Piston Rings

[MarkieB]

so as I may have to adjust the cylinder measurements on my belching n/a d, there's a possibility, even temporarily, of needing to make certain adjustments from the standard [including standard oversizes]; for instance keeping the normal pistons temporarily, while fitting marginally oversize new rings. $57.83 for a dedicated piston ring filer sounds a bit steep, although it looks as though good swiss files aren't such bargains either. Is it worth it, do standard rings need filing normally, is filing your own rings even a good idea? On the swiss file front, what kind of grade would be good for filing rings, or as the rings are hardened would a diamond file, what grade, be necessary?

I gather that a groove cleaner is a costly replacement for a broken old ring that serves just as well, so I hopefully wouldn't need that; is the ridge reamer a good idea to even the grind?

http://www.mytoolstore.com/kd/kdengi07.html

Am I right in thinking it's possible to at least deglaze cylinders with a hand drill [not bench], so potentially feasible without removing the engine?

[Les Henson]

You can as a somewhat temporary measure replace the piston rings and then get many more miles out of an otherwise worn-out engine. If your engine is badly worn (to the point of piston slap), then fitting new rings will have very little effect and they may well break within a short time - therefore wrecking your engine. You need to measure the bores, they go egg-shaped with wear. Each bore has to be measured at 4-points - 3,6,9,&12 'o' clock posituions to determine ovality of the bores. A quick view of the state of the bore will be what you can see down the side of the pistons when the head is off and they are halfway down the bore.

You can use a piece of old piston ring to remove excessive coke from the ring grooves, so there's really no need to use a fancy tool as long as you're careful. As for the lip at the top of the bore - I would only remove carbon build-up as the lip will help to retain compression in what will still be a worn engine. The Rings - get the next size up, and then use a diamond file, carbon stone, or wet grinder to remove metal until the ring gap is as it should be for new rings. As for de-glazing, I didn't think that with modern fuel you get that problem anymore?

Les.

[landi41]

Yup! i have named this "The Mexican Motor Job"

Here is how it works..........

re-new the connecting and main bearings with standard......

use the next oversize piston rings and file the end gap ( with afore-mentioned tools) to .003 (thou)

If you are brave............. Run a ball hone up and down the cylinder bore a few times......... before doing anything...............

Button everything up and enjoy many more miles of "Happy Motoring "

[MarkieB]

Thanks guys, that gives me a bit of optimism. May prevent the locals from getting restless too, providing my miles of happy motoring are less smoky than they have been up to now. Basically that hopefully gives me the time to either think of full-on overhauling, or of putting a 200tdi in, or both [to keep a spare engine in reserve]

I've just got a set of straight stones, so I hope it's possible to make oil grooves with coarse straight stones, or perhaps I'll need another set. Suggestions are I think 240 grit for ball hones, I've got 180 [coarse] + 280 grit straight stones.

I'll lift the head in the near future for an inspection at least, so I'll report on whether there is glaze; it's more stuff such as ovality/grooving that I think I'll see, possible piston damage; I'm hoping to possibly make minimal improvements on that when I temporarily talk chicano to my engine B)

What I'm considering is trying to order at least 1 oversize piston on sale or return, then at least doing one cylinder properly, so that could involve removing ridges, grinding the cylinder to +.020, etcetera

found a good web resource, looks as though they could do non-standard o/s too:

http://www.hastingsmfg.com/service_tips.htm

Diamond file for the new rings it looks as though it'll be then.

Main bearings themselves may have to wait; the cork seals business sounds a bit involved, plus I'm hoping to avoid lifting the engine itself for the time being; although I'll sort the connecting bearings.

My only other question is this Hylomar business, most discussions seem to involve 200tdi engines, showing a difference of opinion between the 'dry' team or the 'Hylomar only' team; is my n/a d less sensitive, could I basically refit the head without Hylomar?

[Niall_CSK]

Definately run a hone to break any glaze or laquering whenever fitting new rings. You still can get laquering that has the appearance of glaze with modern fuels depending on how low the sulpher content, how they interact with the LO you are using and what type of driving you do. Quick test is to rub the bore with a white cloth soaked in clean deisel, that will remove carbon deposits (poorly burnt fuel or LO), if the cloth comes up relatively clean try the same again with some vinegar, if the cloth gets brown then low temperature laquering is preventing the rings getting the best seal they can.

Even if things are a bit tired, unless the bores are really oval which as said is well worth checking, new rings and a glaze bust will reduce you blow past and bring the power back a bit.

Run in with a decent mineral oil and then change to a high grade (low sulphur) mineral or semi synthetic oil.

[Les Henson]

I've never used a gasket sealant when replacing a head gasket. The machined faces should be good enough to do the job with a new gasket and nothing else.

Les.

[MarkieB]

Yup! i have named this "The Mexican Motor Job"

I hope you're not thinking of this kind of work:

it'll be a while before my welding skills are up to it

[white90]

Nice to see a rock behind the wheel to stop it rolling away, Very saftey minded

[Les Henson]

Christ that looks soooooooo dodgy!

Les.

[John_T]

I don't know if you can get them (or something similar) but I have fix plenty of smokers in the past for skint owners by using "Apex" piston rings. These were cast iron with a stepped top ring to take account of the wear ridge in the bore. They were easy to fit and gave another 10k before smoking again.

[Des Morgan]

Christ that looks soooooooo dodgy!

Oh, I don't know. He has got 2 pieces of timber holding it up, so he can't be all that irresponsible.