HC pistons from corksport

[birdy85]

hey guys i was just wondering about a couple of things about HC Pistons?

What sort of power gains can be expected from this mod

Is install impossible for a person who has medium knowledge of the mazda fs engine?

Do you think it is worth getting getting for me(you can see my mods below, BTW every that say "waiting to be installed" is in fact installed)

And just another question - what sort of power do you think i am pushing with these mods- i have an aussie car - i don't know if that makes any difference.

Thanks guys

 

[scorch70]

I dont have an answer for you, as Im definitely not the engine expert around here. However, if you are looking at HC pistons, you should probably look at the whole package - cams, rods, bearings, etc. No sense in doing things half assed.

Also, you will be forced to run your highest grade gas there down under if you go high compression. Or else - BOOM!!

Twilightprotege is another member from your corner of the world, and he is pretty knowledgeable about all things engine. You might PM him.

let us know how it goes if you decide to do it (dyno before and after if possible).


scorch70

 

[95ProLeila]

You'd have to run premium at 10.7:1?

 

[scorch70]

You'd have to run premium at 10.7:1?

From what I have read on here and other sites, yes. Someone correct me if I am wrong.


scorch70

 

[ogsp5]

Yes you are correct, plus some type of EMS in combo

 

[mp3moose]

I have gotten away with running 92 octane, but cams will help out a lot with higher compression. I wouldn't recommmend installing them yourself unless you have proper tools and really know what your doing. They will run off your current ecu btw.

 

[uclap5]

anyone know if they will throw up some code through the OBD-II? here in cali emmisions are strict and i am wondering if i would get red flagged or something for raised compression

 

[flat_black]

From what I gather, you can swap out the pistons/rods from beneath the engine, which implys that you can also get to the crank and whatnot... Were I to do this, I'd end up getting a 4k loan, and get HC forged pistons, rods, Toga crank/main bearings, Toga high flow fuel pump, crank scraper (which is on the way) or custom baffles for the oil pan, knife edge the crank, and some cams, and a junkyard head to port up. Hehee. Mmmm... I can dream. =)

 

[p5sundevil]

dont install them by yourself, the HC pistons from corksport are worthless if you are really going for an all motor high compression buildup, your best bet is pauter rods and have custom CP pistons made that after all your other mods you will be closer to 12:1 compression and that is where you will see significant gains.

Personally before HC pistons(because you really should have a new ecu for these) I would suggest getting a header and then cams and cam gears next, based on your cam specs and if you have some flow work done to the head while your in there you will know what compression pistons to get in order to give you your final engine compression.

Also if getting new pistons like these I would recommend the eibach valve train kit with the new valve springs, this will make things safer with custom cams and higher compression and will allow you, with an ecu, to raise the rev limit to say 7500 or so and get even more power in a broader band

 

[akhilleus]

U will definately need some type of ems upgrade as well as the other items mentioend to even make it worth it.

 

[SpicyMchaggis]

i have to run 91 as it is..higher compression would light my wallet on fire..

 

[akhilleus]

especially these days...i guess u have to run high octane cause of your timing adj, right spicyM.?

 

[Gen1GT]

It's not a bad idea to get the 10.7 pistons, since it's pretty economical. I'm getting the Miata 10:1s for my car, but then again, I'm doing the engine build myself, so I can keep it economical.

Also, with your intake and exhaust set-up, I'd say you're at 110whp.

 

[p5sundevil]

i dont know about the gas thing, i always figure for the 20 cents extra over regular, i will only pay a maximum of 4bux extra, times say 3 fills a month that 144 a yr to use premium....over 12 months that aint bad......or so i keep telling myself.

 

[twilightprotege]

birdy - think of a light weight flywheel as well. with all the extra power, it'll be all above redline (so you'll need a piggy back computer atleast - i'll be getting a chiptorque to lift the rev limit) and because the engine will be spinning so quick - a light flywheel will help reduce stress

but like the guys say - cams cams cams. we're lucky because we get to start with 9.7:1 compression

 

[SpicyMchaggis]

yeah, that is pretty sweet that you guys get 9.7 over there across the pond..yeah..if i run anything lower than 91 it will ping like hell..although it does fluxuate from place to place..good 89 works well..or generic 91..

 

[iluvmacs]

According to my engine dyno similator, the compression increase will MAXIMUM give you 15 horsepower. You'll get better mileage, but you'll have to run PLUS gas at the least, which cancels out the mileage.

Not worth the time unless you have high overlap cams.

 

[mp3moose]

Kyle, why did you have ping problems at stock compression on 91 or worse?

Iluvmacs, Actually, I get better mileage out of 93 octane on the highway.

 

[twilightprotege]

exactly. HC pistons dont show a huge gain unless you get big cams

 

[95ProLeila]

If miatas have 10:1 pistons factory (what's the overall ratio?), what type of fuel does mazda recommend?