Building A C15 Cat Using C18 Crank And Rods

The c18 has more torque and more cost associated with it

IPD is developing a c18/5.7 bore piston and sleeve to work with the c15 6.75 stroke. It will yield a 17 liter combo. It’s not ready for marketing yet but they are working on it

 

I'd be curious to see the torque numbers.

 

industrial C18s are 18:1 comp. its too much for an on highway application with the horsepower and every changing load/RPM. with a 7cz file thinking it has 23 injectors when its fitted with 25 injectors or if its from a higher HP application anything up to a 27 sized injector will put ridiculous amounts of fuel into the pots generating heat. typically the heat it generates is more than a truck cooling system can stay on top of and they over heat. the driver is constantly having to drop gears an lift off the throttle to maintain a coolant temperature that is acceptable.

that combination generally means liner recession and head gasket failure comes very early. the 7.2 inch stroke doesn't help things either with the RPM fluctuation seen in an on highway application.

the C18 crank and rods wont work with a C15 piston. the wrist pin height is all wrong and the piston will hit the head. its likely the C15 oil jets will be smashed by the C18 rods and crankshaft stroke.

if you want to use an 18 crank and rods, use an 18 piston and liner and mill the piston bowl to drop the comp down.

tractor pull guys have been using c15 ACERT cranks with 6.75 inch stroke, getting custom rods made ($10K a set) and using C18 piston and liner. very expensive engine making about 17 ltrs displacement.

as mentioned above IPD have made, but not released ( I have seen one set in the flesh) a custom piston that will fit a C15 ACERT rod and crank. its 5.7 inch bore and uses a C18 liner. it means you can now use the factory 15 ACERT rod and crank with these pistons and liners to make 16.9 litres displacement at 16:1 compression

 

Wow, there are 16.5:1 and 14.5:1 pistons available for the C18, might want to do some more research.

Your comments about injector sizing are way off, a properly set up truck cooling system has no issues keeping an engine cool that uses large injectors.

 

yes those are the pistons available, my mistake. I make the error of assuming machine engine, not industrial hence my mix up with compression ratios. my apologies, you are correct.

as for my injector comment, over here I have seen several C18 in road trucks. road trucks with large radiators and ACERT water pumps. we gross from 130-240 ton with the trucks they're in working in ambient temperatures of 40-50 degrees C. if they pull up a decent grade at 100% throttle they can not keep them cool at anything over 800hp. if they drop a gear or 2 and come back to 75% throttle the temp instantly drops out. on the flat is a different story, they will stay cool.

 

I agree, Australia is a total different working environment and max GVW they pull it's no wonder they stay cool at all.

 

a frightliner with a factory 40 ltr cooling system pulling 100-130t gross in 45 degrees C ambient... the driver manually turn the fan on full time. if they don't the coolant temps literally go betweem 100C and 103C and the fan cuts in and out all day non stop. even with 82C thermostats and standard horsepower they run that hot. dropping a gear and 10km/h is the only way to stay sub 100C

a mack or Kenworth with a big radiator and 55ltr cooling system will run at 92-98 in the same scenario one gear and 10km/h down.

add horsepower or a driver that wont lift off the peddle and they are plus 100C all day long.

 

a C18 with 2113025 injectors 750HP non wastegated turbo C16 7CZ 600hp standard flashfile makes well over 800 hp at the engine. the 475 6nz file brings it back to around 650HP on the engine dyno.

800HP in our temps with 130-180T gross will struggle to stay cool being held at full load in the highest gear on a long uphill pull. I don't know any guys that own trucks like that that don't say they drop a gear and climb the same hill a bit slower but at 2/3 throttle to maintain suitable coolant temps

 

Any of your issues with heat can be attributed to the climate and weight, I have close friends that run 211-3028s, they don't haul nearly they weight but they all pull more than what is normal for the states, none of them have temperature issues. Those injectors are in a combo of C15 and C18 engines.

 

It may not completely eliminate heating issues at 240 ton and 50 degrees, but if you throw an extra air tank on the frame and run coolant lines to it, the added capacity will really help keep things cool

 

If I'm not mistaken, a bigger circle crank with the same rod length will make a faster piston speed.?