sonic test sheet

[hbstang]

GOOD NEWS I GUESS.i looked the block over really close and found the block DOES have  2 sleeves,one in #3 and one in #6,so it makes sense now.i also have this listed for sale here for $4200.dan.
would like to get opinions on this 427 short block i have.we didnt remove pistons to do this.so the mid is as far down as the piston can go 3.78 stroke.

[BH107]

I sent you an email about it. In my opinion its pretty thin on the major thrust side of #3 and #6. Most I've talked to like to have at least .125" there at minimum, some more for performance use. The other problem is that since you didn't pull the pistons you can't see if its that thin at the bottom of the cylinder as well. Its a shame, the rest of the cylinders are all really thick for as much as it has been bored.

[jayb]

What is the bore of the block?  That is pretty thin on the thrust sides; I'm surprised how thin it is, because all of the 427 sideoilers I've sonic checked have been pretty thick on the thrust surfaces.  Unless that block has been bored to death, I would be very suspicious of those numbers.  Sonic checkers are not always perfectly accurate.

Have you tried the drill bit test to check the accuracy of the sonic numbers?

[hbstang]

jay,the bore is 4.280.i tried to do a drill bit test from the water opening in the deck.i didnt want to remove the screw in feeze plugs.i didnt get any real results.he uses a dakota sonic tester.the engine has been ran,and the cylinders look really nice.i was suprised that most of the cylinders look good.dan.

[cammerfe]

What's the intended purpose? For constant competition you may have a potential problem on your hands, but I'd not be afraid to use it for the street. But as was said, you have a suspect situation due to a lack of bottom measurements. And there is an 'art' to the use of a sonic checker.

KS

[jayb]

jay,the bore is 4.280.i tried to do a drill bit test from the water opening in the deck.i didnt want to remove the screw in feeze plugs.i didnt get any real results.he uses a dakota sonic tester.the engine has been ran,and the cylinders look really nice.i was suprised that most of the cylinders look good.dan.

I know its a pain, but I'd really suggest you pull one of the screw in core plugs and do that drill bit test.  Then you will know if the sonic results are accurate.

[BruceS]

Lets say the thin numbers are correct for #3 and #6.  What are the pros / cons of sleeving them?

Bruce

[jayb]

As far as I'm concerned sleeves are a great repair if done properly.  My 428CJ has had a sleeve in number 5 since 1982, and still runs great.  One thing about sleeves though is that if you sleeve two adjacent cylinders, you can develop a crack between them at the deck of the block.  So you want to try to avoid that.  My experience with sleeves has also been with the thin ones, .090" wall I think.  No sense in taking any more material out of the block than absolutely necessary, IMO...

[Qikbbstang]

can very easily take a common outside spring caliper and feed it in the blocks forward and rear large water jacket openings and do a decently accurate mechanically derived wall thickness test from which to compare the electronic numbers?
     No big deal, just mark the calipers roller wheel with Sharpie so you can determine/count off the number and fractions of turns. Tighten it down on cyl wall through large block jacket opening. unscrew the wheel adjuster keeping track of turns and once free return the marked wheel to where it was on the wall = there is your wall thickness to simply measure in an area that you can compare to the elec derived figures.
   FWIW I recall my machinist advising the cyl walls need to be dingle berried/not scuffed to get a valid test as well as scale/crud free inside the jackets.
    Logically I always thought a minimum of one mechanically derived wall reading of any block to be tested should always be taken by the sonic tester operator to insure the sonic testers accuracy right out of the gate. Nothing better then using the same casting/alloy to calibrate the sonic tester. 

http://www.use-enco.com/CGI/INSRIT?PMAKA=635-6525&cm_mmc=Didit-_-SEM-_-GglProd-_-GglProd&003=18299132&010=635-6525&{copy:002}&{copy:004}&{copy:005}&10=635-6525&gclid=COOBiJXfyLgCFabm7AodNgwABA

[Heo]

When i worked as a weldor we had a....assosiation controlling
the welds with xray and so on .they allso controled the thicknes
on tubes and such with sonic tester. I asked them if they could
sonic a block for me but they dont wanted to do that beacuse
they said it was hard to get a corect reading on cast iron.
This was on the other hand guys that measured things that
could kill a bunch of people  if they got an inacurate reading.

So what im saying is the Reading could be wrong

[ScotiaFE]

I may have missed something, but what is the intended use of this short block.
A weekend ice cream getter or a full tilt boogie wheel standing strip car.
Cause if'n your going for ice cream throw the heads on and off you go.
Now if your going to pound the crap out of it, throw the heads and on and pound the crap out of it.
You said the bores look "and the cylinders look really nice". That`s as good as it`s going to get for your 427.
Any boring will just make it more unstable.
The odds are you will toss a rod or smoke a bearing before you loose a cylinder.

Just asking what is the actual problem with the short block?
There are very few perfect Ford 427 sideoilers left.
 

[Barry_R]

Looks like a normal bored 427 to me.  I see lots of them with sonic numbers under .100 once they are that far oversized.  Challenge is that they generally get thinner at the contact of the floor of the water jacket down lower than you measured.  If it were mine I would put a 1-2" fill of hardblock in the thing to stabilize the cylinders and touch hone it - & go driving.  I have several like that that are out running right now without apparent incident.  Not my favorite deal by a longshot, but the cloverleafed bores on a 427 seem to take this much better than the round core 428s or 390s do.

[hotrodfeguy]

Also to put in a word, this block has the corner supports like a marine block has, it has less chance of crashing a piston through whole-sale. I would say more like a thermal crack allowing water in the piston at best. I agree a .106 wall is not a # you would want to make a 600HP engine with. But hell I would run it, if worried block fill a bit and have fun with it. Not like these grow on trees and we pluck em out of the back yard. 

[hbstang]

i updated the sonic sheet to show the 2 SLEEVES i found after looking very close.

[jayb]

That definitely improves the situation. The sleeves are made of a better material than the cast iron in the block, so they can be thinner.  I've run sleeves as thin as .070" in an aluminum block.  I think you are good to go with that block.