EVO piston orientation

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Jul 15, 2020 | 02:17 PM

#21

Mattbastard

Grand HDF Member

Joined: Nov 2009

Posts: 4,315

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From: Tampa

Those do look like cast aluminum knock-off pistons of some kind.

Jul 15, 2020 | 06:44 PM

#22

drm1978

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Joined: Aug 2014

Posts: 302

Likes: 49

From: Gambrill, MD

Quote:

Originally Posted by Dan89FLSTC

I think it is a piston used on early Evo`s, I think they had bigger valve reliefs in them.

According to the FSM, the raised area on the wrist pin boss is the left side of piston.

Remember, OEM pistons are the same for front and rear, don`t go by valve reliefs

The wrist pin is slightly offset, that is what makes the orientation of the piston critical.

OEM pistons use the raised portion on the pin boss to denote the left side of piston, later part number OEM pistons use an arrow to denote front.

This piston has both markings...

According to the Factory Service Manual for my 1993 FLHTCU...

"The arrow on top of the piston points to the front of the engine"

-Dave

Jul 20, 2020 | 11:12 AM

#23

Dan89FLSTC

Seasoned HDF Member

Joined: May 2008

Posts: 21,143

Likes: 12,707

From: South Carolina

Quote:

Originally Posted by drm1978

According to the Factory Service Manual for my 1993 FLHTCU...

"The arrow on top of the piston points to the front of the engine"

-Dave

OP is not interested in what we say, he is listening to the guy who has been putting them in backwards for 20 years...

Not sure why he came here and asked...

Last edited by Dan89FLSTC; Jul 20, 2020 at 11:13 AM.

Jul 20, 2020 | 05:27 PM

#24

franka

Thread Starter

Intermediate

Joined: Jun 2020

Posts: 27

Likes: 4

From: crawfordville

I came here for advice. i got different opinions here that were more confusing. I was sure the arrow went to front but after they showed up with arrows marked all over then maybe i had something i had never seen before. I was just making sure i was right. They went in arrow to front. But i guess there are smart *** every were you go. Just looking for confirmation not smart *** comments.

Jul 20, 2020 | 05:47 PM

#25

Dan89FLSTC

Seasoned HDF Member

Joined: May 2008

Posts: 21,143

Likes: 12,707

From: South Carolina

You got conflicting instructions from the people who sold you the pistons, not from me.

I told you how they were supposed to go in, raised portion on wrist pin toward left, and arrow toward front.

You said the guy told you that the raised part on the wrist pin goes toward the cam, which was the opposite of what I told you.

Go back and read your own posts.

Now you are saying they went in with the arrow toward front (which is the way I told you from the beginning).

Bye

Last edited by Dan89FLSTC; Jul 20, 2020 at 05:53 PM.

Jul 20, 2020 | 06:28 PM

#26

Dr.Hess

Seasoned HDF Member

Joined: Aug 2007

Posts: 8,199

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From: NW AR

My book (1986 FSM) says:

Jul 20, 2020 | 06:39 PM

#27

Dan89FLSTC

Seasoned HDF Member

Joined: May 2008

Posts: 21,143

Likes: 12,707

From: South Carolina

Quote:

Originally Posted by Dr.Hess

My book (1986 FSM) says:

I already posted that but the OP wasn`t havin any....

Jul 20, 2020 | 07:22 PM

#28

Beemervet

Ultimate HDF Member

Joined: May 2006

Posts: 6,590

Likes: 444

From: Ohio

Quote:

Originally Posted by franka

But i guess there are smart *** every were you go. Just looking for confirmation not smart *** comments.

Another satisfied individual!
(What we have here is a failure to communicate)

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Jul 20, 2020 | 08:09 PM

#29

98hotrodfatboy

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Joined: Mar 2010

Posts: 21,093

Likes: 7,622

From: Poolville

It's not easy being a teacher some will listen and others will listen to too many and get confused.... As a novice it's hard to decipher between right and wrong... At times there will be conflicts We all have them... I'm just glad the OP put that one piston in that had the arrow pointing forward in the front cylinder pointing forward cuz that definitely was the exhaust valve relief from the top of that piston...