dallasite21

OK, so here is the next problem in my cutlass Saga. I have a rebuilt 455, doesnt even have 400 miles on it yet. The engine ran fine, but apparently a bolt/nut fell into the carb while I was removing my breather. I was driving and all the sudden it started making a loud noise and lost power. I pulled off onto a residential street and got towed home. Pulled all the plugs and found that the one in #6 was detroyed. Compression checked all Cylinder and they were fine except #6. It got 0 compression, so next I pulled the heads and thats when I discovered that I had a cracked piston. Im so pissed, however the question is... what else should I be concerned about on the repair. The engine hasnt even been broken in yet, so I really dont want to deal with another rebuild. I did stop the car as soon as it started losing power. Can I simply replace the piston and rings maybe the rod just in case, or based on history does this kind of damage generally require repairs at multiple areas. The piston appears to be the weakest component of all, and Im glad it broke as opposed to the crank, cam etc. The valves on the head even looked ok. I will attach some pics a little later. Your input is greatly appreciated.

costpenn

At this point, you need to drop the pan, look what's inside, carefully look at the rod for straightness and check cylinder walls. I'd just replace what's busted and see what happens first.

Call me at 972 489-0191 if you need a single piston. I can fix you up along with a gasket set - I know the owner ....

www.enginetech.com

DeltaPace77

I'm with "costpenn" as what happened is quite serious. Suprised the cylinder bore didn't get damaged, but I'd have a real good look at the head combustion chamber, and possibility of a bent valve. Maybe lay the head on it's backside, and see if the chamber holds fluid. As mentioned, I'd pull a couple pistons for rod damage, and have the assemblies weighed, before replacing anything. Maybe check the Corvette Forum for member "billla"(yes 3 L's), as a master engine builder, and a really good guy.

bdub217

OP - What your address I'm buying you one of these



I know it's not funny I'm just trying to lighten your mood a bit!!!!! Hope the damage is minimal!!!

ah64pilot

I want to see pictures...It sounds like you might have gotten lucky and just need a piston and rings.

I'm in Dallas for the week and we are trying to get together one day for dinner. If you guys can make it check out the Dallas Texas Members thread in The Clubhouse for info.

dallasite21

I have tried 3 different times to post pics and it gives me a message about security and to contact the administrator. Ill keep trying

dallasite21

Here are a couple pics.. will post more later

dallasite21

Here are a couple more pics of the cylinder. There is a scratch on the cylinder wall. By the way, I do have a ben valve as well and will need to get that replaced. So at this point Im lookin at the following.. assuming there is not damage to the crank etc...

1. Piston, Rings, & Rod Replacement
2. 2 valves replaced

ah64pilot

Let's hope that's all you need! I'll keep my fingers crossed!

droldsmorland

Any time I see damage like this I want to see the rest. If it was me Id pull the engine and disassemble. And start over.
Several reasons...safety...reliability/confidence it won’t leave me stranded, piece of mind etc...and it’s easier to deal with it out of the car.

If the piston looks like that what’s the rod and rod bearing look like. Both took a good pounding to crack a piston.

Spend a little now verses grenading an engine later.

Rickman48

Could you post a picture of #6 combustion chamber?
Interference had to create damage there, too - at least have it magnafluxed!

costpenn

Thanks for calling yesterday. Looking at those pics, this is a lot more serious than just a piston cracked along the crown:

1. Whatever was in the cylinder, it was big and solid enough to blow BOTH the lower pin bosses out of the piston - which means tons of metal down in the pan

2: It looks like you had some secondary contaimination of the adjacent cylinder.

While you might not need to actually do any machine work, I think it would be best to pull the motor apart and check/clean everything out. Again, I can fix you up on the parts you will need. I can have my company do an analysis of a a couple of lifters to see how much metal got in the lube system - which will be the ultimate determinig factor in whether you'll need machine work.

Sorry for the bad news....

Joe

costpenn

Just noticed those bosses are broken from the top of the piston - still MASSIVE force required to do this damage to one of the strongest parts of the piston

DeltaPace77

Sorry to see what actually happened, but kinda knew from your intial posts. Anything that falls into a combustion chamber, usually gets tossed around in there several thousand times at high speeds. Gotta know, the results can't be good. I'd say time for another complete rebuild, with cylinder overbore, if your block can take it. Wish there were better news, but what it is.

oldcutlass

I'd like to see what the head looks like also?

dallasite21

Well here are som pics of the head. Tou can see where something was dancing all over the surface. The valves are leaking as well only in that cylinder. I also added some other pictures of some of the other valves. One looks normal, and the other appears to be coated with silver metal. I am assuming that all the small metal chips from the bolt melted down on the valves. I almost wanna set this car on fire... One problem after the next. Engine doesnt even have 400 miles on it yet.

oldcutlass

Tough break! Keep us posted.

DeltaPace77

Well, I wouldn't exactly burn the car, as stuff happens, and lessons get learned. I've built several engines, and had my share of early failures. Built one for a buddy that over revved the crap out of it since day one, and spun some rod bearings, tearing up a crank journal. Ate the cost and time of this rebuild, and wasn't happy about it. Luckily, guy eventually came clean, and shared the cost's. Guess least he could do, as was using all my tools, engine picker, ext, to do all the swap work on his end.

Bill in NC

You really do need to pull that engine back apart and get all of that metal out of all the areas you can't see. Check ALL of your valves as debris can swap cylinders through the intake. Check the camshaft/lifters and make sure you also check the push rods. Good luck, but don't give up. My 455 has been through 2 separate piston failures due to tight cylinder wall to piston clearances.

My442

I had a Milodon oil pump pick up drop the pick up screen due to poor welds.

My oil pressure went to zero....lost the cam, bearings, everything.

Called Milodon and they laughed at me.

I sued them and won.

My engine damage was over $4,000.

Good luck fixing yours.

w-30dreamin

Dallasite21,
Sorry to read about your engine problems.
I hope you don't mind if I ask a question of anyone who might be in the know.Just trying to help my education of engines along.

With just 400 miles on this engine,is the black carbon that is seen in the combustion chambers, on the pistons and in the head ports a normal amount for 400 miles?

Thank you

dallasite21

I wish I knew the answer to that question. I can only tell you that I went through 3 different carbs because I couldnt quite get it to run right a first, so maybe that was from poor fuel combustion during breakin and first 100 miles or so.

dallasite21

Guys I do have another question. My car was overheating even prior to this. It would get to climbing above 220 on the highway but would run between 195 and 200 in the city... I should have sufficient cooling based on having a champion 2 row aluminum radiator with 1'' tubes, a Milodon high volume water pump and thermostat and new clutch fan and shroud all in place. The fact that it seems to over heat at highspeed makes me concerned about piston clearance. Question is how do I check that? Since I have the heads off I want to make sure thats not an issue.

DeltaPace77

Yeah, some of my engine builds have done this too. Seems, if I drive the car up to temperature for awhile on the highway everythings fine. Then pull off for a fuel stop, runs hot after that. Apparrently the cooling system takes a gulp of air, and there are burp tanks kits availible for this, that mount above engine level. I almost never drive my car like this, so really haven't been worrying about it much. Probably worth starting a new thread on this though, before putting everything back together.

dallasite21

Ok, so here is the update. I may be one lucky sob. I pulled the piston and the rod looked good, the crank looked good, the oil did not appear to have alot of metal shavings or anything in it. The cylinder may be a little suspect... there is some metal shavings from the piston that need to be cleared out, but it appeared that most of the metal stayed on top of the piston. Besides that It appears I may just need a valve replaced, a pushrod and new piston. Im no pro but it looked better than I expected. Maybe some of you more experienced guys can have a look and tell me what you think?

J-(Chicago)

It sure looks like you got lucky to me. The screw was probably a softer metal than the bore, as it doesn't look gouged up. the bore gauge will let you know the extent of the damage. You are EXTREMELY lucky that the piston pin didn't carve itself into your cylinder wall. Check the valve seats, and post pics of the carnage there. Also, the cross hatching doesn't look so good. It looks more like tree rings than X's

67cutlass67GS

Wow that hurts, sorry about the mishap. dont feel bad we have all done things likke that or at least very close to it...

gregvm

I agree that it seems to have an excessive amount of carbon on chambers/intake valves for only 400 miles....
Also seems to be something going on with #4...almost looks like the piston smacked the head, better check things thoroughly on #4 & #8.

What's the piston to wall clearance? I also agree that the cross hatch on the hone doesn't look so great. Was this done by a reputable builder?

Hope it turns out the easiest route for you!

By the way, how did the screw get IN there in the first place, and why did you run it, if you knew the screw fell in the intake??

Greg

joesw31

Pull your engine and make sure that the pistons are fine, need to have the rod checked and make sure its not bent. I have to agree that there is a lot of black carbon.