87.2mm vs 89mm

[Wrist Watch]

A Lil knowledge input.

The plain simple situation, someone with some know how give me some inpurt on the better of the two options..

Boost build 4--wheel ish. No specific demands..breakin the 4 is all i need.

B18 block with AEBS close deck sleeves, 84mm..
But leaving the 87.2mm stroke of the B18

---or possibly switchin out to the 89mm 20B/Z crank, I'd really only do this if in a short time the 89mm crank became availible, and i know the larger stroke would fall in love with the boost., but point is.....Would it be worth it? Or could i just , edge that power out just as safely elsewhere and not worry about havin a big mouth b series.

[crx3]

If your "B18" block is a LS/RS variant (B18B) then it already has 89mm stroke, if it is a GS-R or Type-R (B18C1/B18C5) then the stroke was reduced to 87.2mm to enable quicker RPMs and increased reliability at RPMs above 8K. That being said, I had my B18C1 sleeved to 84mm and installed an Eagle 89mm crank, matching Eagle rods, and Wiseco 84mm pistons. The low end is great on the low boost setup I'm running, and the VTEC kicks in early using the Hondata. Highway passing in 5th means never having to downshift unless there is a point to be made. Before I did the 84mm X 89mm, I did the research, and it is not uncommon to see OEM high performance cars running this combination or similar. The Mitsubishi 2.0 turbo in the EVO and Diamondstars is a 85mm X 88mm. I no longer rev my engine past 8K RPMs, but I don't really need to either.

[Mr.Burner]

alot of people in the SFWD are using GSR/R blocks and using LS guts. it works very well. and you got the stroke.

[Wrist Watch]

Well 84x 89 isn't a big offshoot because factories want to come as close to an over squared engine as they can without sacrificing torque, efficiency, reliability due to a bunch of max proportions..

The only problem is, i don't really intend on running "low low" boost, the 84mm resleeving is going to be a closed decked AEBS 84mm job..

I was wondering since the sleeves themselves won't be hurt too bad on the boost issue should i go for the big stroke and more torque down low, or should i worry about stayin ahead with the 87.2?

[crx3]

I'm only running low boost because I have a Eaton M62 blower w/o an intercooler. The Eaton is only capable of supporting approximately 300 HP max. My engine build is capable of supporting probably twice that, but the blower won't. I had the motor built to be very robust in case I changed my mind and want to install a higher output power adder. A nice Full Race setup would be fun. The 84 x 89 is a stock CRV bore and stroke, so it's Honda approved. How many LS/VTEC setups out there run the 89mm stroke w/o problems. The CR/VTEC sometimes gets a bad rap because the stock Honda B20 block has weak one piece cylinder liners. I have the Benson open deck ductile iron sleeves which have a proven track record. The GS-R stroke is just fine, but I had to buy a new crank and rods, so I went with the LS/CRV rotating assembly topped with CRV size pistons. The "danger zone" in stroked B-series blocks is way beyond 89mm, and is usually reserved for all-motor race cars where power is more important than day to day driveability and reliability. Custom cranks and decked blocks are for the track and big budgets.