dlx111

So Ive read through a lot of threads, a lot of old incomplete threads and a lot of old info that was never updated. Im looking at building a B20 for boost for my eg. Ive already outlined pretty much everything I need the only hang up I have is what compression/pistons I should ACTUALLY use. What I would like to do is run a Nippon or YCP piston but Im not sure if my compression is going to be too high for a reliable/long lasting setup. Recently I saw Boostedboiz on youtube build a B20/vtec using YCP pistons making 450 at 8lbs on E85. When I saw he had the High Comp pistons in there I thought that was kind of a risky move but then I started looking at building something setup minus Vtec head. Power goals are 3-400 dont really care for high numbers just want a good reliable powerband and safe motor.

I know a good tune is critical which I plan to have. I know people have good setups hitting the numbers Im looking for but I really havent seen the compression numbers on the piston setup Im looking at.

My parts list
Low comp B20 keeping B20 head stock
b18 or Skunk2 IM
YCP or Nippon Piston
Eagle rods
ARP rod bolts
Walbro 450
Precision injectors
Turbonetics super 60
log manifold
Hondata
3"dp and exhaust straight pipe

Autoworks

What CR does a YCP or Nippon piston net in a B20?

Outside of that...you could do what you want on less pump than a 450, and I'd also use "more" turbo ( 300whp would be great on a Super 60 and would make plenty of trq to go with it, but not 400whp)...I'd also suggest a better injector.

dlx111

Autoworks

I'd suggest spending a little more and getting a better piston/rod combo (ie. Wiseco 10.5:1/H Beam) and call it a day...just my $.02

dlx111

Autoworks

The piston set is sub $500, readily available, and will be a better fit than the cast set you're looking at for the application. Cheap is relative here...it's a trade off.

dlx111

Yeah I know cheap doesnt equal reliable lol.

Balor_Gr

For the b20 please pick the cheapest forged piston and do a CSS job.
If you do you WILL crack a sleeve. And you will pay twice.
Cheapest everything including turbo and manifold will be faster from a ball bearing GTX fancy top mount manifold stock sleeve b20 turbo.
When i say cheap turbo by no means a china one.
Now that i think of it a CSS non vtec head B20 turbo will yield bigger and safer numbers from a vtec non css b20 turbo.
If you really want Nippon turbo pistons they offer a 84.5mm turbo version. But i wouldnd use em on a b20. On a b16 b18 maybe.

Chance EG

CSS does not correct the biggest issue with the B20 blocks however, which is the siamese sleeves on cylinders 2 & 3. Jeff even acknowledges this on their website, the B20 block is the only block not guaranteed up to 500+WHP.

If OP has the option of using an LS block, that would be much safer with their 82mm sleeves.

dlx111

2x0

dlx111

2x0

Chance EG

Correct on the tuning and fuel choice aspects. That being said, there's only so much that computer magic and unicorn juice can do for you. Eventually thicker, more robust sleeves are just needed.

I would consider anything above 400WHP on stock B20 sleeves a matter of time before a 2/3 crack forms.

Balor_Gr

600+ CSS B20 lasted one year and a half.
Id do 400whp on a b20 CSS and feel safe.
Stock sleeves anything over 300 will kill it.
If you dont crack it it will be because you baby sit it too much.
And youll have this blackness in your heart everytime you WOT it. You know the "will it break" thinking that eats your brain.

2x0

I would also consider anything above 400 on stock B18 sleeves to be a matter of time... always have heard B20's are weaker but does the extra displacement actually mean you can make roughly the same power with lower cylinder pressure?? Or do people just have different comfort levels and expectations/*****.

Chance EG

This is really what it boils down to. That and most people either aren't broadcasting or aren't entirely honest with their goals as far as longevity with the cars. Most people aren't thinking 25K, 30K miles down the road.

What I meant in that quote was 400+WHP with CSS and stock sleeves. I meant without an iron sleeve job done on a B20 block to get rid of the siamese matching.

Most torque gains on an engine come from added stroke and not bore, so torque numbers between a B18B and B20 are typically very comparable. As for cylinder pressures I have no idea.

Note that in the video he said he already had 2 cracks, and had heating issues with the engine across two different cars. He'd likely been rolling around with those cracks for awhile, it's not like the engine made it a full 18 months without damage.

dlx111

Lol this would be me and this is why Im trying to find a b18 just for that piece of mind, not saying it still couldnt happen but id rather have a ~300hp that Im not scared to push than ~400hp that i wont push more than half throttle cus im scared itll crack