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Discussion Starter #1
I am rebuilding a 1.9 and I can't find the acceptable journal diameters. Does anyone happen to have them? Thanks.

-Walt
 

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Discussion Starter #3
Thanks- another friend dug up an old manual with the numbers I need. Anyone have a set of standard 1.9 HO pistons they want to get rid of?
 

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Are you asking for new or used pistons, because it's not a good idea to just slap in any old piston; it won't seal properly. they wear according to the engine they're in. For about $50 I know you can pick up a new set of stock (but heavier duty) cast pistons.
 

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Discussion Starter #5
Are they dish, dome, or flat top and where can you get them? As of now I have pistons from a 90 lx and I am going to be using a hemi head. I would like to get a set of domed or at least flat top pistons to bring the compression back up.
 

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Watch the years though, the compression distance(distance from centerline of wrist pin to "top" of piston) is different between 1986 and 1987. 1985 and 1986 are 1.577 or something, and later pistons are 1.377 or something so make sure you are buying the right ones, I got mine through Northern Auto Parts.

Alex
 

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It's not the compression distance that differs, but the wrist pin location and rod length. The cranks are the same, and can even fit in a 1.6L block. The rod journals differ on later years, though. '86 and back have larger rod journals than later years.
 

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True but when using late rods and early pistons it sure seems like compression distance( my pistons go almost a quarter inch above deck! I have decided to keep my new pistons though and source a good used set of rods and crank, but one low has not come through for me yet.

Al
 

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That's because early pistons have a lower wrist pin location (due to a shorter rod) and later models use a longer rod (with higher pin location in the piston). Combine an early piston with a late rod, and you have the piston crown way above the deck.

Combine a late piston with an early rod and you have a 4:1 compression ratio (possibly an exaggeration as I've not done the math to confirm this).

I like the late models as they're better for high revs, although the wrist pin location can still easily be moved up .1 to .2", and a longer rod used to improve high rev stability further, and decrease cylinder wall loads. Torque will suffer a little bit, but it's not that severe since the CVH is already a very long stroke design.
 
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