dropped valve (how)

[MartinR]

no i have not dropped a valve in the inlet (touches wood), but was wondering what actualy causes this? bad design/living on the limiter?

also could remaping the ecu via say an rstuner etc...... i.e raising the limiter slightly cause this by putting more strain on the engine. i am thinking of getting a re-map/rstuner in the near future but worried doing this may cause problems.or is it just bad luck that this happens?

cheers

 

[MicKPM]

It can happen for a number of reasons; mainly abuse, component fatigue, cheap replacements used, bad luck, etc... i'm not a mapper so will not comment on products such as RSTuners contributing but i doubt it.

 

[Dan]

no i have not dropped a valve in the inlet (touches wood), but was wondering what actualy causes this? bad design/living on the limiter?

also could remaping the ecu via say an rstuner etc...... i.e raising the limiter slightly cause this by putting more strain on the engine. i am thinking of getting a re-map/rstuner in the near future but worried doing this may cause problems.or is it just bad luck that this happens?

cheers

i doubt its a map problem theres usualy a safe amount you can get from an engine that doesnt cause reliability problems

lack of servicing and pure bad luck would be my guess :S

 

[Hoofy]

The most common cause as far as I'm concerned is damaged valve guides. Abuse will cause the top end to burn oil and less oil means higher temps. Then, once there's a lack of lubrication for the stem to move up and down the guide, it just takes one instance of it failing to return to its closed position and the valve has dropped. And then....guess what, BANG!! Piston hits valve! My mate's fisher fury did it last year, snapped the camshaft in two places!!

 

[MartinR]

cheers for the replies i shall go forth and remap it then.

hoofy exactly what i was thinking,mine is serviced every 6k and always keep an eye on my fluids and don't do much driving like its stolen

 

[Dan]

cheers for the replies i shall go forth and remap it then.

hoofy exactly what i was thinking,mine is serviced every 6k and always keep an eye on my fluids and don't do much driving like its stolen

if your worried about anythin dude just give the guys at RS tuning a call they know everything that is needed to know about mapping these things

 

[Chip-mk1]

Exhaust valve failure is often down to bad mapping as a major contributing factor, but inlet valves tend not to be.

 

[Silent_Scone]

Just one of those things, wouldn't say the F4R is common for it though. But doesn't take much for it to be catastrophic, few seconds and it's already tried to do a few hundred rotations..bye bye aluminum head

 

[Martin_172]

im currently doing a top end rebuild on a 1.2 16v due to this, turns out the car im doing hasnt been serviced in 6yrs 60k miles lol

EDIT: the dipstick is snapped too so god know how much or what the oil is like in it!

 

[MartinR]

im currently doing a top end rebuild on a 1.2 16v due to this, turns out the car im doing hasnt been serviced in 6yrs 60k miles lol

EDIT: the dipstick is snapped too so god know how much or what the oil is like in it!

flol 6yrs 60k thats bloody bad that is:dead:

 

[Jackpilk]

I'l be putting a load of pics up soon of the aftermath of the valve dropping on me a few weeks ago.

 

[Martin_172]

flol 6yrs 60k thats bloody bad that is:dead:

funny thing is it was running sweet as a nut before this lol!!

 

[Jackpilk]

Have a look, unless you've just eaten..

http://www.cliosport.net/forum/show...th-(dropped-valve-pics)&p=8247735#post8247735

 

[Chri5]

also could remaping the ecu via say an rstuner etc...... i.e raising the limiter slightly cause this by putting more strain on the engine.

Raising the limiter doesnt mean you have to take it there in every gear! :rasp:

 

[MartinR]

Raising the limiter doesnt mean you have to take it there in every gear! :rasp:

lol barely seen the limiter don't drive it that hard well not all the time

 

[DanielG]

Exhaust valve failure is often down to bad mapping as a major contributing factor, but inlet valves tend not to be.

Interesting. The two engines I've had drop valves did it on the exhaust side both times. Car was running unmapped CatCam 428's.

I'l be putting a load of pics up soon of the aftermath of the valve dropping on me a few weeks ago.

Almost as bad as my first time. Except I had mine fail at 6500rpm. Got a lovely hole in the block and bits of my valve found stuck in the cat converter...

Can view the aftermath here: http://danielgphoto.com/clio/engine/

 

[Dan519]

increasingly common unfortunately. I personally put it down to valve bounce when hitting the limiter, and worn valve guides. The vast majority of the engines I've seen do it have been owned by those who "enjoy" the limiter a bit too much

 

[SBV116]

^ lol, agreed!

 

[Chip-mk1]

Interesting. The two engines I've had drop valves did it on the exhaust side both times. Car was running unmapped CatCam 428's.

Well given that the 428s flow a lot more air near the rev limiter, it will mean that your car will have been far too lean if it hasnt been remapped to suit, so I'm not surprised to hear that at all, if you fit a 3rd engine it will probably do the same eventually too.

 

[Laine_16v]

Mine self destructed at 7500rpm on the limiter with 421 cams. I wont build another F4 cams without uprated valves now (probably won't do it again anyway).

Not pretty and very expensive lol

 

[DanielG]

Well given that the 428s flow a lot more air near the rev limiter, it will mean that your car will have been far too lean if it hasnt been remapped to suit, so I'm not surprised to hear that at all, if you fit a 3rd engine it will probably do the same eventually too.

I am on the 3rd... stock this time.