Engine and Transmission Tech

Under what circumstances would you want to consider nitriding? What engine parts? Crank and Cam?

David, IMHO, always on crank. Cast iron cam, probably not. "Parkerizing" is accepted process for cast cams. Technically, nitriding is used on higher alloyed steels like 4130, 4340 etc. Iron cranks are usually "Cool Cased"(brand identity). Good Luck, roverman.

Nitriding is not a good idea on a Rover crank. We sent a batch of cranks and rods for tuftriding and they came back nitrided, 3 or 4 quarter mile passes is all the cranks lasted, had up to 0.010" wear on the journals. We tuftride and shot peen, with particular attention to the fillet radii. Never a problem with this set up, have seen 7,500 regularly and 8,000 plus briefly, supercharged on methanol, making about 400 bhp on a 3.5. For nitriding to be really effective it needs to be a suitable nitriding steel with the correct alloying elements to form the hard nitride compounds.

Alan

Alan, your thoughts on Tufftriding con rods ? Have you cryo treated any engine parts ? I'm collecting parts for my first batch,for cryo, perhaps 300 lbs +/- ? Onward, roverman.

Tuftriding is an asset, for con rods a very good idea, as is shot peening, anything that increases toughness and induces surface stress is going to prevent or at the least slow down stress cracking. We always tuftrided Rover rods, when we got hold of Carillo's we didn't bother as they are already treated from the factory, not sure of all the treatments they use though. We now have Carillo style Scat rods and they appear to be treated similarly to the Carillo's. Only 2 full passes on these to date so early for statements. We have never tried Cryo, although all reports say it helps with the material properties. If we start getting close to the limits on these parts maybe we will get all mad scientist again lol! Then again if we get past 600 bhp with a 3.9 the driver will probably be more than happy he is going fast enough!

Alan