Help! Pistons Out Of Order

[WillAnton]

Gents,

 

I'm sure this is a story a lot of you can relate to...

 

I was disassembling the 16v 4age I'm putting into my ke38 wagon. After taking the pistons, rods and bearings out, I put them into seperate bags and lined them up in order. Here's where it gets crazy... I was propositioned into a three way by 2 swedish ladies who came walking through the front gate. In the throws of passion, the bags containing said engine components got moved before I had a chance to mark the bags with their respective order numbers! CHAOS!

 

Now, having finished the marathon session with my new foreign lovers, I'm back to working on the 4a.

 

I've attached photos of the markings on the bearing end caps.

 

As far as I can tell, three pistons are identical and one is different.

 

Three of the pistons have a '2' on the side of the bearing end cap and a '1' on the bottom. The other one has a '1' on the side and a '3' on the bottom.

 

Can anyone help with this conundrum?

 

[B.L.Z.BUB]

Gonna need pics of the ladies as well, for science.

[Banjo]

I wish I could relate to all your story. What was the attraction. Did they drive a Corolla, or did you have a Volvo parked in your driveway at the time ?

 

Do the pistons have 1,2,3 & 4 stamped on the top face ?

 

Cheers Banjo

[WillAnton]

B.L.Z BUB, I'll see if I can find some. Lense was a little foggy though.

 

Banjo, that would be ideal! Sadly no.

[Banjo]

Seeing it was the girls that got you into this mess, then you should get them back around to sort it out for you.

 

The casting number on the bottom of the bottom conrod slipper bearing cap means nothing. It is the stamped numbers on the side of the conrod & cap that should match.

 

It could be that these are not original to this engine, and that they have been mixed up, or line bored as conrod/cap pairs previously.

 

The rod & cap are usually ground in pairs on the side, where the numbers are eventually stamped. If you look at the third picture in your original post, it looks like the grinds do not match up. This may be because of the casting itself, but maybe because they were never ground together originally, and are a mixed pair.

 

 

Cheers Banjo

Edited March 12, 2013 by Banjo

[WillAnton]

That is entirely possible as this engine came out of a drift car and was turbo'd at some point. Some internal mods may have been performed.

 

So...what happens if I just go and pop the pistons back in and hope for the best? They all seem to fit but apparently the stamp on the botoom is a tolerance designation. I may have to go and get some digital vernier calipers and see If I can sort it out that way.

[CorollaNut68]

the most obvious would be after you tighten everything down and then can't turn the crank.

I didn't see any in the pics but mine have marks stamped in the sides across both halves that line up when the correct halves are together. A different mark on each set, like the "D" in the top pic and numbered 1,2,3,4. on the bottom, so someone probably used whatever they had but would have had to bore them....and did not mark them. It's gonna be a real b**** to sort out.

[altezzaclub]

Pay the money and have an engine shop measure crank, bores, pistons and big ends with the caps on. They can sort out which will be OK with which, and you just chalk it down to education, which is always expensive.

 

When you have it right, use a centrepunch to put a dot on #1 rod and cap, two dots on #2 rod and cap and 3 dots on #3...

 

three pistons are identical and one is different.

if it was mismatched when you bought it I would have it all measured up before assembling it again. Never trust someone else's work!

[oh what a nissan feeling!]

I may have to go and get some digital vernier calipers and see If I can sort it out that way.

 

Doubt that very much, at best you will end up more confused. Take it in and get it measured.

[ke70dave]

pPending your cashola situation, just properly rebuild it?

 

New pistons and rings, new big end bearings.

 

Do conrods care what bore they are in if they have new pistons, piston rings, and big end bearings?

 

Might be a question for the machine shop that you get to hone the block.

[WillAnton]

Righto. Looks like I'm off to a shop for some help. Was hoping that it could be done all DYI.

 

Not sure if I'll replace the pistons and big ends though. They're in really good shape. I only took them out due to a tiny bit of surface rust in one of the bores. Ah well. RDO tomorrow so I'll see what they say. I'll post up what they said in case anyone else is stupid enough to get themselves in this situation?

 

Am honing the block myself.

[altezzaclub]

Am honing the block myself.

In that case definately get them to clean & measure everything. They can tell you which piston should go in which hole from the wear sizes, and how much of a hone each cyl will stand, and if the crank is straight in the block..

 

It would be sad to rebuild a dud motor because someone else threw all his rubbish bits together to build a quick sale. That is what we found with the "18RG motor from my race car, freshly rebuilt..." :glare:

[oh what a nissan feeling!]

Rod caps have to go with the correct rod, pistons with new rings should go in the same hole, but don't have to as such. a crappy supercheap 'hone' on a drill is not a proper hone, not even close.

[styler]

One trick is to mix and match for a while and feel the joins and fit by hand if you have the magic touch,

seeing since two swedish ladies just walked in for a 3 way this should pose no problem!

[Banjo]

Hi Will,

Found this picture of conrod/cap matching marks you can do with a centre punch or drill. This is not a Toyota engine, but it gives you the idea.

 

 

This is what Altezzaclub was referring to in his first post above.

 

It tells you which rod & cap are a pair, & which cylinder it belongs to.

 

Cheers Banjo