Anyone ever seen this:

[mulot30th]

Remember my apex motor that was leakdown tested to 30-40% on all 4 cylinders?


now that it have been completely dissasembled by my engine builder...


All 4 cylinders have their top portion 'tapered' open and the nicasil on all of them is looking pretty bad. pistons are okay (no deto sign of any sort), but rings are complete junk.

the verdict has been its because I ran too much boost on the bone stock motor (18 psi - 290hp - strait c16 - no deto - no knock), causing too much pressure on the cylinder sleeves and they 'opened' like a taper up top which got them out of round and then rings were toast because of that and nicasil followed... at least that is what we think.


Anyone else ever seen this happen or am I the absolute badlucked person owning a yamaha?

 

[yamaha69]

i am going throw the same thing just took motor apart and same as you ???????????is wat my answer is

 

[Ted Jannetty]

Remember my apex motor that was leakdown tested to 30-40% on all 4 cylinders?


now that it have been completely dissasembled by my engine builder...


All 4 cylinders have their top portion 'tapered' open and the nicasil on all of them is looking pretty bad. pistons are okay (no deto sign of any sort), but rings are complete junk.

the verdict has been its because I ran too much boost on the bone stock motor (18 psi - 290hp - strait c16 - no deto - no knock), causing too much pressure on the cylinder sleeves and they 'opened' like a taper up top which got them out of round and then rings were toast because of that and nicasil followed... at least that is what we think.


Anyone else ever seen this happen or am I the absolute badlucked person owning a yamaha?

You don't have detonation but your cylinder pressure is still to high at the wrong time, this is caused by timing not boost.

This is also what causes head gaskets to fail.

Peak cylinder pressure must occur 15 degrees After Top Dead Center so it does the most work pushing the piston down.

Your peak Cylinder pressure could be occuring at 0-5 degrees ATDC which would push the cylinder walls out.

Any boost pressure above 15 psi should have an MSD ignitions system so we can pull timing VS boost.

I pull about 7 degrees at 22 psi.

I have MSD ignitions available.

 

[ultimate]

well....all depend with which gas you run,better gas like c-16 you can put more timing.but if you run 0n c-12 don'T need to pull timing before 20psi for max hp AT 10:1 RATIO COMP.

BUT STOCK COMP YOU MUST TO RETARD!

testing on dyno!but many options can be done.:

msd ign is only a security on high boost, cause no really hp gain on dyno!

PS:MULOT your really not lucky. don'T stop to work the ligh coming soon,,RUN 10:1. ITS BETTER FOR YOU!

 

[mulot30th]

I did not run any timing retard device but I were running pure C-16 (117 octane racing fuel)

This year I don't have MSD, but I installed the Synergy timing retard box.

 

[Remmy]

Wow, you learn something new every day. Does the MSD ignition and Synergy timing box serve the same purpose? Which would be the better route to take on a boosted Apex? Ease of installation?

And just to clarify, anything over 15 lbs of boost is not safe without pulling out some timing?

Sorry for all the questions but this topic has me concerned about running 18+ lbs this winter like I've been planning.

 

[Turbo Tim]

Wow, you learn something new every day. Does the MSD ignition and Synergy timing box serve the same purpose? Which would be the better route to take on a boosted Apex? Ease of installation?

And just to clarify, anything over 15 lbs of boost is not safe without pulling out some timing?

Sorry for all the questions but this topic has me concerned about running 18+ lbs this winter like I've been planning.

I ran my Apex at 17-19 psi 2 winters with just a headshim 1204 miles no probs , I don't think you're going to have the same extreme cylinder pressures that he had. ( he was running stock compression if I read that right )

 

[mulot30th]

Wow, you learn something new every day. Does the MSD ignition and Synergy timing box serve the same purpose? Which would be the better route to take on a boosted Apex? Ease of installation?

And just to clarify, anything over 15 lbs of boost is not safe without pulling out some timing?

Sorry for all the questions but this topic has me concerned about running 18+ lbs this winter like I've been planning.

MSD is not exaactly the same as synergy.

synergy retard the stock timing system using the stock timing curve as a baseline and stock fire system.


MSD use its own trigger and coils, and does not rely on stock system at all. The main benefit is the ability to get a better spark energy and naother advantage (for drag racers) is the two step (two separate timing curves/ rpm limits) you use one curve to build boost with no load on engine and the other is the running curve.


All in all I would have chose the msd it I could have found a way to install the trigger on another place than the engine's mag cover which on my sled is right next to my turbine housing...... = bad idea. that is why I went synergy way hoping I can get enough spark energy...

I even shortened my battery wires to the minimum and increased the wire gauge to insure maximum energy going to the stock spark system.

 

[mulot30th]

Wow, you learn something new every day. Does the MSD ignition and Synergy timing box serve the same purpose? Which would be the better route to take on a boosted Apex? Ease of installation?

And just to clarify, anything over 15 lbs of boost is not safe without pulling out some timing?

Sorry for all the questions but this topic has me concerned about running 18+ lbs this winter like I've been planning.

I ran my Apex at 17-19 psi 2 winters with just a headshim 1204 miles no probs , I don't think you're going to have the same extreme cylinder pressures that he had. ( he was running stock compression if I read that right )

You are right. 18 psi with stock compression... is a big no-no.

 

[Remmy]

Thanks guys.

 

[Otis RX]

Remember my apex motor that was leakdown tested to 30-40% on all 4 cylinders?


now that it have been completely dissasembled by my engine builder...


All 4 cylinders have their top portion 'tapered' open and the nicasil on all of them is looking pretty bad. pistons are okay (no deto sign of any sort), but rings are complete junk.

the verdict has been its because I ran too much boost on the bone stock motor (18 psi - 290hp - strait c16 - no deto - no knock), causing too much pressure on the cylinder sleeves and they 'opened' like a taper up top which got them out of round and then rings were toast because of that and nicasil followed... at least that is what we think.


Anyone else ever seen this happen or am I the absolute badlucked person owning a yamaha?

You don't have detonation but your cylinder pressure is still to high at the wrong time, this is caused by timing not boost.

This is also what causes head gaskets to fail.

Peak cylinder pressure must occur 15 degrees After Top Dead Center so it does the most work pushing the piston down.

Your peak Cylinder pressure could be occuring at 0-5 degrees ATDC which would push the cylinder walls out.

Any boost pressure above 15 psi should have an MSD ignitions system so we can pull timing VS boost.

I pull about 7 degrees at 22 psi.

I have MSD ignitions available.

Ted...am I walking down a slippery slope??? 18# sounds like I'm looking for trouble?? Can timing be pulled on the stock system?

 

[Ted Jannetty]

Everyone is welcome to consult with me directly for they're particular application to weed out all the variables.

This is not a topic that should be generalized.

Specific Details, like distance/time at full throttle, base compression, altitude, fuels, intercooler used, turbo size/specs, exhaust system, A/F ratio, all play a part it what you can or can't get away with.

Ted. 203-753-7223

 

[Need for Speed 2]

18lbs of boost and 290 horse that seems off a bit compared to what we have seen here . What boost set up are you using?

 

[mulot30th]

18lbs of boost and 290 horse that seems off a bit compared to what we have seen here . What boost set up are you using?

More than probably the engine was already toast before doing these dyno runs.... that is why.

 

[mulot30th]

By the way I started this topic to be informative for any other trying to go the hi boost route without doing it properly...

I never intended to offense any one