# b16 pistons in a b18b1

Discussion in 'Engine Building' started by cxjon, Jul 20, 2003.

1. ### cxjonSenior Member

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how does this yeild higher compression?

i looked thru the reference sectioni saw the bore was the same and stroke was different. know what bore is but i what to know what stroke is?

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Stroke is the vertical distance traveled by the piston in the bore of the engine. Piston choice is independent from stroke. The reason why the B16 pistons will raise compression in the B18A/B is because the dome is larger. The larger dome pistons fill up th combustion chamber more at the top of the stroke, compressing the air/fuel mixture more, which yield your higher static compression numbers.

3. ### JDMilanSenior Member

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4. ### cxjonSenior Member

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so whats the difference between pistons ie b16b, b16a, b18c1 and b18c5

5. ### cxjonSenior Member

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my friend found a b18b1 that needs a little tlc for about 600 near me. i am looking to do something similer to wildbill so any help would be great.

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The main difference is dome volume.

B16B > B16A > B18C5 > B18C1

for piston dome displacement. The B16 pistons have larger domes than the B18C pistons because of the combustion chamber size... B16 combustion chamber = 42.7cc while B18C1 combustion chamber = 41.6cc.

Rough guesses on standard stuff from the compression calculator:

B18A/B + USDM B16A pistons = 10.8:1
B18A/B + JDM B16A pistons = 11.0:1
B18A/B + JDM B16B pistons = 11.4:1

That should give you something to start from.

---

The other main difference is the skirt coating on the ITR and CTR pistons.

7. ### cxjonSenior Member

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so ctr pistons well yeild higher cr thats cool.

8. ### B16Super ModeratorVIP

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dont forget deck height too. Like the reason the B16B pistons have the highest dome of them all, but in a B16B block only have a 10.8:1 CR. this is because the deck height of the B16B block is the same as the B18C blocks (just destroked with shorter rods), but taller than the B16A. so, the piston does not travel as close to the combustion chamber as they would in a B16A motor.

EDIT:
and something is wrong with that compression calcualtor, because they say the B16B/B16A blocks have the same deck height, and they do not.

9. ### JDMilanSenior Member

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I think an 8mm difference, somewhere in there but they are not the same for sure.

Milan

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