Drag and Drive Engine Disassembly

[MrHorspwer]

Steve Morris disassembling Cleetus McFarland's 2,500+ HP big block Chevrolet.

He notes the engine has over 3,000 miles of street driving, over 150 passes, and regularly runs 6.40s @ 220+ MPH.

It's actually all pretty... boring. Engine oil is gross, but methanol is really hard on oil. One failed roller lifter that could have been a big problem but likely happened very recently. Also some crazy rod bearing patterns caused by excessive pressure: A byproduct of operating an engine at 57psi of boost that wasn't build to run 57psi of boost.

 

[SubieRubyRoo]

You can do an awful lot with a twin-turbo’d big block. The key is getting it connected to the ground. 6.40s are pretty dang stout!

 

[MrHorspwer]

Second video talks more about the rod and main bearings. Cap side of the rod bearings is showing signs of an oil issue and the main bearings are showing more issues with excessive loading. Morris again notes that this is a wet sump engine not made to be running the boost they're throwing at it. For the pressure and power the engine has been making and the ETs the car runs, he says it should for sure have a dry sump oil system.

Also, the rods will all be thrown away. Methanol is a very violent combusting fuel and soft aluminum rods are used to act as a cushion. Problem is, they stretch a lot when you spin the engine really fast. These rods are all stretched out of spec.

 

[ctechbob]

I watched a few videos of them doing a D&D with that motor. I forget exactly why, but they have to set the valve lash multiple times a day (has to do with heat and the expansion of the block as I recall). Found that pretty interesting the things people would do to play at that level. I could never be bothered, drag and drive to me would be putting fuel in the thing and maybe changing the oil. Kudo's to them to actually do it though. They're forever pulling the valve covers off.