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| New Volvo 122S B20B Mahle piston 0.030" with rusty rod |
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| Balanced connecting rod - cap |
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| Balanced connecting rod - top |
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| Gudgeons out , bolts still tight which I didn't realised when taking the picture I thought everything was ready for the assembling... |
When assembling the pistons to the rods with the gudgeon pins it very important to do it the right way.
- On top of the piston you can see a mark; this mark should face to the front of the engine
- On top of the pistons there's also a number (1, 2, 3 or 4); this number should correspondent with the cylinder bore number. Number 1 is the cylinder bore at the front of the engine
- On the rods and their caps you can find the same numbers for the same purpose
- When connecting the rod with the piston make sure the rod marking numbers face away from the camshaft side when installed in the engine.
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| On top of the piston you can see a mark this should face to the front of the engine You can also see a number (no. 2 for this one) |
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| Numbers/marks on the rods and the rod caps |
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| Thre right way to connect the rod to the piston, see the marks/numbers on both |
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| Pistons assembled to the rods with the gudgeon pins |
Some Maths
I was curious what the new engine capacity should be with the 0.030" Mahle pistons.
The formula to calculate the capacity of an engine:
Capacity (in cc) = (π/4 x bore² x stroke x # cylinders)/1000 (note: π ≈ 3.14)
Original engine: (3.14/4 x 88.9² x 80.0 x 4)/1000
≈ 1986 cc
Rebuild engine with 0.030" (0.762 mm) Mahle pistons:
(3.14/4 x 89.66² x 80.0 x 4)/1000
≈ 2020 cc
An increase of 34 cc !
Hello! First, Thank you very much for you helpful posts! Second, I'm trying to install my engine properly but now I discovered one problem. The engine was in a oversize drilling and I asked that would they also install pistons and rods for me and I'll continue it from there. From your posts I discovered that the machinist installed the rod wrong way pointing 1/1 to the camshaft. How big fault is this, should I dismantle the engine? Thank you and all the best for the year 2015!
ReplyDeleteHi Asko,
ReplyDeleteThe rods and their bearing caps should go back in exactly the same way as they came out. Don't take the risk. If your engine is still disassembled it wouldn't take to long. Good luck with your project!