Difference between sizes Rods

[fusca66]

What changes with the change size in engine of the rods?
HAve many sizes:-5.500"-5.700".....
My engine is 2110, with original Vw rods, if I put one 5.7" the engine that wins it? Torque?
Thank´s
_________________
Bug 1966 2280cc
Bug 1951 1900cc
Bug 1952 typ4 1800cc
Sp2 1972 1700cc

Na duvida não ultrapasse

[vdub1971]

When you change your rods it will change the rod ratio. The shorter the rod (lower rod ratio) the more efficient the engine with be at low rpm due to increased piston. Speed and the more side load on the pistons and cylinder. Higher ratios (longer rods) and you will have less side load and will not be as efficient at low rpm's. That is the theory anyways.

[jamestwo]

Best article on the subject.

http://www.victorylibrary.com/mopar/rod-tech-c.htm

I like short rods, but ultimalty they limit your Peak HP. I built an engine with wedge port heads, and fairly large cam-FK 45 It ran out of power at 6300 rpm. The rods are so short and piston speed was so high, that it has maximized air flow at the low rpm. I did that because I wanted peak power under 6500 rpm.

Take the same motor, put a longer rod in it and it would have added 800-100 rpm and some HP, but loss low end torque.
_________________
hEY, lOOK, i'M WRONG HALF THE TIME, AND THE OTHER HALF i'M NOT SURE WHAT THE HECK i'M TALKING ABOUT. MY POST ARE FOR MY OWN ENTERTAINMENT VALUE ONLY.

[58 Plastic Tub]

[jamestwo]

That what i have also, is 2332 with 5.325 rods. Did you use Wisco pistons, or was you able to get the Cima's to work.

I have posted this pic a million times, so for all the regulars excuse me. Here picture of my mock up.

_________________
hEY, lOOK, i'M WRONG HALF THE TIME, AND THE OTHER HALF i'M NOT SURE WHAT THE HECK i'M TALKING ABOUT. MY POST ARE FOR MY OWN ENTERTAINMENT VALUE ONLY.

[58 Plastic Tub]

Venolia.
_________________
Stan Galat
"A single point in isolation is a reference point. Two points is a line. Three points is a trend. Trends don't lie."

[Bad bug]

Jamestwo i once wanted to build a 2332cc t1 for a daily drive with short rods but when i looked at the rod ratio i was turned off. I read the article that you sent the link for and now you have me thinking again. One of my reasons for not wanting the short rod 2332 was that the pistons wouldn't have much skirting to prevent them from rocking in their bores.

But these pistons seem to have good skirting on them to reduce that. So i was thinking that this engine will and could make 200HP without reving to the moon. I wonder what it would do with 40 x 37.5 valves in the head.

[fusca66]

Thank´s all!!!
As I understand the short rods are good for street, to turn up early as the 58Plastic said.
And James said it lost with the torque rods long? I thought he earned in torque. James you know how many hp's gains with long rods?
About the placement of rods on my 5700 motor, I'll have to put a spacer around .300 or .400 right?
Would be a service reliable?
_________________
Bug 1966 2280cc
Bug 1951 1900cc
Bug 1952 typ4 1800cc
Sp2 1972 1700cc

Na duvida não ultrapasse

[gerg]

Good thread.

I am fixing to start on a 2332 IDA engine in the next few weeks. Was asked about rod length today and it looks like the shorter rod is preferred on the street. As much fun as my 2276 is in my bus, I never take it over 5 - 5.2k RPM, so I doubt I'd ever hit an 'out of power' ceiling if it is 6k or higher.

Any ignition suggestions with IDAs? I figured I'd run the SVDA from Aircooled.net, but understand the IDAs don't have the vacuum port? Sending them to Art Thraen for the progression circuit work - he doesn't know it yet.

Anyhow, what would be a good distributor? Someone was talking up distributor-less crank trigger systems today, but I don't know about any of them as of yet.
_________________
Gerg

. . . I got 99 problems and my bus ain't one . . .

'65 Sunroof Beetle
'65 Vert
'60 Singlecab

[fusca66]

[DarthWeber]