My 427 SOHC Build..... Finally the time has come!

[ScotiaFE]

According to my factory specs for a 427,  0.004" to 0.010" with a wear limit of 0.014".
Looks like your in the zone.

[cobracammer]

Awesome. Thanks Howie. On to the next step!!

[My427stang]

Your .005 should be fine as Howie stated, however FYI its not "runout"   Runout is typically measuring for a bend in the crank, oval shape on a single journal, or mis-machined surface like a flywheel by measuring the wobble, for lack of a better term.

Runout can be also thought as "how far the measurement you are checking changes as it turns"

What you measured is thrust clearance, which is very important, and too tight is worse than too loose.  Odds are you'll gain at least a thou the first time you push the clutch in too.  You are good to go

[cobracammer]

Thanks.  After you said that, I had to go back into the manual to see what they call it.  LOL  I am about 1 step up from calling things "Do-hickey" and "Thing-a-ma-jig".  For my own self betterment, I am going to try and get the correct terms before I post. 

[lovehamr]

Also on my list of rookie things overlooked.....  I do not have a Crankshaft key.  I am going to have to order one for this RPM crank, but I want to make sure I get the right one.  When I look at a ford FE crank key for a Scat crank, people have been saying that the Mr. Gasket BB Chevy ones are the correct ones.  I am wondering if the RPM international crank is the same?

Also there looks like a separate key to hold the balancer.  Is that correct?  so 3 keys in total?  The one that holds the balancer seems to be a long key

The whole crank key thing threw me the first time I built an FE as well.  If I'm remembering things correctly, there should be 2.  One is nothing more than .25" bar stock which you can buy at a lot of hardware stores for a few cents per foot then cut to size.  BTW, I'm pretty sure I still have some around here.  That one indexes the crank sleeve and oil slinger.  The other is a half moon type and indexes the balancer.  I'm sorry but I don't know the size, my machinist had a small box of them, rumaged through them and found one that would work.  I'm sure most machinists would have a selection like that.  Hope that helps man.

[cobracammer]

Thanks,  I went ahead and purchased the bar stock one as well as a pack of the chevy half moon keys.  I read that these aftermarket cranks use the chevy ones and not the stock Ford FE ones.  Like you said, if they don't fit, I will see if the machineshop has some extra laying around they can spare.

Thanks!

[cobracammer]

OK on to the next question!!!  I had the day off today, so I started with the Rod bearing clearance.  I have been a little nervous about the machine work on my Crankshaft, but so far so perfect!  In measuring the Cranks rod journals, I made 2 measurements on each (Since there is 2 rods to a journal).  Each came in at 2.200....  again being a little cautious, I have been leaving the Micrometers in the garage so they are acclimated to the temperature in there.  I went back about 20 minutes later and remeasured, and again they all came in at 2.200.
After locking in the Micrometer at the first journals measurement, I "0" out the dial bore gauge.  I unwrapped the first Eagle ESP H beam rod (upgraded with ARP 2000 rod bolts)... cleaned it, cleaned it again and cleaned it again (until the towel showed no residue).  Then I unwrapped the Speed pro bearings and cleaned, clearned and cleaned.  I rubbed it down with WD 40 and torqued it all together to 75 Ft Lbs.  The measurement I am looking for is between 0.002 and 0.003.  The measurement (top to bottom (90 degrees from the bearing seam) came in at 0.0025  however when I measured the diameter where the bearings seams are, it came in at 0.004....  I know that the rod bearings are supposed to be football shaped in order to hold more oil where the load is the heaviest during combustion, but is 0.004 ok?  I stopped at the first one just to come on here and ask.  As all of the crank rod journals measured in the same, I think I will have these measurements (or fairly close) all the way down.  Can anyone advise?

Thanks!

[jayb]

When you measure the .004" you are not right on the bearing parting line, are you?  The correct place to measure would be just slightly off the bearing parting line.  If you are doing that, then the measurement is correct and although it is likely that you would have no problem with those clearances, this would be a good place to replace one of the bearing shells with a .001" undersized one.  That would change your measurements to .002" and .0035", which would be a better set of measurements.

I'd recommend that you go ahead and measure each journal and each rod/bearing combination, and see if they really are all the same.  Many times they aren't...

[cobracammer]

Hi Jay,


Yes the 0.004  is directly on the parting line.  90 degrees from the parting line I get 0.0025.  I will measure the rest one at a time to see how it goes.   It sounds like an "undersized bearing is thicker?  the undersized refers to the Crank journal being smaller in diameter....  That would make sense.  And with only 1 shell being replaced, that makes it 0.005 right?  Then, if you replaced both shells, then that would be 0.001
I think right off of the seam was around 0.0035, but ill measure again to be safe.
thanks Jay 

[jayb]

Right, undersize refers to the crank journal, and a bearing that is .001 undersize means that each bearing shell is .0005 undersize.  If you are at .0035 when measuring just a bit off the parting line, I'd run the bearings as is.

[cobracammer]

Thanks Jay.  I will double check each one as I go.  Worse comes to worse, I can either order a new set of undersized to swap a shell here and there, or I can try swapping out the Speed Pro bearings for the Clevite bearings that came with the rods to see if they measure up any better.  I understand that I cant mix brands, so if I try out the clevite, it will be both shells all the way across.

[KMcCullah]

Good read so far Jason. I think I read somewhere on this thread that your using a RPM crank. Pay attention to the style of rod bearings your using. If your RPM crank is untouched it will need an "H" style or chamfered on one side style of bearing because RPM leaves a fairly large radius on the edges of the rod journals.

[cobracammer]

Thanks I will check.  I have noticed that the Eagle forged rods I am using have a large chamfer in the side that faces the crank weights and a small chamfer on the side that faces the other rod.  Does the bearing have to be chamfered even further>?

[KMcCullah]

Your rods may have way more chamfer than needed. It's been a while since I've seen an Eagle rod. But I wouldn't add any more chamfer to an already chamfered bearing.

[jayb]

Thanks I will check.  I have noticed that the Eagle forged rods I am using have a large chamfer in the side that faces the crank weights and a small chamfer on the side that faces the other rod.  Does the bearing have to be chamfered even further>?

The Federal Mogul bearings I usually use have one side chamfered more than the other, and that side should go towards the side of the rod with the larger chamfer.