Choosing The Right Engine

[RRob]

I'd go 25/30, biggest capacity and VCT. Make sure comp ratio is good, and get a real ECU to tune it.

[Hterrygqt]

Thanks mate, so iam guessing shaving the head for more comp, or different sized head gasket?

[Tai1or Made]

its all about having something different then the next bloke.

Hence 12A.

[RRob]

I chose the NEO head and ran a thicker than standard gasket. Tomei type A cams and gears arrive this week, aiming to fatten up the midrange.

[The Bogan]

4.0 LTR

[AngryRB]

4.0 LTR

starting to agree here, was down at power cruise today, i must of saw atleast 3 falcon turbo motors that had been transplanted into imports and a vl.. also with a massive garrett bolted on

[Hank Scorpio]

12A.

This.

With a dirty peripheral port. All the torque you'll ever need above 9,000rpm

[discopotato03]

My view is that for a 4WD to work properly it needs to make good torqe at very low to mid range revs and who cares about top end .

I also think twin cam heads do bugger all for most engines at very low revs , currently Nissan is having dramas with their V8 contender and not having a two valve head can be a disadvantage in a CR and rev limited engine . I doubt very much that a SOHC RB30 would give anything away to a twin cam one in the rev ranges that a diesel truck would use .

Something to look into is the RB34 that is now available , these are a stroked and slightly bored RB30 and if cubes are everything to you worth considering . You would have to check but I think the rebuilt short motor is something like 5-6G in your lap .

IMO the bigger the engine is the less boost it needs in a turbo app and you get a better more evenly shaped torque delivery curve or maybe plateau .

I would be wary of high rev performance because it can be a little peaky and even road car engine power curves in a significantly heavier truck .

Also high revs is where larger power numbers come from hence the diesels you speak of never have high Kw numbers - because they don't rev .

Anyway provided an RB30 mates to your gearbox and you don't have legal issues its a reasonable plan . Otherwise if your truck doesn't owe you much sell it and find an earlier RB equipt GQ or whatever and go from there .

Lastly , like most car lighter is always better but truck wise they seem to be getting bigger and heavier .

A .