SloGta

Alright, I just pulled my motor out of the T/A and stripped it down and got it all ready for the machining. Had it hot tanked and magnafluxed and they tell me there is a crack in the lifter valley. WTF, i dont understand how the block could have been cracked when the motor just rolled over to 100,000 when it was pulled and before being pulled was running top notch, no signs of ANYTHING being wrong. So the T/A is now getting down graded to a stock '94 roller 305 I guess it will just be a temp. fix so i can work on the rest of the car while i save up money for a crate motor. oh well, sorry about the vent, but it sucks when stuff like this happens and sets your project back. Also, i was thinking maybe the machine shop swapped blocks on me? just a thought. Anybody else have a similar experience?

P.s. sorry for the long post.

ME Leigh

I've had it happen to me before, the lifter valley cracks but leaks minimally. The block was pulled friom a running vehicle and had a crack in the lifter valley, rendering the block usless. I could have welded it but scrapped it instead..

EvilCartman

iTrader: (1)

Same thing happened with the 350 I had bought for 50 bucks. It was pulled from a running truck but it had 3 cracks in the lifter valley. I bought a 350 block for 75 bucks from the machine shop and sold the heads off the other 350 for 50 bucks hehe.

RB83L69

Lifter valley cracks usually means it froze.

They often don't leak enough to be noticed.

Lo-tec

I had one that cracked when being cylinders where being bored out. You can check your block to see if it's yours. Part of vin# is stamped on pass side front deck.

ede

it's common, can be welded or as cheap as you can find a builder engine just start over with a new used piece

EvilCartman

iTrader: (1)

Not always. My machinest was saying there were problems with a range of years for lifter valley cracks in blocks. Mine happened to fall in those years (87). It was a poor casting which ended up cracking.

littlebagz

I have an engine in a Monte Carlo SS that had the same problem.

The crack was about 12 inches long right in the side if the lifter valley. The machine shop sent me to a shop that did cold metal stitching . Stiching is a cold repair, and once the block is used again and it gets hot the repair actually becomes tighter.

Once the block was repaired it was pressure tested to 75psi with no leaks. I would reccomend stitching vs welding or brazing from a reliability standpoint.

Vader

I've used the stiching staples on machine tool castings. They work well, but I would use them in conjunction with nickel welding the casting for greatest strength. I've repaired some large castings that operated at hundreds of tons of pressure (which is what split them in the first place) using this method.

However, ede is probably right (no surprise there, eh?). For the expense of repairing the crack, and potentially seeing the same thing elsewhere in the casting due to the same core shift, you might just want to find a better used block as a starting point.

SloGta

Well im kinda glad to see its not just me Im thinking of just saving for an ls1 swap or something, but its just an idea. also, Is the identifing number the one on the little jutt out where the water pump bolts to, and what exactly do i match it to? I highly doubt i will fix the block, but maybe if i can find some one who can do a good repair, it could be a possibility.

dyeager535

If you know the block was original, probably wouldn't hurt to check VIN stamping.

I had a machine shop bore my virgin block .060" by accident, but at least they owned up to it. If they screwed up on yours somehow, and had a bad block lying around, they could easily have said the bad block was yours.

They'd have to be REALLY underhanded to do something like that, but things like that happen unfortunately.

five7kid

iTrader: (14)

My cracked valley experiences:

'87 LB9 longblock, had been rebuilt with .040"-over dished pistons, two different castings of heads (one TPI, one TBI type). No evidence of leaks, but when cleaning up to "upgrade" my LG4, discovered the cracks. Still sitting upsidedown on the garage floor while I try to figure out how to get rid of it. Shame, the crank/bearings are in great shape.

Unknown year 010 4-bolt main 350. Purchased as a rebuilt (.030/.010) longblock sans tin. First one head cracked on the exterior casting line, after running it with replacement heads for about 4 months the oil turned milkshake. Out of the original "rebuilt" longblock, I salvaged crank, rods and pistons. Hauled it to the dump when moving from San Diego to Colorado.