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Scat Rod Bearing Tang.....we have a verdict!!

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 Post subject: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Fri Jul 23, 2010 7:46 am 
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I noticed, after posting in the 'you might be a gearhead' thread that there is a possible issue with the direction of the bearing tangs on my scat rods. In this picture, all of the pistons are facing in the same direction, but the tangs are not. I spend a good deal of time inspecting and measuring the rods before I installed the pistons on them making sure they were symetrical. I couldnt see any way that indicated how they should be installed, so I went ahead and put the bottom end togeather. Somehow, it never ocurred to me to look at the bearing tangs, from this picture I can now tell that 2 are installed one way, and 3 are installed the oposite way. I have a feeling it might be fine to run it this way since the rods are symetrical. Can anyone offer some insite into this?
I guess every other engine I have assembled had factory rods and I just put them back in the way they came out. I dont want to tear the bottom end back apart, but I can if I have to, its just sitting in storage right now.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


Last edited by death 4kqt on Fri Jul 23, 2010 11:17 am, edited 1 time in total.

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 8:24 am 
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hmmm, this would be good to know for sure

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 8:40 am 
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did a bunch of interweb searching and couldnt find anything too helpful. Most people have a rule of thumb (i.e. tangs towards intake or exhaust) but most of that applies to a stock rod. Since the scat appears symetrical, im not sure its important. Does the tang have any more function than just correctly locating the bearings? if it has some oiling function, it seems like its direction might be important........I hope someone has a good answer.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 8:45 am 
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Might be a good question to sent to Scat?
you have my attention now.


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 8:49 am 
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URQ wrote:
Might be a good question to sent to Scat?
you have my attention now.

that is a good idea, sent them an email.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 9:18 am 
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this is way important. at least with my 20v 4cyl it is. the scat rods should be numbered on the cap and on the big end of the rod where the cap meets. the numbers need to a) match and b) line up. you cant take a bearing cap off of rod A and but it on the big end of rod C, no bueno. also, the tang (once again for my 4cyl20v) should be facing the intake side of the motor.

edit: if i had a rod here id show you what im talking about. but if you go look at yours there is an engraved number on each one. number should be a few digits long.

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 9:24 am 
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well bearing caps are all exactly as they should be, I do know that much. I just want to know WHY the tang direction is important on a symetrical rod. I am hoping the people at scat will explain and I can offer a good answer.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 9:34 am 
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Line up the honing marks on the cap/rod. there is no such thing as a symmetrical rod/cap, they go on the way they were honed.

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 9:43 am 
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you are missing my question. The rod caps are all on correctly, im not that much of a newb. its the direction of the rod versus the direction of the piston that I am trying to figure out. Look a the picture, the tangs are all on the same side of each rod, and each cap is on the same direction it came. some of the tangs are facing the exhaust side, some are facing the intake side. I want to know which of these are correct. Most likely some of the pistons and rods will need to be removed, pistons removed from rods and the rod turned 180 degrees, then reinstalled onto piston and back into engine.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 10:07 am 
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The tangs go in whatever direction they need to go for the rod to fit properly. If the rods are symmetrical (usually are, for inlines) then it doesn't matter.

As mentioned, it only matters that you put the tangs on the same end of each rod.

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 10:11 am 
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Noisy Cricket wrote:
The tangs go in whatever direction they need to go for the rod to fit properly. If the rods are symmetrical (usually are, for inlines) then it doesn't matter.

As mentioned, it only matters that you put the tangs on the same end of each rod.

this is what I think too. I KNOW all the bearings caps are aligned correctly to their respective rods (and you can see that in the picture). I do have the feeling that I am ok, like you said.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 10:17 am 
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I'd imagine if it mattered, it would be in relation to the way the motor spun, and the tang would be on the side where it could do most to stop the bearing from spinning, but I don't know if this is actually the case.

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 Post subject: Re: Scat Rod Bearing Tang direction...is it important?
PostPosted: Fri Jul 23, 2010 10:27 am 
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bimmerboy wrote:
I'd imagine if it mattered, it would be in relation to the way the motor spun, and the tang would be on the side where it could do most to stop the bearing from spinning, but I don't know if this is actually the case.

this was my major concern.... Got an email back from Scat.

my email:
Quote:
Hi,
I have a set of your connecting rods that I will be using in my audi 20 valve turbo inline 5-cylinder engine. I have already assembled the bottom end, but I noticed in a picture that I took (before assembly) that the bearing tangs are facing different directions. I never took that into account, and I am not wondering if it is important, or if I can run the bottom end as it is. I attached the picture to the email, in this picture, all of the pistons are facing the same direction, while some of the bearings tangs are not all the same. This is how the engine was assembled. Thanks in advance for your help.
-Dana Curtis



Response:
Quote:
Dear Dana,



As long as the rods are centered on the journals you are good to go. You shouldn’t have any problems.



If I could be of any more assistance please feel free to contact me by email or by phone.


Thank you,
Michael Sutton


So I guess I am good to go!

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Fri Jul 23, 2010 4:32 pm 
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if there were a right and wrong, you would have 3 wrong ones and two right ones....but you know that is how things go. :P

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 Post subject: Re: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Fri Jul 23, 2010 4:50 pm 
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Good to know


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 Post subject: Re: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Fri Jul 23, 2010 4:54 pm 
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pkw wrote:
if there were a right and wrong, you would have 3 wrong ones and two right ones....but you know that is how things go. :P

hah, you know thats how luck would have it :D

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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 Post subject: Re: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Mon Mar 21, 2011 3:15 am 
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hi, the bearing tangs meet together on ALL engines , they do not seperate by 180 degrees,

mk


death 4kqt wrote:
I noticed, after posting in the 'you might be a gearhead' thread that there is a possible issue with the direction of the bearing tangs on my scat rods. In this picture, all of the pistons are facing in the same direction, but the tangs are not. I spend a good deal of time inspecting and measuring the rods before I installed the pistons on them making sure they were symetrical. I couldnt see any way that indicated how they should be installed, so I went ahead and put the bottom end togeather. Somehow, it never ocurred to me to look at the bearing tangs, from this picture I can now tell that 2 are installed one way, and 3 are installed the oposite way. I have a feeling it might be fine to run it this way since the rods are symetrical. Can anyone offer some insite into this?
I guess every other engine I have assembled had factory rods and I just put them back in the way they came out. I dont want to tear the bottom end back apart, but I can if I have to, its just sitting in storage right now.

Image


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 Post subject: Re: Scat Rod Bearing Tang.....we have a verdict!!
PostPosted: Mon Mar 21, 2011 6:20 am 
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krawczuk wrote:
hi, the bearing tangs meet together on ALL engines , they do not seperate by 180 degrees,

mk


death 4kqt wrote:
I noticed, after posting in the 'you might be a gearhead' thread that there is a possible issue with the direction of the bearing tangs on my scat rods. In this picture, all of the pistons are facing in the same direction, but the tangs are not. I spend a good deal of time inspecting and measuring the rods before I installed the pistons on them making sure they were symetrical. I couldnt see any way that indicated how they should be installed, so I went ahead and put the bottom end togeather. Somehow, it never ocurred to me to look at the bearing tangs, from this picture I can now tell that 2 are installed one way, and 3 are installed the oposite way. I have a feeling it might be fine to run it this way since the rods are symetrical. Can anyone offer some insite into this?
I guess every other engine I have assembled had factory rods and I just put them back in the way they came out. I dont want to tear the bottom end back apart, but I can if I have to, its just sitting in storage right now.

Image

the question was not if they mate together or not, i know they both end up on the same side. The question was to the tangs go on the leading edge of the rod or the trailing edge. The guys at SCAT told me it did not matter.

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Dana

-1990 90q 1.9tdi swap in progress
-4kq efi 10vt<- sold
-99.5 f250 6-speed superdooty diesel
-1990 90q 20vt: 3b swap >sold
-1990 90q 20vt: 11.7 @124.5 >sold
lots of other audis that are long gone


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