I am planning a 396 solid roller nitrous motor. I am leaning towards a 5.850 rod length, but the prices go up considerably. What direction do you experts lean towards. I am looking at up to 250 hp shot of nitrous on the motor. This is not a street car, BTW.

Michael

 

Why only 250hp shot if it's a race car?

Anyway, I wouldn't lose any sleep over rod length. But I wouldn't build a 396. I'd go only 0.010" over (392ci with a 3.875" stroke) to preserve as much cylinder thickness as possible. If you do that, you will need a custom piston. If you go that route, a 5.85" rod is a good choice. If you use an off the shelf piston, go with 5.7 or 6" rod.

Rich Krause

 

For a stroker to see heavy nitrous you probably want to shy away from 6" rods. Shorter rods will have 2 benfits:
a) more meat in the piston (nice for juice)
b) less dwell time to risk detonation

The difference between a 5.7 and a 6 probably isn't worth much hp or protection, but the extra meat in the piston makes the 5.7 more atttractive if you had to choose one or the other.

Many guys seem to be going with 5.85 as a nice compromise if you can swing a few extra bills. All depends on how many ponies, NA/N2O, you plan on shooting for.


Personally I'm looking for 6" rods and a 3.8" stroke to make a 388... although a 3.875" stroke would probably make me favor a shorter rod.

 

Also with a 5.85 rod you move the ring lands down to keep them away from all the heat

It all depends on your pocket with this one. If you go 5.85 rod plan on spending about $800 for a set of custom pistons. If you go 6", a good off the shelf piston such as JE will run you about $600. Im on my second set of pistons, not only does the cost to have them made suck, but the down time as well.
Think about it

 

Thanks for the replies. Sleeper, what part of Minnesota are you from. I grew up in the North St. Paul area.

Michael

 

I myself am building a 396, the 5,850: rod length is good simply because there are off the shelf pistons readily availiable for that length vs the 6.000" where the comp ration is like 12:1 with an off the shelf on that rod length and you'd want a custom piston that route....So you are finidn many pluses over the 6" the only thing is side loading, which I doubt should be too much of a problem seein how you will be .150 longer than stock length anyway...