What is the advantage of using a 6" rod in a 383 stroker build. What are al the pros and cons of each size rod?

 

Torque!
POWER!
CUBES!
PERFORMANCE!

 

CONS:
1. EXPENSE
2. OIL RING OVER PIN
3. SEE 1 AND 2

 

Wasted effort unless you're building a competition race car.

 

PROS:
1. FLATTER TORQUE CURVE (MAYBE)
2. MORE OIL BURNING FOR THAT SLEEPER LOOK

 

Pros:
Less side load on piston.
VERY slight increase in high RPM torque.

Cons:
VERY slight decrease in mid-range torque.
Much more perf can be gained by spending the extra $$$ on something else.

 

thanks for the tips guys. I think I am gonna stick with the 5.7" rods

 

BTW: The length of the connecting rod has nothing to do with "CUBES".

 

good one!

 

First off, pistons can be had without the ring-over-pin-hole feature. Do some research folks. And even if they didn't, they make inserts for that sort of thing .

Long rod Pros:
Less side loading of piston and overall less stress on the crank, piston, and pin.
longer dwell time at TDC which equates to higher cylinder pressures and more power.

Long rod Cons:
Price... nope, pretty much equal
Ring-issue..... nope, can be overcome easily
Guess that means there are none

Seriously though, do some reading and you will find that the rod length that is ideal for your combination can actually hinge on things like cylinder head flow (especially exhaust port) and camshaft design. There are many volumes out there, just read em .

 

Name one.

 

Mine .

Ross

 

I've never seen a piston for a 6" rod and a 3.75 stroke that didn't have the oil ring over the pin hole with a support ring, that's why I went with 5.7" rods. The compression height is so short with a standard deck block i don't know how they'd fit all three rings above the pin bore. A 1.125 compression height doesn't really leave any room for rings, as opposed to a 1.425 comp. height w/5.7" rods, and that's hard enough to find a decent pistion without the ring lands all up near the top.

 

 

Well, to be fair, I should allow the other shoe to drop.... I certainly was not aware of this info until I got into my 383 build. But that is sort of my point.... Research, research, research....

They are able to keep some meat on the ring lands by using thinner oil retention rings. My rings measure 1/8" where most are 3/16" ..... I guess we will see how well that works out seeing as I only have 200 miles on my 383 so far, but I asked around various engine builders a bit and none of them had anything bad to say.

My pistons are Ross part number 90765 and I used Speed Pro rings, part number 9968030.

 

I've got a set of BB pistons and rods in my garage, rods are 6.135 and all the entire ring package is above the pin hole.

Do those count? LOL

Jake

 

weisco thats #2

 

Less side loading of the cylinder wall's thrust surfaces; less acute rod angle; slightly longer piston dwell time at TDC.

That's more than 10 words though. Sorry.

Jake

 

The only other consideration is if it is N/A engine or not.. FI engine, even with the ring gaps above the pin, the ring gaps will be thinner, and more prone to breakage.. This is only my opinion, and this topic can be beat to death.. I do not see a problem on a N/A setup, but either way the gains are usually minimal by going with a longer rod. .

 

Ive got 6.250 rods in my 302 (4.030x3.000). I run 11.1 to 1 compression on 92 oct. and it never pings because of the longer rod ratio. As for you guys that think short stroke motors have no bottom end tell that to my tires. This thing pulls 1300 rpms in 6th gear happily. The trick to long rods isnt the length as much as the rod ratio. My rod ratio is 2.1 to 1. If you cant get to at least 1.85 to one there isnt much advantage to running longer rods. The difference between 5.7/ 6.0 inch rods in a 350 is slightly less cylinder wall loading and maybe a longer torque band. You might also get .2 compression increase (or cushion)(no the longer rods do not increase compression, they will allow for more). If you are going to use nitrous or forced induction Id rather have a little more room on the rings for heat dissapation