rb26dett 2.7L stroker kit

[wreckedhead]

is it worth the price tag

http://turbulence.com.au/shop/product_info...products_id=135

i thoguht they would be more expensive then that, can anyone confirm if the kit is any good

[Mazinger]

Never heard of this company Grex, and it seems to me that 2.7 is done more by bore than stroke (cant rember stock rb26 bore).

From a recent discussion on another forum i understood that a 2.7 wont give that much extra power really, but if you are doing it to keep safe then it would be good.

but grex..... hope they are not releates to MotoRex in the usa

[wreckedhead]

grex is a good company, have many products from them but i was just hoping to find some info if anyone has purchased this kit or have it installed already

[666DAN]

Grex...isn't that Trust?

[Amaru]

That price is just for the pistons, doesnt include the conrods or crankshaft that come in the higher priced ($10,000+) kits.

And yes, Grex is Greddy is Trust etc. They are the same company, but technically they are different.

[DoughBoy]

Woa that's an utter bargain, you'd be hard pressed to buy just the crank for that price! But otherwise, what Amaru said!

[Blitz]

Never heard of this company Grex,

As mentioned, Grex/Trust/Greddy all fall under the same company. Trust sells different components under each of the 3 sub-brands. ie Grex is predominately engine hardware

[Blitz]

is it worth the price tag

http://turbulence.com.au/shop/product_info...products_id=135

i thoguht they would be more expensive then that, can anyone confirm if the kit is any good

MrChams is running the Trust 2.7 kit in his R32

[mrchams]

I sure am... there are different kits from what I understand.

The kit that I have is 87.5mm GREX pistons and GREX H pattern rods.

The larger 2.7ltr piston kit helps my Greddy T78 spool up quicker.

Due to the cost of after market cranks, I am running a standard crank that has been shot penned and cryogenically treated (dunno what the hell that is but hey...)

The standard cranks are pretty strong. Before my rebuild this crank held 720hp with no signs of breaking. Not sure what there limit is.

I'm still running in the engine. Once I have it tuned I'll let you all know how I went for power.

The kit on the link above is just the over sized 87mm piston kit.

MrChams is running the Trust 2.7 kit in his R32

[Merli]

How do you get the extra stroke necessary for 2.7L from a standard crank and 86.5mm pistons? :confused:

[mrchams]

This is not the stroker kit.

The piston size makes it 2.7ltr.

My pistons are 87.5mm not 86.5mm. Typo

If you check out this link, you can calculate the displacement

http://www.benedict.esu7.org/sblock/ccfrm.html

It's something like this (don't quote me on it)

Bore radius squared x pi x stroke x no. of cyl = Total cubic displacement

How do you get the extra stroke necessary for 2.7L from a standard crank and 86.5mm pistons? :confused:

[wreckedhead]

damn, when i saw the pic and the price i already got the credit card out, but for pistons only hm doesnt seem worth it,

[R31Nismoid]

I sure am... there are different kits from what I understand.

The kit that I have is 87.5mm GREX pistons and GREX H pattern rods.

The larger 2.7ltr piston kit helps my Greddy T78 spool up quicker.

 

I'm still running in the engine. Once I have it tuned I'll let you all know how I went for power.

how much difference? Just outta interest.

And running in an engine? Thats over-rated in this day and age

[Merli]

Ahhh okay...

Std bore & stroke (86x73.7) = 2568cc (juuuuuust enough to claim 2.6 Litres )

87.5mm bore & std stroke = 2659cc (also juuuuuuuuuuust enough to claim 2.7 Litres )

Did you do these internal upgrades by themselves? Could you really tell the effects of extra 100cc capacity? Or did you do other things like camshafts, cam gears, etc etc at the same time?

[mrchams]

The stoke on the trust piston is 75.7mm and the piston size is 87.5.

http://www.benedict.esu7.org/sblock/ccfrm.html

Regarding the mods etc,

It's not just the pistons that has given the improvement but extensive head work.

The head work included modifying the bowl shape, different angles on the valves and valve chamber, valve guide modified, cam area opened for bigger cams and the obvious port enlargement.

I am currently running the standard cams with adjustable cam gears.

Bigger cams will be fitted soon once I decide what size to get.

Yes, I did notice the difference. The engine does feel like it has more down low torque but I can't say till we tune it on the dyno.

Ahhh okay...

Std bore & stroke (86x73.7) = 2568cc (juuuuuust enough to claim 2.6 Litres )

87.5mm bore & std stroke = 2659cc (also juuuuuuuuuuust enough to claim 2.7 Litres )

Did you do these internal upgrades by themselves? Could you really tell the effects of extra 100cc capacity? Or did you do other things like camshafts, cam gears, etc etc at the same time?

[mrchams]

I don't agree with not running in an engine.

My mechanic use to work for Nissan Japan.

They did test on how to run in RB engines. He told me that the best result was when they ran the engine up to 4,000rpm for the 1st 1,500km then oil change then up to 5,000rpm to 5,000km.

He told me the bore was perfect after such a run in.

The test also involved using mineral based oil in some engines and full-synthetic in other engines.

The full-synthetic oil run engines came out much better.

how much difference? Just outta interest.

And running in an engine? Thats over-rated in this day and age

[mrchams]

The price is very high just for Greddy pistons.

You should be able to get the pistons for approx $2500 and the rods for approx the same, $2500...

damn, when i saw the pic and the price i already got the credit card out, but for pistons only hm doesnt seem worth it,

[Merli]

The stoke on the trust piston is 75.7mm and the piston size is 87.5.

http://www.benedict.esu7.org/sblock/ccfrm.html

How exactly do you increase stroke by 2mm with a piston upgrade on standard crank? :confused:

And I don't need a web calculator, I remember my Year 7 volumetric formulas :Oops: Probably the first time I've used them since high school

[Merli]

They did test on how to run in RB engines. He told me that the best result was when they ran the engine up to 4,000rpm for the 1st 1,500km then oil change then up to 5,000rpm to 5,000km.

 

He told me the bore was perfect after such a run in.

The test also involved using mineral based oil in some engines and full-synthetic in other engines.

The full-synthetic oil run engines came out much better.

5000km run-in??? That would take most people 6 months to complete. You really think that's a feasible run-in time?

What engine parts could POSSIBLY need 5000kms bedding in time??? :uhh:

No comment on the full-synthetic running in oil use... People have different ideas on that one, but the vast majority believe that mineral oil for the first 1000kms or so is still the best way to go.

[2rismo]

The full-synthetic oil run engines came out much better.

And the rings were properly seated and in full seal?

Adrian