What to do with my rb26

[Grettar1]

Ok the story starts with my buying a very nice 89 gtr. The motor was rebuilt I was told and have all receipts. Collared crank, n1 oil pump, n1 water pump, ACL bearings, Manley rods, cp pistons, head ported, bronze guides installed, still had stock turbos, and a cometic head gasket and intake gaskets. Lower end balanced. Car ran great when I got it, was doing some cleaning up of the engine bay and had the radiator cap off and noticed some oil floating in there (ok, bad sign. But using a cometic head gasket I figured ok that's the problem. Driving to work I lost boost, front turbo spit the wheel and just my luck it got sucked in the motor. Needless to say bad engine scoring in 1,2,3 cylinders. I took it apart tonight and the story gets even better, my block is cracked in 3 places I can see. And there it damage to the head on 1 and 2. Need advise where to go with this. I know I need pistons, what block to go with stock or n1, and can this head be machined? It's damaged on the flat part, not the chambers. I have heard it is hard to machine the ceramic debris off? My crank, rods, oil pump, and all other parts should be reuseable I believe. I don't want to be cheap about this, but I want to build this the best I can cost effectively. I also have already purchased a pair of 06u00 nismo turbos for this. Any advice is greatly appreciated.

[Skym]

Stock short block cracking around coolant galleries to head bolts is common on a stock RB26. Check the usual like engine mounts, signs of overheating or engine running lean, running cold water through a hot block (common cause of block cracking), unbalanced crank damper on front of engine (most switch to aftermarket damper), out of balance flywheel or crank to name a few area's to look at. It's usually harmonics or heat problem.

Another option to prevent block cracking (harmonics) is a custom girdle plate, custom billet main caps to replace the stock girdle, etc -

http://www.spoolimports.com/spool-billet-main-caps/nissan-rb

As far as I know, N1 block has bigger oil, coolant galleries (to prevent bubbles from blocking coolant galleries) and so does a N1 head. I would replace both head, block. Once head warps you still have to worry about where the cams go in the head, so might not be straight anymore and require a line bore to straighten it out.

Also on race engines they run a air separation tank (header tank) to remove bubbles, N1 waterpump to reduce creation of bubbles at highwer rpm (cavitation).

With oil pump, switch to Tomei oil pump for higher oil pressure, volume if exceeding stock rev limiters for more hp or running higher boost levels. Many learnt the hard, expensive way that the oil pump should be upgraded. You'll need to enlarge the stock sump to at least 9 litres with baffles / box section around pickup, one way trap doors to compliment the higher volume oil pump (Tomei oil pump moves more oil).

Another option is a external mounted oil pump (could buy the oil pump in the states for alot less $$$$, but needs to be setup for a RB engine) -

http://blog.rossperformanceparts.com/category/engine-protection-kits/nissan-rb26/

External oil pumps -

http://blog.rossperformanceparts.com/category/aviaid-pumps-and-tanks/

With N1 oil pump you should have the Reimax oil pump gears installed, as stock N1 oil pump gears can crack.

Also there is the ROSS crank trigger kit to replace the stock CAS.

With RB engines you can go overboard a bit when seaking big hp with reliability.

Best advice is to set a budget, hp level that's not too expensive. Best hp level is 460-500hp at engine which would be achieveable with a relatively stock engine, N1 oil pump with Reimax gears, enlarged sump with baffles (Tomei sell a universal baffle kit with trap doors for stock sump for not much $$$).

[Grettar1]

Well, almost have it dismantled, so far the crank, rods and bearings all look like new. I'm going to bring the head to my machinist to see if can be saved. If so, biggest expenditure will be an n1 block and pistons. As long as it's apart it's getting all the parts needed for longevity. Tomei sump baffle, mines valve cover baffles and rear head drain. Along with type b poncams, tomei dumps, nistune, I have 660 denso injectors, dw300 in tank pump with a bosch 044 inline. Then hopefully it will be reliable and close to 650hp at the crank.

[Bruizer]

I've had a stock block and an N1 block side by side and both look the same around the coolant jackets. I've cracked a stock block with 300hp and haven't cracked the N1 yet. But is it worth $2k+