Distributor will not sit all the way down..

I got a 1962 327 sbc and for some reason the dizzy will not sit all the way down on the intake.It sticks up about 1/8 to 3/16.the oil pump is a melling HV pump and intake is a 4x2 wiend and dizzy is a unilite mallory.Could it be this pump is for big block??..I have tried everything to get it to sit down..Any help would be appreciated..

 

you did line up the notch in the shaft? Or did you try turning the crankshaft, and letting the distributor drop in place when the notch lines up?

 

I did..I took the pan off also and it looks like it is in place..

 

Squirrel beat me to it while I was typing. Have you cranked the engine over or turned the crank over by hand a couple of times to see if the distributor drops down on the intake. It's pretty normal for them to not drop down all the way when you set them in.

 

Is it possible you have a front sump pump? The drive on a front sump is a little longer than a normal pump.

 

What he said!^^ Try turning the motor with light pressure holding down on the distributor, if it doesn't go down might be a burr on the shaft ,or inside the bottom of the distributor, if not you might have a big block drive rod

 

Wouldn't be the oil pump but could be an incorrect intermediate shaft. If you have a big block shaft in a small block it will cause the distributor to sit up even when fully seated in the notch on the shaft. It will engage the camshaft drive gear and the engine will run but your right side lifters and rockers won't get proper oiling as the distributor is not sealing the oil passage correctly.

Hopefully it is just a case of the distributor not being all the way seated down in the correct intermediate shaft.

 

I just got the motor together so it's pretty tight.I will hook a battery up and see if i can crank it..

 

you could also just pull the plugs, eh? (Drop a squirt of oil into the cyls too, so it's not totally dry when you crank it over).

 

I did check on the shaft and it was for a small block..Is there a difference in big block pump and small block??as far as pump shaft

 

Take the cap off and wiggle the rotor a little as you are dropping it in, I've had to do that in the past. Another thing make sure it's not hanging up on the distributor hold down clamp.

 

is the manifold new? just wondering if the manifold had been cut to fit shaved heads

 

If it is a B.B. Chev. pump you need a 5.625 length oil pump shaft best I remember. I suspect that the distributor is not dropping into the oil pump shaft though. As stated earlier apply pressure to the rotor and rotate the assy. You can also just try to drop the distributor in at different locations and if it fully seats then the shaft is not aligned with the slot at the base of distributor at the # 1 position.

 

I have a long screwdriver that I scored a line on the end of the handle, in line with the blade. I use it to turn the pump shaft to line up with the tang on the distributor, before I install the distributor. Works almost every time.

 

Has the distributor been used before or is it new? I bought a new one for a 305 I was building and could not get it to go in. Found out the housing was drilled off center and the gear would hit the cam and not line up. I had to take the guts out of it an put into an old housing and it fell right in place.

 

I had that problem once and had to file the end of the distributor shaft where it fits in the groove in the oil pump shaft because it was not fitting in completely. Didn't have to file a lot but once I did, it dropped all the way down.

 

Make sure the gear isn't upside down.

 

What he said, has happened to me and I spent two days figuring out why it was not going all the way down.

 

Crossed my mind too, although 1/8 to 3/16 of an inch would be quite a bit.

 

If the engine can't be rotated with a breaker bar or flywheel tool I would be concerned about that.

 

I had this happen recently with a BBC. The MSD that came with the motor fit fine, the Vertex mag would not drop. Turns out the oil pump shaft was mushoomed just enought to not slip inside the dist. gear. The gear on the MSD was opened just enough to allow the fit. Pain in the ass to swap the drive, but that is what it took to cure it.

Hopefully yours will be one of the simple solutions mentioned above. But if not look down the hole with enough light to see if the ears on the shaft are splayed out.

 

If that oil pump is for an early nova, it will do exactly what is happening. The oil pump on the earlier models were shorter. Just a thought.....good luck!

 

This is the second post where someone has mentioned a difference in length of the oil pump. I am not familiar with what your are speaking of. In every generation one small block chevy I have seen the oil pump (factory application; not dry sump) mounts to the rear main cap.

Regardless of stock, high volume (longer gears in the pump so the pump housing is longer but does not change the mounting point) or front sump application the pump mounting point is the same. The intermediate shaft is attached to the oil pump and is driven by the distributor shaft when the distributor is installed.

The only time I have seen the failure of a distributor to seat on the manifold, as described by the OP, is when a big block intermediate shaft was mistakenly used as the big block shaft is longer than the small block shaft. In that case the distributor sat about a half inch above the manifold and was completely seated into the intermediate shaft.

I've been out of the automotive machine shop business for quite a while but I am still willing to learn. Can someone explain to me what the difference is in the oil pump mounting point on an early Nova (front sump application) that would make the distributor sit high?Ready to learn.

 

Another thought is, do you know what the distributor is for,is it possible it's for a tall deck block? I had a customer about 25 yrs ago bring in his car for the same problem, turned out he had an accel for the chevy truck block. same as the newer tall deck heght,
measure it against a known small-big block distributor

 

This is taxing the old memory banks.......I used to run a Melling "big block high volume pump" made for small blocks - as I remember it the difference was the shaft length - which tells me the pump shaft length is different between big and small blocks, and you could have a big block pump. About all the help I can be - check the other stuff first !

 

This is exactly what I thought hearing this....

 

Just a thought. Is this a new engine? If so, could the dist housing flange be hitting the intake? I always leave the intake bolts loose when I install the dist for the first time , get the dist centered and down, then tighten the intake bolts. Lippy

 

1964 Chevrolet Nova with a factory V-8 has it's own special oil pan, oil pump, which is shorter, and a distributor shaft that goes from the distributor to the oil pump is about 3/16 of an inch shorter than any other small block motor. All three of those items have different part numbers. They are Nova only. I know this because I have installed a regular oil pump drive in a Nova and the Distributor sticks up 3/16 of an inch above the maniford. The oil pump still mounts on the main exactly the same as all other small blocks. It is just tighter to the crank. Terry.

 

All though im not familiar with the dist you are using, if its an after market one many of them such as msd are adjustable the flange on the bottom of the dist is movable. They are made this way because as previously stated it is done for head milling purposes.also there are three different intermediate shafts to cope with the same problem.i see you are going to attempt a startup.donot pull dist down with clamp and try to start. The dist will seize because of too much end loading and sometime breaks the cam and dist gear. Dont ask me how i know this. Hope this helps

 

37.5 Nailed it perfectly. I experianced the exact same thing with a Nova pump and shaft the Nova takes a shorter shaft. I had to go to 6 parts store to find the old grey haired man that new this, dropped in the new shaft and never looked back.