B18C7 into GSi

[rc_]

I've used those NPR ones in the first link. There are reviews on Honda tech etc and many reports of successful builds.

Mines in a b18c2, has done a bunch of track days without any issues. It never burns oil like it used to pre-build and feels like it picked up a few kw.

The castings seemed pretty good, but I have no idea if the teflon coating will last. It looks different to the oem coating on c7 pistons.

One thing to check is if they are USDM versions (I think p73AO?) because they have lower compression than the jdm. I think the Audm is the same as us anyway.

Just keep in mind they most likely won't be as durable as an OEM or forged pistons. So far mine have been good for a few years in any case.

[beeza]

Hi aldo,how many km on the b18c7?

cool read btw

[aldo10]

Thanks for the responses folks much appreciated.

Beeza had tallied up 215000 kms. Previous owner had given it a bit of a hard life I suspect. Interesting that the machinist has found that the seller to me wasn't telling the truth on a rebuild. All internals are originals. He tells me the bottom end has never been apart.

I thought it went pretty well to be honest and the fuel economy was ok too. He says they are a pretty robust engine.

Anyway I just want a tight motor that I can put some distance work on without having to cart a 44 gallon drum of oil with me.

My final oil consumption test revealed 6 litres of 10/30 synthetic was chewed up in 4200kms.

[beeza]

Yeah,that's heaps.

Thank you mate u got me to look into it.

Looks like about 1 litre of 10/40 nulon full synthetic in 3000k's.157,000k's.Same engine. Was compression tested 220/240/240/240 but added cerma which restores compression,so need to test again and monitor oil consumption. I've only had the engine for the said 3000km.

I know these engines burn a bit of oil,seems mine is burning a bit more due to lower compression in the 1 cylinder like yours but not as bad...,yet

Thanks for sharing this mate.

[YeahByuddy]

They usually blow up at 160'000kms

[aldo10]

Compression in mine was still all above 200. Oil control rings were gone.

[beeza]

Piston rings?

So these pistons will bump up the compression by the looks of it. It says 11.8 - 12.6 depending on head/block combo.Stock is 11.1

Must be cause they are oversized?

[rc_]

Piston rings?

So these pistons will bump up the compression by the looks of it. It says 11.8 - 12.6 depending on head/block combo.Stock is 11.1

Must be cause they are oversized?

Oversized bore will lower the compression slightly but not much. Don't go by what the eBay ad says it is too general, use some of the online calculators for b series. The calculators vary a bit so it will only be a rough idea.

[beeza]

Ah true.So they are a stock replacement then,but .5mm over sized? A compression is tester only $20 off ebay,just bought one.

[aldo10]

At this stage I'm unsure of the oversize spec. I'll know by next week. He's just left it up to me which piston brand I would like to go with.

The vehicle is a long term keeper so decisions.

[rc_]

Ah true.So they are a stock replacement then,but .5mm over sized? A compression is tester only $20 off ebay,just bought one.

Yes, stock P73-AO dome shape.

Check your stock pistons, the part number should be on the top. If they are p73-AO they are the same dome volume. Otherwise P73-OO (JDM) are higher compression, I think 10.6:1 vs 11.1:1. I would think the audm are the same as usdm with the lower compression, But with an unknown motor beat to confirm the part number on the piston or cc them to know for sure.

If I were to do it again I'd probably get some oem pistons from the US or amayama, they are much cheaper than here.

Example

http://www.icbmotorsport.com/intyrpikitb1.html

[beeza]

Nice one rc,bookmarked! Thanks mate.

So to swap over pistons only,car goes up on hoist,remove sump etc and pistons are removed from the underneath yeah? 5-6 hours labour + pistons.

600 + 400 = $1000? Does this sound right. Need to change anything else while it's open?

I'm just planning for future. .