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Old 05-24-2011, 12:18 PM   #1
alchemy
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Default Hey Oldtimers, I'm thinking about the Bon Ami trick

We've got a flathead powered car that has a recently rebuilt engine that drinks oil. Even tried a fresh hone and new rings again. Same thing. It's been driven 1,500 miles since the rebuild, probably 800 after the re-hone. Isn't really smokey, just needs oil added maybe a quart every two tankfulls.

I'm thinking of trying the Bon Ami or Comet down the carburetor trick this weekend. Has anybody done it? I need details.

I've heard of just sprinkling it down the carb with the engine running, and I've also heard of mixing it with gas and dribbling that down the carb. Or maybe should I mix with water and dribble that down? I'm thinking the gas mix is not the best bet in case a little blows out of the cup and lands on the generator right there in front of the carb.

Here's the engine particulars: 99 Merc block bored 3-3/8" with solid skirt three-ring pistons. Has a tall Weiand intake with two 97's on top.

So, how did you do it? What mix did you use, what RPM, and how much? I will change the oil after this operation.

Thanks.
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Old 05-24-2011, 12:25 PM   #2
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Never done it myself,,,but a Buddy that should know,says it's a last resort at Catapillar,,,,Bon-Ami is the stuff to use
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Old 05-24-2011, 12:29 PM   #3
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I'd be tearing it down to find out what the problem is....
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Old 05-24-2011, 12:31 PM   #4
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by alchemy View Post
We've got a flathead powered car that has a recently rebuilt engine that drinks oil. Even tried a fresh hone and new rings again. Same thing. It's been driven 1,500 miles since the rebuild, probably 800 after the re-hone. Isn't really smokey, just needs oil added maybe a quart every two tankfulls.

I'm thinking of trying the Bon Ami or Comet down the carburetor trick this weekend. Has anybody done it? I need details.

I've heard of just sprinkling it down the carb with the engine running, and I've also heard of mixing it with gas and dribbling that down the carb. Or maybe should I mix with water and dribble that down? I'm thinking the gas mix is not the best bet in case a little blows out of the cup and lands on the generator right there in front of the carb.

Here's the engine particulars: 99 Merc block bored 3-3/8" with solid skirt three-ring pistons. Has a tall Weiand intake with two 97's on top.

So, how did you do it? What mix did you use, what RPM, and how much? I will change the oil after this operation.

Thanks.
Alchemy
We always use a soda straw and blew it straight into the cylinder through the spark plug hole.

It always worked for me that way.

You got chrome rings?
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Old 05-24-2011, 12:51 PM   #5
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

How is the valve stem clearance and ring clearance?
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Old 05-24-2011, 01:00 PM   #6
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

If the oil usage is too high, then the spark plugs will be loaded with the burned residue. If the plugs look good, let it go and get more miles on it.

A quart every two tanks is not really that bad for vintage engines.

Visible blue smoke is bad, but none or just a haze you can see at night in the headlights of the car behind you is not bad.
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Old 05-24-2011, 01:02 PM   #7
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Two things come to mind here.
First off modern machine shops are not set up to use torque plates on flat heads
Modern ring sets are great but require precise fitment.

And 1 quart every other tank full ain't way out of line on a fresh flat head.

Reguardless of old wives tales pumice (the abrasive in cleanser) down the intake is not good for any engine.

Patience Grass Hopper give it some time.
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Old 05-24-2011, 01:06 PM   #8
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Back in the 60s when I was running a 3/8X 3/8s flattie I found those 3 ring pistons had so much taper built into them that in a few thousand miles I was blowing lots of smoke and using oil. The orignal design of those were for racing so low oil use was not a factor. I finely went to some 4 ring std style pistons. You using modern 3 piece oil rings? If not try a set that has those in it. Use ONLY Bon Ami drizle in 2-3 teaspoons dry at about 2000 RPM. The Bon Ami trick was even recomended by Cat Tractor Co.
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Old 05-24-2011, 01:22 PM   #9
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I vote with the "have patience" crowd. They'll seat in better and better as you rack up some miles.
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Old 05-24-2011, 01:28 PM   #10
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

When that engine was assembled, were the O-ring seals installed on the outside of the intake valve guides ? If not, it'll suck oil up between the guides and the block. It's an oft overlooked item. New ones are available from various sources.
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Old 05-24-2011, 01:29 PM   #11
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Ps; I wouldn't dump anything thru an engine.......... 4TTRUK
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Old 05-24-2011, 01:37 PM   #12
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

If they are chrome good luck gettin them to seat, If they are cast time will be on your side.
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Old 05-24-2011, 01:45 PM   #13
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Before you try the Bon Ami, try this. If you know the piston fit in the cylinders, less than three should seal. Warm it up good, and wind it out in first and second gear to valve float. That helped one of mine years ago. About 65 in second and it finally sealed up. If your pistons are at .004 to .010 clearance, it may never seal.
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Old 05-24-2011, 01:46 PM   #14
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

The machinist is a respected local guy who has been building flatheads and four-bangers for decades. He retired his regular business and still has a waiting list for the Model A engines he builds out of his home shop. I trust his machining and the tolerances.

The pistons have regular cast rings. Not the new modern thin ones, and not chrome rings. I've also assumed he installed the seals on the intake guides.

To all the guys saying "have patience", for how many miles? Isn't 1,500 enough to seat the rings?
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Old 05-24-2011, 01:48 PM   #15
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by Ole don View Post
Before you try the Bon Ami, try this. If you know the piston fit in the cylinders, less than three should seal. Warm it up good, and wind it out in first and second gear to valve float. That helped one of mine years ago. About 65 in second and it finally sealed up. If your pistons are at .004 to .010 clearance, it may never seal.
Wind it out and hold that speed for how long? A few seconds or a few minutes?
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Old 05-24-2011, 01:52 PM   #16
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Wind it out as far as it will go, then shift. Really rev it up, it may seal.
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Old 05-24-2011, 01:54 PM   #17
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by alchemy View Post
The machinist is a respected local guy who has been building flatheads and four-bangers for decades. He retired his regular business and still has a waiting list for the Model A engines he builds out of his home shop. I trust his machining and the tolerances.
Sounds like you should be asking him what he recommends. Throwing grit into a new engine on purpose sounds like a bad idea just on general principles. If you were him, which conversation starter would you rather hear? "I think it's using too much oil", or "I thought it was using too much oil so I ran some Bon Ami through it". At least let him give you his 2 before you decide to go for a no-turning-back fix.
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Old 05-24-2011, 01:59 PM   #18
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

For you younger fellows, this is how a Cat 14 A engine was broken in. That is a mid fifties D8 dozer, 1246 cubic inch inline six. At overhaul time, you put in sleeves, pistons, rings, and bearings. The rings are hard chrome plated for long life. When the motor is started, it is let idle at different RPM's while the hood and belley pan are put on, a good two hour job for two guys. The engine is run up to governor speed, and it should be smoke free by then. If not, one can of Bon Ami sink cleanser is cut open, and dumped into the two cupped hands of one guy. With the air cleaner off, the other guy gets up on top and as he opens the throttle wide open the first guy shoots his hands near the intake and it goes POOF right through and makes a dust cloud out the exhasut. After that, no more smoke. Put it to work for another ten years.
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Old 05-24-2011, 02:05 PM   #19
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

30 w (API SA) non-detergent next oil change and 1000 miles? It might be the modern oil is too slick for the engine?
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Old 05-24-2011, 02:05 PM   #20
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by alchemy View Post
The machinist is a respected local guy who has been building flatheads and four-bangers for decades. He retired his regular business and still has a waiting list for the Model A engines he builds out of his home shop. I trust his machining and the tolerances.

The pistons have regular cast rings. Not the new modern thin ones, and not chrome rings. I've also assumed he installed the seals on the intake guides.

To all the guys saying "have patience", for how many miles? Isn't 1,500 enough to seat the rings?
Alchemy
Cast rings shouldn't be a problem seating at all. Usually where you run into a problem is with Chrome Rings when the bores are not properly honed.

@ 1500 you may be right on the edge of breaking in or you may actually look for a different plce for your oil to be going. Like a leak? I know you'd think you would notice a leak.

Anyway just something else to think about.
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Old 05-24-2011, 02:07 PM   #21
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

back in 1976, I had a Porsche 914 that we had a 1914cc motor built for. The rings wouldn't seal. Took it back to the engine builder and they fired it up and help it at about 2,000 RPM. They then poured Ajax down each of the carburetor throats (it had Weber 48IDA's on it). I about had a heart attack. They said "if it doesn't work, we'll pull it out and rebuild it again". Damn if it didn't quit smoking and no more ring problems.

Honestly if you haven't got a decent seal in 1500 miles, I think there is a good chance that you could have glazed the cylinders. More miles isn't going to break the glaze. So it's either pull it apart and re hone it, probably with new rings or try the abrasive trick.
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Old 05-24-2011, 02:27 PM   #22
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by alchemy View Post
The machinist is a respected local guy who has been building flatheads and four-bangers for decades. He retired his regular business and still has a waiting list for the Model A engines he builds out of his home shop. I trust his machining and the tolerances.

The pistons have regular cast rings. Not the new modern thin ones, and not chrome rings. I've also assumed he installed the seals on the intake guides.

To all the guys saying "have patience", for how many miles? Isn't 1,500 enough to seat the rings?

Last rebuild I had done it took 3000 miles to seat the rings....after that all was right with the world...last time I heard the guy had put like 10,000 miles on it with no issues or major oil consumption
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Old 05-24-2011, 02:34 PM   #23
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I wouldn't do it to a fresh engine. If it's working on the piston rings and cylinder walls, it's also working on the valve stems and probably enough is getting by to "lap" the piston skirts too.
I'd drive it a few thousand miles more. If it doesn't stop by then, you'll probably be able to see where the problem is when you tear it back down.
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Old 05-24-2011, 02:56 PM   #24
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I'm alchemy's brother and the car belongs to our father.

Here's an easier to read summary of what's been done:

- The engine, as a whole, has 1500 miles since a full rebuild.
- The builder came back @ 700 miles post-rebuild and re-honed the cylinders.
- The engine has 800 miles post re-honing.

Personally, I'd be hesitant to pour a gritty material down an expensive pair of carburetors and in to a relatively expensive to re-build engine. I'd consult pops about whether he wants to risk having to do another rebuild of the short block, or just live with the excess oil consumption. Given how little the car gets driven each year, I suspect he'd lean towards the latter.
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Old 05-24-2011, 06:21 PM   #25
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

NOTHING else will work except Bon-Ami....we used it on our sprint car to reset worn rings, it would keep the oil smoke away for a 50 lap race.
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Old 05-24-2011, 07:41 PM   #26
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Have you run a compression test? What oil are you running? What did things look like at 800 mile hone? I would let the engine builder advise me, before bon ami.
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Old 05-24-2011, 08:07 PM   #27
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Just remember:Bon-Ami and Comet are two completely different animals. Bon-Ami is about the consistency of talcum powder-Comet is GRIT.
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Old 05-24-2011, 08:38 PM   #28
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Years ago a neighbor had a Monkey Ward rebuilt flathead installed in his 50 Ford. It burned oil for a few thousand miles. He took it back a few times and they just said give it time. Sure enough after a few more thousand more miles it broke in and he put a lot of miles on it.
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Old 05-24-2011, 08:49 PM   #29
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Cat sells Bon-ami in a can with a cat label,yes,it works.
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Old 05-24-2011, 09:31 PM   #30
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

put some harley oil in it - 70w
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Old 05-24-2011, 10:18 PM   #31
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Dont do it If I done anything I would put a quart of reslone in it drive it around the block come back and change the oil and drive it.Give it Time
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Old 05-24-2011, 10:34 PM   #32
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

It wasn't done to a Cat unless the rings didn't seat. It was not standard procedure and is considered a last resort. Cats use hardened sleeves and rings. I don't think it is a trick that is meant for a normal cast iron block, which is not to say that it won't work.
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Old 07-28-2011, 03:22 AM   #33
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Hello all,
I'm new here but have been building engines for twenty plus years as a professional, many things to say, but I'll start at CAT and the use of abrasive cleaners to bed things in, CAT uses high silicon (read very hard) cylinder liners, flathead fords are cast in soft grey iron, you couldn't find two more different materials when considering how abrasives might stick to the sides, soft iron will hold a lot more of the abrasive for much longer, and soft iron bores with soft iron rings will eventually wear in. If it's only been going for 800 miles and intermitantly at that you probably shouldn't worry.

Get the car out, fill it with a good running in oil and put some miles on it, just go on a 500 mile hamburger run, that is; think of a town 250 miles away, drive there buy and eat the burger and drive home. check the oil regularly on the way.

Most people treat a newly built engine too gently pootling around town and glazing it up. on a 500 mile trip you lose the inhibitions and let it work a bit, it'll do wonders for you and the car.
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Old 07-28-2011, 06:07 AM   #34
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by Ole don View Post
For you younger fellows, this is how a Cat 14 A engine was broken in. That is a mid fifties D8 dozer, 1246 cubic inch inline six. At overhaul time, you put in sleeves, pistons, rings, and bearings. The rings are hard chrome plated for long life. When the motor is started, it is let idle at different RPM's while the hood and belley pan are put on, a good two hour job for two guys. The engine is run up to governor speed, and it should be smoke free by then. If not, one can of Bon Ami sink cleanser is cut open, and dumped into the two cupped hands of one guy. With the air cleaner off, the other guy gets up on top and as he opens the throttle wide open the first guy shoots his hands near the intake and it goes POOF right through and makes a dust cloud out the exhasut. After that, no more smoke. Put it to work for another ten years.
That IS how it's done---works on Cummins as well.
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Old 07-28-2011, 08:05 AM   #35
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Just to clarify, there is a big difference between "glazed" and "gummed" an engine that runs for few miles a year often gets gummed up and dose similar things to being glazed, the difference is; a good hard run will blow the gum out try that first then think about "deglazing" if that doesn't work.
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Old 07-28-2011, 08:15 AM   #36
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Back in the 60's I had an occasion to Bon Ami a pontiac engine that wouldn't seal. I used marvel mystery oil and a table spoon of bon Ami and rev the motor to 3000 and poured it through the carb. As I remember it was a quart of marvel and I had mixed it well and it did solve the problem and assisted in seating the rings. The motor would have had to come out so it was a gamble and it worked and all was happy.
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Old 07-28-2011, 08:21 AM   #37
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Although this wont help the O/P, maybe I, or someone should start a thread with a " proper engine break-in procedure " routine. Many folks either rebuilding thier own engine or installing a crate engine, might not really know how to break in a new engine while driving. Not saying this is what happened here, but there are many variables that could give issues with the end result of rings not sealing. I will say this, sadly for the O/P, a BIG RED flag went off when I read about rehoning 700 miles after the initial full rebuild, hope things get sorted out. TR
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Old 07-28-2011, 08:30 AM   #38
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

There are stranger things than the Bon Ami trick also, even done by the factory's. In the 70's when I was attending Honda { motorcycles } private school, next to us was the BMW factory school. I became friends with one of the guys from BMW and we got talking engine design. We at Honda were looking and studying cylinder Cross hatch patterns under a microscope. He laughed and said with the cast iron cylinders- we just brake the glaze, soak the cylinders in water for a few hours and then leave them out at night to RUST!!. and yes, then they assembled the engines. Cast cylinders, cast rings and lots of RUST, taught by the BMW Factory in thier private school, TR
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Old 07-28-2011, 08:38 AM   #39
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

First time I heard of the Bon Ami trick, was from an aircraft mechanic friend. So they use it on aircraft too. Who wouda thunk?
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Old 07-28-2011, 08:45 AM   #40
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

H&H flatheads does!

Quote:
Originally Posted by 48 Chubby View Post
Two things come to mind here.
First off modern machine shops are not set up to use torque plates on flat heads
Modern ring sets are great but require precise fitment.

And 1 quart every other tank full ain't way out of line on a fresh flat head.

Reguardless of old wives tales pumice (the abrasive in cleanser) down the intake is not good for any engine.

Patience Grass Hopper give it some time.
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Old 07-28-2011, 08:49 AM   #41
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Lots of very interesting info in this thread...
Totally my opinion, but I think the differences stated here in the metals used for a Cat sleeve and a flat head are significant.
I totally respect the old timer engine builders, and their tricks usually work well.
I think you should run this engine for another 1500 miles or so to give it a chance to naturally break itself in first, before resorting to the other recommendations.
Good luck, and keep us posted...
Cheers,
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Old 07-28-2011, 08:50 AM   #42
34toddster
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

What compression reading do you have in each hole?, although that really doesn't affect the oil ring too much maybe you have only one cylinder that is using all the oil, have a close inspection of the plugs, if all 8 are within spec drive the thing another 3000 miles before start dumping shit in a perfectly good engine. Good Luck
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Old 07-28-2011, 09:07 AM   #43
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I've heard of the Bon Ami deal, and there is indisputable evidence that it works. For me, I'd rather pour oil into an engine than abrasives. Drive it a couple thousand miles and see if it gets better.
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Old 07-28-2011, 09:19 AM   #44
alchemy
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Since somebody brought this thread back, I'll give the latest details. I have not poured anything down the carb. The car now has 2,500 miles on the engine, with 1,800 since the rehone. It still drinks a quart of oil every 15 gallons of gas.
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Old 07-28-2011, 09:26 AM   #45
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I have done the Bon Ami trick a few times and it has worked, but I am more in tune to the drain the oil put in some cheap straight 30 and drive it like you stole it for a few hours. Vary your speed including a few wide open spurts and don't baby it, after a hundred or so miles change to the oil you are going to run and your oil consumption will be a thing of the past
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Old 07-28-2011, 09:36 AM   #46
lippy
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I'm with Terry, I would change the oil, and run the shit out of it. Cyl pressure will help the rings to seal against the cyl walls. Are those two carbs working correctly, is it maybe rich and washing the cyls down and losing ring seal? Just thinking out loud. Valve guides and seals will cause a lot of oil burning and it's hard to see at a constant speed. When you wind it up and back it off is there smoke? If so I'd look at the seals and guides. Plugs should be showing this oil burning. I don't care for the Bon Ami deal, though it makes my fawcett look nice. Lippy (Don't run a flathead but I do have a flathead) and one in the shop also.
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Old 07-28-2011, 10:03 AM   #47
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I am a retired mechanic and I would not pour an abrasive into a known good engine. This engine needs to be driven. The oil consumption is not excessive on a engine with so few miles. I would on the other hand drizzle water into a running engine. Warm the engine up and dribble the water slowly into the carburetor throat while holding the RPM at 2500rpm or so. The steam produced will clean up any residue in the combustion chamber, including the cylinder walls. Check the spark plugs afterward to insure that they haven't been damaged.
What worries me about using an abrasive is that you will never be assured that it is all out of the engine. I can't imagine the long term health of the engine would be improved by this last ditch effort.

~Alden
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Old 07-28-2011, 11:12 AM   #48
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

I won't recommend adding BonAmi or not, BUT, in the mid-60's, while in high school, working as a parts helper at a local Chevy dealer, the shop manager, told me that in 55 when the new 265 V8 chevy engined cars arrived at the dealership, most smoked and used oil, and that they were informed by GM to add BonAmi down the carb throat at around 2000 RPM, and according to this seasoned GM mech/shop foreman, it worked wonders for the new V8's. I never saw it done, but he had no reason to BS me. Totally different engine than a flathead, but ring seating was apparently an issue for GM in the mid 50's. I am also a aircraft mechanic (A&P) and I NEVER heard of anyone pouring BonAmi in an aircraft engine. Certainly not manufacturer or FAA approved. Opposed aircraft engines use updraft carbs, so it won;t pour in, but I guess it could be sucked up with the engine running or poured in an upper spark plug hole. Certainly not recommeded by Continental or Lycoming I'm betting. You can always pour in the BonAmi, I would try driving it some more to seat the rings. On aircraft engines, with chrome rings or cylinders, the breakin procedure was critical. If not done properly, the cylinder had to come off and be re-ringed or possibly replaced.

Outlaw
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Old 07-28-2011, 12:09 PM   #49
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by chickenridgerods View Post
I'm alchemy's brother and the car belongs to our father.

Here's an easier to read summary of what's been done:

- The engine, as a whole, has 1500 miles since a full rebuild.
- The builder came back @ 700 miles post-rebuild and re-honed the cylinders.
- The engine has 800 miles post re-honing.

Personally, I'd be hesitant to pour a gritty material down an expensive pair of carburetors and in to a relatively expensive to re-build engine. I'd consult pops about whether he wants to risk having to do another rebuild of the short block, or just live with the excess oil consumption. Given how little the car gets driven each year, I suspect he'd lean towards the latter.
Mike, I really think the answer lies in the reason WHY it was "re-honed" at 700 miles. Why was this done? I'm really trying to help you and your Dad here, I suspect what ever happened with the first hone job, might not have been rectified with the second honing job, thank you, TR
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Old 07-29-2011, 02:02 PM   #50
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Quote:
Originally Posted by Traditions Racing View Post
Mike, I really think the answer lies in the reason WHY it was "re-honed" at 700 miles. Why was this done? I'm really trying to help you and your Dad here, I suspect what ever happened with the first hone job, might not have been rectified with the second honing job, thank you, TR
I don't know the particulars on the build regarding ring type, clearances, whether a torque plate was used, etc, but they did the re-hone because the engine never stopped consuming oil in those first 700 miles. Same issue as current. Don't remember if it was better, worse, or about the same, though.

The car has seen all sorts of driving in those 2500 miles: in town, highway, drag strip (HAMB drags), gravel jammin', etc.

To be honest, I don't think putting another 500-1000 miles on it will change much at this point.
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Old 07-29-2011, 02:29 PM   #51
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Cylinder bores out-of-round maybe? Honing would not fix that.
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Old 07-29-2011, 02:36 PM   #52
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Default Re: Hey Oldtimers, I'm thinking about the Bon Ami trick

Thanks Mike for replying. Thats what I was anticipating you would say. Sorry you and your family are going through this. If I may suggest, stop for a bit and consider the correct options. If your going to take the engine apart again, you need someone who can accurately measure each piston. Not just one. Then hopefully this same person can accurately measure the cylinder bores for size, taper, and flare in the center of the bores. Now determine if these pistons are still usable, if not you will need to rebore and hone or hone to the next size over. If forged pistons are available for your particular engine, {they are expensive}, a good machinist can probably touch-up hone the bores enough for the forged pistons to run just fine. Either way, I would highly absolutely recommend a new set of rings. Make sure to set the end gaps correctly before using them, and they are made of the correct material for the type of finish you have on the cylinders. The machinist must know what type of ring you are using so he can match the stones to give the correct finish for the ring material. You also need the correct finish and the correct X-hatch on the cylinders for the rings to seal. Finally, is clean, clean, and clean again before you assemble. Also have someone who know how to check the valves and guides properly while your apart. Now is the time to make sure you are not running real rich, so you wont wash down the cylinders when you freshen the engine this time. Check your ignition timing and advance now before you tear it down again so when the engine is fresh you don't hurt it. I'm not trying to build you a race engine, just one so this will be the last time you rebuild this one and you and your family can enjoy many, many miles, TR
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