaser

I can't seem to find the discussions about the differences between the different Stepdown distributors and their advance curves... Anyone with the link or information handy, it would be appreciated.

Thanks!

hudsontech

Both manuals available in the on-line library.

http://hetclub.org/burr/lithomepage.htm

Filed under Manuals in the 1948-1954 section.

Hudsonly,
Alex Burr
Memphis, TN

Glowplug

Some of the performance "details" about Hudson distributors were not published in the maintenance manuals. The September 1953 Hudson Merchandiser has graphic and textual information showing the curves of the distributors being used in Hudson engines. (This document is available on line at the URL that Alex Burr noted in the previous post) The attached JPG is a photograph of a Motor's manual chart which compares Hudson Distributor technical details on a easy to read sheet. Historically the information published is a bracketed specification that is achieved with clean weights, properly operating springs and vacuum advance canisters. Note that the canisters diaphragms are a weak link in the equation. When operating properly the spring within the neck of the canister must be shimmed to obtain the proper advance. Testing the mechanical and vacuum advance with out a distributor machine is pretty difficult.

GrimGreaser

Looking up the specs... the Hash 4203A distributor has very different advance curves than the early 4009 distributors. Is one markedly better than the other?

Changing tracks a bit, what advance do these engines really like for performance? The reason I ask is I plan to get efi and spark control set up on my Hornet eventually and need a little more advance information than just factory curves. Also thinking about adding a knock sensor for better spark control. Anyone added one before? Wondering if the valve action would interfere with knock sensing.

Frankvintagefullflowcom

Okay.....I'll be the jerk.
First: "Hash 4203A" ? There's nothing Hash about a '46-'47 Hudson 212
Second: The 212 "Splasher" is of a drastically different design than the later full pressure lubed sixes using the 4009 distributors (or any other ) . It's not a matter of which is markedly better than the other.....they were engineered to the requirements of each application and are not in any way close to being interchangeable. Each version is a compromise to achieve the best overall results.
Third: "Performance" is a vague term. It can mean maximum output with no regard for fuel economy or longevity, or it may be the best possible fuel mileage under optimum conditions......I'll guess that's not the one you were referring to.

If you have an EFI mod in mind, None of the stock "off the shelf" distributors will get you what want anyway and certainly won't be compatible with an EFI system unless it's "fuel only" but that won't get you the "performance" you desire. Presumably, you will be utilizing a programmable engine management system that you will need to custom-tweak as you perfect it, possibly starting with the advance curves from the manuals and progressing from there until you find the best results......hopefully without catastrophic failure along the way.
I hadn't considered the possibility of knock sensors "hearing" the valve train in a solid lifter engine......might be an issue.
I'll be the first to agree that the 12 port Hudson Sixes lend themselves well to the idea of MFI or even Sequential Port FI and I've long dreamed of doing one myself one day......or a thousand days. A TBI set-up is cheaper and easier but where's the fun in that? I'll bet someone has done some or all of those and can offer more than just my guesses.

First step: suck on the vac adv. line and see if the diaphragm is ruptured and go from there.

Okay guys.....hit me.

F

ski4life65

Frank

I think Grim is referring to the 1AT 4203-A that is in the 55 Hornet 308, and not the 1GW 4203-A that is in the splasher.

Frankvintagefullflowcom

Ooooops.I knew that would come back to bite me......In my defense, I assumed (you know what that means) that he meant the 4203 A that was on the sheet in the prior post.
I stand erected......again.
Frank

GrimGreaser

Frank, we all step in it eventually.
I got a Chrysler 6 electric distributor for Christmas and already have a 'locked out' setup made to slip in for spark control, with the 1AT-4203A internals ready to go when I get the engine back together with a carb. Aside from the O2 sensor setup, i now pretty much have all the hardware collected for a either a GM TBI system or a Ford 300 MPI system. I'm really interested in the Mega Squirt setup which is about as DIY as you can get, yet while I can read about small blocks all day, the flathead info is a bit thin...

Clutchguy

If I could scan a picture, I would post pictures of Clovis Burrow's '46 P/up with a 308 and twin GM throttle bodies. I think he was trying to get his truck to run good at high altitude. He did a tremendous amount of work to accomplish this. It had P/B and P/s too.

Frankvintagefullflowcom

Grim,
Thanks for being understanding. I've really felt bad about that and hoped you wouldn't send anyone to "take care of me".
I was going to suggest that you have a look at DIY Autotune but I see you're ahead of me on that one, too. Of course, almost everything is SBC/BBC related ........yawwwwwwwwwwwwwwwwnnnnnnnnnnn, but that largely applies to the pre-made stuff. I have had a couple of short email discussions with them in the past and they seem to be regular guys. It's quite exiting to think about creating a custom system for our engines and it appears to very doable, almost without limits.
Frank

bob ward

A good book for those wanting to DIY an EFI system onto a Hudson or a brand X but don't really know where to start, is Electronic Engine Management by Frank Munday. Amazon has them or there is usually one or 2 on ebay.

GrimGreaser

Yeah, I have several books on my list to get. The Mundy book as well as the book from the guys at DIYautotune.

Now to just get my engine rebuild finished...