I am in the process of collecting parts to build up my B20Z to handle a huge shot of nitrous. I was aiming for a 150 to 200 shot. Already on my shopping list are JE pistons, eagle rods, arp fasteners (head, wrist pin, etc), steel head gasket, and a blueprint and balance. What I wasn't sure about is how much the stock sleeves would be able to handle. Are the stock honda B20Z sleeves made out of iron, or are they coated? I am trying to decide if I should resleeve the block or just get a block guard. Do all block guards have to be welded in? I was worrying about the heat from the welding compromising the integrity of the sleeves and block.

 

For headgasket, you probably want to go with a cometic. Now you want to do all this on a b20 which is NOTORIOUS for having weak sleeves so you have to be VERY carefull, one mishap and its all over. I know from experience (check sig) so listen. whatever you do, use a STOCK ECU or an engine management system do NOT, i repeat, do NOT use a chipped ECU. I don't recommend a block guard but no they do not have to be welded in, you need to have them presfit (or hammered) in and then you MUST bore and hone. I would recommend having your block pinned or posted by a shop (unless u know how). Lastly you WILL need a progressive rate Nitrous controller. Introducting your motor to 150+ shot of nitrous is a big no no, thats when things start to break. I was going to build a progressive rate nitrous controller, still want to, just gona take some time tho.

 

So the B20's do have weak sleeves. I am beginning to think that a complete resleeving will be required to pull this off safely. I have also heard bad things about block guards.

 

Check out some pictures of B20 cracked sleeves sometime, notice they all crack in just about the same place and its usually cylinder #3 (hottest).

 

I may send my block to golden eagle to get it resleeved. Besides the sleeves, does anyone know any other weak points in the B20Z?

 

accually i thought B20 block has one of the strongest sleeves/blocks. all 4 cylinders are siamesed togeather. the B18B/B18C/B16 blocks have individual cylinder sleeves.

i dont think i have seen cracked B20 block...........unless they have been put to major stress............i'd like to see this.

anyway to answer your questions. if your serious about running that big of a shot i would highly recommend re-sleeving the block. also stainless steel intake and oversized stainless exhaust valves. a good head gasket to hold the pressure. ARP head bolts, low compression forged pistons (9.5:1) and good strong connecting rods (crower, eagle, carillo) and of course fuel (injectors, fuel pump)..............

good luck.........

 

stock b20 sleeves, high comp. and nos do work together. Im running 11.2, 84.5, stock sleeves and a 120 shot. I would not recomend this to everyone, I'm trying to see how much the sleeves can handle. For reliability I would sleeve your block to begin with

 

golden eagle my friend , that is the best thing you can do