Cords piston rings

[Stevelivingfree]

I have done a search and can see no mention of Cords Piston rings. Has anyone experience with them in a Fiat? They seem to have been popular in the 50-80s as a way to bring more life to an engine that is starting to smoke. The following is a link to their website - http://www.cordsduaflex.com/index.html. A conversation with them suggested their rings could take care of up to a 12 thou gap between cylinder & bore, almost double the 6 thou that appears in my manual . They seem to be regular conversation on some of the old British car forums.

[maxdog]

I used Cord rings in my old banger , oil guzzling car back in England 50 years ago . They were not much more effective than the rings I replaced . This may be because the bores and piston ring grooves were too far gone. The block really needed to be rebored but was already at its maximum oversize .
Steed

[ORFORD2004]

I use total seal ring

[So Cal Mark]

if the bore is that worn, why would you disassemble the engine and merely replace rings? If the piston can rock due to a worn cylinder, not only will the rings wear quickly but you'll also get weird wear patterns in the cylinders

[Stevelivingfree]

Thanks for responding.

I seem to have some wear in #2, but the other 3 are not too bad. I am looking to get a non smokey version of my current '72 and am looking at lots of options, from a Cdn$5k rebuild plus shipping to (& from) Ohio or Wa to just getting her running again. An oversize bore means cutting and sleeving or bigger pistons. Did not get a warm fuzzy talking to Vics about oversize piston availability. Hope to be driving it this summer.

Rings and bearings I think I can do myself (will be first time in a bottom end but I have a trusty Haynes manual....Risk is I do not know what I do not know..), pulling, stripping for bore work and rebuild seems like a big step for my limited knowledge. Local machine shops (Vancouver Island) do not instill confidence ~ cannot get parts, never looked at a fiat, etc. and am not 100% sure I want to spend Cdn$5-6K. Seems like a lot of cash to run for maybe 2-3k Km a summer when I see some nice Ca versions looking for sale with this work already done at ~ Cdn $10k. Figure if worn bore rings can get me another 20k Km over 5 years, what does it mater how the bores end up as there is still a later option to bore and sleeve. Car also needs shock towers done, other than that is in nice shape but without more love than I will give her will never be a show car.

Hence the sniffing around for the bodger options...Orford2004 - how are the total seal rings working for you?

On another site I had comment that these pistons may not be 1608 stock. Anyone care to share an opinion?

[ORFORD2004]

Orford2004 - how are the total seal rings working for you?

No problems with my turbo

[So Cal Mark]

I wouldn't plan on getting 20000 good miles with worn cylinders, you won't gain much just replacing rings. I'd expect compression loss and oil usage

[dom]

The first engine I rebuild was my 1608. I had no experience. I found a good machine shop to do the bore work. They don't need to be familiar with fiat engines just make sure that they do good work. Assembly was easy and straight forward. I went .4 mm oversize. You should be able to find oversize pistons, I found a few sources. Bottom line it was not complicated and the result was perfect, probably better than if I paid a builder to do it for me. Why? I took my time. i suggest to either leave it or do a rebore, doing just rings will accomplish nothing except waste your time.

[Stevelivingfree]

Thanks for the votes of confidence and the suggestions to just get on with it...

If I go the way of 'get in and get dirty' do any of you have any recommendations for how to overcome the fact that I do not know what I do not know?

I have a recent Haynes manual and 2 dog eared copies of the Clymer Publications (1977, 3rd edition & 1985 7th edition), is there other valuable reference material I should get?

For example, as I have not been inside one of these before, I do not know if the pistons I see with the head off are stock or if someone has already been and played with this engine. See photo above... Can anyone start me off by suggesting how I can check? The Clymer manuals show flat top pistons in the sketches but no photos of actual pistons.

If these are not stock, which I am beginning to think may be the case, what other changes could I expect to see? Would someone go to the effort to change pistons and leave cams standard? How can I check my cams?

Should I try to reuse them and sleeve bores or look for some oversize stock pistons? - no 93 oct in my neck of the woods; even 91 is not available at all local gas stations.....

I can take photos and am not afraid to ask questions... One long thread or a hundred short ones?

[RRoller123]

There is a "Shop Manual" available that puts the Hanes and Clymer to shame. Definitely do a search and get one of those. None of them are perfect, but it is about a 9/10 where the Hayne's etc are probably a 3-4/10. It will have good spec tables, plenty of pictures (if you get a well printed copy). Hundreds of pages. There are also field service bulletin letters published elsewhere on the net that are of value too.

[So Cal Mark]

it really doesn't matter what pistons are in the motor if you're going to replace them. Buy flat top pistons in oversize and bore the engine for proper clearance. Any machine shop that is doing block work can do this. If you were planning to replace rings, it's not much more to do a complete rebuild.

[dom]

Knowing that you don't know is what you need to know, it's a good sign.. It will be work and time spent asking questions checking sources and learning.. I was like you and had to figure this all out step by step. In the end it will seem so simple but in the beginning I know how you feel there are only questions. I can check to see if I have any stock pistons for a 1608 to compare if no one knows off hand what they should say on top. How do you know that number 2 is worn or that your smoke problem is from worn rings. Did you do a compression check or leak down test. You cannot tell by looking

[Stevelivingfree]

Thanks again Dom for the constructive suggestions. Car was smoking like a banshee. Burnt a quart in approx 300 miles. Smoke was always present at start up, but also a big puff on rev climbing in low gear followed by consistent stink behind me.

Plugs dirty & covered in carbon chunks.

Did compression test dry, then wet.
Dry = 145, 145, 150, 140
Wet = 165, 170, 190, 165 I then ran through them again and got
Wet2 - 160, 160, 170, 155
With hindsight, I may have put more oil in #3 and less in #4 as my oil can ran out at the start of #3.

Pulled head. As expected, lots of carbon inside the domes and on top of pistons. With the springs out there is plenty of slack between the exhaust valves and their guides. There is no carbon to speak of behind the inlet valves. There is some crud on the back of the exhaust valves but not ridiculous.

Found a local bush mechanic who came round for a fee. He seemed to think the carbon behind the exhaust and my compression numbers suggested the valve seats were doing their job.

He measured my bores with a T bar tool, did one reading for each piston and told me #2 was odd. I repeated multiple times to try and check repeat-ability of measurements , also did at top (about 1/2" below the brown ring) & bottom (at top of piston on lowest point) of bore. Got some fairly repeatable numbers. I am sure they are not 100% accurate but they were measured in the same fashion multiple times and I think give me a fair comparison between the bores. #4 still confuses the hell out of me but if I assume it has no wear and is the nominal 3.150, I guess I have approx 2 thou of error on my vernier. This puts actual for #2 @ 3.159 = 9 thou of wear.

Results.
Bottom of bore Thrust direction = 3.151, 3.152, 3.1505, 3.148
Top of bore Thrust Direction = 3.154, 3.157, 3.1525, 3.154

Bottom of bore Fore-Aft = 3.151, 3.1515, 3.150, 3.1485
Top of bore Fore-Aft = 3.151, 3.1515, 3.150, 3.150

Only marks on piston top is an arrow pointing in direction of inlet.
There is also a number on the inlet cam - 36 in a circle.


I have not yet removed the sump.

[dom]

If the pistons only have an arrow then they are stock. Oversize pistons will have the amount of oversize and an arrow stamped on the top. Not sure about the cam but it is probably stock which is what you want unless you want a high HP build. There should be enough material in the cylinders to do a rebore since it has not been done before but I am not sure about number 2 or why that even happened.
Being that your compression is good your valve stem seals may be an issue. Also make sure your crankcase ventilation system is not plugged.

[RRoller123]

Yeah, with good compression numbers like that, it may be that you are pulling oil up the breather and burning it, causing the symptoms.