Is .002 run out at the flange too muth
I think it is. But the main question is how much run out do you have at the end of the transmission shaft with it bolted to the crankshaft.?? You can sometimes move the shaft to a different position for less run out. You need .001 or less at the end of the transmission shaft to be a smooth engine. Facing the flange is a very simple operation if you need it done. Any machine shop should be able to do it reasonably. Well as reasonable as anything at a machine shop can be done. Nothing is cheap anymore. Good luck ...
From a past thread, "The Ford manual and the article say that there should be no more than .001 run-out.....".
And another thread:
And a few more if you do a search for Crank flange runout.
The ford manual says no more than .001. There is a lot of space between that flange and the output shaft on the driven plate. A little run-out at the flange is a lot at the end of the shaft.
The flange doesn't pilot the flywheel, the flange dowel pins facilitate this. The crank flange slip fits inside the flywheel, suggesting that there could be as much flange runout as this fit up will allow.
The crank flange needs to be square in order to set up the magneto correctly, and to limit run out at the back of the transmission. Once you bolt the flywheel to the flange, the flywheel does follow the imperfection of the flange. So, in my opinion, get the flange corrected at a machine shop.
You might find this interesting reading.
Sorry, too large.
It is an article about re-establishing crankshaft center-lines and squaring all the mating surfaces.
If anyone wants a copy email me.
Ron the Coilman
Be sure both sides of the trans shaft are true. Reason is the inside of the flange rests against the flywheel and you don't want wobble. Also make sure the flange of the crank is true. Alignment and balance are the hallmarks of a smooth engine.
nobody said this yet so i will do my 2cents worth. the crank flange is really not the end of story, the trans main shaft is. so, before you get all worried about machine cost, check the runout on the trans shaft while bolted to the crank. you have 2 options by changing to different dowel pins, it may get better, and it may get worse. ideally, a true flange and main shaft will certainly be best, but i would try moving it and check again
Nobody here can really answer your question correctly because you've left out a critical piece of information. Is the run out measured on the outside diameter of the flange, or on the face of the flange?
I would not worry about .002 run out on the O.D. but would not like to see .002 run out on the flange face, where it meets the flywheel/transmission shaft.
Jerry Its on the face of the flange
Thank you all for the info. ill try the fly wheel and the trans shaft and see what I get
I will admit I haven't done many of these, but on one engine, that was together before I started on it (didn't need a full rebuild--biggest problem was someone set the trans bushings way too tight), I first mounted the flywheel, and as I recall, there are two positions available; I had to pick one that gave the least run-out (I believe it was within tolerances), but the trans shaft took about three tries to get it to not run-out. There are 4 surfaces to deal with, and I'm willing to bet that not all of them are in perfect parallelism to each side; but often careful selection of positions can bring about harmony, grasshopper!!
Sorry, somehow that sounded like Cain on Kung Fu, couldn't resist!
Your mileage may, and likely will, vary!
I second David D's post. The flywheel, crank flange and transmission shaft can go together four different ways. In my experience one will be better than the others, and I have always managed to achieve very small shaft-tip-runout with one particular combination and maybe a 001-002 brass partial shim between two of the mating surfaces.