Are USDM B18C5 Pistons the Same as JDM B18C Type-R


DV8

DV8

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Getting really confused... LOL
 
I'm 99.9% sure they are different

I'm trying to find information on it to show you

I know 110% JDM B18C-R has 11.1:1 Compression ratio and B18C5 is 10.6:1
 
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The reason I ask is I'm looking to go oversize and the majority of the pistons available in the US at a reasonable price are lower comp...
 
They are different.

P73-00 (JDM) : 5.96cc dome
P73-A0 (USDM) : 3.64cc dome
 
USDM b18c5 pistons are P73-A0

JDM b18c ITR pistons are P73-00

Still trying to get accuracy on the difference as there is a lot of crappy info surrounding them but theres one thing for sure they are definately 100% different.

Even if theres not much of a difference the USDM ones are lower CR






[edit] beaten to it
 
Barryl85 said:
USDM b18c5 pistons are P73-A0

JDM b18c ITR pistons are P73-00

Still trying to get accuracy on the difference as there is a lot of crappy info surrounding them but theres one thing for sure they are definately 100% different.

Even if theres not much of a difference the USDM ones are lower CR

[edit] beaten to it
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correct, tad lower compression which means the shape would be different. Not sure if the dome on the head is any different tho...
 
I'd still use them if there a fair bit cheaper than anything else you've seen. .5 in C/R isnt worth the bother.
 
Rich777 said:
I'd still use them if there a fair bit cheaper than anything else you've seen. .5 in C/R isnt worth the bother.
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I see what your saying here but when i do something i like to do it right and do it exactly the way i had in mind.

Knowing once it was built that it could have been better even if that difference in CR only produced a few more lbs torque or few horse power i wouldnt be happy.

If it was my build and i had the money i'd be buying the JDM ones or i'd use PCT CTR ones.
 
I know what you mean lol. The thing is are we ever honestly 100% happy ? There's always something else what you could of done whilst it was apart...

You won't notice that amount of C/R on the streets... Maybe on paper yeah, but does that really matter ?
 
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Rich777 said:
I know what you mean lol. The thing is are we ever honestly 100% happy ? There's always something else what you could of done whilst it was apart...

You won't notice that amount of C/R on the streets... Maybe on paper yeah, but does that really matter ?
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Exactly and i mean on both your points.

Only thing is though I think every little helps when scavanging for N/A power
 
True specially with a NA engine. I guess its all down to budget and how fussy you are. Its still going to make a load of power and pull well either way.
 
Personally I think I'd rather spend the extra and either match or go up in compression. On that basis should I go for B16B pistons, or maybe CP 11:1s?
 
DV8 said:
Personally I think I'd rather spend the extra and either match or go up in compression. On that basis should I go for B16B pistons, or maybe CP 11:1s?
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If you want the best performance buy B16B PCT pistons - one things for sure though make sure you have a good tuner if you run these.

If youd rather play it safe but still have good power / torque go for the JDM ITR pistons.
 
Barryl85 said:
If you want the best performance buy B16B PCT pistons - one things for sure though make sure you have a good tuner if you run these.

If youd rather play it safe but still have good power / torque go for the JDM ITR pistons.
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They are like rocking horse poo to get hold of though, anyone have the part numbers for oversize JDM ITR pistons and rings?
 
Heres an example of what can happen if its not tuned properly - this was my mates B16B piston.

5506425621_2d32e6fff9_b.jpg
 
Welcome to Detonation & Pre ignition. Its every engines best friend....

Any pic's of the side of that piston Barry ?
 
Barryl85 said:
Heres an example of what can happen if its not tuned properly - this was my mates B16B piston.

5506425621_2d32e6fff9_b.jpg
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Ouch that looks worrying, guessing it'd be okay to cruise around on run in without a tune?

Would these CP pistons offer better compression:
SC7136 B18C5 81.50mm (+.020" Overbore) 11.5:1
 
OEM Honda 81.25mm oversized P73 B18C Pistons part no: 13020-P73-J00

OEM Piston rings to fit 81.25mm oversized pistons part no: 13021-PR3-003

On lings honda prices are;
Pistons: 106+vat
Ring: 74 +vat
 
You won't damage anything if you just baby it around. I'd still retard the ignition timing bit though.

I'm sure you will need forged rod's to go with the CP pistons as the pin's are a different size.
 
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