NB8B Engine rebuild

[C-Gazer]

Since I had to remove my NB8B engine due to an oil failure (my fault) I plan to upgrade the pistons and rods. The engine is standard and runs a 2860RS turbo and I am looking for a max of only 250HP. This is contary to most turbo people who are after 300Hp +. My research has shown the CP pistons and Eagle rods are popular with forum members. Does anyone know if these items can be sourced in Australia? There is also the option of replacing the oil pump with the Boundary Street/Strip high flow pump. Does 250HP really need the Boundary pump upgrade? All advice will be appreciated.

[NitroDann]

For 250whp, not even pistons and rods are necessary.

Dann

[chops]

Dann is probably right but if you have it all in bits anyway can't be a better time to upgrade those parts. I run a 2860rs with JE pistons and Carillo rods with the Boundary oil pump. Very easy for a 250hp goal to climb

[Caffeine]

I went with this set (I went with 10.03:1 compression but my car's not turbo);

http://realstreetperformance.com/Shop-b ... -1-8L.html

But that was a few months ago when the AU dollar was a bit stronger so it was less than $1000. Bear in mind with these wiseco pistons you need to remove the oil squirters (or get the pistons machines to provide clearance) Also if you get the overbored sizes you'll have to have corresponding machining done to your block.

[hks_kansei]

Also if you get the overbored sizes you'll have to have corresponding machining done to your block.

I thought it was standard practice to have the block bored to suit the pistons regardless of stock or overbore.

There are manufacturing tolerances in parts, so most machinists will measure each piston and bore the block to suit that piston (ie: you'll get each piston back from them numbered to match a cylinder)

[Caffeine]

Also if you get the overbored sizes you'll have to have corresponding machining done to your block.

I thought it was standard practice to have the block bored to suit the pistons regardless of stock or overbore.

There are manufacturing tolerances in parts, so most machinists will measure each piston and bore the block to suit that piston (ie: you'll get each piston back from them numbered to match a cylinder)

If you're going for a stock size, what are they going to bore out? Perhaps they may hone the cylinders.

[hks_kansei]

If you're going for a stock size, what are they going to bore out? Perhaps they may hone the cylinders.

Usually they do a hone (i'd be concerned if they didn't)

But when the engine in my partner's car was rebuilt (rebuilt to factory specs, using new OEM size pistons) the machinist made sure to have the pistons on hand before machining anything so as to make sure the clearances were correct.


Either way, I'd be talking to the machinist at the time.
Any corners cut in the machining stage will cause nothing but problems later on.

[Lokiel]

Carillo rods are rated to 1000hp and while lighter than many other rods, they cost a LOT more.

Eagle/K1/Manley rods cost 40% of the price and are rated to 600hp which is double what many MX5 owners should try and achieve hp-wise anyway.

You can get Eagle/K1/Manley rods AND pistons for the price of the Carillo rods alone!
Manley rods have the added bonus of being "Manley" - no more hairdresser car for you!

I chose CP pistons over Wiseco pistons since Jason from MX5 Plus said that the guy who does all their engine work prefers them as they require less machining to balance.

You can stick with your OEM pistons up to around 300hp and wont need to rebore the cylinders (if they're in good condition) but if you're going to spend the $$$ to rebuild the engine, most people for peace of mind get new pistons with a slightly larger bore and bore the cylinders out accordingly.

I got all my stuff from the US when the A$ was king so saved a fortune but you can still save money buying from the US if you purchase a pistons+rod kit - these can be found on eBay. You save if you buy them together and when shipped together the S&H will be cheaper. If the goods themselves total over $1,000 you will get stung for import duty though so take that into account too (ie. it may end up being cheaper to purchase them seperately and shipping them sepertaley - DAMN YOU LOW A$).

Spend some time on MT.net too reading through the FAQ regarding "How to turbo" - they can be arseholes but the site is dedicated to Turbo Miatas so should answer any questions you have (just be sure to use the Seach facility FIRST before asking a question that's been asked a bazillion times already, otherwise you'll get deservedly "e-raped").

[chrons_rotary]

I'm currently rebuilding my BP VVT engine, with the goal of 250-300hp, bought all my parts and just went with Manley rods and NPR standard pistons/rings. Iirc the NB8B came with a better oil pump than the earlier models (someone correct me if im wrong), so not going to worry about that.
My VVT engine had less than 100k kms on it, all tolerances were within standard, so didnt need to order anything oversize. I suggest checking all tolerances before ordering anything.
I accidently bought some Wiseco XX Piston rings in 83.5mm if you wanted to buy them from me to suit 83.5 pistons?

[C-Gazer]

Thanks guys for all the replys to my post.
I managed to seize the engine due to reversing the lines to the remote oil filter and by putting the oil pressure switch on the oil pump supply side on the sandwich plate. This showed oil pressure but no oil was running through the filter to the engine. The exhaust cam shaft seized at the bearing behind the exhaust sprocket shearing the locating pin and the bolt on the sprocket . Last Thursday I dropped block, crankshaft and head to the local reconditioner. He contacted me today saying he is trying to source the bearing cap and an exhaust cam shaft as the existing cam shaft picked up a lot of metal when it seized. The bores still have not been checked and nothing will be done until I supply oversized pistons if they need boring.
One positive thing to come from this experience is seeing the head gasket I have and realising why my coolant reroute did not help much with the cooling the 94-00 gasket has an extra 9 holes compared to the 01-05 I have.

[Caffeine]

I might have an exhaust cam available next week. I sourced a new head for my engine so I have the old head.

[Caffeine]

I might have an exhaust cam available next week. I sourced a new head for my engine so I have the old head.

Actually, cancel that, my new head has cams that are unusable, so I'm using the old cams in the new head.