Piston as seen using an endoscope
Discussion
Guys, piston, chamber and valve thermal barrier coatings certainly make more power, just coating the inlet valve alone is worth measurable power on the dyno, coat everything and you will get at least 3 to 4% more power
Piston coatings weigh next to nothing! lol, if F1 could use the coatings they for sure would, I remember seeing an F1 piston with a thermal barrier coating, rules change every year
The more heat you can trap in the combustion area including head block and pistons the more power your engine will make, remember engines are glorified compressors, they heat air, make it expand and turn this expansion energy into rotary motion, the more air you trap in the cylinders the more heat you generate, most of the heat generated goes into the cooling system and out the tailpipe, any percentage less heat escaping from the total combustion area directly corresponds with an increase in power output, we are not talking huge gains but everything counts in a race engine
Piston coatings weigh next to nothing! lol, if F1 could use the coatings they for sure would, I remember seeing an F1 piston with a thermal barrier coating, rules change every year
The more heat you can trap in the combustion area including head block and pistons the more power your engine will make, remember engines are glorified compressors, they heat air, make it expand and turn this expansion energy into rotary motion, the more air you trap in the cylinders the more heat you generate, most of the heat generated goes into the cooling system and out the tailpipe, any percentage less heat escaping from the total combustion area directly corresponds with an increase in power output, we are not talking huge gains but everything counts in a race engine
Rwdfords said:
Here is what a race piston Should look like
Is this with uncoated components and no strange fuel additives? Carbon colour is usually a function of temperature which is why the hottest items like the plugs and exhaust valves are brown and the cooler ones like inlet valves and piston crowns black. Are your colours perhaps just a function of very hot components for whatever reason? Not saying this is a bad thing, or a good one I suppose, but it's interesting compared to most of the engines I've seen.Rwdfords said:
Guys, piston, chamber and valve thermal barrier coatings certainly make more power, just coating the inlet valve alone is worth measurable power on the dyno, coat everything and you will get at least 3 to 4% more power
Piston coatings weigh next to nothing! lol, if F1 could use the coatings they for sure would, I remember seeing an F1 piston with a thermal barrier coating, rules change every year
It's been tried and investigated several times but the main issue we have been told by one of the big ceramic coating firms is most legal and suitable thermal barriers from our era and the vast majority of those available commerically today rely on the structure beneath them being rigid. F1 pistons are as light weight as it is possible to make them and deform during use, unsupported areas outside of the little end boss etc. esentially "spring" with loading at TDC and BDC. In addition the engines run into det at some points during their operating life, especially in the days of qualifying engines etc. which again can damage a ceramic coating as the softer aluminium under it is essentially dented leaving the ceramic unsupported. Piston coatings weigh next to nothing! lol, if F1 could use the coatings they for sure would, I remember seeing an F1 piston with a thermal barrier coating, rules change every year
There are some companies supplying DFR/DFV pistons which are coated but these engines are based on a 1960's design and do not have anything in common with a modern V10 era F1 engine. They are spring valve and only go to an absolute max of 11K Rpm for a start. We don't make peak torque unti 12.5K.
At 18,000RPM the advantage in thermal efficency (if you consider how long the burn actually has to complete and exert useful effort on the piston crown) vs the sacrifice in piston weight and therefore max RPM acheiveable to make the piston strong enough to support the coating and running the engine in an area where it will be totaly det free at lower RPM I would suspect makes it unworthwhile to persue as a viable option.
This is a TJ engine, you can see the piston design etc. very clearly.
This engine was producing inexcess of 300bhp/litre in qualifying spec, the only coatings used was Xylan on the skirts for friction reduction.
Pumaracing said:
Is this with uncoated components and no strange fuel additives? Carbon colour is usually a function of temperature which is why the hottest items like the plugs and exhaust valves are brown and the cooler ones like inlet valves and piston crowns black. Are your colours perhaps just a function of very hot components for whatever reason? Not saying this is a bad thing, or a good one I suppose, but it's interesting compared to most of the engines I've seen.
Yes this was running race fuel blended with regular fuel ending up with around 100 octane, no strange additives, also no ceramic coatings, engine running with 80 to 90*C coolant temps max, no overheating present and no sign of detonation, 12 to 1 SCR and 9 to 1 DCRIn a race race engine black pistons = too rich of a fuel mixture, wet spots on the piston crown where you can see the alloy underneath = areas being washed by fuel that has dropped out of suspension and it is not being burned (to a lesser degree any darker areas also equal some fuel dropping out but still being burned), you can notice a slight bit of this at the bottom of the piston crown pic, this is the squish area furthest away from the spark plug
4V chambers are arguably more efficient as they have the spark plug located in the middle of the chamber but dome shapes and valve relief edges can restrict flame travel somewhat, DV believes good 2V chambers are more efficient than 4V in terms of efficiently burning the mixture, I would prefer a good 4V chamber (DV poliquad would be ideal to generate swirl) with smoothed out valve relief edges, larger inlet reliefs to improve low lift overlap flow are also important
Here is a good introduction to reading and altering burn patterns:
http://www.circletrack.com/techarticles/piston_tec...
Also some decent information here, dimples can be used to improve wet flow, reducing chamber wetting by fuel dropping out of suspension, the better the mixture quality the more torque is produced throughout the rev range
I believe 2V has a substantial advantage at low and mid rpm's at least due to much more chamber swirl mixture motion before ignition, 4V chambers tumble rather than swirl which certainly looses some low end torque vs a 2V head that promotes swirl, not all 2V inlet ports promote swirl such as the lotus twincam head with its ports feeding straight into the center of the cylinders but when the port entry angle is offset from the bore center a lot of swirl can be created as with most 2V heads
http://www.circletrack.com/enginetech/ctrp_0309_ra...
poppopbangbang said:
It's been tried and investigated several times but the main issue we have been told by one of the big ceramic coating firms is most legal and suitable thermal barriers from our era and the vast majority of those available commerically today rely on the structure beneath them being rigid. F1 pistons are as light weight as it is possible to make them and deform during use, unsupported areas outside of the little end boss etc. esentially "spring" with loading at TDC and BDC. In addition the engines run into det at some points during their operating life, especially in the days of qualifying engines etc. which again can damage a ceramic coating as the softer aluminium under it is essentially dented leaving the ceramic unsupported.
There are some companies supplying DFR/DFV pistons which are coated but these engines are based on a 1960's design and do not have anything in common with a modern V10 era F1 engine. They are spring valve and only go to an absolute max of 11K Rpm for a start. We don't make peak torque unti 12.5K.
At 18,000RPM the advantage in thermal efficency (if you consider how long the burn actually has to complete and exert useful effort on the piston crown) vs the sacrifice in piston weight and therefore max RPM acheiveable to make the piston strong enough to support the coating and running the engine in an area where it will be totaly det free at lower RPM I would suspect makes it unworthwhile to persue as a viable option.
This is a TJ engine, you can see the piston design etc. very clearly.
This engine was producing inexcess of 300bhp/litre in qualifying spec, the only coatings used was Xylan on the skirts for friction reduction.
Interesting information there which makes sense in terms of very low piston crown thickness and big rpm's not being suitable for ceramic coating as they would tend to crack, what you said about heat transfer vs rpm's also makes sense, however most engine tuners will never see an F1 engine and I believe any car racing engine will benefit from ceramic coating, not a huge advantage but this along with a few other mods could be enough to win a race in a very competitive classThere are some companies supplying DFR/DFV pistons which are coated but these engines are based on a 1960's design and do not have anything in common with a modern V10 era F1 engine. They are spring valve and only go to an absolute max of 11K Rpm for a start. We don't make peak torque unti 12.5K.
At 18,000RPM the advantage in thermal efficency (if you consider how long the burn actually has to complete and exert useful effort on the piston crown) vs the sacrifice in piston weight and therefore max RPM acheiveable to make the piston strong enough to support the coating and running the engine in an area where it will be totaly det free at lower RPM I would suspect makes it unworthwhile to persue as a viable option.
This is a TJ engine, you can see the piston design etc. very clearly.
This engine was producing inexcess of 300bhp/litre in qualifying spec, the only coatings used was Xylan on the skirts for friction reduction.
Edited by Rwdfords on Friday 11th April 15:39
Rwdfords said:
Interesting information there which makes sense in terms of very low piston crown thickness and big rpm's not being suitable for ceramic coating as they would tend to crack, what you said about heat transfer vs rpm's also makes sense, however most engine tuners will never see an F1 engine and I believe any car racing engine will benefit from ceramic coating, not a huge advantage but this along with a few other mods could be enough to win a race in a very competitive class
An F1 engine is so far apart from anything road based they can't really be compared. Yes they have rods, pistons and cylinder heads (unless its a 415T) but that's about where the comparisons end due to the materials used, extreme weight targets and the fact the engine is a stressed member. A VJ weighs eight kilos more than the 1.8L K Series as fitted to an Elise.... the Elise K-Series makes 120PS, The VJM 733. The BHP/KG is where the F1 engines really amaze especially when you consider they are also all that ties both ends of the car together 
Pumaracing said:
Eee bah gum. That's some serious valve lift tha' knows. Must mean very large diameter followers to generate sufficient valve opening speed.
Indeed! Large diameter DLC'd buckets on pneumatic springs. The air valve system is really the key to these engines performance and ability to rev this high with this amount of valve lift. Huff said:
Opening valves that far at up to 18Krpm (i.e against springs/pressure that will close them fast enough...) must take some serious cam drive power!
The cams are gear driven with a very small transfer chain to provide drive from the front cover gearset to the end of the inlet cam which in turn gear drives the exhaust cam. The air valve setup is more efficient than springs but there's still a relatively massive amount of power consumed driving the valve train.poppopbangbang said:
Indeed! Large diameter DLC'd buckets on pneumatic springs. The air valve system is really the key to these engines performance and ability to rev this high with this amount of valve lift.
Exactly, the valve lift and valve open area under the lift curve is what creates or rather unlocks all the flow of the really nice port shapes, without pneumatic "springs" using normal valve springs those engines would never run to those kind of rpm's and hp would be massively reducedThe pneumatic springs generate huge amounts of seat spring pressure vs valve springs, and the pressure is most likely constant throughout the valve lifting and closing motion, pneumatic springs are a cam profile designers dream!
I have also seen rockers being used in F1 engines, with a light rocker sitting on top of the valve much like motorbike engines, I prefer rockers like this over buckets
F1 Honda engine up to 2008
http://www.racecar-engineering.com/articles/f1/hon...
Here you can see the rockers, I like this since it both creates a lighter valve mass but also notice the cam lobe is much wider and not as pointy looking as a "flat" follower lobe due to the relationship between lobe and follower pad curve, more pressure on the rocker pad but I still much sooner this over buckets that are near flat and spin
As nice as the Honda looks it was over 100bhp down on everyone else at that point so maybe not the best example to follow for out and out poke 
Our stuff comes out look very much like the 04/05 pistons but with a little more carbon around the exhaust side. Generally the stuff we run did have a slightly higher fuel burn rate than others as there was some amount of charge cooling utilised from excess fuel.
Our stuff comes out look very much like the 04/05 pistons but with a little more carbon around the exhaust side. Generally the stuff we run did have a slightly higher fuel burn rate than others as there was some amount of charge cooling utilised from excess fuel.
poppopbangbang said:
As nice as the Honda looks it was over 100bhp down on everyone else at that point so maybe not the best example to follow for out and out poke
Our stuff comes out look very much like the 04/05 pistons but with a little more carbon around the exhaust side. Generally the stuff we run did have a slightly higher fuel burn rate than others as there was some amount of charge cooling utilised from excess fuel.
100hp down from All of the other engines from 2003 all the way to 2008?Our stuff comes out look very much like the 04/05 pistons but with a little more carbon around the exhaust side. Generally the stuff we run did have a slightly higher fuel burn rate than others as there was some amount of charge cooling utilised from excess fuel.
Regardless the burn pattern is clearly very good and all of the parts are light years ahead of a modified conventional production engine for rally/race, so in my opinion this IS is good example of a proper burn pattern, in fact a very good one since those engines run to mega high rpm's and the higher the rpm's the more efficient the total chamber shape has to be in order to speed up flame travel, burn the mixture as soon as possible, creating high cylinder pressures just after TDC
You say your team was running extra fuel for charge cooling, and the crowns were a little darker in places, well doesn't it make sense to you that the the darker areas are a result of the richer mixtures?
Can you explain why your engines had a "higher fuel burn rate" are you trying to say it had a faster more efficient ignition burn rate? and if so do you have any idea why this was the case, where were the advantages in chamber + piston shape? what ignition advance were you using at max power vs other engines?
Charge cooling with rich mixtures and combustion burn rate are two separate things altogether, can you clarify what were you trying to say there?
Have a good day
poppopbangbang said:
The air valve system is really the key to these engines performance and ability to rev this high with this amount of valve lift.
Could be done with a Desmo system -- IIRC the Ducati GP engines revved a little higher than last season's F1 stuff (talk was of 20k rpm). But no-one wants to put in the development/pay someone in Bologna! (Unless, maybe, Audi -- who for reasons that are still a mystery, bought Ducati -- decide to go into F1.) Edited by TheRealFingers99 on Sunday 13th April 13:32
Ducati are only the most well known users of the Desmo system, I would very much doubt that they hold any patents
on the mechanism,in any case, after this many years of useage the patents would have lapsed.
Desmo valves were tried in F1 applications quite a few years ago IIRC,this in the days of higher RPM limits, the extra "complication" (probably weight, bulk, ease of adjustment and manufacturing cost) was found unnecessary.
One of the main reasons for using the system, apart from marketing purposes that is, has been negated by progress in the field of reliable valve spring design and production, which was ,according to those who were there, a major problem in the 50's, nowadays air springs are ,I believe ,universally used in F1 engines.
on the mechanism,in any case, after this many years of useage the patents would have lapsed.
Desmo valves were tried in F1 applications quite a few years ago IIRC,this in the days of higher RPM limits, the extra "complication" (probably weight, bulk, ease of adjustment and manufacturing cost) was found unnecessary.
One of the main reasons for using the system, apart from marketing purposes that is, has been negated by progress in the field of reliable valve spring design and production, which was ,according to those who were there, a major problem in the 50's, nowadays air springs are ,I believe ,universally used in F1 engines.
Auntieroll said:
Desmo valves were tried in F1 applications quite a few years ago IIRC,this in the days of higher RPM limits, the extra "complication" (probably weight, bulk, ease of adjustment and manufacturing cost) was found unnecessary.
Exactly! air pressure to control valves is the most light weight efficient design hence why it is so popular in F1 and will continue to be unless rules change which is unlikely to happen since it is a key component to making top end high rpm power from low ccRwdfords said:
100hp down from All of the other engines from 2003 all the way to 2008?
For the first few years yes and again at the start of the V8 era. Honda ended up in a situation where whilst the engines could match the power of other suppliers the reliability at these levels couldn't. The choice of rockers for valve actuation and small bore/long stroke was key to this. Rwdfords said:
Regardless the burn pattern is clearly very good and all of the parts are light years ahead of a modified conventional production engine for rally/race, so in my opinion this IS is good example of a proper burn pattern, in fact a very good one since those engines run to mega high rpm's and the higher the rpm's the more efficient the total chamber shape has to be in order to speed up flame travel, burn the mixture as soon as possible, creating high cylinder pressures just after TDC
You say your team was running extra fuel for charge cooling, and the crowns were a little darker in places, well doesn't it make sense to you that the the darker areas are a result of the richer mixtures?
Can you explain why your engines had a "higher fuel burn rate" are you trying to say it had a faster more efficient ignition burn rate? and if so do you have any idea why this was the case, where were the advantages in chamber + piston shape? what ignition advance were you using at max power vs other engines?
Charge cooling with rich mixtures and combustion burn rate are two separate things altogether, can you clarify what were you trying to say there?
Have a good day
y You say your team was running extra fuel for charge cooling, and the crowns were a little darker in places, well doesn't it make sense to you that the the darker areas are a result of the richer mixtures?
Can you explain why your engines had a "higher fuel burn rate" are you trying to say it had a faster more efficient ignition burn rate? and if so do you have any idea why this was the case, where were the advantages in chamber + piston shape? what ignition advance were you using at max power vs other engines?
Charge cooling with rich mixtures and combustion burn rate are two separate things altogether, can you clarify what were you trying to say there?
Have a good day
I think you've misunderstood the term "fuel burn rate" which is generally used to describe fuel consumption of the car over a given distance, usually a lap. We ran map options which were generally richer than Toyota and Honda (similar to BMW) for race use, especially in hot climates. Usually IRO 13.6:1 AFR to 13.3:AFR on the pot with ignition advance between 38 and 42 degrees. These values were set by the driver on advice from the engineer depending on what scenario was under way.
Hope that makes it clearer.
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