To sleeve, or nit to sleeve...

[BLACK MAGIC RACING]

To make a long story short, I have an on-center stage 2 block, it's bored to 4.1" I need opinions on wether its worth sleeving or not to make a turbo motor...

 

[Squid4life]

Goals with said motor?


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[BLACK MAGIC RACING]

I'd like to go low 9's, in my 2900 lb car. IE- around 700-750 hp

 

[Mike E]

I'd like to go low 9's, in my 2900 lb car. IE- around 700-750 hp

Naturally aspirated or turbo?

 

[BLACK MAGIC RACING]

Turbo

 

[BEATAV8]

Hell ya sleeve it. I have a sleeved 109 block no regrets there.

 

[Squid4life]

Good sleeves are nice and thick, will be plenty strong for the HP level.


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[Squid4life]

I have a 153 on center block with all holes sleeved. Haven't used it yet but would have no issue putting it on a hot street car.


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[Jay Wicks]

Why sleeve the block? How thick are the walls?

 

[Squid4life]

Why sleeve the block? How thick are the walls?

Ahhh, good point. Maybe a sonic check will tell you the block is still good as is. I talked to Dan at DLS a year or so ago and he said he has gone that big before, or bigger.


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[turbobuick]

Zero reason not to sleeve a block just make sure whoever does it is skilled at it which any competent machinist should be. My block has a sleeve and has held up with no issues. All alum blocks have 6 sleeves. It doesn't make a block any weaker depending on why it needs a sleeve to begin with. IE I put a sleeve in one block when I torched a piston and didnt want to bore all 6 cyl out another .030 to clean it up, so we sleeved the one hole and finished the rest .010 over.

A sleeved hole because a rod knocked a hole through it is another story.

If you have a block that is weakened due to damage from a rod I would sleeve it and hardblock it. There are really no downsides to that either even on the street. I had a block that was concreted and drove it around sat in traffic etc, I really don't think it ran any hotter than it did without the hardblock. We only filled it to within an inch of the deck.

 

[Mike E]

I wouldn't be scared to sleeve it if everything else is good.

Before you bother sleeving it check the max width of the combustion chamber in your heads. I've had a couple sets of stage 2 heads and both were setup for a 4.090 bore. You can run something like that on a smaller bore but you have to run a 4.110 bore headgasket, which has .130" of material between bores.

So, if a sonic check says the cylinder walls are good at 4.100 then the only disadvantage is a thin head gasket between the bores. If your heads are big, you might have to run that crap head gasket anyways.

For reference, some guys run sbf nitrous motors with 4.38 bore spacing up to a 4.200 bore and they have less head bolts and nitrous makes a lot more cylinder pressure than a turbo.

 

[BLACK MAGIC RACING]

No damage, I'll get it sonic checked soon. What are some reasonable numbers?

 

[Mike E]

.200" thick on the thrust sides is fair. You might be able to get away with a little thinner, but the rings seal will suffer.

 

[BLACK MAGIC RACING]

Great, thanks for the replies! I'll get it checked out and post the results here

 

[BLACK MAGIC RACING]

**update!!!** block ALREADY has sleeves on all 4 corners, I think it's junk.

 

[Mike E]

Existing sleeves shouldn't be a problem if you're going to sleeve all 6 holes. A good machinist can bore them to the point they just break free and pull them out and replace the sleeve. You'll have to find the exact OD sleeve that's in there now to replace it with. The only problem would be if the sleeve OD in there now is so big it won't leave enough meat when you put sleeves in the middle holes.

 

[Jay Wicks]

The block may be able to be used as it is. Sonic the block, 360 degrees, including the deck surface. Rockwell for hardness including the sleeves, this will also help determine what ring composition that you may want to use. Inspect for a step at the bottom of the cylinder to determine how the sleeves were installed. Dial bore gauge the cylinders, with a plate installed, for taper as well as wall runout. THEN, you can determine how to procede with what you have...........

 

[BLACK MAGIC RACING]

Unfortunately for me, the walls of 2 cylinders were taking on water, and there is some corrosion damage. I'd love to be able to use it as is, but I don't think it can happen... Bores are stepped at the bottom for sleeve retention.