Discussion
Good afternoon all,
I'm looking for opinions on how to proceed here. First a bit of background: I've stripped the engine to the block and crank and made some neat, thick industrial cardboard bungs to plug up the bottom of the cylinders and sealed them in from above with decorators caulk. I've cleaned the bores using carb cleaner, which actually makes the surface rust look worse than it is, in my opinion anyway. The car had all oil and water mixing and I suspected HGF but it seemed to run sweetly enough, not withstanding the clouds of white smoke coming out of the exhaust. I only ran it briefly for this very reason. It was also difficult to start which on further inspection I put down to having approximately 7 litres of fluid drained out of the sump (coolant and oil) and on even further inspection, the state of the bores. The piston rings were pretty tight at first but I've carefully managed to get the pistons out without much of a fight and they look ok to me at first inspection.
Taking the remainder of the engine out isn't really an option, hence the bungs/ tape etc. Im planning to use a shop vac to clear most of the escaping dust as I clean up the bores. I've bought a three legged hone but the stones are coarser than I'd hoped (180).
I'm now contemplating either 240 stones or a flex hone with 240 grade silicon carbide 'bobbles'. I've read everything I can find and found this to be good inspiration so far: http://www.pistonheads.com/gassing/topic.asp?t=813...
Advice appreciated
Many thanks to you all. That's confirmed it for me - I was leaning towards the flex hone after some reflection.
Do any of you have any recommendations about where to buy these flex hones from?
eBay and Amazon list them but they're supplied from the states and not exactly cheap in the first place. Thinking about it, i might actually try the place I'm going to use for the head skim and pressure test.
Do any of you have any recommendations about where to buy these flex hones from?
eBay and Amazon list them but they're supplied from the states and not exactly cheap in the first place. Thinking about it, i might actually try the place I'm going to use for the head skim and pressure test.
The bores are 73.4mm diameter so I was looking for a 3" diameter tool in a 240 grade and I think I need silicon carbide for Iron liners (from what I've read).
I've contacted the uk distributor (pacehigh) for a price and asked them to clarify that I've specified the right tool. I'll post back when I get a reply.
I've contacted the uk distributor (pacehigh) for a price and asked them to clarify that I've specified the right tool. I'll post back when I get a reply.
Thank you for the detailed reply and the advice.
I think I'm going to try my new three-legged hone with the 180 stones after all. My hands are a bit big to attempt it with sandpaper in any case.
Most of what you can see in the pictures is actually a varnish as far as I can tell. The pictures aren't great at this resolution and the brake cleaner I used prior to taking top picture gives the impression that they're actually quite rusty.
I think I'm going to try my new three-legged hone with the 180 stones after all. My hands are a bit big to attempt it with sandpaper in any case.
Most of what you can see in the pictures is actually a varnish as far as I can tell. The pictures aren't great at this resolution and the brake cleaner I used prior to taking top picture gives the impression that they're actually quite rusty.
It's a bit of a project really - mainly something to learn on without too much risk. Having got this far I decided there wasn't much to be gained by cutting corners, that's why I've decided to take the block out and do as best I can.
I've got a bore comparitor gauge so I'll be making some investigations soon.
Eventually I suppose I will sell it on but not until I'm confident it's all ok. If I did make a real hash of things then i suppose I'd just have to break it for spares.
I've got a bore comparitor gauge so I'll be making some investigations soon.
Eventually I suppose I will sell it on but not until I'm confident it's all ok. If I did make a real hash of things then i suppose I'd just have to break it for spares.
That's good to hear Paul.
I've got the rest of my engine out of the car now. I just need to strip the block down now.
I'm going to practice using my new mic and bore gauge before I attempt to measure the bores as they stand. Then I'm considering getting a local reconditioner to do the honing on their machine as they only want £30 for all four bores. I'm thinking it would be best to advise what I need in terms of finished size.
The manual says my bores are 73.400+/-.005 mm. Can anyone advise what is the most I could hone out before needing a rebore? Apologies if it's a stupid question (i.e. Top limit).
I've got the rest of my engine out of the car now. I just need to strip the block down now.
I'm going to practice using my new mic and bore gauge before I attempt to measure the bores as they stand. Then I'm considering getting a local reconditioner to do the honing on their machine as they only want £30 for all four bores. I'm thinking it would be best to advise what I need in terms of finished size.
The manual says my bores are 73.400+/-.005 mm. Can anyone advise what is the most I could hone out before needing a rebore? Apologies if it's a stupid question (i.e. Top limit).
Dear all,
As promised, I'm posting back now I have more to add. Yes, it has taken me that long. I've been busy with other things as well as this and I always take my time anyway.
I'm happy to say the engine is now back together, back in and running sweetly.
The bores were much better condition than the pictures might have you believe and cleaned up nicely after a very light hone at a machine shop.
I did measure up the cylinders after cleaning up the block and they were within the limits Mignon states above.
The +/- tolerance point you commented on Mignon was my brain fade and not the manufacturer's recommendation.
As promised, I'm posting back now I have more to add. Yes, it has taken me that long. I've been busy with other things as well as this and I always take my time anyway.
I'm happy to say the engine is now back together, back in and running sweetly.
The bores were much better condition than the pictures might have you believe and cleaned up nicely after a very light hone at a machine shop.
I did measure up the cylinders after cleaning up the block and they were within the limits Mignon states above.
The +/- tolerance point you commented on Mignon was my brain fade and not the manufacturer's recommendation.
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