Piston source recommendations (nice pix :)

[worzella]

Gents and Ladies -

 

I tore down my 1975 '02 M10 this past Monday/Tuesday with my brother and am now seeking

some direction in sourcing pistons so the bottom end work can begin. The head is an E12 (stamped 82,

so a later replacement) and the cylinders have been bored once over with KS 89.22 piano tops pulled out.

 

My assumption is that the best next step is to find 89.47 second over pistons and get the bores machined

appropriately. Ahh, but the finding seems to be the first challenge. Looking for some recommendations

or advice that might not be obvious. Below is my research with a couple of questions sprinkled in to help

my education. I am just interested in a stock street occasional driver rebuild.

 

Max of course has KS at the right size but $1200 bucks!!!!!

 

 

Top End seems to be able to make anything I want for $700, but after doing lots of reading there are lots of warnings about forged

versus cast and "Make sure you know what you are doing!" I need to understand if this Top End set is appropriate for a basic stock

street rebuild

 

Walloth & Nesch looks most promising, offering Mahle at ONLY $208 each... $832 total. But I have never ordered from overseas, so

not sure if there is anything to worry about there.

 

 

And Ireland has a full +1 over offering, but if I don't need to bore the block that much it seems to me it should

be avoided. The price is awesome and the Out of Stock reflects this. I have not checked on an ETA for more stock.

And also, in all of my reading on the FAQ, there were some harsh comments about Ireland pistons.. but the posts

were 10 years old, so not sure how relevant.

 

 

Finally, the KS site itself offers Mahle for a decent price, but they too are out of stock and appear to be based in

Czechoslovakia, so dealing with that might be too much.

 

 

I can't find any piston offerings any more on BavAuto or Blunt site, but i suspect they might be able to offer them

somehow???? I think Roger's Tii had something, but they were expensive too.....

 

OK thanks for reading the whole post and givng me some clues

 

Randy

 

 

 

Edited March 17, 2017 by worzella
Political correctness

[jrhone]

Depends on the route you wanna go. You do know there are more than one type of piano tops right?  So just piano tops doesn't tell the full story. There are high compression (9.5:1) and low compression (8.3:1?). With pics you can see the differences between the two. Put an ad in the want to buy section. I did and found a good set of used pistons. Plus you may run across people who may have a new set as well. Who's doing your engine work?  They may have a lead on pistons as well. The other thing is if you go the custom piston route you may also want longer rods and shorter pistons to increase the stroke. That's the route I would go if boring and getting new pistons.  

Edited March 17, 2017 by jrhone

[02Les]

1 hour ago, worzella said:

Walloth & Nesch looks most promising, offering Mahle at ONLY $208 each... $832 total. But I have never ordered from overseas, so

not sure if there is anything to worry about there.

 

 

Note with W & N you will pay the "excluding VAT price", so the total would be around $700. However, you may get hit for duty when they arrive in the US. For some reason, I have never been charged duty on my W & N purchases, but I believe some people have.

 

HTH

 

 

[PaulTWinterton]

The Mahle pistons that W&N sell are very good quality and consistent in measurements and weight.  My machine shop loves them.

 

Ordering and delivery from W&N is near painless.  You can get UPS at a cheaper rate and 5 day delivery or DHL at a higher rate and 2-3 day delivery.  I've order a lot of stuff from them over the past few years and they make few mistakes. They take responsibility when I've had any problems or if I've been unhappy with the products.

[HBChris]

Have the machine shop check the bores before ordering next oversize, they may only need a honing.  W&N would be my source.

[otisdog]

Hmmm...W & N offers UPS?  I needed about 13 Euros worth of parts, and the shipping was 49 Euros. I asked about this, and was told that they only offer the 49 E flat rate. This was a couple of weeks ago.

So I end up making these high dollar orders to save on the shipping...

[PaulTWinterton]

1 hour ago, otisdog said:

So I end up making these high dollar orders to save on the shipping...

 

Yeah, me too.  Even UPS from W&N is not cheap and it's 5 business day delivery.

 

Most of the time you folks have it better in the US.  Domestic deliveries happen in a couple of days for little money. In Canada nearly everything 02 crosses a border and we are subject to duties, taxes, shipping premiums, and longer delivery times.

 

The upside to W&N is that I can order on a Sunday night (Monday morning in Germany) and it will arrive at my door on Wednesday morning.  Germany to the PNW in 2 days.  That's a joy.   That's using DHL at 49E.  

 

 

 

 

[Conserv]

2 hours ago, HBChris said:

Have the machine shop check the bores before ordering next oversize, they may only need a honing.  W&N would be my source.

 

+1

 

Since I'm not overhauling engines on a regular basis, I'd probably have my machine shop examine the bores, opine on what it will take to clean them up, order the pistons based on the machine shop's opinion, and then have the machine shop hone or over-bore the block when they have pistons in hand.  Conversely to Chris's point, wouldn't you be bothered if you bought second oversize but discovered you needed to bore the block to third oversize in order to clean up the bores completely?

 

Remember what happens when one "assumes".

 

Regards,

 

Steve

Edited March 18, 2017 by Conserv

[tisalover]

I have a set of mahle 89.47 low compression piano tops which just came out of a rebuilt 2000 Tilux motor. I am just going to set these Pistons aside, as I am having a high-performance motor built with higher compression pistons. The Pistons looked fine  in the car and had excellent compression all across. I would be happy to give you these Pistons, and suggest that you call my mechanic friend Neil  at 82 auto works, and offer to pay him To wrap them up, put them in a box and send them to you. They can be a gift from me, helping to make the BMW universe and you happier. I think it is reasonable to offer to pay Neil for his time and hassle of packaging, but how long can it take to box them up and send them to the post office.  Send me a PM if you are interested and I will send Neil's phone number back.

 

Best regards, Peter

[jrhone]

Maybe I missed it but is there anything wrong with your pistons?  Maybe one by hand to clean up the cylinder walls a bit, put fresh rings and bearings in the car and you are ready to go!  I'd measure the ring landings and check the pistons out.  You may not need new pistons....

[Doug Riparetti]

I have a set of S14 rods (144mm long) for $250 plus shipping. If you're gonna buy pistons, buy a set of forged JE or CP pistons, mated to the longer rod

 

831-262-2853

pro4ripper@att.net

[Mike Self]

When I redid my '73's engine at 204k, the machine shop only measured a few thousands wear on the bores; I could have gotten by with honing and standard-sized pistons.   But I had a set of new .5mm oversize sitting on my shelf, so used them.  

 

The point is, have your bores measured to see if you really need oversize pistons, and have the shop check your pistons.  If there is no excessive wear in the ring lands you might even be able to re-use your pistons with new rings.

 

mike

Edited March 19, 2017 by mike

[worzella]

Thank you thank you for all who took time to answer....

 

My quick answers back..

 

- I did not want to be too wordy in my original post (although I am usually anyway).. so I did not provide all of

   the details. Yes, of course, I am awaiting the machine shops analysis and will make final decisions based on that,

  but I was doing some homework on the assumption another overbore is in my future. I base this on measurements

   my brother and i took in his shop of the bores. They showed out of round on a quick check, but we did not go into

   deeper looks since he did not have a high dollar mic to measure the diameter.

 

- Piston tops looked OK, except for #4 which was battered!! Looks like at some point the plug tip or something broke off and

  took a ride for a while in the cylinder and crapped out the exhaust. But all four showed scuffing, with two being able to

  feel slightly the wear.

 

- But the bores looked very good and the cross hatching was intact all over, so appeared to be recent rebuild or

  decent fit of pistons.

 

- Re-using.. well, since #4 is trashed and there was scuff I am leaning toward a new set just for peace of mind and

  since I tore everything apart already. They may be current bore or once over, but I think I will look into the W&N Mahles.

 

- However, the offer for free is very tempting and I will follow up. Worst case I will get them and if I decide not to re-use them I

   promise 100% to pay it forward for free to the next person. Great offer and thanks.. I guess giving all of my Behr A/C stuff

   free to a guy in NYC a few years ago is paying back the karma.

 

OK - I wil let you know how things roll out.

 

Randy