Totally Noob Question

brogelio
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Totally Noob Question

Postby brogelio » Fri Apr 18, 2014 6:00 pm

Hi all.
I just finished my AE86 GTS swap. This is my first project car. And this is my first "performance" car and I'm not used to high strung engines.
I've never taken it to the redline. Go ahead and call me a pussy but the sound and the fury above 5k makes my palms sweaty. :|
That said, during spirited driving (not getting groceries) how high up do you guys take the engine in the rev range?

yoshimitsuspeed
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Re: Totally Noob Question

Postby yoshimitsuspeed » Fri Apr 18, 2014 6:07 pm

brogelio wrote:Hi all.
I just finished my AE86 GTS swap. This is my first project car. And this is my first "performance" car and I'm not used to high strung engines.
I've never taken it to the redline. Go ahead and call me a pussy but the sound and the fury above 5k makes my palms sweaty. :|
That said, during spirited driving (not getting groceries) how high up do you guys take the engine in the rev range?


Bouncing off the rev limiter from time to time on a healthy engine just helps blow the cobwebs out. The 4AGE is meant to spin.

With that said RPM do take their toll long term so the more you beat on it the shorter they will live.
One of my favorite sayings applies here. Everything in moderation including moderation.
Just don't spend all your time up there and you shouldn't have a huge impact on it's life expectancy.

allencr
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Re: Totally Noob Question

Postby allencr » Sat Apr 19, 2014 11:14 am

By now, when going over your self imposed limit, the rings are going to be exploring a new area of the cyl. that hasn't gotten any wear & has a hard carbon build up on it.
Used to be claimed as a cause of broken rings.

yoshimitsuspeed
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Re: Totally Noob Question

Postby yoshimitsuspeed » Sat Apr 19, 2014 12:33 pm

allencr wrote:By now, when going over your self imposed limit, the rings are going to be exploring a new area of the cyl. that hasn't gotten any wear & has a hard carbon build up on it.
Used to be claimed as a cause of broken rings.

It might be a concern if someone put like 100k miles on the motor never going over 5k RPM. It would take quite a long time with a pretty strict limit that was never exceeded.

Jimmee1990
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Re: Totally Noob Question

Postby Jimmee1990 » Sun Apr 20, 2014 5:49 am

The rings and pistons reach the exact same place on every single revolution of the engine no matter what revs(discounting the tiny amount of side clearance they should have in the ring grooves), it's not like revving it harder changes the stroke length or the rod length does it. Don't get started about alloy rods and big revs and rods stretching, this is a standardish 4age we're talking about.

Taking it up to the limiter is fine every now and then. even going over 7000rpm every day is fine. Extended periods of high load is what will do the most damage, not short runs up the street every now and then.

yoshimitsuspeed
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Re: Totally Noob Question

Postby yoshimitsuspeed » Sun Apr 20, 2014 10:51 am

Jimmee1990 wrote:The rings and pistons reach the exact same place on every single revolution of the engine no matter what revs(discounting the tiny amount of side clearance they should have in the ring grooves), it's not like revving it harder changes the stroke length or the rod length does it. Don't get started about alloy rods and big revs and rods stretching, this is a standardish 4age we're talking about.


Funny because I have talked to Loyning, Hasselgren and other engine builders about squish area and rod stretch and they all have said roughly the same thing.
None of them recommend tighter than about .8mm squish area to factor for rod stretch to make sure the piston won't hit the head. A couple suggested that the stock rods will probably stretch about as much at stock redline as high end rods will on a high spinning motor.