Anyone have recent info on T4 piston/cylinder sets?

MGVWfan · Post by **MGVWfan** » Fri Nov 26, 2004 8:56 pm

As I approach the engine teardown phase of my 412 resto/rebuild, I'm wondering if anyone has a recent hack on P&C availability and quality for T4 engines...specifically, the 1.7L and 1.8L engines, domed, dished, and flat-top pistons. I've got an EA that's been refitted with 1.8L jugs, flat-top (I think) slugs, and heads, but I'm still curious about the 1.7L's, too. It's been over a year since there've been any postings on this topic, I figured I'd ask. I'll bet others are lurking with the same question.

Hoping I don't need the info, but thanks all the same.

raygreenwood · Post by **raygreenwood** » Sat Nov 27, 2004 1:09 pm

1.7L domes are nearly unobtanium. I had a line last year on a few sets of repco domed pistons/rings/wristpin sets....in .020" and .040" over...no cylinders...but I think they are out. Save and measure your old domed 1.7's....or maybe ask KB if they will make you a set. If you do have some made...have the dome cut .060"-.070" higher, omit all gaskets and shims, leave the deck at .035-.040" and have the valves and seats done to 42 x36. At about 8.7:1...it will run great in a 411/412 with tuned out D- or L jet. Ray

MGVWfan · Post by **MGVWfan** » Sat Nov 27, 2004 4:02 pm

Thanks for the info Ray...for completeness, what would you recommend for a 1.8L?

raygreenwood · Post by **raygreenwood** » Sun Nov 28, 2004 8:01 am

I have a line on acomplete set of Kolbenschmidt/mahle pistons/cyls. New...1.8L, they are dished. They are at least 10 years old so should be good stock. They are in the $350 range. I don't know much about that piston, but seriously....on dishes...you should be able with no detriment, to have the edge of the dish turned down to at least be flat tops. Let me know and I will tell you who has them. Ray

MGVWfan · Post by **MGVWfan** » Sun Nov 28, 2004 4:54 pm

Thanks for the info...EMAIL me, please, and I'll get in touch if I turn out to need the P&C's. Who knows, I might get lucky, the ones in there might just be good enough.

Didn't get to drop the engine on the 412 this weekend, too much to do on the wife's Voyager. 22 years of MoPar FWD's, I've NEVER seen a driveshaft snap. Yep, that's what happened, the shaft snapped at the outboard (Rzeppa) joint. Not a big job, but enough to take me off the 412 this weekend.

caxambas · Post by **caxambas** » Mon Nov 29, 2004 8:19 am

I have a set of 1.7 German P&C new in box. They are also of the dished kind.
Jos

MGVWfan · Post by **MGVWfan** » Mon Nov 29, 2004 4:09 pm

Thanks caxambas. If you'd be so kind, please EMAIL me, too, that way I'll have options, EA-original 1.7L or 1.8L (though both will require further work to get to "flat top" state...), if I need new P&C's.

caxambas · Post by **caxambas** » Mon Nov 29, 2004 5:36 pm

I send you an email, no time rush, nobody knows, nowhere advertised.
Jos

MGVWfan · Post by **MGVWfan** » Thu Jan 13, 2005 7:12 pm

Update...

Hey guys (Caxambas and Ray), since I posted this, the previous mechanic/owner (keifernet from the Samba 412 forum) has found me, he's been filling me in on the last overhaul my 412 had about 10 years ago, and I've also pulled the left head for a look-see. The cylinders appear to be in excellent shape, no perceptible wear, and unless something's very hidden and very wrong, the pistons should be too, and they're dished 1.8L Mahles (or Kolbenschmidts, he didn't remember which, but he definitely knows it's one of the two)...so, I've got a low mileage, high quality set of 1.8L P&C's already, in decent shape. Ray, you say turning the rim of the pistons down to flat-top profile shouldn't be that big a deal...then maybe that's the way to go, pull the slugs, clean them, have them turned, new rings, lightly hone the jugs to let the new rings lap themselves in better, and reassemble. What kind of $$$ is it to turn a set of pistons, usually? Thanks guys.

raygreenwood · Post by **raygreenwood** » Thu Jan 13, 2005 8:28 pm

It may be worth finding a like make of piston in the junkyard...and seeing if a good machinist/mechanic...may have an opinion of wether it could be turned down to flat tops...or more.
Have a look at your engine configuration before you start any of this. Bear in mind, that turning them to flat tops will remove even more metal than ust a dish did. In order to get a nice tight deck, you will probably need to have the heads flycut.
Domes are nice. They are especially nice in the 1.7 head. Though many complain that the 1.7 heads are restrictive and the chambers too small to have any worth, they have plenty of meat to allow unshrouding, they do benefit from cleaning up the intake side lightly....and even enlarging slightly if you go to larger (42 x 36) valves ...and say 2.0 diameter runners and careful porting on the exhaust port. But bestly...they have a nice combustion chamber shape. That includes large quench areas...and the "dimple" that is designed to interact with the domes by letting them get very close to the deck area. Perhaps with about an .040 deck, and domed pistons on the 1.8 head...a "dimple" could be easily fashioned to get some of the same interaction. Just some thoughts. Ray

Guest · Post by **Guest** » Fri Jan 14, 2005 10:32 am

That's why I posted, to get more info. Thanks for the good words Ray.