piston ring questions

[3100 MPFI]

Are the 3400 SFI pistons rings the same as the 3.4 DOHC rings, or can the 3400 SFI rings be used on a 3.4 DOHC?

I know the part numbers are not the same, but are they interchangeable?

I am rebuilding that 3.4 DOHC that broke a valve, and the DOHC rings are REALLY expensive. A friend of mine has a set of 3400 rings saying that should work, but I would like some confirmation on this before I just do it.

[3100 MPFI]

anyone?

[ssdurango]

Fit the rings in the bore, measure the end-gap. ect, measure, measure measure, and you should be fine!

[series8217]

Fit the rings in the bore, measure the end-gap. ect, measure, measure measure, and you should be fine!

It's not that simple. They need to have the right ID for the piston's ring lands, as well as the right thickness. There are very specific design considerations here.

Just buy the 3.4 DOHC rings. I've found a set for less than $100. Try newengineparts.com. Shop around.

[DEI37]

Yeah, that's not an area to "cobble" on, unless you like rebuilding engines.

Autozone has a kit with head gaskets, rod bearings, ring set, and a lower gasket set (whatever that might be), for $105. The part number for that set is CH34RY01. I used '95 CS DOHC as the lookup reference.

[3100 MPFI]

well, the car is a 1995, and the thing is, I already have most of those parts.

I am only swapping out 1 piston, but I figure that I should go ahead and do them all.

For now, I am putting that twin cam rebuild on the back burner. I think I will get my 3100 running first. They both need about the same amount of work, but at least the 3100 parts are cheap.

I am not working right now, and I need to get one of these cars running before I go back to work. 3100 = cheaper parts, so I will do it first.

[5speedz34]

QQ, are all 3.4 rings the same? 91-97? Ohh and is there ever any performance gain out of rings?

[series8217]

96-97 has different ring thicknesses. They don't interchange.

Yes there can be performance gain from rings.

[Superdave]

if you have the old rings just re-use them... make sure to ridge-ream and hone the cyls first and you'll be fine.