Rb34 / 24U (Rb26 + 800Cc) - Project RB high deck engine (and related builds)

[anon32]

Updates?

[GTRNUR]

Still waiting on the clutch. I've got to chase that up today as its been a couple of weeks. It is a custom made NPC unit though and I have no idea what their turn around time is.

[anon32]

I may have missed it but are you running a custom crank and what stroke are you aiming for

[anon32]

Never mind found it so a 90x90 bore x stroke having then squared is meant to be ideal isn't it? So this is gold

[GTRNUR]

I don't believe square, under or over really makes any difference to be honest. It is just one of those facts that IS about engines.

A lot of people have a differing opinions about what works and what doesn't. What it comes down to is more displacement is better if you are after more torque and power, and less lag. Simply because your moving more air.

This is an 89mm bore and 90mm stroke too. Although the sleeve design will support a 90mm bore still, while retaining more cylinder thickness than a 24U block would have with an 87.5mm bore.

Edited June 3, 2015 by GTRNUR

[bigmikespec]

Still waiting on the clutch. I've got to chase that up today as its been a couple of weeks. It is a custom made NPC unit though and I have no idea what their turn around time is.

What is the need for custom Ian?

[GTRNUR]

Based on recommendations from Trent @ Mercury and Dan (owner of LK Motors who's dyno we used), they actually agreed on the same type of clutch and I am fairly certain it is a custom setup. There is a pull to push converter required, and I believe it uses 1 x carbon and 1 x copper organic disc although don't quote me on that. I believe it is identical to the setup in Mercury's Nitto.

To be honest I left it in their hands to sort out and just paid the bill. I've been too busy with other work this past 3 weeks, which is good considering what will end up being a 4000-4500 change over cost.

Not to mention the brand new exedy carbon twin plate that is in the car is probably a paper weight now. It would be interesting to know if it is salvageable, or if its now looking completely shagged.

[anon32]

Once you receive the new clutch will you be re tuning it or should it still be fine given the last was slipping?

Or just doing a power run to see numbers and confirm all is fine?

And what is the price on rotating assembly for this being it's a custom crank?

Edited June 3, 2015 by anon32

[bigmikespec]

Based on recommendations from Trent @ Mercury and Dan (owner of LK Motors who's dyno we used), they actually agreed on the same type of clutch and I am fairly certain it is a custom setup. There is a pull to push converter required, and I believe it uses 1 x carbon and 1 x copper organic disc although don't quote me on that. I believe it is identical to the setup in Mercury's Nitto.

To be honest I left it in their hands to sort out and just paid the bill. I've been too busy with other work this past 3 weeks, which is good considering what will end up being a 4000-4500 change over cost.

Not to mention the brand new exedy carbon twin plate that is in the car is probably a paper weight now. It would be interesting to know if it is salvageable, or if its now looking completely shagged.

Are the plates munted on the Exedy? If they are, I would think they are very expensive to replace.

[GTRNUR]

The slippery clutch is still in the car. Not sure how shagged it is yet.

Yes when the new clutch arrives the wick is being turned up.

My goal is still to make 500kw atw on a soft E85 tune, which it should do with ease. 450kw looks to be easily achievable on a low boost 98 tune. Trent wants to turn up the boost to 30 and see how it goes in top end. We'll see, I might have to go for some drinks if that happens and just leave him to it.

[anon32]

What's a rough figure on rotating assembly ?

[GTRNUR]

And what is the price on rotating assembly for this being it's a custom crank?

I was lucky with this Nitto crank as it was a one-of that they had on the shelf, so I got a good deal.. Not sure why they made it either. Possibly just because...

I've just made a new crank for one of the next two engines which is 87.8mm. All up cost for that came to about $5700 I think, as it is essentially a customised Nitto Rb31 crankshaft, however using GTiR rod journals and it retains the oil squirters in the RB26 block. Prototypes aren't cheap.

Edited June 3, 2015 by GTRNUR

[anon32]

So essentially this will come in around $20,000 all said and done sake price as Tomei engine but with 800 more cc

[GTRNUR]

I'd rather not go putting any kit style guestimate pricing out there just yet. I am planning on doing 2 more prototypes.

Once they deliver some fruit, I will be asking for a production run of crankshafts and the necessary components as a bulk order. This will significantly reduce the costs as well as raise the bar on the quality of the product at the same time.

[anon32]

Sounds good

[Marko R1]

Subscribed

[NISR32.5]

Anymore updates?

[GTRNUR]

The new NPC clutch is here but the push to pull converter must have fallen off the boat on the way from Japan, MIA.

I did put an R35 brake setup on the car though, which makes stopping as much fun as accelerating!

[No Crust Racing]

Pics of brake setup k thx.

[MrFijiGold]

Thread needs more pics