Has anyone heard of running 5.565 length rods? The reason I am asking is I bought a motor last year that was supposedly built by MTI and was a supercharged motor. I broke the motor down to refresh it with some new bearings and such and found out that it has the 5.565 Eagle H-beam rods and wondered if anyone has heard of anyone running these length rods or not. The motor also has a Callies Stealth lightweight crank but since whoever put this combo together they had to add quite a bit of weight to get the rod, piston combo to balance out. I am thinking about going with a longer rod and different piston combo since I dont see anyone running this short of a rod but I am asking you guys if there might be a reason why they went with this short of a rod on a 383 LT1 motor. Like I said above this motor was supercharged before but I will be going with a direct port nitrous kit and shooting around a 250-300 shot.

Thanks for any help guys.

Glenn

 

TTT

 

5.56" rods were the length used on the Chevy 400sb from the factory back in the 70s. These rods are REAL good for side loading the hell out of the cylinder. Look at any 400sb with the original rods after pulling a head and you'll see lot of scaring on the 12 & 6 o'clock positions of the wall. Trust me I've seen enough original 400s over the years. Last 400 I did still had scaring even after a .030 bore.
Go with the longest rod you can afford.
Steve...

 

You should do a search on this. There are adantages to running a short rod on a blower motor. But the "400" rods are too short.

Rich Krause

 

With a S/C 383 perhaps they wanted the 1.56 or so compression height on the piston to get the ring package a little farther down on the piston. Piston could also be beefier to take the extra pressure from being blown. The down side is the extra heavy metal and a heavier rotating assy. I agree with Rich that 5.565 is a little short. 5.7s are nice.

As to shooting a 300 shot on a lighter, shorter compression height piston...it might work. Then again, it might like the beefier piston for that, too. Ask your engine builder for his recommendation.

 

Yeah I did a search and was reading up on the shorter rod but everything was for a 5.7 inch rod and not a 5.565 rod. I was getting happy cause I was just going to leave it alone and go with it but I found out it has the shorter rods than the 5.7's so that is the reason I asked this question. Looks like I might just go with what I had in my old motor (6" rods) since they did get me in the 10s on a 175 shot so it cant be all that bad

Thanks guys for your help and believe me I didnt want to beat this topic to death again and I wouldnt have if I would have had the 5.7 rods