Camaro XV

[RussMurco]

Originally Posted by mikels

First Thomson 427SC engine was built and run way back in 2008. This was for his Pontiac Solstice and utilized LSX block, LS7 heads and Harrop 2300SC. Engine made 990+ crank HP with an aggressive cam, and dropped to 850 crank HP with milder cam as installed in car. After over 100 dyno pulls and 5000+ miles installed in car, engine was disassembled and all parts blueprinted / inspected for wear. All looked great. Keep in mind this was never used for road-race or extended high duty cycle use, so powertrain cooling was never an issue.

At same time this was ongoing, Thomson was developing a twin-turbo LSX generating 2000+ HP. Original engine was 440 CID and dyno testing reveled that after few pulls, crank bearings were distressed, and had they not been coated bearings, a bearing failure would have been likely. Issue was traced to crank deflection under load, so stroke was shortened (increased overlap of throws and mains) to increase strength. Engine then completed 150 full power pulls on dyno (2058 HP average) and subsequently disassembled. All bearings looked like new.

Fast-forward to today:

Based on these and countless other engine builds, testing and further development, Thomson 427SC engines have proven themselves robust even under extreme racing type usage (Mark's cars being one of the most aggressive test beds used). We continually refine and improve package based on knowledge gained over each build and test data. This includes not only hardware selection, but assembly clearances, powertrain cooling requirements and calibration refinement.

Mark has said on many occasions that not only are the Thomson 427SC engines the most powerful he has ever utilized in his builds, they have also been the most reliable and driveable as well. And hard to dispute the results.

Not sure if this directly answers your question as we lack the technology to measure oil film thickness, but empirical data based on many, many engines supports where we are today (with headroom to grow ).

And...

Originally Posted by mikels

In this case, there is 3 sources of heat - engine, supercharger and AC. Breaking that down further, engine heat in form of coolant and oil, supercharger heat in form of air and AC in form of refrigerant.

Engine heat in coolant and oil comes from the inefficiencies of an IC engine - only about 1/3 the energy released from combustion actually makes power, another 1/3 goes into cooling system (coolant & oil) and 1/3 goes out exhaust.

Since this is a SC engine, also have to take into account mechanical energy used to drive supercharger - in Red Devil and Mayhem, this worked out to ~120-140HP. So Mayhem generating an output of 878 HP is actually generating over 1000 HP already - and that also nearly equals the amount of energy we need to release from cooling system.

Complicating this further, we have the heat from the intake air charge to reduce as well - and use air-to-water heat exchanger with a stand-alone cooling system to then convert this with a water-to-air heat exchanger in front of car. Since delta-T is critical for heat exchanger effectiveness, we package the intercooler radiator in front of the cooling stack (all the heat exchangers in front of car) to get greatest delta-T for charge air cooling. This adversely effects radiator efficiency as air temp reaching front face of it is already heated above ambient. And we have 1000+ HP worth of heat to dissipate from it.

Packaged between the CAC (charge air cooler radiator) and the coolant radiator is the AC condenser. At least Mark hasn't become too much of a wimp is his old age to want to race with AC on, so while this doesn't add heat to air flowing through, it does add pressure drop of airflow through entire cooling stack.

We also have engine oil to contend with - and can either use oil-to-air heat exchanger, or oil-to-water. If oil-to-water, this is more KW to release through radiator. If oil-to-air packaging, airflow restriction and preheated cooling air have to be considered.

All this is converted to heat transfer equations and calculated to optimize the entire cooling system of heat rejection balance.

Drag racing is easy - you can get away with a whole lot if only running in <10 second bursts of WOT. Road racing makes this much more difficult as entire system reaches equilibrium.

And haven't even talked about trans and diff oil cooling yet....

Dave

Wow... This is above and beyond the most informative, real-world experience information I have ever read on a forum of any kind. On occasion I think I have most all the knowledge I need to accomplish a goal, then I get slapped into reality with posts like these and it makes me thirsty for more information.

I am so grateful that you guys share this information with us, I learn something every day on this site. Being a "fly on the wall" has never been so interesting!

Thanks!!!

[Rybar]

Originally Posted by mikels

Mark has said on many occasions that not only are the Thomson 427SC engines the most powerful he has ever utilized in his builds, they have also been the most reliable and driveable as well. And hard to dispute the results.

Interesting. So Mayhem's motor is more powerful than the Mule's TT SBC? I always wondered what Mark's thoughts were on comparing his latest cars to the Mule. That thing was so far ahead of it's game when he built it. Love that car I hope Charley never sells it.

[CarlC]

Originally Posted by mikels

First Thomson 427SC engine was built and run way back in 2008. This was for his Pontiac Solstice and utilized LSX block, LS7 heads and Harrop 2300SC. Engine made 990+ crank HP with an aggressive cam, and dropped to 850 crank HP with milder cam as installed in car. After over 100 dyno pulls and 5000+ miles installed in car, engine was disassembled and all parts blueprinted / inspected for wear. All looked great. Keep in mind this was never used for road-race or extended high duty cycle use, so powertrain cooling was never an issue.

At same time this was ongoing, Thomson was developing a twin-turbo LSX generating 2000+ HP. Original engine was 440 CID and dyno testing reveled that after few pulls, crank bearings were distressed, and had they not been coated bearings, a bearing failure would have been likely. Issue was traced to crank deflection under load, so stroke was shortened (increased overlap of throws and mains) to increase strength. Engine then completed 150 full power pulls on dyno (2058 HP average) and subsequently disassembled. All bearings looked like new.

Fast-forward to today:

Based on these and countless other engine builds, testing and further development, Thomson 427SC engines have proven themselves robust even under extreme racing type usage (Mark's cars being one of the most aggressive test beds used). We continually refine and improve package based on knowledge gained over each build and test data. This includes not only hardware selection, but assembly clearances, powertrain cooling requirements and calibration refinement.

Mark has said on many occasions that not only are the Thomson 427SC engines the most powerful he has ever utilized in his builds, they have also been the most reliable and driveable as well. And hard to dispute the results.

Not sure if this directly answers your question as we lack the technology to measure oil film thickness, but empirical data based on many, many engines supports where we are today (with headroom to grow ).

It does Mike, thank you. I dabble in heavy industrial applications but usually dealing with the rolling element vs. babbit side. The proper selection of the lubricant type, delivery systems, cooling, filtering, structure rigidity, etc. are all very similar.

In the end, the rubber meeting the road will flesh out the weaknesses. Thanks for sharing.

[Stielow]

Originally Posted by Track Junky

I'm probably going to step out on a real thin limb here but I dont see the purpose of running coolers for rear diff, power steering, and trans when you may run 25 minutes a session at most?

With over 700 - 800 HP on tap and my driving style I can over temp the diff in 3 laps. The power steering I can over temp autoXing in a few laps easy. I have less data on the trans but while I'm at it I add one. If someone is not going 10/10ths then the extra cooler are not needed.

If your car is running lower power then the coolers are not needed. I have gotten diff so hot that it has ruined gear sets. I forget how many Watts the diff buts out but it is not insignificant.

I will add a disclaimer here. My builds are not normal and my duty cycle is not normal. Heck if I run a full 25 min. session I get a lot of stuff real hot.

Mark

[Track Junky]

Originally Posted by Stielow

With over 700 - 800 HP on tap and my driving style I can over temp the diff in 3 laps. The power steering I can over temp autoXing in a few laps easy. I have less data on the trans but while I'm at it I add one. If someone is not going 10/10ths then the extra cooler are not needed.

If your car is running lower power then the coolers are not needed. I have gotten diff so hot that it has ruined gear sets. I forget how many Watts the diff buts out but it is not insignificant.

I will add a disclaimer here. My builds are not normal and my duty cycle is not normal. Heck if I run a full 25 min. session I get a lot of stuff real hot.

Mark

Well I probably should have known better to question an engineer. I was just thinking how much power and weight loss you would gain without those items.

Thanks for the explanation.

[formula88]

Some photos of Camaro XV's progress from the weekly Saturday morning pilgrimage to Sled Alley.....

[GregWeld]

Thanks Gordon!



That was a great start to my Sunday morning!



Maybe I could out bid Charley on this one and then show up at a NorCal Shelby Club event with it and put a whoopin' on some unsuspecting old Mustangs....


HAHAHAHAHAHAHAHA --- In my dreams!

[Che70velle]

Originally Posted by GregWeld

Thanks Gordon!



That was a great start to my Sunday morning!



Maybe I could out bid Charley on this one and then show up at a NorCal Shelby Club event with it and put a whoopin' on some unsuspecting old Mustangs....


HAHAHAHAHAHAHAHA --- In my dreams!

Outbid charley? Now that's funny!

[PTAddict]

Wow. This one goes to Eleven.

[Vince@Meanstreets]

You mean it's not in paint yet?!?!