Euphues

Okay, hopefully I am worthy of the advice of this forum this time.

I have torn a junkyard motor completely apart. I am taking it to the machine shop for a clean and inspection. The crank was able to be rocked forward and backward by hand. So, failed thrust bearings? There's wear on the rod bearings and the mating surface of the crank. Bummer.

Cylinder walls look great but the skirts of the pistons don't l9ok very good. I'll have them cleaned and inspected.

I am planning the following and need input. The motor will be put together then go in the car in the spring. It may run on factory ecu and tune for a while until I can afford an ECU. I'm considering MS or the adaptronic.

My shopping list consists of manley rods, supertech 83.5mm 8.6:1 pistons, weisco xx rings, acl bearings, Apr head bolts, boundary oil pump, Gates water pump, oem gasket kit from good-win, and a gates timing kit. Am I missing anything?

I want to have the block bored, honed, and ringsome gapped. Is the align hone, balancing, ect. necessary or worth the cost?

I'll have the head rebuild and decked if it needs it.

I'd like to have a 280whp street car with a lower hp safer autox/track tune. I'm looking for some head room and margin of saftey in case I decide to go 300+hp in the event I install a 6 speed.

Is the ATI damper worth the cost at these power levels when I already have a boundary oil pump? some people say no, some say yes.

I'm also wondering what miata or bp specific advice I need for building this thing. I am new to miatas and any tips would be appreciated.

Feel free to poke holes in my plan but please be constructive/helpful! I will be ordering parts Monday or Tuesday.

Thanks guys!

Euphues

Bump, looking for input before ordering

ryansmoneypit

iTrader: (6)

Yes to a quality damper. 949 or ATI. The list looks good.
Don't order bearings until you know what size to get.

Euphues

Is it necessary to upgrade the valve springs?

sparkybean

By my research i put the 5-speed at a street 250 ftlbs or track 225. 280whp is pushing it a little.

Standard head bolts are good up to over 350hp (look at patsmx5 build).

Also interested in valve spring info.

shuiend

iTrader: (24)

What I have seen is that 5 speeds seem to go with no rhyme or reason. Part of it is mechanical empathy and other parts is luck. I know plenty of spec miata's drivers that go through 5 speeds regularly, while I have known turbo track guys to get a few years out of them at double the stock horse power.

huesmann

iTrader: (1)

A big chunk is probably driving style.