I vote for the acetone method.....and if the chemical is hot it works better.
As a thought....we used to de-carbon a running engine with water..!
Method was....get engine very hot....drizzle water down the carb so thee engine stayed running....rev the heck out of it....repeat as necessary.
Only problem encountered....piece of carbon might stick in the valve seat...that was the reason for reving the engine..to pound out the carbon bits.
Bob

Yup, that's an old "hill billy" trick that I've seen old time mechanics use, don't think I'd try it on a P-car engine though. :eek:

I recently cleaned basically every nut and bolt from the top end of a 964 engine in petrol. Razor blade, petrol and stiff brushes on outside of cylinders, wire wheel for the pistons.

Dito for me Tom. I talked to Tyson Schmidt about it, and he was perplexed as well. I think once Waynes book comes out, I'll have to give her a refreshing.

Why not just glass bead them? I thought that was the preferred way.

Tim

Guys,
You know, it might all hang together. Wearing valve guides allow oil into the cylinder. Long term, this causes a carbon build up. This increases the compression in the affected cylinders and this variation would affect the idle smoothness.

Next, the Nox levels. Increasing levels indicate hotter conditions, a result of higher compression.

I have 60k on my 87. Idle is a little doggy, it uses a little oil and the Nox has been increasing over the last couple of smog inspections.

Ned Monaghan

Kind of off the subject, but if your town has a wholesale restaurant supplies store/warehouse, look for the large coffee makers and consider using one as your small part soak tank.

What you'll get is a stainless steel receptacle with an internal basket. This setup lets you soak in the fluid, but use the basket on its internal stand to allow air dry/drip above the surface of the solvent. Removing the basket and the stand lets you drop the basket (without stand) into the solvent, making dunking and removal of small parts and whatnot very simple.

Finally, look for the coffee makers that have the spout just about 1" up from the bottom of the unit. This lets you drain off the "good" solvent, leaving the gunk at the bottom. A swipe with several paper towels removes the gunk: pour the solvent back in.

John

a bench grinder wire wheel for the piston crowns, a broken piston ring for the carbon in the ring grooves, and a bead blaster for the heads, after the parts washer has removed all the gooey stuff. haven't used MEK for years. bad stuff!

Doug Z., just curious, what are your plans regarding rings? I know this has been debated before, I wondered what your take was on the various opinions. New or not to (re)new, that is the question.

OK, I'm game.....

New rings work perfectly, provided that the ring grooves are within spec. If your pistons are good, new rings are the way to go. That simple.

I agree with Tony and with JW as well (always a safe bet). I'd STRONGLY suggest letting JW put the cylinders in his BFPW (large parts washer). I believe with all my heart that without running my cylinders through that washer, my new rings might not have seated properly. After washing, the cylinder wall was kind of stone-like, rather than shiny. Very matte. And my engine never made any smoke. Today it burn almost no oil at all. When I get done with an oil change, the oil level is only about a half-inch above the low mark, and I may or may not need to add oil before the next change!

I did not take the case halves to JW, and he probably would not have put them in his parts washer anyway. It is on those that I primarily used the nasty MEK.

Doug, you will save yourself a great deal of time, agony, danger and sore fingers if you just take all your parts to John. He da man!

Oh and of course you will probably take them in neat little baggies all marked properly, and he will dump all those bags into a pile and sort from there.

Won't really know until I have things apart and begin to measure.
I've been getting a lot of good advice from JW and my local wrench. Ring grooves are critical. If they are out of spec, the worn grooves may cause new rings to break. Old rings may be alright to reuse *if* the gaps are still within specs.

Presently, my engine has 75k miles on it, and consumes no abnormal amount of oil. It doesn't smoke, and is mechanically quiet. I'm thinking I won't find much wear when I take it apart.

All those near marine supply stores..... most sell a product that is specifically made to remove carbon deposits... Im not sure what chemical it is, but you fog your engine with it..... then start it after a 24 hour soak...... It will smoke for at least 15 mins after the restart...... but you wont have any mosquitos either

you can also use it it directly on piston dome if you have youw engine apart

JW's Secret Sauce
 

Doug,
It was driving me crazy that I could not remember the stuff that JW mentioned. Finally got it:

John said: "there's a product called jone's motor purr that would probably free up anything it came in contact with. it's not widely available, so call them and ask who has it in your area. 310.532.8602. great for noisy hydraulic lifters too. don't breath it."

There ya go!

"jone's motor purr"?? :confused: :D :confused:
LMAO!!

That *is* TOO funny. . . .I guess we know who needs to do the rebuild now :D

great for noisy hydraulic lifters

Yep,.......just pour the purr, punk!

Just think what would happen to anyone OTHER than JW who recommended Jones Motor Purr [in the familiar silver can] on this board. Torn and bloodied!

It's a keeper.;)

Thanks Tony for making my day with a good laugh!
I'll be searching the local stores for that "familiar silver can".