Engine

Back to Drivetrain.

Build Plan

• 94-97 or 99-00 Miata Block (in theory identical)
• 99 Miata Head
• Displacement?
• Pistons?
• Crank?

Do we want to try to do this ourselves or just pay Flyin Miata a metric asston for one of their absurdly expensive builds?

Parts Research

• Block: 94-01 blocks are effectively identical for our purposes (piston change). Trying to find an affordable 99 full motor is becoming difficult.
• Head: Maybe just look for a 99 head and put it on a 94 full motor?
• 2002 Oil Pan: 207$ from Mazdacomp, 10-400
• 2002 Oil Pan Support Plate: Asked Bob what the support plate is -- if it's the baffle plate (10-406A), then it's 66$
• 2002 Oil Pump: 198$ from Mazdacomp
• Eagle H-beam rods: 291$ from random sketchy place
• Carillo A-beam rods: 850$ from 949
• 949 Racing Rods: 329$
• Wiseco Coated Pistons: 796$ from FM (exclusive), includes rings/wrist pins
• ACL Main Bearings: 82$ from FM
• ACL Rod Bearings: 51$ from FM
• ARP Head Studs: 117$ from 949
• FM ARP Head Studs: 167$ from FM
• FM Head Gasket Kit: 215$ from FM
• Rebuild Gasket Set: 201$ from Mazdacomp
• Inconel Exhaust Valves: 33$/ea (264$/8), 1mm oversize
• Intake Valves: 22$/ea (176$/8), 1mm oversize
• Supertech Valves: 18$/ea (288$/16), 1mm oversize
• Mazdacomp Engine Mounts: 35$/ea, NAY1-39-040
• Supertech valve springs/retainers/seats: 314$ from 949
• Supertech shim-under-bucket lifters: 359$ from 949 + 5.5$/shim
• FM Valvetrain Kit: $379 from FM, includes springs/retainers/seats

May make sense to get an FM head, and just do the block myself.

Bob Bundy's Build

400+rwhp w/a big turbo

• 2.0L FM Stroker
• 94 Block
• 2002+ Pan/Support Plate/Oil Pump
• 99 Head
• Ceramic coated top wiesco pistons. (now standard at FM)
• Oil Squirters Blocked off. (much less oil consumption haven't found a downside and they don't fit with the new pistons anyway now standard with FM builds)
• FM now has Inconell exhaust valves. I think these are really needed on a track car. I've burned exhaust valves twice I think related with over oiling oil control rings using squrters and after market pistons. I don't have inconel exhaust valves yet though.
• ACL race bearings
• Stock cams
• 1mm over Supertech Valves/retainers
• Port/polish

TrackDayHookey's Build

420rwhp with a Rotrex centrifugal supercharger

• 94 block, 99 head.
• 1mm oversize Supertech pistons, 8.6:1, but with deck shave and head work the engine is about 9:1.
• 1mm oversize Supertech valves (both intake and exhaust) and Supertech springs (the relatively low seat force version as I don't plan on revving past ~7500).
• Rods from 949Racing.
• 1000 cc injectors.
• Integral "stage 2" intake cam - a little more lift.
• I ported the head. I might even have made it better. Valve deshrouding, clean up the bowl, match the head ports to the intake manifold.
• Custom intake manifold.
• 100 octane gas

Injection

What injectors will we need? 1000cc or can we get away with less? I got 392whp on the Alltrac with 880cc injectors without coming too close to maxing out.

Alternator

Any weight or efficiency gains to be had with some sort of aftermarket alternator?

Links

Mazda B Engines Wikipedia Page