Does overheated = ruined block?

[Ziegelsteinfaust]

I overheated, and cooked my 350 in my Stepside.

It did start back up after it.cooled down, but it minimally blew the head gaskets + scored the cylinder walls. Although no rod knock could be heard.

Someone told me who I think is wrong. That overheated blocks are not worth rebuilding due to changes in the cast iron. As I never worried about thing like this before when building engines.

I am planing a warm 280-300~hp DD style 350 engine for my dads B-Day/Christmas gift.

Is there some truth to what he told me.or overrated. As it will be bored, and honed again.

[geezer#99]

Old wives tale!
What changes could occur if you consider these things.
Overheating is coolant at 270 F.
Exhaust gases are close to 800 F.
Combustion temps in the cylinder about 4000 F.

[kaycee]

My wife overheated my 350 TO THE POINT OF ROD KNOCK. we were young ang broke all the time but I drove it daily daily for over a year. Finally got enough coin to have it rebuilt to a 355. Best motor I ever had and was a stout SOB and never ever gave me any problems. So dont go off of what someone thinks is wrong do some test on it (compression)to name one and then go from there.

[cwcarpenter98]

I cooked the 3.9 V6 (iron block and heads) in my 95 Dakota to the point that the engine locked up. Both heads were warped bad, but the machine shop was able to machine them flat again. They didn't have to machine the block. I've put well over 10k miles on it since then without any engine issues.

I wouldn't be worried to send it with a 350

[Ziegelsteinfaust]

Originally Posted by kaycee

My wife overheated my 350 TO THE POINT OF ROD KNOCK. we were young ang broke all the time but I drove it daily daily for over a year. Finally got enough coin to have it rebuilt to a 355. Best motor I ever had and was a stout SOB and never ever gave me any problems. So dont go off of what someone thinks is wrong do some test on it (compression)to name one and then go from there.

I personally pulled the heads, and could see scuff marks in the bore.

Having put new gaskets on similar engines to get them back on the road only to have them smoke, and consume alot of oil.

So I pulled my project car engine to put in the truck. I scored the engine in a wrecked vette from my dads friend, and honestly enough. It is a better truck engine then muscle car engine for me. Having a 114 LSA cam designed for emissions legality. With my preference for 106 solid cams in muscle cars.

So either way besides the immense frustration, and anger from the engine blowing. The truck is turning out the way I want. Just not when I want.

Although I wanted it to be a nice basic 350 package to cruise for a year or so. I had planed to just polish up the engines performance with a new distributor, weight kit, and better q-jet the week it died. With eventually headers, and dual exhaust.

[Dead Parrot]

The OEM 350 block in my 75 was overheated twice while my dad owned it. Both times it was due to a stuck thermostat. Both times cracked a head gasket. Neither time seemed to hurt the block. Both times we just had the heads checked over and replaced the gaskets and it still ran fine. By the 90's, it was burning a little oil and got swapped out with a basic Hecho in Mexico 350. Kept the block for future project. Other then the oil burning, it was still a smooth running engine with lots of power and no odd noises.

[Tom]

Block is fine after machine work.

[sweetk30]

i have a 366 BBC engine here that was so HOT it warped the heads to the point they jumped up on the last 2 head bolts being removed the the torque pattern . . . then the heads were cracked in 2-3 places each and seats and guides dropping out . . . . then the pistons had frozen rings and aluminum melting off them . . .

so yes you can kill one . . but to what level . this one i scrapped all of it . but little over heat no problem with correct checking and machine work done .

oh ya the head surface on the heads and block were BLUE like a brand new rifle barrel would be .

[cwcarpenter98]

Originally Posted by sweetk30

i have a 366 BBC engine here that was so HOT it warped the heads to the point they jumped up on the last 2 head bolts being removed the the torque pattern . . . then the heads were cracked in 2-3 places each and seats and guides dropping out . . . . then the pistons had frozen rings and aluminum melting off them . . .

so yes you can kill one . . but to what level . this one i scrapped all of it . but little over heat no problem with correct checking and machine work done .

oh ya the head surface on the heads and block were BLUE like a brand new rifle barrel would be .

That's not just overheated, that's a nuclear meltdown