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View Full Version : Distributor vacuum can - where?


scumdog
09-07-2016, 10:27 PM
Well I may have found why it was hard to get a good idle with the 390 in my Thunderbird - and why my gas mileage was not as good as it could be.

Turns out the diaphragm in the vacuum advance had ruptured, I discovered that when I took it out of the motor prior to removing the intake manifold.

Anyway, I had a look on the Internet for a new one but only found complete distributiors for sale.

Is there a source of vacuum cans to suit my distributor?

Yadkin
09-08-2016, 06:47 PM
http://www.oreillyauto.com/site/c/search.oap?keyword=distributor+vacuum+advance&year=1964&make=Ford&model=Thunderbird&vi=5149489

Depending on the OE number on your distributor.

Yadkin
09-08-2016, 07:09 PM
Before you spend money on the old distributor one thing that you should be thinking about is the amount of timing and advance that you should have with the fuel that you are using. In 1964 my car was designed for premium fuel, not sure of the octane, and the initial timing set at 8 degrees BTDC. The mechanical advance added 24 degrees off idle to 2800 RPM.

The advice that I have received for my engine with EFI and 93 octane street gas (10% ethanol) is 16 degrees initial, mechanical advance starts at 1500 RPM and adds 18 at 3500 RPM. No vacuum advance. The reason given is that modern fuels burn slower.

Because of that reasoning, EFI or carburetor shouldn't make much of a difference in these recommendations. But I'd like to hear what others are using.

Tuning the advance curve is not easy to do with the stock Ford distributor. I couldn't find spring kits or limiter kits for mine. I ended up buying a Pertronix D133700. It has three sets of springs and three sets of limiters so you can tune it fairly precisely. It's more like a GM style with these assemblies much more accessible. It has a vaccum advance in case I needed it. It is slightly taller than the OE unit so I had to modify my air cleaner a bit to make it fit, but it does and I can still close the hood.

scumdog
09-08-2016, 07:10 PM
Ah, I knew somebody on Squarebird would have the answer!
What a great site and what great members!

(And I know just the man to visit O'Reillys!)

scumdog
09-08-2016, 07:19 PM
Before you spend money on the old distributor one thing that you should be thinking about is the amount of timing and advance that you should have with the fuel that you are using. In 1964 my car was designed for premium fuel, not sure of the octane, and the initial timing set at 8 degrees BTDC. The mechanical advance added 24 degrees off idle to 2800 RPM.

The advice that I have received for my engine with EFI and 93 octane street gas (10% ethanol) is 16 degrees initial, mechanical advance starts at 1500 RPM and adds 18 at 3500 RPM. No vacuum advance. The reason given is that modern fuels burn slower.

Because of that reasoning, EFI or carburetor shouldn't make much of a difference in these recommendations. But I'd like to hear what others are using.

Tuning the advance curve is not easy to do with the stock Ford distributor. I couldn't find spring kits or limiter kits for mine. I ended up buying a Pertronix D133700. It has three sets of springs and three sets of limiters so you can tune it fairly precisely. It's more like a GM style with these assemblies much more accessible. It has a vaccum advance in case I needed it. It is slightly taller than the OE unit so I had to modify my air cleaner a bit to make it fit, but it does and I can still close the hood.

Thanks for the advice, there's a distributor savvy man in town I can get to check my total advance- I run no less than 96 octane and 98 when I can get to the city. ( our octane rating is a tad different to your - probably rates as 91 and 94 to you guys).