black99

This is just a question but I figured you guys would know best.. How many miles can you usually get out of a bridge ported motor if it is taken care of properly??? I would imagine the bridge port would shorten the life of the motor. Does it??? If it does, anyone know an estimate of how many miles you can get out of one??

racedriver

43,217 miles, no more, no less

Mr rx-7 tt

iTrader: (5)

I've heard 43,216.8...

black99

Ok, come on guys I was being for real.. This is a question at least I figured maybe some of the australia/new zealand guys would know. I know it isn't a everyday common occurance that someone puts a bridgeported motor in their car, much less and FD, but I was wondering if there was anyone with bridgeoported motors here on the forum that may be able to tell me how longs their motors lasted. I know there are many variables, the way the engine is treated, built, how much boost, etc, but I was just looking for some real world figures on how many miles you can get out of a bridgeported motor..

HWO

I heard 43, 217.3 actually


Actually it all depends Who built the motor, Who tuned it, How it is driven, When it is driven etc etc etc

peejay

Bingo!

I remember, one guy on r.a.rotary had a monster port that lasted 13 YEARS... Dunno how many km's on it though.

Why should the port affect engine life? Of course, the way you drive it definitely does... My 20kmi+???mi engine has low compression now, and it's just a mildly extended port... it's also sucking coolant ever since I made ONE 1/4mi pass on a cold engine... stupid me.

black99

I know that with a piston driven engine, modifications such as cams, higher compression, etc will effect engine life and I think most of that is because if you are doing those modifcations then you aren't exactly driving the motor like a stocker, and the motor is likely to see higher revs, launches at certain rpm's, etc.. I guess I thought a bridge ported motor wouldn't last as long as a street ported motor persay because usually if you have a bridge ported motor, you have higher boost, and the motor is being taken to higher revs to get the most use out of the bridge port. I think I do have my question answered a little bit, because like everyone knows alot of how long a motor last depends on how it is driven and all the factors you guys specified.. I know of course if I had a bridge ported motor I wouldn't exactly be babying the car everywhere I go.

soul assassin

i was told my motor will last 30-40k no more!

13BAce

That means 3-4 years for most people. That's not too bad, especially when you have over 500 RWHP.

peejay

30-40kmi means rebuilding it once a year, for me.

But see, it depends on the kind of USE the engine gets... if you only drive a car 10k per year or less, you're probably only going to be driving it to and from the races, so you're going to be at high throttle/high revs most of the time,

Meanwhile, drive that many miles in a couple months, you're mostly going to be doing a 3500-4000rpm cruise most of the time.


BTW - I thought the advantage of a BP turbo engine was that you needed LESS boost to make a given HP... less boost means less stress on the turbo, able to use a more efficient part of the compressor map, less heating up of the intake air, etc. IOW in theory (to my thinking) a 500hp BP engine should last longer than a 500hp extend port because it's under less stress.

Plus they idle sweeeet.

Freaky Monkey007

The advantage of a bridge ported engine is that it takes less boost 2 get a give # hp.. But how many people do u know are gona stick wit the same boost as when they had an sp when they know they can make more and do it safely??

black99

Wow, 30-40k?? That seems like alot of miles, especially for someone not going to use the car as a daily driver, which with 500+rwhp and the elements of everyday like rain, snow, etc, I don't think there are alot of people who would use a 500+rwhp rx7 as a daily driver.. Almost seems worth what some shops want to charge to bridge port a motor, just to get the extra hp...

peejay

That's the fun part. It only costs extra time when you do it yourself.

God I love rotaries.... when I wanted to build-up my 429, I looked at swapping in a hotter cam. It would have required pulling the heads and having them machined for different valve seals that permit more lift, machined for adjustable rockers and guides (which I'd also have to buy), have the pistons fly-cut for valve clearance, etc etc etc. All told it would have cost more money than everything I have put in to my RX-7. For a *cam swap*.

Needless to say, THAT car stayed stock, engine-wise...