Can someone ( who has tested this out eg. N/A not forced induction ) fill me in on how strong ( eg. Kilowatts. ) the standard rods are in a 6g74 engine.

I cant speak from direct experience, but i do know that the 6G72 rods are quite a bit thicker than those found in the 6G74. Some of the hi-po magnas use these rods when going FI.

6G72 Rods are slightly thicker/stronger..

bentattoo.. I swear I've raced you a few times on Beaudesert Road

SuFz :ninja:

Does that mean if I find after market roads for a 6g72 that they will go straight in. Small end -22mm Big end tunnel 53mm C/C 141mm?

I've had a TH 3.5l with 200 plus km when I was a young fella I'm not
Gonna lie I thrashed the F out of it and not one problem didn't
Use oil and was a great engine. I think 3.5l n/a are very strong and
Can take alot of abuse without hiccups. My new TH sports now has a new tj engine
From mal. Engines still very young has alot of power and is very smooth
Haven't done alot of km on it but the 3.5l engines are very smooth refined strong engine.

Does that mean if I find after market roads for a 6g72 that they will go straight in. Small end -22mm Big end tunnel 53mm C/C 141mm?

No, the 6G72 rods are shorter and have a smaller big end (50mm from memory). There are however two types of rods found in 6G74 engines: the older thick rods (~22mm) and the newer thin rods (~18mm). Don't know exactly when the newer rods appeared - some comments I've seen suggest with the TJ. The newer rods are also used in the 6G75.

Can someone ( who has tested this out eg. N/A not forced induction ) fill me in on how strong ( eg. Kilowatts. ) the standard rods are in a 6g74 engine.


Really it's Revs that are going to kill your rods, not the power.

Earlier 74 rods were bigger and heavier. Having said that the IPRA guys use 6G75 rods, revving pretty hard with no problems I believe?

Correct, centrifugal forces at high revs to be exact

Most if not all TH's have the Fat Rods and everything before it i reckon

Really it's Revs that are going to kill your rods, not the power.

Earlier 74 rods were bigger and heavier. Having said that the IPRA guys use 6G75 rods, revving pretty hard with no problems I believe?
Do you know what the measurements of the 6g75 rods are
( eg. Small end, big end, C/C ? )

There are 2 6G74 rods, an early rod, up to the end off TJ series 1 roughly. There is no actual change over model specific but it's around there= approx 770 grams. Then from TJ series 2 the lighter 74 rod= approx 630 grams was introduced with lighter counter weighted crankshaft to suit the lighter rods. The 6G75 uses the same rod but the 75 piston is approx 45 grams lighter than the 74.

We rev the 6G75 which have standard internals IPRA Magnas to 7300 with no dramas. The problem with high revs is not the rod on the 74/75 but the pin boss of the piston.

If your worried I'd use the ealier heavy rod with ARP bolts.

Hope this helps you, Cheers Dave