Jump to content
SAU Community

Recommended Posts

as the aftermerket crank swinging at a bigger angle to create the displacement

so those kit add EXTRA stress to the bearing

Extra stress on the bearings?? we are talking going from 2.6 to 2.8 here, and some of that capacity is gained from the overbore! And you are dealing with a crank that is MORE balanced than the stocker, so id say without the nasty harmonics or vibrations that ive heard people talk about, wouldnt there be less stress on the bearings than a stock rb26 crank (at the same rpm)?

as sydneykid has explained, the square 3litres "have superior rod/stroke ratio (1.79) to RB26s' (1.65), this means less side loading on the rods and the crank."

BUT, as i originally posted i dont want another 3litre thread so lets talk no more of it, i want Jap stroker crank experiences here :)

ok back to topic the three HKS kits as i understand them are

stage 1 (600ps rating)

crank

rods

pistons

$6819.12(deliveried)

stage 2 (800ps)

crank

rods

pistons (but the pistons are coated)

$8,720.87 (deliveried)

stage 3 (1200ps)

crank

rods (22mm judgen pin)

pistons (but the pistons are coated)(22mm judgen pin)

$10,738.65 (deliveried)

in my opinion i think stage 1 is good valve for money full forged stoker kit internals for under $7000 deliveried and i believe it to be capable of much higher hp then rated, coating pistons does make that much of a difference (600 to 800ps) and if i had known earlier about this kit well my current build might have been alot different. I could only see someone going above stage 1 (straight to 3) if you were out to break some hp(dyno) or drag records.

my 2 c

ps HKS conrods are simple awesome

thanks for the RELEVANT post pnblight!

I was just about to go for the stage 2 kit, then remembered that customs will make me pay 25% on top of that cost (10%gst + 15% duty)! Might it slip through?? most probably not, as apparently they are shipped in a reasonably sized wooden crate, and the declaration from nengun (or whoever) will state the value of the parts..

Now youve got me thinking about the step 1 kit. In true Jap fashion it is likely to be underrated. If a combination of stock crank, average quality upgrade rods and pistons can support 600PS, then surely the HKS 'baby' kit can handle 700+ps. I would think they would quote for an extremely long reliable service life supporting 600ps, perhaps circuit car reliable, in which case under street conditions should easy support more. Any thoughts on this??

thanks for the RELEVANT post pnblight!

I was just about to go for the stage 2 kit, then remembered that customs will make me pay 25% on top of that cost (10%gst + 15% duty)!  Might it slip through?? most probably not, as apparently they are shipped in a reasonably sized wooden crate, and the declaration from nengun (or whoever) will state the value of the parts..

Now youve got me thinking about the step 1 kit. In true Jap fashion it is likely to be underrated.  If a combination of stock crank, average quality upgrade rods and pistons can support 600PS, then surely the HKS 'baby' kit can handle 700+ps.  I would think they would quote for an extremely long reliable service life supporting 600ps, perhaps circuit car reliable, in which case under street conditions should easy support more. Any thoughts on this??

from there other kits you can say the crankin stage 1 is good for 1200ps the rods in stage 1 good for 800ps as both components are the same the only factor down rating the kit is the piston coating ,I think a quatity forged piston from HKS would be capable of alot higher ps rating i think the reason for the rating is more to given a justification for the price differences between the kits as who would pay the exact money if the rating were more like

stage 1 900ps

stage 2 1000ps

stage 3 1200ps (for example only)

do you see what i mean

sly33 would it be possible to maybe try buying it for america instead as the free trade agreement (might be cheaper just an idea)

pete

if your paying 10K for parts i reckon it's worth hopping on a plane over there and picking it up yourself. sure it costs $2K but you will save money on frieght (maybe $400?) plus can possibly negotiate a cheaper price (save maybe $500-$1000) and save duties ($1400). you would have to take the crank as carry on (carefully packed in a bag) and put the rods/pistons in your check in. could be a bit ambitous you say but on my last trip to japan i carried over 50kg back. more than 30 of that carry on.

i got funny looks carrying on some springs flying domestic, imagine the looks when they run a fat crank through the scanner! haha

Main problem with that idea for me is that i wouldnt have the time to go over there! But youve got me thinking.. i know guy whos just moved there.

Edited by SLY33

pete, i see what you mean.

but surely there are other diff's than just some piston coating to justify the extra $$? i heard or read somewhere that step1 and 2 cranks are forged counter, whereas step 3 is full billet crank like the JUN one previously mentioned??

not exactly sure..

Edited by SLY33

To quote Tomei on their 2.8 counter weight crank:

"Only 200cc displacement up. It causes dramatic change to RB26. Change is super response and big torque."

As i mentioned earlier, the 200cc extra must make more of a difference than most people would think.

To quote Tomei on their 2.8 counter weight crank:

"Only 200cc displacement up. It causes dramatic change to RB26.  Change is super response and big torque."

As i mentioned earlier, the 200cc extra must make more of a difference than most people would think.

I think you will find (and I may be wrong), that the HKS step 1 kit does not come with conrods, the kit uses 121.5mm rods, so you use your old ones.

Also, all 3 cranks (step 1, 2 and 3) are different, but I believe they are all 12 counter types.

The Tomei RB28 kit includes Arrow rods but uses an 8 counter crank (from the Z tune)

hi mik, ive found that depending on who supplys the kit, most kits come with rods. The only place i found that sold the kit with no rods is Xspeed in Perth.

so is a 12 counter better than an 8 counter? I dont know a whole lot about cranks and only since investigating these kits was the first time id ever heard of a full counterweight crank.

according to the HKS website the step 2 kit is just crank, pistons and rings and is 498 000 yen retail (tax exclusive for use outside japan). the step 3 kit is crank, rods and pistons and rings and is 950 000 yen retail.

it gets frustrating when once source of reliable information says one thing, and another reliable source says another!

heres what nengun offers from HKS, all with rods

HKS 2.8L Kit Step 1 Rated 441kW(600ps)

Compression ratio (Gasket Size)

* 8.70 (t=1.2mm)

* 8.4 (t=1.6mm)

* 8.1 (t=2.0mm)

Parts Included

- Forged piston kit

- Fully forged & balanced counter crankshaft.

-H cross section connecting rods.

* To cylinder block and baffle plate et cetera

Escaping processing becomes necessary.

HKS 2.8L Kit Step 2 Rated 588kW(800ps)

Compression ratio (Gasket Size)

* 8.70 (t=1.2mm)

* 8.4 (t=1.6mm)

* 8.1 (t=2.0mm)

- Forged piston kit (nickel plated & piston surface has a final molybdenum coating).

- Fully forged & balanced counter crankshaft.

-H cross section connecting rods.

* To cylinder block and baffle plate et cetera

Escaping processing becomes necessary.

HKS 2.8L Kit Step 3 Rated 882kW(1200ps)

Compression ratio (Gasket Size)

* 8.70 (t=1.2mm)

* 8.4 (t=1.6mm)

* 8.1 (t=2.0mm)

- Forged piston kit (nickel plated & piston surface has a final molybdenum coating).

- Fully forged & balanced counter crankshaft.

- H cross section connecting rods.

* To cylinder block and baffle plate et cetera

Escaping processing becomes necessary.

Guest
This topic is now closed to further replies.



  • Similar Content

  • Latest Posts

    • Because people who want that are buying euros. The people with the money to buy the aftermarket heads and blocks aren’t interested in efficiency or making -7 power, they’re making well over 1,000hp and pretty much only drive them at full throttle  best way to way make money is know your customer base and what they want and don’t spend money making things they don’t want. 
    • It's not, but it does feel like a bit of a missed opportunity regardless. For example, what if the cylinder head was redesigned to fit a GDI fuel system? It's worth like two full points of compression ratio when looking at modern GDI turbo vs PFI turbo. I'm pretty reliably surprised at how much less turbo it takes to make similar power out of a modern engine vs something like an RB26. Something with roughly the same dimensions as a -7 on an S55 is making absolutely silly power numbers compared to an RB26. I know there's a ton of power loss from things like high tension rings, high viscosity oil, clutch fan, AWD standby loss, etc but it's something like 700 whp in an F80 M3 vs 400 whp in an R33 GTR. The stock TF035HL4W turbos in an F80 M3 are really rather dinky little things and that's enough to get 400 whp at 18 psi. This just seems unwise no? I thought the general approach is if you aren't knock limited the MFB50 should be held constant through the RPM range. So more timing with RPM, but less timing with more cylinder filling. A VE-based table should accordingly inverse the VE curve of the engine.
    • I've seen tunes from big name workshops with cars making in excess of 700kW and one thing that stood out to me, is that noone is bothering with torque management. Everyone is throwing in as much timing as the motor can take for a pull. Sure that yields pretty numbers on a dyno, but it's not keeping these motors together for more than a few squirts down the straight without blowing coolant or head gaskets. If tuners, paid a bit more attention and took timing out in the mid range, managed boost a bit better, you'll probably see less motors grenading. Not to name names, or anything like that, but I've seen a tune, from a pretty wild GT-R from a big name tuner and I was but perplexed on the amount of timing jammed into it. You would have expected a quite a bit less timing at peak torque versus near the limiter, but there was literally 3 degrees of difference. Sure you want to make as much as possible throughout the RPM range, but why? At the expense of blowing motors? Anyhow I think we've gone off topic enough once again lol.
    • Because that’s not what any of them are building these heads or blocks for. It’s to hold over over 1000hp at the wheels without breaking and none of that stuff is required to make power 
    • Dort sounds above 3k rpm are dorty 🤣 I might krinkle black the alloy 🤔
×
×
  • Create New...