anyone know if these are currently available at any of the International dealers or is it just the 'RE NEWED'(or whatever they call the rebuilds) engines and/or blocks that they sell? I'll probably do an inquiry at an international dealer sometime if no one knows on here but thanks for anyone's time for a reply

 

I don't think they are making these blocks new anymore but a remanufactured motor from IH is ok. Everything is new but the casting which is ok and can be kinda good. The block is already seasoned so when they reworked the motor and line honed the block she will be ready to go.

If they are still making the block from the original tooling I wouldn't want one. They tooling for the casting will be worn badly by now that the coreshift would be horrible.

 

Better to just have a seasoned one I guess, I just always worry about cavitation, I dont think either of my motors have ever had the right antifreeze or additives (sca.. etc) they are both 86's, I do plan on doing a little acid washing by circulating some coolant system flush through the coolant system before breaking the motor down for a rebuild, the other motor I want to rip out of the truck and then jsut set it in my garage somewhere, what should I do to keep the insides from rotting out before storage?

 

If you have a motor out of a truck you can knock out the the coolant plugs and get a pretty good look at the cylinder walls. You can use a small mirror also. All the 6.9 block I have are fine and not all of them have ever had any coolant additive since they were new. Or most likely they haven't.

 

well that news is definitely reassuring! I think cavitation must only happen in certain parts of the country where people's water has bad mineral content or something.

 

It was supposed to be related to the vibration frequency and on a specific location on the cylinder wall.
The bubbles just formed and corroded through.

The additive prevented the formation of the bubbles.

When I was at the dealership, we were burned a few times on these pinholes coming through, primarily in cylinder #8 and sometimes in #7, shortly after rebuilding the engine.

I would much rather have a new one!

There was one guy that had #8 sleeved and a few days later #7 started leaking!
Boy was he pissed!

 

Cavitation is from vibration induced bubbles.
SCA addatives deposit a sacraficial layer over the inside of the cooling system, so the bubbles eat the sacraficial layer instead of the block.
Cavitation is much more likely in a 7.3 than a 6.9 since the blocks are almost identical except the 7.3 bore is 110 thousandths bigger.

 

My brother was a engineer for Cummins a few years ago, and now I am getting into the diesel scene, I asked him about the coolant additive issues. Putting it in laymen terms for me, he explained the SCA's were bascially a chemical that forms a "slime" all over the coolant passages, and like was said before, the cavitation eats the "slime" rather than the cast iron block. I asked him about chemical levels, and he said it's a little tricky, and the test strips should be used, since the effect of the chemicals does wear off, and also he said when they got too much chemical in the coolant, it started affecting the waterpump seals, making them leak.

He also confirmed that diesels are more affected, because of their higher compression ratios, and that what I read somewhere(maybe in this forum) is true, that the cylinder walls actually expand out and then contract during the combustion process, and that's what's causing the cavitation.

 

That is correct. Engine blocks and heads move around and bend alot. Even though it is a fairly brittle cast iron. Those bubbles bust up against the cylinder walls at around 20,000 psi.

It is amazing that an engine lasts as long as it does. Think about this. Alot of engines last 10,000 hours. Thats true engine hours not clock hours. A true engine hour is 100,000 rpms. Not idling for an hour. Mulitiply 10K by 100K. That is how namy times it has rotated. That is a huge number. 10 billion times. Look at how many times these individual parts and to do there job. Nozzles spaying fuel. Valves opening and closing. Pistons moving up and down.

I have always found that amazing.