DC350

I really gotta find out what i am gunna do to my engine to really kick it....just lemme know what you think about porting engines

AreExSeven

Pros -
Adds Power
Opens engine up to add alot more power
Good HP/$ Ratio

Cons -
Shortens Engine Life
Raises Emissions (If that is a concern to you)

I haven't actually done it yet, but thats what I know based on reading about it.

petrosc

How does it shorten engine life?


Petros

AreExSeven

Not too sure. Like I said, I've not done it to my own engine, that was just information I gathered from reading stuff here. And maybe it was just higher level than street porting shortened life.

PistonCivic

well it wouldn't really shorten engine life the same way a bridge prot would. it just removes the excess material around the existing port and doesnt really change much. if you take good care of your engine there are no cons (except emissions )

CIVIC

ZachSpazz

I thought you were a hater or ignorant of the RX-7...I'm confused.

Samps

who ever PISTONCIVIC really is; probably forgot to post under his original screen name.

fasthack

The only way that it would shrten the engine life is because it shifts the powerband up, so you would be driving at higher rpm usually and that causes stress that would shorten the life of the engine.

TheTwinTurboRX-7

Craig, you are on crack. That is so not the case. Street porting increases power all across the power band. That would just not be the case man. Oh, and good try at sounding officious.:

Ryde _Or_Die

So we're looking at pros only, no cons? Can anyone with a streetported engine confirm this? Thanks.

peejay

yeah my street ported 12A could put a stock 13B to shame with its powerband stretched ALL OVER the tach!

there ARE NO DOWNSIDES to street porting. Well, maybe one... you have to pull the engine out, tear it down, and port it... but if it's apart already then it's no big deal. Just make sure you don't open up the port runners themselves or you'll lose all that nice low-end torque... yes it'll cost a little high end HP but it's a fair trade in my opinion!

ka8legend

Dynocharts seem to suggest that streetporting only gives about 20rwhp for series 5 motors, could be less on the iv. As it was mentioned above, if it aint broke, spending an extra 1500-2 grand for 20rwhp isn't exactly the best bang for the dolluar. Stripping the car by 400lb could probably accomplish the similar 1/4 times, but that's a different story. But I'll give it second thoughts if someone were to sell hiser car with ported motor for cheap. BTW will it pass emissions?

petrosc

Thanks for the replies guys. Keep them coming. I was just concerned when one guy mentioned that it would make the car unreliable.


Petros

DC350

how much does it cost to Port an engine...it is not something to be done by the home mechanic?

RX-7Impreza

what are you talking about 1500-2 grand, try 10-20 dollars in dremel bits and a little patience. even on the high end that is 1rwhp per dollar. id say that is the best bang for your buck you can get anywhere.

Justin

RX-7Impreza

can definitely be done by the home mechanic, as long as you know what you are doing

Justin

stinkfist

If your motor set up is stock and you street port a motor it may get you around 20 hp to the wheels. if you add an exhaust to a stock motor that gets you 20 RWHP that same exhaust can give you 30 RWHP to the wheels. then your around 50 RWHP over stock. These are not exact #'s,just examples.
Bolt on mods will net you more gains on a street port engine than on a stock port engine.

And yes, a street port can pass emissions.


Mike

ka8legend

Those # are from my local SF Bay shops. Heck just removing & reinstalling the intake manifold/plenum would cost $700. Of course if I had the time and tools and resources, I could have a true dual exhaust that Mazdatrix sells for over $1400 made for quite cheap as well. But I don't have the time nor patience any more. At least not for an N/A. Modding a TII or Cheving an NA, now I can possibly make time for.

NZConvertible

I don't think anyone would be silly enough to pull their engine apart just to do porting unless you've reached the limit with just bolt-ons. But if it's apart for a rebuild, why not!
Go to http://www.mazdatrix.com/faq/porting.htm for a little DIY info.

ka8legend

Agree! And for me at least, what if after putting everything back in there I might have dropped a corner apex seal, or skipped a needle thrust bearing, you know the little stuff that got lost in the shuffle/pool of grease-Deja vu. Of course there's that stinking feeling, did I torque every single bolt in there to the proper spec? I'll gladly pay anyone here $500 to come over my place and port my motor and all the R & R work, and change my clutch while you're at it cause my mech wants $750 for a clutch job, yikes!

TurboII RudeBoy

hey ka8legend u got a legend coupe?u ever been to the legend forums?

RX-7Impreza

thats funny, i always get that sinking feeling if anyone else touches my motor.....hmmmmmm......

i guess its al a matter of skill vs money


Justin

ka8legend

I got a stock, rice-free G2 coupe that's got some ballz for a whale. I'm trying to mod my NA to match its 40-70 times right now. My wife thinks I need therapy cause one is like 30db louder than the other on the freeway. Oh well she ain't riding no more. I rarely go to that forum cause of the format, but it's recently changed to where it feels just like this forum w/o sponsors/ads. So I might sign up later on. I see you got a g2 as well, any mods like DV8?

ka8legend

Hey, I trust your work and a few others around here. It's from that sound of confidence. But would you do it for $500? I'll stand by to watch and make sure it's done to my liking. I'm very critical, but very forgetful sometimes.

RX-7Impreza

i would suggest my friend Adam, if he'll do it. Mazdaspeed7 is his forum name. dont get me wrong, i would love to work on your engine but i get wary of doing other peoples engines. and it would take me a while to do it with the workload i have right now (college is kickin my ***, hard). I will tell him about you,

Justin