Why Run In?

[kev-yorks]

About time to get another debate going why do people run in there engines. Can anyone say they\'ve killed there motor through thrashing it from the off.
Any motor of mine gets run up to temp checked for leaks and pressure then driven. Speaking to the RX8 guys they are told by Mazda fluctuate the revs for the first 600miles (don\'t just sit at one rev) no limit to what revs they use, then abuse it. So why is it so many spends months babying there motors after rebuild? Especially when you look through the rebuild posts and it seems its not apex or housing damage that kills most motors but water seal problems.
 
Kevin:driving

[Clarky]

Yes i would also like to know the thoughts on this , as i have just finished my rebuild, and done 60 miles, and have been advised to keep it no higher than 3000rpm for the first 500 miles, then 1000 miles at 4000rpm.

[antnicuk]

i personally think that most of the reason is for it to be run in for the longest period possible so its longer before it comes back having been detonated.  

most tuners map their cars straight after rebuild.

It may need a few hundred more miles if you have new bearings, but to be honest 4000 rpm is a massive amount of revolutions so not a great deal of difference between 4 and 8.

Some people say compression gets better after a few miles, that may be the case but compressions constantly changes throughout the life of the engine regardless.  It gets a bit higher then slowly gets lower...

[LRP]

was just thinking the same 2 nite ive just covered 450 with a rebuild and im wondering how long to keep off the loud pedal get my new plugs 2mrw to keep up with the fueling, then seeing greg for a map update then to start building boost . happy days hopefully

[banned advertiser]

The RX8 is N/A, a turbo\'d car must put so much more pressure on an engine that the smoother the surfaces can be worn together the smoother the car must run.
I guess?

[davehg]

now now leighton, take that lead out of your shoes :rollin


be good to the engine and it will be good to you......... (now its had its tantram)

[kev-yorks]

i personally think that most of the reason is for it to be run in for the longest period possible so its longer before it comes back having been detonated.

Bit controversial that one Tony i like it.
hamc my own personal opinion and its only that is its a complete waste of time running in. When you first fire up the seals settle themselves in place or at least you hope they do. No one uses running in oil anymore so that reason is out the window also and to be honest if you lose a seal in the first few thousand miles you will do that anyway. Its not down to lack of bedding in but a underlying problem that was there anyway. Much better to find out in a month rather than waste a load of fuel playing with the thing then find out the first time you open it up you\'d got a problem.
 

be good to the engine and it will be good to you

Don\'t forget Dave Mazda also recommend taking it to the red line every time out is that being good to the engine?
 
Once again Guys before i get flamed personal opinions only just trying to start a bit of a debate on this to see if we can get some hard technical reasons for running in when Mazda don\'t seem to think its required on a RX8.
Regards Kevin

[nikp]

I only put 500 miles on mine before getting mapped. Apparently i have read and understood (and posted on here somewhere) that if you just get going straight away from the off you\'ll get more power but shorted engine life.

[LRP]

now now leighton, take that lead out of your shoes :rollin


be good to the engine and it will be good to you......... (now its had its tantram)

me lead in my shoes ! would i im paranoid at the moment every little abnormal noise makes that big smile go to worry !!! keep telling myself it will be ok hav faith ,the first time i redline with no problem i may smile with out my spine tingling out of my body:Talking1

[davehg]

hi kev, i always take mine to the red line at least nce in a drive 8,300rpm cough cough and its good for the engine, ive doene both on engines ie run them in by gradually building up the revs and leterally starting it up and thrashing it down the road.

PS thats on a T04R single

[antnicuk]

Hamc,
as you have used ALL new parts, i would give it a few hundred miles of getting up to temp and cooling down before getting it mapped for high rpm, boost, but most engines only use new rotor housings, but as kev says, just opinion.  My engine will only be given a couple of hundred, but this to make sure there isnt a problem with a leak or something similar.    So far so good......

[John Yorke]

Best reason for running in, I would have thought to bed in the seals, I know for a fact you get better compression after a gentle bedding in period [run in] of 500+ miles thus more power.
Depends what you intend the engine for, on race / drag applications runnin in is done after the 1st lap / 1/4 mile:Giggle

[kev-yorks]

As stated at the start though John how many engines die of old age. Water seal failure seems to be the main cause of the rotary demise in the UK

[Prof]

I suppose if you\'ve a turbo\'d car, then running it in under 3000/4000 RPM keeps the boost levels low, which must reduce the stress on the seals and housings as they \'bed in\', once this process has been observed - and it may only need a couple of hundred miles - who knows, the engine should be well sorted for all out power.
 
I tend to let mine hit the buzzer at least once on a journey, conditions permitting, but I did observe the running in ritual, as it\'s part of Rotechniks warranty.
 
My engine is running nicely now, so hopefully fate will smile and the insurance man will let it live for a while longer.

[nikp]

Water seal failure is by far the most common cause of engine failure from hearing most peoples stories. However, that\'s got nothing to do with your running in period of course! :p