sc440
Well-Known Member
So I get my 440 short block build back from machine shop, and find this was wanting.010-.015 below deck looks like crank was ground different on #5 and 7, which I have a positive deck height. Should I be worried about this?
440 short block
- Thread starter sc440
- Start date
Rebelrouser
Well-Known Member
Yes I would be. You can install a thick gasket to get the right piston to head clearance, on the tall ones, but then the other cylinders will be down on compression. The whole idea behind blueprinting an engine is that all 8 cylinders are exactly the same.
not so famous bob
Well-Known Member
dam thats terrible , sounds like un equal length rods !! Never heard of just grinding two journals , not kosher to me !!
I would prefer all bearings to be the same. Rebuilt ford motors are not the same when you get their crate motors. 10 thou. here and 20 thou there. Up and down all over the place. Dose not work for me. Also, each jug should be the same bore.
sc440
Well-Known Member
So I am checking deck height of pistons here, 5 and 6 are on the same rod Joe Al of crank, everything seems close except for the deck height of 5 and 6, seems to me like the crank on that journal wasn’t ground same as the others?
sc440
Well-Known Member
Meant to say #5 and 6
Lefty71
Well-Known Member
No way would I do that....
Send the crank out to Ohio Crank to confirm this issue. If they can't fix it, or get it within spec, then sell it and get a true crank.
Grab a straight edge and your feeler gauges and check the block deck from front to back.
Valley side , outside , I think your block is off.
Valley side , outside , I think your block is off.
Is the stroke on #5 and #7 longer? That would seem to confirm one journal was ground with an offset. Definitely an issue, whatever the cause.
sc440
Well-Known Member
Here is a better picture everything is pretty close right side of block 2 and 8 are both .011 down, left side 1 and 7 are within a couple of thousandths, the problem is cylinders 5 and 6 are positive sticking up out of cylinders.005 and .007 thousandths. Decks look pretty level to me not perfect but plenty close. With exception of cylinder's 5&6 which seems to me the crank on that journal was ground different then the rest
Runcharger
Well-Known Member
That's effed up, It looks like the crankshaft was ground wrong. You can check how far in the hole they are at BDC then you'll know for sure whether it's an effed up crank or wrong height rods or pistons. It has to be fixed. Crank ground wrong will be longer stroke, wrong height pistons or rods will be the same stroke.
sc440
Well-Known Member
Really not sure what can be done to fix it, mill pistons on 5 and 6 about .015 to .018 to match the rest or buy new crank. I already paid a well respected shop a bunch of money and end up with this. This bottom end was all balanced.
sc440
Well-Known Member
I just checked at bottom it is ground about.020 different
PRHeads
Well-Known Member
- Local time
- 10:52 PM
- Joined
- Aug 31, 2018
- Messages
- 1,992
- Reaction score
- 2,889
- Location
- So. Burlington Vt
Was the crank ground as part of this build, or was it ground previously?
It would have been nice if they’d have called about that.
For a beater, I’d leave it.
But for a “good” build, I’d replace the crank.
It would have been nice if they’d have called about that.
For a beater, I’d leave it.
But for a “good” build, I’d replace the crank.
Similar threads
- Locked
