[Dave Y.]

We all hear about putting 6" rods in a sbc 400,.. but has anyone used 6" rods in a 350 sbc? and what are the pro and cons of this setup? THANKS DY

[stereodud]

I know it is done in race motors. but im not sure of the benifits

[TurboS10]

I am actually building a 408 right now with 6 inch rods, but the idea is the same. You increase dwell time at tdc and decrease the rod angle. The dwell time helps with better combustion(this is in theory and I have never seen it proven on the dyno), and rod angle helps with engine stress at high rpm.

Chris

[DoubleVision]

Another known benefit of the longer rod is the higher rod ratio and the ability to run 11:1 compression on 87 octane fuel without detonation problems, They also have a much broader and flatter torque curve that standard lenth rods. Longer rods are always a good idea over the standard rods because of all the benefits. the late Henry "Smokey" Yunick`s theory was "run the longest Possible connecting rod you can fit in the engine"

[bullheimer]

i cant imagine 11:1 on 92 octane let alone 87. i know newer cars are getting close due to computer controls, but i'm sure gonna see what develops on this post. i hope sommore engine builders put their $.02 in on this one to make it worth while

[slider in wa]

I certainly had no idea you could run 11:1 compression on 87 octane. I will enjoy the out come of your post. I`m a shade tree guy, so some of you number crunchers jump in on this will ya? Slider in Wa.

[TtopIroc]

well i am getting a 383/w 6 inch rods built by the same guy that builds tony stewerts motors. I will be running 11:1 compression and this is what he told me. In winter 93 will be fine but when summer comes ill be pingging like a **** so ill have to add some racing fuel in.


now thats my 2cents THE END

[TtopIroc]

oh and heres the pros and cons


Longer Rod Pros


Less rod angularity
Higher wrist pin location
Helps resist detonation
A lighter reciprocating assembly
Reduced piston rock
Better leverage on the crank for a longer time
Less ignition timing is required
Allow slightly more compression to be used before detonation is a problem
Less average and peak piston velocity
Peak piston velocity is later in the down stroke
Less intake runner volume is needed


Longer Rod Cons


Closer Piston-to-valve clearances
Makes the engine run a little more cammie at low rpm
Reduces scavenging at low rpm

[slider in wa]

So are these 6 in rods 400 sbc rods? Will they work with the 350 crank? I`m not getting the picture yet.
Thanks.
Slider in Wa.

[TtopIroc]

nope accually 400 rods are shorter than 350 rods (5.7) 6 inch rods are aftermarket u also have to buy special pistons for the 6 inch rods.

now if your building a 383 u get the crank from the 400 but the rods are crap