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XFlow New Pistons - hone or not bother ?
sweston - 24/2/04 at 01:15 AM

From an earlier post looking at putting in some 1300 pistons for my 1600 xflow to up the compression.

Question: Should I hone the cyclinders once the old one's are out and before I drop the new one's in.

Was thinking off doing it without lifting the whole engine out. Take off head and sump and carry on.


paulf - 24/2/04 at 09:09 AM

It is essential that you hone the bores to allow the new rings to bed in. If not you will loose compression and oil and the job will be a waste of time.
I would recommend removing the engine and stripping to bare block as there is a lot of abrasive compond left over which wil have the same effect as putting grinding paste in the sump.
I have in the past done the job in situ but the crank needs to be taped up with masking or insulating tape and the crankcase stuffed with rags to catch the oil and abrasive from the bores, and then very carefully cleaned afterwards.
Paul.

quote:
Originally posted by sweston
From an earlier post looking at putting in some 1300 pistons for my 1600 xflow to up the compression.

Question: Should I hone the cyclinders once the old one's are out and before I drop the new one's in.

Was thinking off doing it without lifting the whole engine out. Take off head and sump and carry on.


Terrapin_racing - 24/2/04 at 10:17 AM

Snap - done this in situ before - but be meticulous with cleaning. I used grease to catch the bits and then cleaned off afterwards (grease over tape etc!).
You must hone though.


200mph - 24/2/04 at 01:31 PM

excuse my dumbassedness. Havent got that far in my book yet, so whats honing?

I think i have a fari idea, but would rather be sure.

cheers
mark


David Jenkins - 24/2/04 at 01:35 PM

It's the process of deliberately scratching the inside of the cylinder bore, which allows the new rings to bed themselves in (it also holds the oil a bit, which helps).

It's usually done with a gizmo that holds 3 or 4 fine stones - this is put in the bore and spun with an electric drill, working it back and forth.

Is that what you were thinking of?

David


200mph - 24/2/04 at 02:07 PM

mmm. kind of, i didnt realise there were stones and spinning involved however

i shall find out more I think.

mark


David Jenkins - 24/2/04 at 02:32 PM

Here's a picture from Frosts...

Cylinder Hone

Not a clear picture, but the description is good!

David


200mph - 24/2/04 at 02:50 PM

cool, that makes sense, but leads to further questions.

1. It sounds as though it would be fairly easy to mess this up resulting in the engine needing new lining(s)?

2. How much of the bore is removed? I assume it will be very thin, like micrometers.

3. Is it difficult to get even down the whole cylinder?

am sure there are other things i wanna know, but they will get addressed in due time I'm sure.

Cheers
Mark


David Jenkins - 24/2/04 at 03:01 PM

You probably could damage the bore if you were silly, but normally you just spin away until there's an even amount of scratching all through the bore. You are looking for a matt finish instead of shiny. You're barely taking anything off the metal - just the depth of the light scratches.

Fairly messy though - you have to be fanatical about cleaning afterwards, otherwise you'll be leaving grinding paste in the cylinders.. not A Good Thing!

rgds,

David


200mph - 24/2/04 at 03:09 PM

tyvm!
is crystal now

mark


Stu16v - 24/2/04 at 09:52 PM

quote:

Havent got that far in my book yet


P.s. you wont find it in 'The Book'....