1.8 VVT "Stock-ish" NA Rebuild
#21
I’ve read everything I can all the way back to 2013 when Emilio and Savington were really into NA BP development and limits.
With the bottom end stock except for Manley rods, limiting factor would be lifter shims and then cams. 7400 rpm redline limited by shims even with supertech valve springs for insurance. Stock cams don’t do well at much higher rpm anyways even with a little bowl work and un-shroud the valves.
Stock 10:1 VVT pistons with a total of .020” decked would give 10.5:1 and with a little un-shroud may get CR to 10.3:1 ideal
Would 155hp be a reasonable expectation on 93 octane. Any other low hanging fruit I’m missing? Btw… parts list is updated with all the Mazda seals and gaskets.
With the bottom end stock except for Manley rods, limiting factor would be lifter shims and then cams. 7400 rpm redline limited by shims even with supertech valve springs for insurance. Stock cams don’t do well at much higher rpm anyways even with a little bowl work and un-shroud the valves.
Stock 10:1 VVT pistons with a total of .020” decked would give 10.5:1 and with a little un-shroud may get CR to 10.3:1 ideal
Would 155hp be a reasonable expectation on 93 octane. Any other low hanging fruit I’m missing? Btw… parts list is updated with all the Mazda seals and gaskets.
#24
Figured I'd post all the engine stuff in this thread and link it to my build thread when it's back in the car.
Bought the largest made in China cheap ultrasonic cleaner I could. Barely fits a 4cyl head! Little bowl blend, little unshroud, little port matching. Got the first of many new parts, but the Gates water pump now has a stamped/ spot welded impeller.
IMG_9972 by D S, on Flickr
QDZA7012 by D S, on Flickr
IMG_9969 by D S, on Flickr
IMG_9971 by D S, on Flickr
IWBJ5729 by D S, on Flickr
Bought the largest made in China cheap ultrasonic cleaner I could. Barely fits a 4cyl head! Little bowl blend, little unshroud, little port matching. Got the first of many new parts, but the Gates water pump now has a stamped/ spot welded impeller.
IMG_9972 by D S, on Flickr
QDZA7012 by D S, on Flickr
IMG_9969 by D S, on Flickr
IMG_9971 by D S, on Flickr
IWBJ5729 by D S, on Flickr
Last edited by bimmerboy; 10-06-2022 at 06:36 AM.
#26
Got all parts back from machine shop. Valve job with backcut, surface head, deck block, and polished crank. Hand lapped valves and assembled head. Short block assembled with original VVT pistons with new OEM Mazda rings after a light hone. Water pump and oil pump installed.
IMG_0137 by D S, on Flickr
IMG_0151 by D S, on Flickr
IMG_0135 by D S, on Flickr
IMG_0141 by D S, on Flickr
IMG_0149 by D S, on Flickr
IMG_0138 by D S, on Flickr
UGTO2471 by D S, on Flickr
IMG_0137 by D S, on Flickr
IMG_0151 by D S, on Flickr
IMG_0135 by D S, on Flickr
IMG_0141 by D S, on Flickr
IMG_0149 by D S, on Flickr
IMG_0138 by D S, on Flickr
UGTO2471 by D S, on Flickr
Last edited by bimmerboy; 11-13-2022 at 09:27 AM.
#29
Update and bringing this engine build to completion. Installation and further updates on Hamster's build thread found here... https://www.miataturbo.net/build-thr...w-mine-106540/
After getting the refaced valves from the machine shop, just wasn't comfortable with how thin the intake valves got and the fact that I'd basically have to get all new shims on the intake side. Figured why not go ahead and just get new Supertech valves all around! Here are some assembly photos of the long block fully dressed ad ready to swap. Paint job makes it look a lot more menacing then it actually will be!
IMG_2076 by D S, on Flickr
IMG_2109 by D S, on Flickr
IMG_2108 by D S, on Flickr
IMG_2111 by D S, on Flickr
IMG_2173 by D S, on Flickr
IMG_2172 by D S, on Flickr
IMG_2171 by D S, on Flickr
After getting the refaced valves from the machine shop, just wasn't comfortable with how thin the intake valves got and the fact that I'd basically have to get all new shims on the intake side. Figured why not go ahead and just get new Supertech valves all around! Here are some assembly photos of the long block fully dressed ad ready to swap. Paint job makes it look a lot more menacing then it actually will be!
IMG_2076 by D S, on Flickr
IMG_2109 by D S, on Flickr
IMG_2108 by D S, on Flickr
IMG_2111 by D S, on Flickr
IMG_2173 by D S, on Flickr
IMG_2172 by D S, on Flickr
IMG_2171 by D S, on Flickr
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