oldguy

I've seen a lot of wrist pins and don't think I've ever seen a worn out wrist pin. More than likely if anything is worn out, it is the bronze bushing in the connecting rod.

Last time I head a head do this. There were bent valves. Perform a leakdown. If no bent valves then you do this. Remove valve cover and front cover. Mark cam gear to chain in one spot. Remove tensioner. Unbolt cam gear making sure not to drop cam gear into front cover or loosing tension on chain to bottom gear. Use the paint mark as a reference to move it the one tooth. Put the 4 bolts back in. Rotate engine with upper front cover off to verify that timing is correct.

Lemme clear something up. Std First over Second Over. In America. STD is the factory hole size. First over is sometimes called "Twenties". or 0.020" over which is 0.5mm. Second over is "forties" or 0.040" or 1mm over. (Some engines like Small block chevys etc will have 0.060 and 0.080" bores as well) Europe has this love affair with tiny oversizes. Sometimes (depends on engines and we are leaving air-cooled stuff out of this since that just messes everything up) First oversize is 0.010" or 0.25mm. Second oversize 0.020" or 0.5mm and then sometimes they will do a third oversize of 0.040" or 1mm. Other times they will stick to the traditional norms of twenties and forties. It varies by engine. To an American machinist, they will look at you like you've lost your ever loving mind if you show up with .010" pistons. Here's the reason. Your hole is out of spec and IIRC the out of spec on an 02 cylinder is like 0.003" too big. So you've got to understand the limitations of the equipment. A dial bore gauge measures diameter across the bore but not in reference to the centerline of the hole. It's just the distance across the hole. The wear in the bore is usually on one side. The thrust side. So a prudent machinist will locate off the bottom of the cylinder, where ring travel is minimal and there is little wear. Now boring a hole 0.010" (first oversize) in some engines goes like this. Set the machine up for 0.008" bore which is really only .004" off each side of the hole. Then you are going to hone out the last 0.002" of the bore to achieve a proper surface finish. Now if everything is great then yes, first oversize would work but in reality, the engines don't have sealing problems until .004-0.005" wear is in the bore. By that point, the hole won't clean up at 0.010" over. As much as people feel that the least off is the best, the reality is that most blocks will require at least 0.020". What ends up happening is 3 of the 4 holes clean up but one has an eyebrow looking wear spot at the top of the rings that won't clean up and then you do the job all over again. Most customers don't want to pay twice and most machinists are not working for free. So either buy the size he says will work or be prepared to loose it all. You can always sleeve a block to standard, that is where you cut out like 0.125" out of the block, press in a new cast iron liner, and then bore it back out to standard. Obviously expensive and time-consuming. I know the local shop here charges $80 a hole + the sleeve which is around $30-40. A sleeved block will need to be surfaced as well. It's possible to do it without but you need a very skilled hand and it still won't be as nice of a job. Now, back when these pistons were made, there were two ways of clearance. The clearance was in the piston or in the hole. A piston has about a 0.002-0.003" clearance between the bore and the piston. This is for expansion. Aluminum piston vs cast iron block. So a Mahle piston is like 88.97 (stamped on top). This indicates to the machinist that the clearance is in the piston. Not in the hole. Sometimes piston manufacturers made a 90mm piston for a bore that was 90mm. So the machinist had to make the clearance between the two and measure it out. So 90mm = 3.5433" So if you've got a 90mm piston that needs 0.002" clearance then you need a 3.545-3.546" hole. This is how sizing pistons is done, clearance is factored in, and the thought into a proper overbore size.

Are you sure they are for a 90mm piston? A 1mm oversize? or are they for stock? If they are for 1mm oversize, I will take them.

Got em here... um.. so here's what came in the mail....A nicely cast and machined piston. On just checking it with a dial caliper, there are some good things and bad things. Good Things, It uses a 02 ring package. Top ring thickness = 1.75mm 2nd ring thickness = 2mm oil ring thickness = 4mm Are these 9.5:1 euro TII pistons? Ehhh Yeah kinda Ok per the old pat allen reference sheet. it should be a 6.8mm dome. These QSC pistons are 7.2mm domes. So I'm not really crying at that stat. Lil Extra dome. lil Extra CR. Not much but you can always remove dome, never get it back. The Meh things Pin to deck height. If you use the "A" value in the scanned book drawing then you should be at 1.240" for TI cars. These pistons are 1.251" pin to deck. So again. more CR, will the protrusion be a problem? Not sure. I think if everything isn't surfaced a lot, then these will be great but if your block and head are decked you might end up with protrusion problems. I checked small bathtub and flat top and those are around 1.231". The bad things The castings look great on most of them. Some of the casting lines are not deburred. There is plenty of evidence that a little china man had a hand whizz wheel and cleaned these up. There is a buildup of extra aluminum on one wrist pin boss that I'll need to clean up with a file. Ugly yes. Structural, No. There still needs to be deburred and cleaned up. I think you could spend 10 mins on each piston, you could run them. I'll run them. I did get atleast 3-4 small flakes of aluminum casting flash / metal splinter type things off the pistons. I'll put up a video comparing them to mahle's side by side

I just bought a set off the guy on ebay. Curious what I'll get in the mail. The factory mahle pistons are no rocket science pistons and the pelican forum is talking about cylinder jugs not pistons. He accepted my "offer" of $125.. for 4 pistons that's not bad, unless they're junk...

it means the piston is 84.98mm in size for an 85mm hole The SP003 stuff is about casting runs and is irrelevant to size.

Rocker arm ratio actually changes through the rotation of the engine to be precise. The center of the lash pad isn't always the point of contact. Duration is usually measured after a certain amonut of lift. Usually enough to take up the slack in the system or at .050 because that's the amount required to compress the hydraulic tappets or lifters. On engines like ours, duration is usually measured at the factory lash or no lash. The importance of schrick cams vs stock cams is the machine required to produce. You've got to understand the cam is not a symetrical profile. Schrick cams utilize more agressive ramp profiles which result in better valve train acceleration at high rpm with better flow profiles.

Alpina gauge cluster is boop... http://www.alpinabmw2002.com/2011/03/alpina-gauges.html

head bolts prevent removal of shafts... impossible to do with head on motor.. have you tried loctite red?

I've experienced endless problems with people hell bent and determined to utilize a total seal gapless top and gapless second only because leakdown numbers win races to encounter oil control/seating issues because the gasses get between the two rings and flutter the second and the angle cut in the second does not allow proper oil control as in a conventional napier style or torsional style ring thus solving a problem that does not exist. The basic m10 ring package with a moly top. cast second and practically any style oil control ring will break in and seal acceptably on almost any hone surface unless you've broken out some exotic stone for like nicasil line bores. The basic M10 ring package does not need to be examined and replaced unless you're building a specialized race motor.

found your problem There is no HP in an m10 to be gained by utilizing these and they require specific cylinder wall roughnesses. This is especially true if you're utilizing a gapless second ring. If so throw it away and reinstall the piston with a plain jane cast iron ring. your problems will be solved.

before you re-engineer the planet, have you sat down with the parts book for turbos and looked up the parts by size. find it hard to believe that no one utilies those snap rings, thrust bearings, or journal bearings.

Make it out of steel. Weld it to the bottom of the strut. Powdercoat the strut/spacer combo one dark color. keep moving. Or get a "different brand ball joint" with a much thicker flange. However you want to slide it in. Someones got to see it to challenge it. Someones got to know what the original part looks like as well. If it's not shiny and your not bragging about it, unless you allow your competitors to look at your undercarriage, it will never be seen.

When I did something like this. I did clear plexiglass instead of white and then painted the back side of it. Leaves a deep clear black finish. Wraping in vinyl is pretty easy. metrorestyling has almost every vinyl you need even some very nice woodgrain prints.

not to play devils advocate but you've got to understand where the shop owner is. Hi I'm customer from 4 years ago. I paid you to do this work and I swear I haven't run this head at all. It's now cracked. Believe me. Here's some pictures I've emailed you that in this age of the internet may or may not be the head. Not as if you remember. Will you blindly send me a check for $400 to fix this without actually seeing it yourself? I don't think there is a company in the world that would do it with the argument you put fourth. It's laughable that you'd actually think they would warranty it actually. I mean take stores that have what one would consider "gold standard" return policies. Nordstrom, Walmart, Amazon. Dear Amazon, I bought this TV from you 4 years ago. I've finally got around to getting it out of the box and up on the wall. The power supply is broken and the TV doesn't light up. I'd like $400 of my purchase price back for the TV repair man. No I won't return it to you for an exchange. Why won't you just blindly send me money? I can't believe you're out to cheat me. It's an obvious flaw. Why would you ship me a TV with a bad power supply? I can't believe you're not willing to work with me. Whiney Customer. You'd have better luck going after whatever mechanic installed that head with a "fairly obvious" flaw. Didn't your engine builder inspect all the pieces before installation?

thought since there was no TII's the e21 pistons only came in one compression ratio. The E12 pistons came in 2 and the 121's came in two. while e12's look similar to e21's.. the piano is mirrored on the piston and the valve orientation is different. also to note. Since it's a 320i head, the camshaft is likely 320i and the gear on the end rotates backwards of what a 2002's is. need a different cam or dist.

you will find, in general, pistons will change the power across the board; where cams will rob from the bottom the put up top. Carbs can fix that somewhat. DCOE's can be choked to give optimal power to match the new cam power band and develop a synergistic effect. a downdraft 38 or 40 will never ever ever be on the same playing field as sidedrafts.

gotta get one ray

a crud-thug will remove material faster than angle grinder and wire wheel. I just did a section every time I sat down.

Just checked with mahle clevite.. they only list std and 10's.. ur going to either have to pony up and buy halves at dealer prices or find a crank.

I'll buy your display.. I love it... color and wood.. driving from Florida to Alaska this year and need a way to carry gear.. will send pics of it when it reaches the arctic circle...

won't be able to check till this weekend but I probably have a timing cover laying around. pay for the UPS to box it and freight it.. it's yours.

I will make it out there someday.. god that's pretty country...