Building a High RPM Big Single Motor

[bullfrogjohnson]

What is gonna take to make a Dmax live at high rpms in a sled pulling application? I want to be able to make peak power above 4500. Here's what I know......

Turbo: 80mm+ with big turbine wheel to support flow up top with a big housing or a small housing with a gate.

Injectors: BIG, need to be able to get the fuel shot in fast for the higher r's

Bottom End: obviously needs to be built but what about tolerances? what is the math behind deciding what bearings to run, piston to wall clearances, what oil to run, camshaft to run, compression ratio to run, etc.....

Heads: I don't know what to think on heads. I know the dmax has serious drive pressure issues above 3500rpms and adding ported heads that flow better can make the issue worse if the exhaust side is not addressed. So what need to be done to help lower DP and fight against exhaust reversion.

Valvetrain: I don't know much about high rpm valvetrain other than I need valvesprings and need to loose as much weight as possible. Some say you need HD pushrods but others say leave stockers so you have a weak link to bend if something goes wrong.

Lets Discuss:thumb:

 

[S Phinney]

One issues that most seem to overlook is valve guide clearances. That is what seems to cause a lot of the bent push rods that we hear about from what I am hearing. There are ways to reduce drive pressures but building a custom system to bleed it off. It's not complicated to build either.

 

[JOHNBOY]

One issues that most seem to overlook is valve guide clearances. That is what seems to cause a lot of the bent push rods that we hear about from what I am hearing. There are ways to reduce drive pressures but building a custom system to bleed it off. It's not complicated to build either.

Open your guides up to around .0035 and don't run seals on at least exhuast guides. If someone is having issues that will help a ton. I stuck have valves more than once. Busted all kinds of parts. Seals in the garbage can and opening the guides solved it all.