Bottom End Components - 99 v. C900 v. 9k v. 9-3 v. 9-5
Posted: Thu Mar 10, 2011 5:05 pm
Working at a SAAB service shop has many advantages, one of which is a very thorough supply of spare parts from just about any SAAB model commonly found in the states.
Luke's 16v rally build inspired this post, I was looking for a bit of a budget way to get lighter weight reciprocating pieces for my build.
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Turns out that factory 9-3 / 9-5 components may require only a moderate amount of work to fit to a C900 B202 block.
Rod bearings - SAAB used the exact same rod bearings for all C900 / NG900 / 9000 / OG9-3 / OG9-5 and all 2.0L 99's, 1972+.
Main bearings - All early 2.0L cars 1972+ 99 / C900 / 2.0L 9000 (1986 - 1990) use the same main bearings. Later 2.0L and all 2.3L cars 1991-1998 9000 / NG900 / OG9-3 / OG9-5 all use the same bearings.
All 2.0L and 2.3L engines use the same 90mm bore.
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'02 9-3 & 9-5 connecting rods are one-piece forgings, and have split fractured big end bearing caps. They are very slender, right now I don't have an accurate scale to see what they actually weigh, but they are little compared to the B202 turbo rods.
The B205 and B235 rods are marked on the big end '2.0' or '2.3' to designate which engine they came from.
2.0L B205 rods have a center-to-center length of 159mm.
2.3L B235 rods are 153mm.
They all have 56mm big end bearing receiving bores, and 24mm wrist pin bores.
I am going to try to fit a B2x5 reciprocating assembly into a B202 block, I won't have to cut the block deck down too much if I use 2.3L 9-5 rods and 9-3 pistons, rod length/stroke ratio is much better too, the later pistons have significantly higher wrist pin height and much longer rods.
This is a regular B202 setup next to a 9-5 piston on a 9-5 rod - much longer rod length and higher pin height, but only about a 5mm difference in deck height, and the stock 9-5 rings are those new fangled low-tension rings that are pretty thin, supposed to make a bunch less friction.
Wrist pins are 10mm shorter (but thicker wall), and the pistons have reliefs around the pin rather than a full skirt:
Nice hardware, and the crazy shear-fractured big end caps.
The 9-5 / 9-3 pistons also have the crowns hard anodized, though the guys here like to clean them up during head gasket job and scrub most of it off.
The small dishes are 9-3 pistons. They In the 9-3 block with B2x5 head they give an 8.8:1 compression ratio.
The larger dishes are 9-5 pistons, compression ratio is nominally 9.3:1. The CR is higher even though the dish is larger because the crown of the piston is 0.7mm higher than the 9-3, has a little more squish around the perimeter.
Luke's 16v rally build inspired this post, I was looking for a bit of a budget way to get lighter weight reciprocating pieces for my build.
******************
Turns out that factory 9-3 / 9-5 components may require only a moderate amount of work to fit to a C900 B202 block.
Rod bearings - SAAB used the exact same rod bearings for all C900 / NG900 / 9000 / OG9-3 / OG9-5 and all 2.0L 99's, 1972+.
Main bearings - All early 2.0L cars 1972+ 99 / C900 / 2.0L 9000 (1986 - 1990) use the same main bearings. Later 2.0L and all 2.3L cars 1991-1998 9000 / NG900 / OG9-3 / OG9-5 all use the same bearings.
All 2.0L and 2.3L engines use the same 90mm bore.
***********************
'02 9-3 & 9-5 connecting rods are one-piece forgings, and have split fractured big end bearing caps. They are very slender, right now I don't have an accurate scale to see what they actually weigh, but they are little compared to the B202 turbo rods.
The B205 and B235 rods are marked on the big end '2.0' or '2.3' to designate which engine they came from.
2.0L B205 rods have a center-to-center length of 159mm.
2.3L B235 rods are 153mm.
They all have 56mm big end bearing receiving bores, and 24mm wrist pin bores.
I am going to try to fit a B2x5 reciprocating assembly into a B202 block, I won't have to cut the block deck down too much if I use 2.3L 9-5 rods and 9-3 pistons, rod length/stroke ratio is much better too, the later pistons have significantly higher wrist pin height and much longer rods.
This is a regular B202 setup next to a 9-5 piston on a 9-5 rod - much longer rod length and higher pin height, but only about a 5mm difference in deck height, and the stock 9-5 rings are those new fangled low-tension rings that are pretty thin, supposed to make a bunch less friction.
Wrist pins are 10mm shorter (but thicker wall), and the pistons have reliefs around the pin rather than a full skirt:
Nice hardware, and the crazy shear-fractured big end caps.
The 9-5 / 9-3 pistons also have the crowns hard anodized, though the guys here like to clean them up during head gasket job and scrub most of it off.
The small dishes are 9-3 pistons. They In the 9-3 block with B2x5 head they give an 8.8:1 compression ratio.
The larger dishes are 9-5 pistons, compression ratio is nominally 9.3:1. The CR is higher even though the dish is larger because the crown of the piston is 0.7mm higher than the 9-3, has a little more squish around the perimeter.