volkswagon 1.8L piston orientation

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machinedave
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volkswagon 1.8L piston orientation

Post by machinedave » Fri Mar 09, 2018 11:26 am

I am working on a 2000 1.8L 5 valve per cylinder VW/Audi engine. My customer brought in aftermarket H-beam rods and new pistons. The original pistons and rods are gone. I need to know if the bearing tangs go on the intake or exhaust side of the piston. My AREA manual does not say and I spoke with AREA tech and the diagram they have only states witch side the number on the rod goes. Can anybody help me out? Thanks, Dave.

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Re: volkswagon 1.8L piston orientation

Post by Scotty » Sat Mar 10, 2018 12:07 am

If the aftermarket rods have no offset nor a squirter in them it should not matter which way the brg tang goes, the piston orientation has to right though.
Apart from being ocd about the rod orientation....
I get the ocd thing aswell and its always nice to know its done the same as factory.....

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Re: volkswagon 1.8L piston orientation

Post by modok » Sat Mar 10, 2018 2:28 am

The rod has bumps on the side where the bolt is. Bumps face the timing belt. Bumps are on same side as tangs.
Look at pictures to see which side the bumps are on.
I don't know which side the is intake or exhaust.
Image
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Re: volkswagon 1.8L piston orientation

Post by gunt » Sat Mar 10, 2018 5:35 pm

Bumps on the rod face towards timing belt , i always place the tang so they are under pressure on the upward [ no load ] exhaust stroke and no tang under pressure for compression stroke , from what I remember nearly everything ive seen is this way

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Re: volkswagon 1.8L piston orientation

Post by modok » Sun Mar 11, 2018 3:37 am

There is no meaning, at all, to it, but doing connecting rods you tend to develop a very rigid procedure for how it's done. Almost like a ritual.
Part of the ritual is recording which way the rod goes on the pistons, and putting them on THAT way, then double checking to make sure you put them on that way.
If he skips part of the ritual.....it's going to result in a "I think I left the oven on" feeling, if not a complete mental seizure.

So, even though it does not matter, it does matter.
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Re: volkswagon 1.8L piston orientation

Post by 4vpc » Sun Mar 11, 2018 6:58 am

Haha, I always put the writing on the rods facing the same way, it just looks right to me and anyone else who opens it up in the future.
There is no S on the end of RPM.

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Re: volkswagon 1.8L piston orientation

Post by Kevin Johnson » Sun Mar 11, 2018 8:31 am

https://www.ebay.com/itm/01-VW-BEETLE-1 ... SwJLJZgq29

There are usually any number of OEM rod and piston assemblies available on eBay with multiple photos. You should be able to answer your question by close inspection of the pictures.

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Re: volkswagon 1.8L piston orientation

Post by peejay » Sun Mar 11, 2018 11:09 am

modok wrote:
Sun Mar 11, 2018 3:37 am
There is no meaning, at all, to it, but doing connecting rods you tend to develop a very rigid procedure for how it's done. Almost like a ritual.
Part of the ritual is recording which way the rod goes on the pistons, and putting them on THAT way, then double checking to make sure you put them on that way.
If he skips part of the ritual.....it's going to result in a "I think I left the oven on" feeling, if not a complete mental seizure.

So, even though it does not matter, it does matter.
THIS!

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Re: volkswagon 1.8L piston orientation

Post by Kevin Johnson » Sun Mar 11, 2018 3:06 pm

gunt wrote:
Sat Mar 10, 2018 5:35 pm
Bumps on the rod face towards timing belt , i always place the tang so they are under pressure on the upward [ no load ] exhaust stroke and no tang under pressure for compression stroke , from what I remember nearly everything ive seen is this way
Yes, and the Honda engines with counterclockwise rotation also follow that theory. With rods that are completely (or intended to be) symmetric and tangless (cracked or otherwise) their orientation should not matter. The Porsche 928 rods were handed by their morphology and so had to be carefully installed so that the piston pin offset was correctly oriented by bank. I believe some British engine rods were offset by bays 1,2 versus 3.4. It is certainly ok and perhaps desirable for mechanics to be OCD. I liked seeing the daubs of paint that indicate a step had been completed in the factory performance build shops.
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Re: volkswagon 1.8L piston orientation

Post by machinedave » Sun Mar 11, 2018 3:13 pm

My customer has a second block that I am also going to machine so he is going to bring in the OEM pistons and rods out of the next block for me to look at. I think you guys are right that they could go on either way but the OCD in me wants it right.

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