Cleaning Carbon deposits from Valves?
 

Does anyone have any suggestions on safely cleaning carbon from valves without removing the cylinder heads? I'e always been of the opinion that it is best to just tear the heads off and do a valve job, but...

I am doing a major service on an older V8 Ferrari, and the valves have some significant build up on them. Due to the cost of a cylinder head R&R, the customer is reluctant to have me tear the heads down to clean them up. I'm going to do a leakdown tonight and see if we have any sealing issues.

Here's a picture, its really difficult to see the depth, but some valves have 1/16 - 1/8" of crud on them...

seafoam it or gum & sludge remover down the intake .

I know of a couple of ways, but I don't think you're going to like them for use on a Ferrari!


If you start the motor and rev it to 2000-2500 rpm (enough to where it isn't going to stall), slowly pour water into the intake system. It will steam clean the valves. It can get carbon build up off of pistons too.


You could try a tiny vacuum and some oven cleaner. Spray it in there, let it foam up, and vacuum it out before running it.


Toluene or Xylene in your gas helps too. It burns hotter and helps to destroy some of the carbon deposits (I got this tip from an old off-shore guy). Run it at 20% mixture for a tank.

I will certainly run some seafoam when I get it back together.

I have heard of the steam cleam method, but to be honest it scares the crap out of me for some reason! I'm leaning towards making sure the valves are closed, and spraying some oven cleaner or solvent in there, then sucking it out. You think oven cleaner is the best bet? Safe on the aluminum? What about filling the port with some carb cleaner or other solvent?

Some of the valve clearances were a bit more out of whack than usual, I'm hoping that the leakdown results are good.

I can tell you for sure that carb cleaner, vinegar, soaking in pure toluene, etc. won't do a damn thing. It's just not strong enough to break down the carbon.


I'm 90% certain that oven cleaner is safe for aluminum, but that has more to do with me using it on the grill/aluminum pans and whatnot. I've never tried to use it in the method you're using it in.



I HAVE used the steam method and it did work for me. I used it on a fuel injected Dodge Dakota, and I've used it on a couple of old school carb motors. I don't know how well it worked because I never took the motor apart, but it did stop the motor from dieseling (continuing to run when you shut it off), and it stopped some valve noise.

The only issue was neither of those motors are tuned to the same degree that a Ferrari motor undergoes. I really don't know if it would throw anything off, but I don't see why it would?

I remember the water down the carb trick to clean valves and pistons. I also remember sucking in cans of "top engine cleaner" thru the pcv or another vaccum source, until the engine took the whole can, shut it down, let it sit for 15 minutes, then go beat the snot out of it. Smoked like pigs, but seemed to work!

I'm thinking that soaking them might not do too much. I might try it and see if it knocks the heavy gum off of them. Guess I'll try some water spray and sea-foam when i button it all back up. The exhaust comes off next, I afraid to see what they look like :eek:

No over cleaner on aluminum intake. Does weird things to the metal. If you pit up the runners you will be worse off then when you started.

What Mild Thunder said works good I used BG 44K when I worked for ford/mazda, We used to stop traffic with the smoke but never had to tear one down after doing that drop a can in the tank also will clean the rest of the system

I can sell you some BG Products 44K. You add it to the fuel tank and run thru several tanks of fuel and all the carbon will be gone off of the valves and tops of the pistons.

PM me if interested.

Smitty

I don't know how much good some of the above mentioned methods will do. From what I've seen most are preventative, to keep heavy deposits from forming in the first place. Personally I think your idea of performing a leak down test first is the best approach. If the valves are sealing up tight I'd probably leave it alone.
Most of the engines in those type of cars suffer the same fate, too many hours in the city idling at the stop light and not enough time doing what they were designed for, running fast and hard.
BUT........All my experience over the years is with aircraft (piston and turbine) so we may be talking apples and oranges here. It is possible one of the additives out there really does scavange the deposits off the valves but I'd be worried what it's doing to the rest of the engine.

Your assessment is spot on, too many people loaf around in these cars and they get all gunked up. Anything with a 8,000 RPM redline, NEEDS to see 8,000 revs every now and again. My personal cars certainly don't suffer the same fate :evilb:

I ran a leak-down test and it's not good... 90/19 in the worst cylinder, average was 90/40.

I think the heads will have to come off and give the top end a once over. Unfortunately these heads are a royal PITA to remove and head gaskets are brutally expensive.

I'm worried with the amount of buildup that I can't properly adjust the valves even if I wanted to. My concern is if I set the clearances then blow out the deposits, they will be way to tight.

Thanks for the input guys, I was hoping someone had a miracle treatment up there sleeve :drink:

The water through the intake is an old school method that does work. I used to do it to my old high compression muscle cars with no known consequences to me. Another possibility that might make you feel safer is pouring marvel mystery oil in it like the water method. Some swear by it. ATF fluid is also another possibility. The problem with ATF is if the Ferrari as rubber valve seals and it comes in contact it could cause problems because I believe ATF fluid has seal swellers in it.

PS Nothing works better than a hard long wide open throttle run. I had an old torino GT and blew the doors off a TA 455 SD. I all but put him out of sight and backed down to let him catch up...nailed it again and he couldn't get beside me! We pulled over and chatted. He told me he though I blew my engine...I was spewing sparks....twas the carbon deposits. I hadn't had the car long and had 11/1 compression!