427 so block w/ hairline crack?
 

ran accross a side oiler block with a hairline crack between #3 main journal and cam. is this junk? Is it repairable?

thanks Karl

Yes, but....
 

I guess I'll take the first shot at this. It is my understanding that the block CAN be repaired, but that the process to repair it is beyond the capability of most shops. Before the flaming starts, this is not to insult the capabilities of the repair shops. The way it was explained to me, the process involves heating the block up to (literally) red hot temperatures in an oven and then welding the block while in that condition. Welding the block in this manner reduces the temperature difference between the weld and the surrounding material, and so reduces the formation of stress risers due to the temperature differential. If this is not done, the block will crack again at the edge of the weld after a limited number of cold-hot-cold cycles. Some of this (I think) has to do with the composition of the 427 blocks, as they were cast of a high-nickel content cast iron alloy, which was different (stronger but more brittle) than the material used on the other FE blocks. I read somwhere that, after the 427 blocks were pulled from the molds, they were all stress-relieved by allowing them to cool slowly (hence more evenly) while traveling down a temperature controlled oven over a several-hour period. Even so, the original blocks suffered a rather high rejection rate due to casting cracks. I sort of recall talking to my builder once, who said he had a number of NOS blocks still in the original Ford shipping crates. He said that of every three he pulls out of the packing, one has some sort of crack in it.

I offer this as an interested bystander, certainly not as a materials or welding specialist. Perhaps George Anderson or one of the other long-time engine building gurus would help out here.

Optional repairs
 

I have a friend who found a similar crack in his 427 after performing all the machining on the block. The shop he used nearly 20 years ago suggested that they bore the oil hole from the main to the cam over-sized and install a tube to prevent oil excaping from the crack. This is what they did and the engine was built as a stroker (428 CJ crank) and installed in a '70 GT 500. I am not recommending this but I know first hand it worked with no apparent problems. Oh, and when I drove the GT 500, it begged to be flogged, which I happily did.
The second block, a 428, I know of with the same type of crack was welded with a high nickel electode.
If you decide that you don't have the guts to make this repair, I might be interested in purchasing the block from you as a spare.
Good Luck,
Dan

My experience agrees with the above and I would add that today, there are alloy welding rods that allow "cold" welding of cast iron. As above, I don't intend to start a fool flame war, but will add that even with the alloy rod, welding cast iron is not a job for the occasional welder, which includes most automotive machine shops. There are facilities which specialize in this type of work, with engine blociks being only part of their work.

Another alternative is "pinning" the crack. Most any quality automotive machine shop can do this. Is simply stopping the crack from getting longer, by drilling a hole at each end of the crack and inserting a steel pin. Location of the crack dictates whether it is feasible or not.

Although mentioned above, a sleeve was used to contain oil flow, what was not done, or at least mentioned, was stopping the crack from growing, which I guarantee will happen, especially in a mechanically stressed area of the block.

My suggestion is to have a facility specializing in repair of this type having a look at the block.

Al

I know very little about welding or cracks... but

If a 427 Sideoiler block that does NOT have a crack can be had for $4500.00 and the block with a crack cost $1500.00 you save a total of $3000.00 less the cost of the repairs.

Let's say you saved $2500.00 total.

Considering the parts installed in either block and the cost of machining, balancing etc is another $20,000 Would you want a engine that is well over $20,000 with a crack that has been repaired or spend the additonal amount to do it in a block that is healthier.

Intake, carb(s), crank, pistons, rings, heads are going to cost you the same.. Do you really want to take a chance all for what, to save $2500?

I wouldn't. I would be more inclined to put in a Non Sideoiler engine, maybe even a 428 before I take that risk.

TURK

Chopper ,Dan, Al, Turk,

thanks for the feedback, i might be able to live with the welding solution if i can find such an operation locally. The block is available for 1'g or less, and I was thinking of picking it up as a spare after watching the latest 427 block bidding frenzy on e-bay. Turk, are there "good" standard bore blocks around for 3500? if so , from who?


thanks , Karl

Anybody who spends 20K on a engine to do street cruising needs the crack in their skull repaired.
Is there a Doctor in the house??
Cranky:LOL:

As an engineer, for the past 30 years plus, in the large turbine field, anyone looking at a motor that has a hairline crack and repairing the by some shop, who claims they have the knowlege to do this, may as well take monies spent on this and burn it.
Experts in this field have tried this and failed to repair turbine rotors with cracks. Of course a turbine rotor costs quite a bit more than 1.5K. Good luck and save your money. :JEKYLHYDE :JEKYLHYDE :JEKYLHYDE :JEKYLHYDE

Cranky,
You going through engines that cost $8000-$10,000 at a time and getting couple of track appearances out of them is also questionable.

Let's see....$8000.00 divided by 8 miles, equals $1000.00 a mile.
I got 10000 miles and then sold the engine for $12,000. Aproximate cost .23 cents a mile..

and YOU think I should have MY head examined?

TURK

KobraKarl,
I don't know of any sideoilers for $3500.00 any more. If you look in eBay and willing to settle for sleeved blocks or you are willing to sleeve them, you maybe able to get one that is NOT cracked!

TURK

Turk,
Just for the record.

My 427 SO lasted for two years of Track Duty.
My 351 W lasted for four years of Track Duty.

427 cost $4,000 + $6,000 for a rebuild.

351 Cost $3,850


The only reason I switched to the sb is my Ford engine builder advised me if you wanna race get a sb this FE is for street cruising.

That's where that engine is now in a CSX4000 cruiser.

Cranky:LOL:

Having the b@lls to get on a 20K engine is all part of the fun. Didn't say it was smart. :D

Bill,
Getting on it once in a while is a lot different than running it between 3000 and 7000 rpms for 30-40 minutes, four times a day.

The damn engine was just begging to be put in a cruiser. Probably much happier now.%/

Crank:)

So you did ALL that just to make your engine "happier". What a guy....
We love you anyways.

TURK

Well I'm glad you gave it a better home. :D

There are days, when I'm way out in the woods, where I am getting on it like that for extended periods of time. That is the rpm range for my motor.

Still, nothing like what you do with yours. When I become more interested in the racing thing, will definitely have a different car with a less expensive engine.