adamnreeves Posted July 20, 2006 Posted July 20, 2006 I guess the best way is to find a place to clean with acid, friendly for alluminium alloy. I have heard of people using the dish washer when the wife is out! Will this work satisfactory? do I use finish tablets? Added: I know the block will be too heavy big! but the smaller parts, and heads I guess would fit. Quote
Blatman Posted July 20, 2006 Posted July 20, 2006 Isn't it time you started using the techie section? Quote
highwayman Posted July 20, 2006 Posted July 20, 2006 Adam . Surely its worth getting it professional chemically cleaned? You seem to want lots of detail and I'm sure you will be happy with the investment and yes its time for you to migrate to the techie section as these are not newbie subjects anymore!! Quote
adamnreeves Posted July 20, 2006 Author Posted July 20, 2006 Oh, sorry guys, I did not want to be presumptious over my knowledge status! So I am worthy of posting in the Techie section, thanks Quote
Thrustyjust Posted July 20, 2006 Posted July 20, 2006 take it in bits to an engine shop,get them to chemically steam clean it all.They don't usually like doing it unless you give them buisness,so ask them to measure all the bits for wear and buy the rings and shells etc from them.There is a decent place in Witney,Oxon.Can't remember the place,but phone Mark at Owen Developements and ask him.He knows,as we went there for some bits,say Justin Sheldon asks. Quote
Barry Ashcroft Posted July 20, 2006 Posted July 20, 2006 QUOTE So I am worthy of posting in the Techie section, thanks No not realy it's just that you keep filling up the newbie section Quote
adamnreeves Posted July 20, 2006 Author Posted July 20, 2006 So I am worthy of posting in the Techie section, thanks No not realy it's just that you keep filling up the newbie section Including this post I have 2 postings in the newbie section at the moment! I noticed the newbie section has seemed a little quiet of late, but 2 postings constituting a flood? Quote
Blatman Posted July 21, 2006 Posted July 21, 2006 It's not a question of being worthy. You are asking tech questions, mostly. There are some folk who contribute to the tech section that don't contribute anywhere else. You're potentially missing out on some decent knowledge by not using the right section, same as the way you're missing out by not using the search... Quote
Mike H Posted July 21, 2006 Posted July 21, 2006 I took all mine to a machine shop in Warrington. They hot tanked it then measured all the bores etc. It won't be until you've got it properly cleaned that you can see the state of the bores because there'll be plenty of oil baked on. This is what mine looked like: Mike Quote
adamnreeves Posted July 21, 2006 Author Posted July 21, 2006 I took all mine to a machine shop in Warrington. They hot tanked it then measured all the bores etc. It won't be until you've got it properly cleaned that you can see the state of the bores because there'll be plenty of oil baked on. This is what mine looked like: Mike Seem to have a bit of rust on that. My bores are very clean and smooth. No score marks but I do have a very slight ridge at the top that you can only just feel with your finger, I have not got a dial guage but I think a standard rebore of 20 thou or 0.5mm will be fine. It seems that just my heads and valley have baked on old oil. How much does it normally cost to get the engine cleaned/dipped. Quote
Blatman Posted July 21, 2006 Posted July 21, 2006 QUOTE No score marks For my own peace of mind... The score marks in the picture are honing marks and are perfectly normal. If your engine bores are smooth and have no honing marks like those, then the bores are b*******ed and they'll need honing, or a rebore... Oh, and rust on an ally engine? I worry sometimes... Quote
Mike H Posted July 21, 2006 Posted July 21, 2006 The bottom picture is of the outer edge - the one that gets all the thrust. It's covered in a lot of oily gooey cleaning stuff which is all the brown you can see. From the top (of the picture) there are honing marks, a smooth band where they have dissappeared, a lighter coloured band where the ridge is, then the chamfered edge at the mouth of the piston. The smooth band is because it's the thrust side of the cylinder. The lighter coloured band is all the deposits from combustion and indicates how far up the bore the piston rings go. Like I say, you won't really know how big your ridge is until you have it hot tanked or something as it's only then that all the deposits come off. When I had mine rebored I took my pistons too so each bore is sized for it's own piston rather than being std bore +.020. Did you number your conrods when you took them off? Mike Quote
adamnreeves Posted July 21, 2006 Author Posted July 21, 2006 No score marks For my own peace of mind... The score marks in the picture are honing marks and are perfectly normal. If your engine bores are smooth and have no honing marks like those, then the bores are b*******ed and they'll need honing, or a rebore... Oh, and rust on an ally engine? I worry sometimes... I was joking about the rust, ali rust is not red, it is greyish. The redish colour is probably light brown in reality, which is a good sign for this engine, must be low mileage example. I was not suggesting that the marks in the bore where score marks. The score marks I have seen always run vertically. Honing is only usually done to 1 thou and after 128,000 miles I would not expect to see any sign of honing. Honing is only done to help bed in the piston rings anyway. Also honing was not done on these engines by the manufacturer at this time. For these reasons as I understand it, this is why earlier engines needed to be ran in over a longer period than today's engines, as today's engines the bores are honed, in the past they didn't bother/understand. Oh, I am going for a 20 thou rebore and hone. Quote
adamnreeves Posted July 21, 2006 Author Posted July 21, 2006 The bottom picture is of the outer edge - the one that gets all the thrust. It's covered in a lot of oily gooey cleaning stuff which is all the brown you can see. From the top (of the picture) there are honing marks, a smooth band where they have dissappeared, a lighter coloured band where the ridge is, then the chamfered edge at the mouth of the piston. The smooth band is because it's the thrust side of the cylinder. The lighter coloured band is all the deposits from combustion and indicates how far up the bore the piston rings go. Like I say, you won't really know how big your ridge is until you have it hot tanked or something as it's only then that all the deposits come off. When I had mine rebored I took my pistons too so each bore is sized for it's own piston rather than being std bore +.020. Did you number your conrods when you took them off? Mike Very enlightening Mike. What prefix is the engine? Regarding conrods, I have not ventured to the bottom of the engine yet, I am planning on doing this at the weekend. Good tip regarding the piston bores, I am planning on replacing my crank, rods and pistons anyway (I know, grand ideas again!). My engine is only a 3.9 and I had eyes on a 4.8! My engine is 1989 and thus hoping that passing emissions will be made much easier for my efforts/cost. Quote
Blatman Posted July 21, 2006 Posted July 21, 2006 I thought honing was done to aid oil retention in the bores, not *just* to run in the rings. According to this on the Mahle web site honing is for making sure oil hangs around to do it's job. With that vital function in mind, are you sure Rover V8's weren't honed in the 80's? I find that statement staggering if it's true, and shows just how outdated the engineering practices were at Rover in the 80's. Quote
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