Scrounged through the forums and couldn't exactly find a definitive response, is is a two parter:

Part 1: Would increasing the 93mm bore/ 85.8mm stroke of the 6G74 to the 95/90 of the 6G75 essentially serve as an "engine conversion" in terms of performance gains?

Part 2: if yes to the first part, is it worthwhile getting that work done to my baby ralliart?

I dont know but it would be silly to do it. Would cost you 3x the cost of the engine conversion.

Boring and stroking a 3.5L into a 3.8L . . . . . . lots of work involved, and money, and the question has to be asked . . . . WHY, when you can just buy one?

Boring and stroking a 3.5L into a 3.8L . . . . . . lots of work involved, and money, and the question has to be asked . . . . WHY, when you can just buy one?
I guess I was assuming it'd be cheaper to bore/stroke a ralliart engine than it is to work a 6G75 to be a ralliart engine.

Work a 6G75 to be a ralliart engine? I know people have swapped their ralliart engine for a 6G75, get the power much lower down.

Working a 6G75 to a "Ralliart" engine is pointless, the 6G75 is better in literally every way I know of. Ralliart engines aren't prestige or particularly special like say an M engine would be, it's just a slightly better 6G74.

I find this thread confusing.

I would say no as a 6g75 engine has alot more than just a 3.8lt displacement over the 3.5lt 6g74.. There would be some power gain obviously but not near a full engine conversion

6G75 has a lot over a normal 6G74, but the diff between a Ralliart 6G74 and 75, isn't it really just the capacity?

Thought: If the Ralliart motor has finely tuned head flows, valves, etc, then increasing the capacity might spoil the complimentary action of those other items, reducing any benefits?


For the cost of increasing capacity of your Ralliart engine, would it be more cost effective to put in a 6G75 and keep your Ralliart motor aside to swap back in the future when having original numbers would make it a $100k collectors item? :)

The 6g75 heads flow much better then ralliart

The 6g75 heads flow much better then ralliart
Ahhkay. I guess I assumed that the 6g75 was simply a bored/stroked 6g74.