Will this bore clean up, magnum head content too.

-
What if you bore that one cylinder .040 or 60 and use 1 oversized piston? They weigh the same out the box supposedly.
That's thinking out of the box. I like it. Should be able to balance that small amount of aluminum out.
 
What if you bore that one cylinder .040 or 60 and use 1 oversized piston? They weigh the same out the box supposedly.

nice thinking out of the box like said…

…But that’s not cleaning up with .010 more bore.

I very doubt it will clean up with .060 (.030 more.
 
nice thinking out of the box like said…

…But that’s not cleaning up with .010 more bore.

I very doubt it will clean up with .060 (.030 more.

i'm about to try to knock the raised portions off the wall and see how corroded it is. i do see where it looks pitted abought .250" below the deck, i'm guessing it's been leaking a long time and rings always knocked it off lower in the bore.
about to the pull the other head too, crossing fingers they all look good.
 
As a machinist, I'd like to point out that if they sleeve one cylinder, it is going to distort the cylinder beside it....just want to mention that, something to think about.

one thought was getting some .040 over Mahle pistons and selling these H116CP pistons. But that gets me into a sleeve AND bore and hone on the block. At that point it might make more sense financially to use a different block.
 
i'm about to try to knock the raised portions off the wall and see how corroded it is. i do see where it looks pitted abought .250" below the deck, i'm guessing it's been leaking a long time and rings always knocked it off lower in the bore.
about to the pull the other head too, crossing fingers they all look good.

Wait… so a piston has been sliding over that nasty spot down in the bore?

… so that’s all “inny” corrosion? Not “outty” ?
 
What if you bore that one cylinder .040 or 60 and use 1 oversized piston? They weigh the same out the box supposedly.
Like this idea, hope you won't have to buy two complete sets of rings!
And you're telling us this cylinder had 185-190psi of compression? I'd leave it like it is.
 
That's thinking out of the box. I like it. Should be able to balance that small amount of aluminum out.
GM built engines that way. Different bores and different diameter crank journals. the manuals mentioned that when I was working at a GM dealer back in the day.
 
one thought was getting some .040 over Mahle pistons and selling these H116CP pistons. But that gets me into a sleeve AND bore and hone on the block. At that point it might make more sense financially to use a different block.
Where are you located?
 
x2 I have a 360 mag here with aluminum eldebrock heads I would let go.
Its standard bore with KB pistons.
 
Wait… so a piston has been sliding over that nasty spot down in the bore?

… so that’s all “inny” corrosion? Not “outty” ?

almost all is outty corrosion. I scraped it with a soft metal that was cut clean. Then more scotchbrite. Looks better but still really bad. The worst part is up at the top. You can see the bad corrosion.

7C3BC0F0-5D6C-412C-BC0D-67B62534EBF5.jpeg
 
As a machinist, I'd like to point out that if they sleeve one cylinder, it is going to distort the cylinder beside it....just want to mention that, something to think about.
Dingle hone. LOL
 
almost all is outty corrosion. I scraped it with a soft metal that was cut clean. Then more scotchbrite. Looks better but still really bad. The worst part is up at the top. You can see the bad corrosion.

View attachment 1715785680

I'll get some hate, but I'd run it. It'll kinda clean itself up to a point.
 
I'll get some hate, but I'd run it. It'll kinda clean itself up to a point.

No hate here, you are right. A ball hone if possible and let her rip. No it is not perfect, but should get a few more years out of it.

I would at the very least take that piston out, clean it up, and make sure the rings aren't stuck.
 
Thanks guys.
One other bore gas a bit of corrosion. Not as bid as the first we were talking about.

7A0759B7-6474-4E01-A0CE-3C5C4A3F0B62.jpeg
 
Looks like the gaskets caused this.

EFB072A6-177C-490C-9C2B-B64FC0B7DED7.jpeg


so pretty confident my magnum heads are fine, i was told they were new castings with thicker decks and all that stuff. I have no idea what castings they are though. The intake manifold is a ProComp which you can't even get anymore so this is an old rebuild. Pistons look close to zero deck and I was told the cam is a purpleshaft with maybe .455 lift (but that's the big block cam lift, not the small block) so I gotta measure that too.
I kinda want to get this fixed good enough so it doesn't smoke at all and will last a good while in a powerwagon I use for hauling **** and misc work truck stuff. So pretty much everything in the motor as is would be good to go in the truck.
 
Last edited:
btw, the used and abused 8553PT gasket thickness is right at .050" on the fire rings. I think if I use 8553PT again I might spray them with something to help seal. Don't want these ******* leaks again...

pistons must be close to zero deck to be pumping 185-190psi 4 years ago (that was cold too). magnum chamber, i'm guessing it's the Mopar Purple cam 268/272- .450/.455 lift.
 
A zero deck piston, a closed chamber head, is probably not gonna be very happy in a truck situation
 
btw, the used and abused 8553PT gasket thickness is right at .050" on the fire rings. I think if I use 8553PT again I might spray them with something to help seal. Don't want these ******* leaks again...

pistons must be close to zero deck to be pumping 185-190psi 4 years ago (that was cold too). magnum chamber, i'm guessing it's the Mopar Purple cam 268/272- .450/.455 lift.

Not sure where you're located, but if I were you, I'd wait for a half off day at Pick-n-Pull and grab a 'new' 5.9. Every time I go, there are plenty to choose from and on half off weekends, you can pick up a long block for ~$100. Most likely, it'll still have a crosshatch and be useable as-is.

That block you've got isn't worth the headache IMO, when replacements are so readily available and cheap.
 
I would clean it up and run it as is.
I've seen a lot of scarier **** cleaned up and run without any problems.
I realize that there is a ''right'' way to do things and a ''good enough'' way to do things.
For your intended use, the ''good enough'' way would be good enough.
Clean it up and regasket it, but check the head and deck surfaces for straightness and correct if necessary.
The head gaskets failed for some reason.
JMHO...........
 
No hate here, you are right. A ball hone if possible and let her rip. No it is not perfect, but should get a few more years out of it.

I would at the very least take that piston out, clean it up, and make sure the rings aren't stuck.

Right! What do people think when one sits up a while? That the cylinders are somehow protected? Naw, ain't happenin. lol Might not as bad as what he has here, but before I spent big money on it boring and sleeving, I'd try it.
 
Dingle ball hone it until its cleaned up and then measure it. Hopefully itll be ~.032 over and clean enough to not catch a finger nail. Dont worry about the crap over the ring lands. Ball hones wont take much but itll help your to take the edge off anything left. Imagine what a 30 year old barn find cylinder looks like and guys start them up all the time with fresh gas and topping the oil off.
 
second, do these look like stock magnum heads with some gasket matching? the pushrod pinch is .828" at the widest part.
The valves and springs look stock or what?? I see where the pushrod holes in the heads were massaged some but a few were still rubbing.

also is this raised pyramid shape in the port floor stock??

View attachment 1715785278

View attachment 1715785279

AHA, figures, the cheapest magnum castings have the floor vane in the port.

New Magnum heads for 347 with Flow data
 
-
Back
Top