My car has been sitting for 5months, how long should i redline it for to get rid of any carbon build up?

 

Just drive it spiritedly. I'm pretty sure it will take care of itself. Maybe throw some Lucas in there.

 

Who needs the other gears?! just use first and second gear. Forget the other ones. They are for slow grandmas. haha. I wouldn't redline it at all. I would Seafoam it.

 

Um, carbon doesn't build up from sitting. I would take it easy for a while to let the coolant seals go through a couple heat cycles and return to their normal state.

 

What he said^^

Though along these lines, IS redlining good/safe or not??? I have heard differnt things for everyone i ask.

The guy locally that is the only RX7 shop this side of town says it is good for them. He claims to have run his 13b at 14,000rpms without any problems for a long time.

Others say it is not any good. I know that once i get to 6000+rpms it sounds like it is going to explode, of course i have always had v8's and low reving toruqe motors that can't rev at all before. Highest redline i have had was 5500rpm.

So is redlining the 13b really good of really bad? and whats the "safe" limit both in time and RPM's?

 

If you really want to remove the excess carbon I would suggest doing the water treatment.

 

yea, what he said...

i read up on here, somewhere... take a gallon of water, hook up a vac line from the intake manifold. then keep the rev at 2500-3000 until the water is gone. stuff should be flowing out the exhaust. i'm guessing.. warm up the motor first. good luck, i might do this before winter. :P

 

well to answer your question Texas Ace, no normal rotary can go to 14k rpm, i dont care what your shop guy says or thinks. his engine does not rev that high.

REDLINING it persay isnt really "good" but driving it spiritedly is. the carbon buildup thing is mostly a myth, unless you pussyfoot the car for 50k kilometers or something, same goes for using cheap synthetic oil. carbon doesnt build up overnight.

as mentioned, it would be good to put a bit of seafoam or MMO or anything in the engine to lube it before starting. do a bit of dry cranking just to get some oil pressure up, oil on the insides of the rotors etc- then start it up and let it warm up fully. drive it gently for a week or so, change all the fluids and check the plugs+ o2 sensor, and go back to normal RX-7 driving!

 

the problem is that the water pump wont be efficient at that high an rpm (redline) and it just sloshes the water around. Not good.

 

If the car has been sitting for 5 months, follow the instructions for bringing a car out of improper storage:
http://www.aaroncake.net/rx-7/unstore.htm

You should not assume the engine has excessive carbon buildup just because. All the "treatments" risk dislodging chunks of the really hard carbon and damaging the engine.

 

I have personally seen 2 engines where enough carbon built up on the rotor face that it contacted the rotor housing.

 

I have though about doing this as well but won't this get water in the oil? I just chaged it and don't care to do it again so soon.

Thanks, whats MMO by the way?

 

http://www.marvelmysteryoil.com/

 

marvel mystery oil!


oh and aaron, i wasnt referring to the use of solvents in the engine to de-carbon it, i used seafom when re-starting my car after a long period, as a lube- i had no spare engine oil or regualr lube oil etc, and didnt feel comfy spraying wd-40 in there! i just squirted a bit in the spark plgu holes and turned the engine over by hand to get a bit of lubeage happening in there before i started her up!

 

So this is the correct stuff i guess?

http://www.marvelmysteryoil.com/index.php/site/mmo/

Hmm, never heard of it. You suppused to use it like seafoam or in the gas?

 

which is why i made the comment about the 50k kms region. YES, we all know carbon builds up on these engines, ive seen some frigging gross rotors. my point was, newbies think that if they dont redline the engine DAILY, it will die in like a month. this simply isnt true. carbon does not accumulate that fast. sure it will build up over time and ruin things, but not THAT quickly


the only time ive ever seen a carbon locked engine, it wasnt what people normally think, it was like what you said, where there was about 1/4" of gunk stuck on the rotor and it squished against the housing wall and simply had no where to go=stuck!

 

some people say either or- my point was that your seals just could use a bit of lube before you start cranking it a lot. you could even put normal engine oil in there if you have one of those little oil squirters, just put a tiny squirt in the spark plug hole and turn the engine over by hand.

 

One of the engines that had excess carbon saw redline about every other shift for the last 7k miles of it's life. Babying an engine isn't the only way to get carbon buildup.

 

Too much fuel, bad spark plugs, and the stock OMP are the culprits. Since I've been premixing with no OMP my plugs stay much cleaner. I assume the same goes for the engine internals.

 

Yeah, I can agree with this. Was doing a top speed run on a empty country road with no side roads for traffic to pop up on me, was cruising at around probably 120 in 4th @ somewhere around 6k, watching my temp gauge slowly go up. I let off before it got 3/4 of the way.

Personally, YMMV, but I think its only good to push the car on full WOT to probably 1/2 way through 4th gear unless you've tuned and have the supporting mods to push your car that far.


But if your car has been sitting for 5 months, I would recommend seafoaming it, and not running it to redline until you've been driving it around for a week or two at least. Chances are you might pop something. Carbon build up doesn't occur when a car has been sitting. Carbon build up occurs when you baby your car for months/years. I.E. : granny shifting at 2.5k for at least a month or two. And even then the carbon build up is going to be minimal.

 

kek...seals would be destroyed by just starting and redlining...def. seafoam...although I have heard from a guy who has 20B's that redlining if you let them do the CC warmup that's built-in, can HELP, but still needs seafoaming or just babying for a while..