Hi All,

Newbie here.
Just want to know what could be the reasons an engine will break a piston head and cylinder walls.

Friend was driving the car when the engine blew and white smoke came out of the exhaust.
We thought it was a blown head gasket but when we took the heads out, the piston was broken in half and the cylinder walls in pieces.

Can this be repaired or do I need to get a new block? Perhaps scrap this engine and just install a new engine?

Any explanation is greatly appreciated.


http://img58.imageshack.us/img58/4738/brokenpistonheadcrackcytv9.th.jpg (http://img58.imageshack.us/my.php?image=brokenpistonheadcrackcytv9.jpg); http://img58.imageshack.us/img58/1729/blockdriverside1bq9.th.jpg (http://img58.imageshack.us/my.php?image=blockdriverside1bq9.jpg); http://img58.imageshack.us/img58/4996/blockpassengerside1nw3.th.jpg (http://img58.imageshack.us/my.php?image=blockpassengerside1nw3.jpg)

Thanks.
Ed

would you ever trust it if you had it fixed?

Well Ed..... How much do you want to spend? There are ways to fix the block (But it would be hard to be determined with out seeing it in person and having it Dye-Checked. Personally, Get a new engine. It doesn't appear to be a Big Dollar motor, so for a good amount of $$$ you can go new crate, or get something worth rebuilding. Then you won't have to worry about letting YOUR friends drive!!! As for what caused it....The Possiblities Are Endless!!! Running on a low octane fuel that causes "piston clatter" could of caused a crack in the piston skirt and it decided to just let loose. Same thing can happen if something as small as a 1/4"-20 nut gets ingested into the engine. High mileage, high heat, wrong oil for conditions, NO OIL!!!!! And I'm sure that everyone on this site or any site dealing with Mechanical Devices could add to "The List" of Causes. Well Good Luck, Let us know how you take care of "the problem" .
Gary

Deleted by Big Dave

Cheapest solution to your problem is a 350 SBC short block out of a newer pick-up truck. Be advised it will be a one piece rear main seal block with a roller hydraulic cam equipped block. That means a new flex plate for your automatic transmission or fly wheel for the four speed if you have one (the hole in the center of the crank is different as are the spacing for the torque converter).

You broke a stock cast piston. Cast pistons shatter like glass when they break. Since there was nothing to hold the rod in place once the piston breaks so it decided to go for a walkabout, destroying the block (it acts like a forged steel flail; beating the snot out of whatever it can reach).

The block can be salvaged. Why you would want to I do not know. It will require a sleeve in every broken cylinder, block decked, line bored and overbored after checking for cracks and sonic confirmation of wall thickness. The only reason to save that block would be to retain the numbers stamped on the front engine ID pad which further increases the expense of the machine work (the machinist would have to stop the mill before it passes over that portion on the block by hand for every pass he makes).

You can still buy older small journal two piece rear main seal blocks (with the road draft tube) from machine shops and you can find them on line. Some will even have the correct date codes if you look around and are willing to pay for a date coded block. But otherwise a new large journal one piece rear main seal 350 is what will fix your problem. Most people couldn't tell what you have without reading the engine decal anyway.

Big Dave

Hi Dave,
The blown 283 engine is not really the engine of the 1965 Impala SS. It is a 327. I am in contact with someone who has a 327. But friend said to get a 327 4-bolt main. What is a 327 4-bolt main?

http://img84.imageshack.us/img84/2287/impalass283blownenginexr0.th.jpg (http://img84.imageshack.us/my.php?image=impalass283blownenginexr0.jpg)

Hi Dave,
The blown 283 engine is not really the engine of the 1965 Impala SS. It is a 327. I am in contact with someone who has a 327. But friend said to get a 327 4-bolt main. What is a 327 4-bolt main?

http://img84.imageshack.us/img84/2287/impalass283blownenginexr0.th.jpg (http://img84.imageshack.us/my.php?image=impalass283blownenginexr0.jpg)


A high performance motor out of a Corvette (350 to 375 horse and fairly rare), or a heavy duty motor truck motor out of a dump truck or old school bus (also rare today since they have not made one in thirty years).

A 327 is a four inch bore block (same as the 350) but it has a smaller diameter crank shaft (when GM introduced the 350 in 1967 they made the crank stronger by making it bigger around).

Any modern 350 block can be made into a 327 by destroking the engine (98% of the world's population is going the other way and adding stroke to a 350 to make it into a 383 cubic inch motor). The 302, 327, 350 and 383 all have a four inch bore but they all have progressively longer strokes.

302 3" stroke
327 3.25" stroke
350 3.5" stroke (actually it is 3.480")
383 3.75" stroke (if you buy one from GM as a crate motor it has a 3.80" stroke)

A 307 motor is a 283 with a large journal 327 crankshaft (made of cast iron). If you find a 307 crankshaft and drop it into a 350 block you get a large journal 327 cubic inch motor (just like was stuffed into all 1968 cars). A four bolt main 350 block is not uncommon: a four bolt main 327 block is as rare and expensive as the gold it would take to buy it.

Hope that helps

Big Dave

Damn tore that sucker up good! Can't even make an ashtray outta that one. :D

Does the head still have both valves for that cylinder? (e.i.; the exhaust valve) Something hard broke that piston.

Judging by the amount of caked oil/carbon on the tops of the other pistons I'd venture to guess the valve stem seals were gone. Looks like a high mileage engine.

Dave,

Friend found a 327 from a corvette locally for $1000 CAN.
What should I look for to make sure it is a real 327 not a 350 destroked?
Can I use the tranny from the blown 283 motor?

Thanks,
Ed

Scott,

I will check the heads and take pics.
I'll post pics then tell me whether the valves and stem seals are gone.

Ed

Hi Ed,
In your first post you stated the head was damaged. You'd know if a valve hit the piston- it would be bent, have a piece missing or broken off completely. Bottom line is the engine is shot. But ya post a pic of the head on the bad side just to see what damage it took. I'm guessing it's pretty ugly.

And to answer your question about the trans- yes, all Chevy V8 rear bolt patterns are the same for the transmission mounts.

Go to http//www.MorTec.com and look for a 327 block for the year you want. It will list the block casting numbers. Since you are buying a bare block you need only look at the bottom of the block that is normally covered by the oil pan. You will see the nmain caps. They are held on by either two bolts per cap or four bolts per cap. The small journal blocks were all made (cast) before 1967.

Big Dave