I need to know the distributer bore size in the lifter valley for an sbc preferably to the thousanth decimal place

 

distributor is 1.250". i'd guess you can add .010 to that for the block, but just a guess. i have some blocks in my shed if no one can tell you the size in the block.

 

I wouldn't think there would be a .010 clearance between the two because of the fact that the distributer carries oil to the lifter valley.

 

What are you really trying to do? Maybe you could get a more meaningful answer, and to the point, if you approached it that way instead.

 

I thought that "what is the distributer lifter valley bore diameter" was pretty much to the point, but since you asked:

I am having an oil pressure problem. I rebuilt an engine, put in a new crank, had low oil pressure. I pulled the engine and the crank was trash. I put in a new crank, checked the crank size, bearings, plastigauged the caps, all within spec. Cold start up sees 70 psi ... after it is warm, not hot but warm, it sees 15 psi at best with a high pressure, high volume pump. I suspect an internal oil leak from either the lifter bores or the the distributer bore. The only assembly problem I have had was getting the distributer to sit fully on top of the manifold. I am contemplating taking my distributer and cutting grooves for 0-rings on the bosses above and below the oil passages to see if I can remedy the problem. Thus, I need to know the o-ring thickness

 

if there was a problem with the block or distributor i don't think it would of waited untill now to happen. i'd stop using or trusting plasti gage aand get a mic and bore gage. i wouldn't of reused the oil pump and wouldn't use HPHV pump.

 

Sounds to me like you don't have an oil pressure problem; you have a contamination problem.

The motor has metal shavings hiding behind the cam bearings and perhaps in other similar places, and it's just eating cranks and bearings as fast as you can put them in there.

Next time you crank-kit it, as you are surely about to have to do, take it to the machine shop to be torn down and vatted; and instruct them leave ALL oil passage plugs, internal and external, and the cam bearings, out of it. Pick it up, take it to the quarter car wash, and using diesel fuel or Gunk Engine Bright or similar (diesel fuel in a spray can) as cleaning fluid, run some rifle brushes through EVERY oil passage, and use a toothbrush-shaped wire brush in the grooves behind the cam bearings. Then wash the hell out of it by sticking the wand into every one of those oil passages and carefully spraying the cam bearing grooves out. Then take it back, have them vat it again, and put all the plugs and cam bearings in it.

Until you get the metal out of the block, it's going to eat cranks, and it's a waste of time to try to fix the oil pressure problem. That's about like noticing that somebody that's bleeding to death has lost all their color, and putting makeup on their cheeks so they don't look so pale. Total waste of effort.

 

hahahahaha

 

Ok, let me back up. I bought the virgin block from a friend and had it bored and cleaned and cam bearings installed by one of the best engine builders in northwest ohio. The first crank was bad perhaps due to improper bearing/crank sizing. After pulling the engine this winter, I went through and cleaned it, with the crank out. I then re-installed a new crank. I had the crank clearances checked because the engine builder had already checked the alignment and the mains. To double check their measurements I used plasti-gauge.

In speaking with this engine builder, he said this kind of a problem has happened a few times. To compound this fact, I have had problems with the distributer seating.

Now that I am done needlessly defending my actions, please, oh ye of compulsive criticism, tell me the distributer lifter valley bore diameter

 

ede already told you that. You didn't like what he told you.

I already told you what's really going on. You didn't like that either.

Some of us here have seen this sort of thing happen before. Some of it has even happened to us. We're just passing along what we've learned from observation over the years. It's up to you to decide what to do with the information you've been given.

So, oh ye of compulsive "It's not what I wanted to hear so I'm going to keep asking until somebody tells me what I do want to hear", don't be too surprised when (a) O-rining your dist housing doesn't make the slightest difference to the oil pressure, and (b) you find yourself putting another crank kit in that block again real soon.