Cavitation?

[Lumberjackchuck]

Pulled motor to reseal everything since it’s leaking from everywhere.

After I took the heads off I noticed when I turn the engine over manually, cylinder #8 would leave moisture on the cylinder walls. I’d wipe it, cycle again and same thing. Motor is at 250k mi

You must be registered for see images attach

I’m hoping that it’s just some water dripped in it when I lifted the head off. But none of the other ones had this and I’m also hearing now that cylinder #8 is prone to cavitation.

If it is cavitation, would a sleeve fix it or is the block trash? Also, how do people feel about sleeves in this motor? I hear mixed things but then see that R&D likes to sleeve their motors.

 

[SkylabTech86IDI]

Pulled motor to reseal everything since it’s leaking from everywhere.

After I took the heads off I noticed when I turn the engine over manually, cylinder #8 would leave moisture on the cylinder walls. I’d wipe it, cycle again and same thing. Motor is at 250k mi

You must be registered for see images attach

I’m hoping that it’s just some water dripped in it when I lifted the head off. But none of the other ones had this and I’m also hearing now that cylinder #8 is prone to cavitation.

If it is cavitation, would a sleeve fix it or is the block trash? Also, how do people feel about sleeves in this motor? I hear mixed things but then see that R&D likes to sleeve their motors.

Chiming in here because I haven’t seen anyone else respond just yet. I’m still learning these motors so I’m new to them. However, I would imagine cavitation would look like coolant intrusion from the same and singular spot or a couple of locations.

Because it is appearing like sweat, I think what you’ve got there is water during head removal that’s slipped past the rings like you’ve already said.

Hopefully someone more knowledgeable and experienced can chime in. I’m interested.

That being said, I’ve been following a lot of builds on YouTube that use sleeves for higher performance IDI’s and they seem to report fine results that hold up.

 

[Rdnck84_03]

The rear cylinders usually catch some coolant when the heads are pulled. I usually dont pull the block plugs so I almost always get something in the cylinders. You could try drying the cylinder out with an air blow gun and see if it reduces the amount.

 

[IDIBRONCO]

If you weren't having problems with cavitation before, then you most likely aren't now either. Pulling a head off won't cause cavitation to start.

 

[BeastMaster]

I would try this...let the engine cool off completely. Remove the radiator cap in order to release all pressure. Put it back on.

Start the engine. Run it for 10-15 seconds. Shut it back down.

Check radiator pressure again.

If it's pretty high, I would think it's exhaust gases that was forced into the coolant.

Or, run the engine a bit, radiator cap off, and see if any gases are trying to leave via the radiator cap opening.

If so, where are those gases coming from. Just to get a second opinion, stopper the radiator and hose the gases and bubble them through some "bromothymol blue" pH indicator to see if there is CO2 present. If so, the bromothymol will turn yellow as it absorbs the CO2.

bromothymol blue co2 at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

I believe auto parts stores sell this stuff premixed and packaged just for this purpose... Under a different name. Bottles of a blue fluid.

I used this stuff to vet my van when I was purchasing it.

If you want to test it, you can bubble it with your own breath and it will see your CO2 emissions. Or use the tailpipe.

One of these days, I have gotta see if I can reset "spent" solution back to blue with some slaked lime powder.

Here's hoping that while I share what I know about cavitation, that I never have to deal with it. I really like my old IDI, and hope I can keep it running till they plant me.

Festus and his mule, and I'm good.

 

[Nero]

Or use a block tester.

https://www.amazon.com/Block-Tester-BT-500-Combustion-Leak/dp/B06VVBSFTF

I bought this one for at work. Diesel exhaust in coolant changes the fluid from blue to marine green. You will have to siphon some coolant off the top of the radiator, you only want gasses to pass through, not coolant.

 

[BeastMaster]

Yep! That stuff!

I have used bromothymol blue before in a lab and noted it was useful for detecting CO2. But didn't know what to ask for.

Thanks for chiming in. Little tidbits of knowledge sure saves a lot of busywork.

 

[Black dawg]

Have yet to see any of the blue fluid turn color with diesels, even on one with badly blown gaskets. If they are putting combustion into the cooling system, they will push air past the cap and into the overflow.....

Thread got kind of side tracked....looks like a little coolant just got in the cylinder during head removal.

 

[Nero]

You would either run without a cap, and put the tool straight into the cap hole, or run the overflow tube to the tool. I've found its best to do it without the cap. You get faster results.

Hopefully it was just residual coolant.