Jump to content
SAU Community

Recommended Posts

Hi all,

Earlier this year my 25 neo in my 34 did a head gasket during a track day. Had that fixed up and shortly after ran into more trouble which was diagnosed as rings. $6k and 10 months later with a freshly rebuilt motor I hit my 2nd track day of the year and the car has turned around and chewed through another head gasket on the first lap.

Motor was tuned, ran fine on the dyno in heat, didn't make as much power as pre rebuild but we attributed that to the hot weather.

Found shit loads of oil in the coilpack valley, after opening the bonnet up, but only in cyl 1-2, assuming this was spat out of the breather. Motor now has shitloads of blow by, is running on 5 and obviously is spitting white smoke out of the exhaust like crazy.

Trying to figure out how exactly it's managed to eat a head gasket (and do the rest of the damage it's done to my motor) after one hot lap of Winton. Coolant was boiling when I pulled off the track, powersteering was also overflowing (which set my manifold on fire, yay)

before anyone says check your temps, stock gauge said I was slightly above half, which is what I expected given it was a 35 degree day.

Link to comment
https://www.sau.com.au/forums/topic/472788-fresh-rb25-dead-after-1-lap/
Share on other sites

24 minutes ago, OSH1FT said:

before anyone says check your temps, stock gauge said I was slightly above half, which is what I expected given it was a 35 degree day.

This is just going to make people tell you the stock gauge isn't accurate enough track use

I've had a similar experience, except I cooked the bottom end bearings on the 2nd track day. And it had done run in kms plus a light track day on run in tune.
My oil pressure and temp gauges didn't pick up any issues, but they weren't monitoring in the spots with the problem....

Anyway, I learnt that building a motor doesn't always fix the problem that caused the motor to die in the first place.
In my case it was the external oil filter/cooler setup, which remained unchanged between motor builds.

What type headgasket? Thickness? What boost? Aftermarket headstuds?
Aftermarket radiator?

Its probably all conjecture and meaningless until you have worked out what your damage is.

So turbo is gone?

Loss of compression blown gasket or busted rings?  So are there results from a compression test and/or sniffer in the radiator if the thing still runs.

Is the bottom end ok?

Power steer can overheat and overflow but not after one lap usually.

Comes down to what is different between a dyno and the track. Oil surge is possible but unlikely to be fatal after one lap. Bad fuel and or fuel surge will cause problems more quickly.  Damage caused quickly is overwhelmingly combustion related rather than oil/coolant related.  The only other thing that fleetingly comes to mind is an over rev/over boost.

Its a depressing thought but more than one thing may have been busted.

 

Edited by djr81
10 hours ago, djr81 said:

Its probably all conjecture and meaningless until you have worked out what your damage is.

So turbo is gone?

Loss of compression blown gasket or busted rings?  So are there results from a compression test and/or sniffer in the radiator if the thing still runs.

Is the bottom end ok?

Power steer can overheat and overflow but not after one lap usually.

Comes down to what is different between a dyno and the track. Oil surge is possible but unlikely to be fatal after one lap. Bad fuel and or fuel surge will cause problems more quickly.  Damage caused quickly is overwhelmingly combustion related rather than oil/coolant related.  The only other thing that fleetingly comes to mind is an over rev/over boost.

Its a depressing thought but more than one thing may have been busted.

 

So we drained the oil out from the coilpack valley and the car actual runs smoothly and sounds good. doesn't misfire, sounds very much like compression is okay. Will be testing tonight or tomorrow when I can borrow a kit.

Only blowing white smoke under load so I'm assuming turbo is on its way out. Again, gotta pull that off in the next couple of days to figure it out.

Really just cant figure out the connection to the excessive blow by and the turbo going at the same time.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Oh bugger ! Your right ! Good old hydrogen sulfide. Takes me back to the good old school days ! 
    • I've owned a few scooters over the years, a Vespa PX oil burner was my first scooter, followed by a few others, including a little 50cc BeeWee that I used as a barracks bike, and I've had a blast on all of them, they really are the cheapest for of city/suburb transport around The only issue with scooters in Australia is lots of people look down on them due to their size,  maybe they need a big bike to make up for something else where they are lacking, unlike Europe and Asia where every man an their dog owns one, and now that filtering is legal in NSW, local traffic is never a issue Not to say I haven't owned my share of big cc bikes over the years, but they were for more blasting through the hills or Hwy riding where it needed to sit on Hwy speeds Safety wise, I ride like everyone is always trying to kill me, everyone is running a red, or running stop/give way signs, or generally asleep at the wheel, which most people are duringtheir commute, I also ride really safe, and give myself, and everyone else enough room in case I need to pull some hasty evasive actions, I've done a few rider training days over the years, which has come in handy on more than a few occasions  As for mods, there's nothing really, and yes your right about aftermarket exhaust, all you get is loud and obnoxious noises from them, like every 250-300 cc you hear with a aftermarket muffler, in saying this I did put a rear muffler from a 125 Aprilla on one of my old 125 scooters, it was horrendous and no amount of full face helmet and ear plugs would dampen that noise As for coming from the Harley, and what a overpriced POS that was, I no longer do big rides as my poor old busted joints ache after about 1/2 an hour of riding, long cruises are so much more enjoyable now in a car, so a big bike would be pointless   
    • Oh wow, it's easy to forget how cheap these can be. Probably the cheapest way to travel. Though people in cars here tend to be morons and I would not feel very safe. Were scooters ever big in Australia? It used to be the thing growing up in Europe ~20 years ago. 50/70/125ccm Peugeot or Yamaha and some others. Utterly obnoxious Polini race exhausts. Kick stands that slant as much as possible. So loud. So much noise for really not moving very fast at all. But it felt cool at the time. Not sure where I'm going with this, but there is an aftermarket for mopeds! Though I'd have pictured you more for a Goldwing kind of guy after growing out of the Harley.
    • You need to know I am sorry for this.  
    • As the MX5 isn't apparently "manly" enough, and I need something for runs to the local shops, and also take to my part time job at the salon, basically I can keep the MX5 away from car parks and stuff......like "flying lockers", I was wondering what I could buy to fix this issue LOL, I pick up a new Yamaha 125 Delight this arvo from Trooper Lu, basically a R1 that you can fit a slab of beer on between your feet, also, it was $29400 cheaper than a R1, so actually it's 2 x better than a R1    
×
×
  • Create New...