Understanding Warped Head Gasket

[EnergyHOU]

I haven't found anything specifically discussing this process so I was hoping we could get some of the experts here to walk us through what exactly happens, why it happens, and the rate / progression at which it occurs?

I personally am asking because I'm at around 6,200 miles now and what has me curious the most is if this process is something that happens progressively over time, like a "cancer" if you will, or if the gasket warps instantly upon an extreme overheat scenario, however short or long that may last. If I knew for a fact that I was "in the clear", I'd go ahead and make some major investments incl full exhaust, air filter, PCV, etc. and not look back, but if there was a chance I was slowly edging my way towards that warranty work, I'd hold off. Opinions guys?

 

[KTManny]

I second that motion, let's get some experts in here.

 

[CDN Duke]

I think PCV probably improves chances of head gasket not going, depending on how you ride it, as you're likely richening the mixture and hopefully running at lower temps?

That's my rationale for having purchased my PCV (with proper tune from cjwell/Commonwealth), air filter, exhaust etc... l

 

[KTManny]

I think PCV probably improves chances of head gasket not going, depending on how you ride it, as you're likely richening the mixture and hopefully running at lower temps?

That's my rationale for having purchased my PCV (with proper tune from cjwell/Commonwealth), air filter, exhaust etc... l

Is that the story you told your wife?

 

[CDN Duke]

Is that the story you told your wife?

I didn't get into any detail... but seriously, it was my rationale for safeguarding the motor knowing I wanted a reusable high-flow air filter and a pipe. I already had the Akra map flashed before I picked up the bike but I could tell how lean it was with just the air filter added - should note that I was running it with the MNNTHBX open lid...

 

[KTManny]

I didn't get into any detail... but seriously, it was my rationale for safeguarding the motor knowing I wanted a reusable high-flow air filter and a pipe. I already had the Akra map flashed before I picked up the bike but I could tell how lean it was with just the air filter added - should note that I was running it with the MNNTHBX open lid...

Both the Akra and the PCV are on my list of mods.

 

[cornerslider]

I haven't found anything specifically discussing this process so I was hoping we could get some of the experts here to walk us through what exactly happens, why it happens, and the rate / progression at which it occurs?

I personally am asking because I'm at around 6,200 miles now and what has me curious the most is if this process is something that happens progressively over time, like a "cancer" if you will, or if the gasket warps instantly upon an extreme overheat scenario, however short or long that may last. If I knew for a fact that I was "in the clear", I'd go ahead and make some major investments incl full exhaust, air filter, PCV, etc. and not look back, but if there was a chance I was slowly edging my way towards that warranty work, I'd hold off. Opinions guys?

While I don't consider myself to be anywhere NEAR an "expert", I feel obligated to reply..... I feel it is safe to say that you're totally safe to do whatever you choose to do as far as modifications [emoji1360][emoji41]. IMHO, you are probably subjecting your bike to MORE heat by leaving it "stock".... This bike is soooo restricted to meet the EPA guidelines in the USA, it just makes me sad . If I could break-in my 2016 all over again, I'd have done the intake/exhaust/PCV before I even started the bike up for the first time. Be smart about it, get the PCV from commonwealth, with Chads map, and you will have NOTHING to worry about [emoji1360]-


Sent from my iPad using Tapatalk

 

[simpletty]

The issue starts right at the factory. It's not a gasket issue it's a cylinder head issue. From what I was told is that at the factory the assumption was one of two things or possibly both.

1. Not enough coolant being used while milling the head
2. Milling the head too quickly therefore inducing too much heat in the process

both of these will place excessive heat on the head and supposedly it had set up a slight warp of around 0.004". Over time that is a weak point and eventually the head gasket will let go. I was told it's was towards the centre of the head.

Having a PCV or new spal fan will not prevent the leak, it will probably just prolong the inevitable. These bikes run hot, as indicated by the temp gauge and I'm betting the guys on the southern hotter states will see the issue happen sooner, obviously
1-you basically can ride 12 months a year
2-summer temps are hot hot

mines been apart already and has a new gasket, but it was for an oil consumption issue, not a head gasket issue. I would venture a guess to say that not all heads were milled incorrectly,possibly the earlier models only, just speculation on my part. I'm sure there are many guys out there who have had zero issues and have plenty of miles on them.

i am eliminating the thermostat with the use of the y hose kit from motohose.com. I really don't see a need for a thermostat, I'm racing mine only anyway. I can recall on the last day out on the track the fan barely came on ever, it's city riding that builds up all the heat in the stop and go traffic. I recall the fan coming on at nearly every stop light on a hot day. The last race day temps were 85 deg and I was out for 5 sessions to which I dont recall the fan coming on, mind you I had plenty of other things to concentrate on. I do believe that if you are constantly moving, no matter how hard you're on it the fan is needed less and less, so I think a track bike would hold up longer than a daily driver.

 

[gbabyracing]

I believe if you received an even slightly warped head from the factory and couple that with a low cost provider head gasket; chances are pretty good you could blow the head gasket.

 

[Deleted member 452]

I think PCV probably improves chances of head gasket not going, depending on how you ride it, as you're likely richening the mixture and hopefully running at lower temps?

That's my rationale for having purchased my PCV (with proper tune from cjwell/Commonwealth), air filter, exhaust etc... l

FYI- Running a richer map with a PCV didn't stop my head gasket from letting go at 4.3K miles.

 

[btalont]

I have only 1400 or so miles on mine, bought in April of last year. First half was stock and street riding and now mostly track since October last year. I have now added a pipe, MNNTHBX airbox cover, K&N, then Bazazz fueler with ZAFM mapper module and finally replaced the Rad cap, coolant and trimmed the fan shroud. The bike runs cooler now and definitely makes power. I have to believe adding fuel and reducing combustion temps has to help and of course the flip side is more power = more heat for the cooling system. Was at the track this past Sunday and so far no head gasket problem. Time will tell.

 

[SPG]

I think a dirty fuel injector overheated mine. I've replaced the gasket 3 times before I caught the injector. Since then, I've put in a new injector and remapped it. It seems to be holding together now.

As for taking out the thermostat, I'd be pretty hesitant to do that. I cold seized my moto3 bike with no thermostat. I warmed it up but the coolant temp dropped during the first lap and pinched the rings. New piston and sleeve needed. After that, I built a thermostat housing and haven't had a problem since.

-Sean

 

[simpletty]

I think a dirty fuel injector overheated mine. I've replaced the gasket 3 times before I caught the injector. Since then, I've put in a new injector and remapped it. It seems to be holding together now.

As for taking out the thermostat, I'd be pretty hesitant to do that. I cold seized my moto3 bike with no thermostat. I warmed it up but the coolant temp dropped during the first lap and pinched the rings. New piston and sleeve needed. After that, I built a thermostat housing and haven't had a problem since.


I have yet to run a thermostat in any of my race bikes but they are brought up to temp in the pits beforeI head out on the track. This thing runs too hot already with the t-stat in. You must have been out on a really cold day to have squeaked it shut like that. As far as the dirty injector goes, did it have any symptoms from it when it was running? I think that lack of power would have been one for sure.

 

[Mike91]

Mine is a 2015 street bike set up for racing. I rode the bike on the track 4 times and the gasket let go. Less than 1000 mikes on the motor. Darn!@

 

[nino209]

warp head

The issue starts right at the factory. It's not a gasket issue it's a cylinder head issue. From what I was told is that at the factory the assumption was one of two things or possibly both.

1. Not enough coolant being used while milling the head
2. Milling the head too quickly therefore inducing too much heat in the process

both of these will place excessive heat on the head and supposedly it had set up a slight warp of around 0.004". Over time that is a weak point and eventually the head gasket will let go. I was told it's was towards the centre of the head.

Having a PCV or new spal fan will not prevent the leak, it will probably just prolong the inevitable. These bikes run hot, as indicated by the temp gauge and I'm betting the guys on the southern hotter states will see the issue happen sooner, obviously
1-you basically can ride 12 months a year
2-summer temps are hot hot

mines been apart already and has a new gasket, but it was for an oil consumption issue, not a head gasket issue. I would venture a guess to say that not all heads were milled incorrectly,possibly the earlier models only, just speculation on my part. I'm sure there are many guys out there who have had zero issues and have plenty of miles on them.

i am eliminating the thermostat with the use of the y hose kit from motohose.com. I really don't see a need for a thermostat, I'm racing mine only anyway. I can recall on the last day out on the track the fan barely came on ever, it's city riding that builds up all the heat in the stop and go traffic. I recall the fan coming on at nearly every stop light on a hot day. The last race day temps were 85 deg and I was out for 5 sessions to which I dont recall the fan coming on, mind you I had plenty of other things to concentrate on. I do believe that if you are constantly moving, no matter how hard you're on it the fan is needed less and less, so I think a track bike would hold up longer than a daily driver.

funny enough the .004 is right on the money, i have a cup bike and when i saw the issue of the blown head gasket, i decided to go with Chad's thinner head and base gasket, at the same time i took the head to be milled, i asked the machine shop to remove .003 they called back and a said that the head wouldn't clean up unless they when .004 that finally cleaned it up, i was just lucky i got it taken care of before it became a problem, at that point i had about 10 races on the bike.

 

[stevieboy]

I think a dirty fuel injector overheated mine. I've replaced the gasket 3 times before I caught the injector. Since then, I've put in a new injector and remapped it. It seems to be holding together now.

As for taking out the thermostat, I'd be pretty hesitant to do that. I cold seized my moto3 bike with no thermostat. I warmed it up but the coolant temp dropped during the first lap and pinched the rings. New piston and sleeve needed. After that, I built a thermostat housing and haven't had a problem since.

-Sean

If you re-mapped at the same time as you replaced the injector how can you be sure which was the fix?

 

[Deleted member 452]

funny enough the .004 is right on the money, i have a cup bike and when i saw the issue of the blown head gasket, i decided to go with Chad's thinner head and base gasket, at the same time i took the head to be milled, i asked the machine shop to remove .003 they called back and a said that the head wouldn't clean up unless they when .004 that finally cleaned it up, i was just lucky i got it taken care of before it became a problem, at that point i had about 10 races on the bike.

You're engine's probably going to experience detonation under moderate loads from 5-7K RPMs with that head gasket. Chad's aware of this problem so I'm surprised he sold you a thinner head gasket without his complete engine kit that uses a different piston, etc...

 

[=maz=]

All three race bikes in my state that were fitted with the thinner gaskets blew within 30min of running. I went back to OEM on our 2 and haven't had another problem since the warranty work was completed.
I'm almost sure there was a bad batch. No Austrians in the country that month maybe. lol

 

[nino209]

You're engine's probably going to experience detonation under moderate loads from 5-7K RPMs with that head gasket. Chad's aware of this problem so I'm surprised he sold you a thinner head gasket without his complete engine kit that uses a different piston, etc...

well i had the bike dyno tuned by Lee's Cycle in SD, first with the Akra and now I'm running the tyga exhaust, i couldnt use the complete kit due to super sport rules, i haven't had any issues with the bike , it is pumping out a healthy 43hp at the rear, i cant remember exactly but with the Akra it was putting out almost 44, it has about 12 races on it since i went to the thinner head gasket.
i race in the CVMA series and rounds like September, march and April temperatures outside the track could get up to over 100 degrees, so far so good, i plan to do a complete refresh at the end of the season in April, we will see how everything look inside then.

 

[cjwell]

They are hit and miss. Casting quality wise and some other variables... Regarding my thin gasket set they can be used in any build. If using stock cams with them cylinder pressure is higher due to less overlap/trapped cylinder pressure. Some ignition timing should be pulled out of it a peak torque (where cylinder pressure is highest) to prevent detonation. I pull 4 degrees out a thousand rpm below and above peak torque rpm from 40-100% tps in PCV map. That will fix any potential for detonation. It is not a must on all stock engines but we have seen some cases of detonation with added timing that the stock thickness gaskets like. The squish, cam timing, injector flow, cooling system etc must vary more than I would like on the stock production engines, some are fine with added timing some are not so happy. With that being said you will see clear signs of detonation on the piston if it is occurring. It can lead to blowing out a head gasket for sure. If the gasket has failed and no signs of detonation then it is a material casting issue or workmanship. If the head is not flat or the deck no gasket will seal it up! If the head as had more than .004'' to straighten up "I" wouldn't reuse it. The more material you take off the thinner it gets where the problem occurs (the coolant passage exhaust side), every head gasket that has failed has been there, NO where else by me or KTM. By milling it you loose material there and it will relax/warp again even faster. The gaskets are not the problem, it's a casting/material issue.