Lapping piston rings

[Pvt Parts]

Originally Posted by Bob Mulry

Just a quickee................

It doesn't go in the oil!!!!!!!!!!!!!!!!!!!!!

Remove the spark plugs and put the BonAmi directly into the cylinders and crank her over....Use air to blow out whatever you can from the cylinders.....Start it up....Let it run for a bit....Change oil and filter...See what you got....Sometimes better...Sometimes not...It's just a bandaid..

GM also had TSB's about helping ring seal and oil consumption by using GM Top Engine Cleaner in Gas & Diesels.....Gas it went down the carb and diesels it went in thru the glow plug holes...

Just a crutch...

Bob

GM's Top Engine Cleaner was used primarily to decarbon pistons and combustion chambers. Have you ever used it or seen someone else use it. Oh my!!!! I used it many times when I worked at Chevrolet Dealers in the 1970's, mostly to eliminate "carbon knock" when carbon build up was great enough to create contact between the piston and the head.

Here's the process: Bring engine up to operating temp. Open throttle to 3000 to 4000 rpms. Pour the TEC down the carb to reduce rpms to around 2000. By now the smoke is rolling like the building is on fire. Pour the last 1/3 to 1/4 of the can in quickly in order to stall the engine. Let the engine cool 30 to 60 minutes. Fire it up and take it out for a very aggressive test drive.

Most of the time it fixed the carbon knock issue. However, I did see one tech pour the last part in too fast and it bent a rod. Not surprising. I'd be very surprised if it is still in use today. The EPA would have a hay day with the emissions, not to mention damaging the cats.