Greetings from Mississippi! Hey if somebody could answer a couple questions about a 235 distributor you would cause me great relief! I am working on my neighbors '54 Chevy Car. He called me over to adjust a new set of points another person had installed. While we were rocking the car around trying to get the cam to move I noticed the rotor wasn't moving. So I yanked the distributor out & found right away the vacuum advance mech wasn't any good so I brought all of it home. Long story shorter, I've got the distributor in workable condition now & have a new vacuum advance unit but for the life of me can't figure out what actually holds the distributor down! Am I right to think all that holds it down is the male tab on the vacuum advance that indexes with the female slot on the distributor clamp? If that's all that does then man that's a Wimpy piece of metal for all that distributor! I got a 3/8" head hex bolt in the clamp w/ a 1/4" spacer the keep the bolt head away from the clamp edges. And also there is no ledge-collar?- on the distributor itself for the distributor to sit on the block, does the oil pump drive locate the distributor height wise? Thanks for the help, this car belongs to an 85 yr old senior that loves old cars & he bought it at a car lot not running. He previously brought me the carb to repair & I don't know if this car will run or not, it spins free, gonna do a compression check on it when I go back over there. He has this '54 Chevy, a '57 Chevy, a '30 Five window A Coupe & a '29 A sedan. I may have a career over at his place! Andy
Are you sure you have the right distributor? I'll check to see if I have some info for you. Meanwhile, can you post a couple of pictures? That would be a big help.
Distributor drives the oil pump. Distributor moves freely in the block. The distributor hold down clamp is adjustable for timing by using the slot. Timing is marked on the flywheel, you see it thru a hole in the bellhousing above the starter. The vacuum advance stays solid by the steel tube coming from the carb to the distributor. With the engine not running and the clamping system bolted down and the squeeze clamp tight you should be able to turn the distributor counterclockwise about 10-15 degree. There is a squeeze clamp to hold the distributor to the hold down mechanism. It’s very simple and worked fine from the 30’s to 1962.
OK here we go. What I'm asking you see in the photo the SB distributor has a "Ledge" that sits on top the manifold to locate it "Up & Down". The 235 distributor don't have that. Looks like what locates this would be it sitting on the oil pump drive. Where the body becomes larger is above where the advance / clamp resides. It appears to me that all that holds it down is where the male / female parts of the clamp & advance intersect.
Here you can see how the two parts interact together. Photo is a truck unit but fits together the same. The dist clamp is on top of the adance unit & that little "Tab" kinda sandwidges the two parts. I need to make these larger somehow but wife is at work...
The distributor tag is missing, & the ned terminal was shorted & insulation melted. I used an alternator part to repair this, I think it's good. The clamp & advance were horribly bent up, aint got no clue how someone could tear delicate parts like these up so bad! Photo didn't load...
I explained how it’s held down and drives the oil pump. After the tab is fully down into the oil pump and you cannot turn the rotor, pull it up no more than 1/8” and clamp it with the squeeze clamp. That is the installed height; if you need to turn the distributor body keep this height. The vacuum can should be aiming at the 1/8” vacuum line from the carb. If your concerned on the rotor aiming at #1 you can turn the oil pump with a long blade screw drive to line it up. …….DO NOT OVERTHINK THIS.
OK jimmy six this is the answer I was looking for! Pull distributor up & lock the clamp! So all that really holds the distributor is the interaction between the clamp & vac adv unit & pulling it up before locking relieves any pressure on the oil pump shaft! I wanted all my ducks rowed up before I went back over to Mr Youngs house, I hate to learn on some one else's dime! Thanks again!
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