Oily Spark Plugs, New Piston Rings?

[nick9one1 2]

does this look normal or do i need new piston rings?

note the colour of the spark plugs too.

 

[westy 0]

what spark plugs?

[nick9one1 2]

you can see the bottom of them below the valves (head is upside down don't forget) the two outside ones look dry/beige/sooty, how they are supposed to look i think. but the two middle ones look oily/black

[johny105_y2k 1]

i'd say so,

but i'd wait for a more experienced opinion

[Cameron 16]

Could be piston rings or valve guides, maybe if you have a look and see if the valve stems of those cylinders look excessively black and oily. The best way to check the condition of the rings is with a compression test, but I take it you've already taken the engine apart. Im not sure how else you can test them with the head off, short of dismantling the engine further. Have a look at the bores, you should see the criss-cross pattern on them if they still have life in them. That may tell you a little more about the state of the bottom end.

[nick9one1 2]

I can still see the criss cross on the liners so I guess they must still be ok.

I've been quoted £65 for the head to be skimmed, valves faced, ports cut and they are also fitting new guides and giving it a de-coke. so that should cover any porblems from that end. I might just get some rings to be safe.

Any reccomendations on where to get them? I'd prefer an uprated set if theres not much difference in the price.

Edited September 9, 2008 by nick9one1

[Cameron 16]

That's bloody cheap! How are they going to do all that for £65? There isn't really much point in getting new rings without honing the liners or getting new ones. Not really any point in getting 'uprated' rings to be honest, not on a standard 8V. You'd be better off saving your money (standard ones are expensive enough if you buy genuine), getting OE ones and running them in hard.

[nick9one1 2]

well I'm supplying the seals myself. How much are the normal rings? I think i can get Total Seal rings from the states for £50 + postage which shouldn't be too much.

[Cameron 16]

Getting on for about £50 I think. Can't really remember to be honest, my last parts bill caused me some deep emotional trauma and I don't like to think about it. Go for uprated rings if you like, but in my hhhhumble opinion on a std 8V it's 99.75% not worth it.

Also, remember you'll have to factor in the cost of having the liners honed or buying new ones otherwise it makes fitting new rings completely pointless. Have you checked the valve stems for excess crap yet?

[nick9one1 2]

ok thankyou for your advice. no I haven't, my valve spring compressor wasn't up to the job so I took the complete head to the company that's overhauling it for me. It will be coming back assembled so ill never get a look inside. Although i will ask them what it was like. If they were ok I will have to look into honing as new liners are pretty pricey from what Ive seen. To be honest I thought I could just slip the rings straight on.

[Cameron 16]

Well you can, it won't explode or anything but it just means that the new rings won't bed in properly and you'll be down on power. That criss-cross pattern you get when the bores are new or honed acts like a sort of file and wears all the high spots of the new rings down so that they seal perfectly. After a little while it all gets worn smooth hence the importance of running it in hard.

[nick9one1 2]

well I've just had a phone call from the engineering company and they say it has 3 bent valves! 2 exhaust and 1 inlet.

[nick9one1 2]

Just rang QEP and they are sending some out today so i should receive them tomorrow! £69 for 2 x exhaust 1 x inlet and a set of cylinder liner o-rings.