Can you bore a 7.3IDI? Is .010" clean up bore ok? .020"? .030"? Or do you sleeve them?

 

sleeves are recomended,these engines are known for thin cyl walls and are prone to cavatation,especially if the sca's arent kept up.

 

Ok, thanks.

 

Yes you can bore it so you can sleeve it. I would not recommend it. Sleeved engines are far less reliable and then there is the variable as to who does the sleeve job.

Also you overheat a sleeved 7.3l engine once and you could be done for if the piston seizes up and pulls the sleeve into the crankcase.

Seb.....

 

Sleeves don't have some taper or a lip to prevent that?

 

Three sleeved engines lasted me for 28,000 miles.
The sleeves dropped down below the deck of the block on all three and cracked the block.

Never again.

I bought a salvage yard 6.9 and did a minimum bore to clean the cylinders up and rebuilt that. So far so good, it has already lasted longer than my first sleeved 7.3 did.

 

I had already decided I'd do a 6.9 before a 7.3. Makes me wonder about my gasoline 400 though. Has one sleeve... cylinder 8 I think.

 

There is just no way to hold a sleeve in place. I have seen sleeves that are locked with a lip between the block and it ripped the sleeve right off the lip.

The only sleeved diesels that work are the ones that replace the entire cylinder wall with a sleeve that seals against the water jacket with O-rings on the bottom and top. On these sleeves the cooling water is right against the entire sleeve.

Volvo uses this system on their industrial diesels a lot. You just pop a sleeve out and pop a new one in. You buy a new sleeve c/w piston, rings and pop it right in. No machining, or honing required. Of course the blocks on these motors are massive compared to the 6.9l IDI.

Seb....

 

Most of the big diesels have wet sleeves. Makes rebuilds easy.

But when you look at the cost of a 10 plus liter engine, you have to be able to rebuild it reliably several times to recover the cost.

 

hmmmm-had a 428 sleeved many years ago--never did come loose--and---have a 7.3 thats sleeved now--the same way the other was done years ago--step on bottom of bore--freeze sleeve--heat block slightly--red locktite around sleeve--and drive her home--and he only shaved the sleeves flush--and didnt shave the block---like one said--depends on the machine shop--and their knowledge--