internal 3400 mods

[gectek]

ok a few questions, i was looking at maybe cutting some rotational weight on the assembly, so i was thinking about cutting the ears off the end caps on the rods, also machining the flat spot on the end cap down and maybe contour the flat spot on the top of the rod as well. what do yall think...?

also the age old question of knife edging the crankshaft...should i do it and how extreme should i go, if you have seen a lunati knife edged crank its not like some that castillo has pictured...input please

[silvergtjrad]

Honestly, I would not bother with any of that. The costs associated with all of this, compared to gains arent justifiable in my opinion. A crank scraper is good enough, and the 3400 already has a windage tray as well.

[SappySE107]

The cap on top of the rod is used for balancing. You could ruin them if you cut them off. Focus on the beams and leave the rest alone other than polishing. For the crank, tear drop and knife edge are both proven to help but it isn't cheap to do that kind of work.

[MidnightriderZ24]

that would greatly increase top end. around us knife edging a crank will be around $200, go with balancing it too.

[gectek]

yah i think ill just get a crank scraper off here, and run with it balanced and the rods shot peened if it isnt too much. i think for my next block ill look at all the blueprinting stuff. im reading a very interesting book right now, by SA design books called engine blueprinting. not like ill practice any of that stuff myself but i will keep it in mind for the other stuff. i think ill leave the rods like this of course besides maybe shot peening. and the balancing and straightening of the crank...

[JohnnyReb]

Most of the time you only look at knife edge/teardrop to gain full potential from a engine only after you have done other major work and the engine is already near all out. If you already have the top end working at full potential with good head work, intake work and valve train yea go for it. If you are working with a unmodified or slightly modified you are going to get more hp per dollar elsewhere. High end crankwork might free up a couple ponies on the top end, I would be real surprised to see a 5 hp gain. Tungsten steel or other heavy metals used to balance a crank can be expensive if needed. You could potentially spend 300 to 500 in crank work and rebalancing your crank. And if you are running a engine near its full potential you would probably be better off spending a few more bucks to convert it to dry sump.