Board logo

cleaning a rusty engine block- how to?
Craigorypeck - 31/8/12 at 10:11 PM

I picked up a block thats in not the best of shape. the bores aint too bad but the outside, crank case area and places where a wire brush and electrolysis wont reach are rusty, any locost ideas folks? Dont want rust floating about!


myke pocock - 31/8/12 at 10:19 PM

Recently hear of someone using Cillit Bang on a block but must admit that was an alloy one. Worth a try???


crutch - 31/8/12 at 10:53 PM

apple cider vinegar, or white vinegar.

give it a good soaking and then wire brush it.


mcerd1 - 1/9/12 at 12:02 AM

thats a rusty pinto
does it look that bad in real life of is the camera playing tricks ?

I spent ages working on mine with various chemicals and it never cleaned up the way I'd have liked

in the end the engine builder hot dipped it (not sure what he had in the tank exactly) when he was reboring it anyway and that worked a treat

from this
pinto block before
pinto block before


to this (with a bit of paint to of couse...)
pinto block after
pinto block after




[Edited on 1/9/2012 by mcerd1]


Craigorypeck - 1/9/12 at 12:23 AM

no, thats how it is mate... i dont care bout the outside cause a wire brush will sort that to a reasonable state but the inside is the problem. is it even worth trying to sort?


cliftyhanger - 1/9/12 at 05:31 AM

looks like it will need a rebore with that rust?
Get a machine shop to clean it, for whatever it costs it will be a proper job and less grief.


Nickp - 1/9/12 at 07:02 AM

Remove all core plugs etc then blast out every orifice with a hot pressure washer, until nothing else comes out. Then some sort of chemical dip at an engineering shop I'd say.


snapper - 1/9/12 at 08:23 AM

If the bores arnt pitted it'll take a hone, if they are then an overbore.
Mains are ok with a light emery and new bearing shells
Block face and sump face will need a light skim
Oil filter face needs to be reasonable for an oil tight fit

[Edited on 1/9/12 by snapper]


imp paul - 1/9/12 at 08:44 AM

you could soda blast as its very very gentle and leaves a very smooth finish . it would be like new and as for the bores there not that bad as above run a wet hone down them all should be sweet or for locost way get a wire wheel on angry grinder the type m mart sell looks like brass in colour and work very well but do shed wire a lot lol i did a mini block this way

[Edited on 1/9/12 by imp paul]


David Jenkins - 1/9/12 at 12:49 PM

quote:
Originally posted by cliftyhanger
Get a machine shop to clean it, for whatever it costs it will be a proper job and less grief.


That's what I did - I asked the people who did the rebore (Scholars) to give it a thorough cleaning inside and out, including all of the oil & water passages. Didn't cost a lot on top of the rebore, as I guess that all they do is remove all of the plugs and stuff and shove it a machine; not a huge amount of man-hours. It certainly was squeaky clean afterwards - I had to brush oil on the inside shortly after I got it back as it was starting to show a faint film of rust!


Craigorypeck - 1/9/12 at 02:36 PM

I have just read that molasses gets rid of rust, but takes ages. Gonna give it a while in the electrolysis bath to start.
I asked the guy where i get machining done about his dip and he said it wont take rust off, just grease and oil.


mcerd1 - 3/9/12 at 07:22 AM

quote:
Originally posted by Craigorypeck
no, thats how it is mate... i dont care bout the outside cause a wire brush will sort that to a reasonable state but the inside is the problem. is it even worth trying to sort?

sounds like its worse inside than mine was
mine wasn't very rusty inside, it just took a hot dip followed by a rebore and a grind to flatten off the top


ss1turbo - 4/9/12 at 12:55 PM

Cola...full fat, cheapest brand you can find.

If you don't believe me, try the penny trick first.


Craigorypeck - 7/9/12 at 06:28 PM

electrolyses did a good job, then a wire brush attachment on a drill to get the layer of muck off..





The bores dont seem too bad but 2 have lite pitting that can be felt under finger. I cant give it a bore or it'll be too big, a piston ring from the old cracked block in this block has the exact same gapping, (it will be getting new rings) most i can give it is a hone, a glaze busting maybe- if even, Machine shop is open after hols next week so some pro advice and measuring will be availed of. knowing my luck it'll be no good!!


mcerd1 - 9/9/12 at 09:39 AM

quote:
Originally posted by Craigorypeck
The bores dont seem too bad but 2 have lite pitting that can be felt under finger. I cant give it a bore or it'll be too big, a piston ring from the old cracked block in this block has the exact same gapping


what size are the bores at the moment ?