Bloody "precious" RB engines!

[blind_elk]

How I long for an engine like the old L-series. You could treat them as bad as you liked, and they remained bullet-proof. Not like these precious little darling RB engines you get nowadays.

I was at Winton Sunday when the engine started billowing smoke. After I pulled into the pits, I found the dipstick lying across the engine bay, and the RHS of the engine bay protect-a-coated in brand new Castrol 5W/30 Synthetic R with Nulon E20 additive.

Dropped it over to Speed Technology today, and they confirmed my worst fears - #2 piston has a pretty bad case of leak down. And the spark plug had no ceramic left :Oops:

So now it's time for a rebuild. My question is - should I go to the expense of forged pistons, or will Mr Nissan's OE pistons be sufficient to support the 180-odd 4wkw the engine is producing? If I should go "forgies", whose pistons?

TIA

[2rismo]

Sounds to me like proper tuning with aftermarket management would be a good start. If you don't intend to double the power output during the rebuild process, I'd stick with Nissan OEM stuff and spend my money getting and keeping it reliable.

The pistons in RB's will take much more power than what you're suggesting you make right now so as a matter of priority, I'd investigate the reason the motor popped number 2 in the first place. Is your fuel pump stuffed? Is there another, bigger problem?

Good luck buddy

Adrian

[siksII]

i would also personally never use oil that thin, especially for hard use you could spin a big end...

stock pistons are fine for that power level, although nowdays forgies are not too much more if you shop around, so i would go for forgies.

[Duncan]

I'd take the forgies, $1300 for Arias with rings from ROcket in Sydney, and you can machine it all up oversize. Might as wll do all that while its out.

I had to put standard pistons back in, and after chemical and manual cleaning, new rings, rehoning the block it still cost me over $500 for that and I've just ended up with a looser engine than mr nissan wanted int he first place. For an extra $700 may as well do it properly.

But since I understand your car isn't exactly overstressed, I'd check out what the problem was? Fuel pump dying? busted injector? Just a dodgy spark plug and unlucky?

[blind_elk]

I'd take the forgies, $1300 for Arias with rings from ROcket in Sydney

Got contact details for Rocket?

[Duncan]

Rocket Industries

40 Huntingwood Drv Huntingwood 2148 (02) 8825 1900

[Busky2k]

Just wondering, what prompted you to use Nulons E20? PTFE gets lots of bad rap in engines...

[Keegs]

think yourself lucky, I put a rod out the block at willowbank tonight....god damn stock bottom end running 1.2bar and 7500revs...it would have been putting out around 400+hp but still....the bottom end should have stuck, stupid pos....anyway. What do you guys reckon for the rebuild, throw me ideas, im pretty sure ill stick to another 25 block, obviously foged, but what brand...I was going to go tomei rods and pistons, but does anyone know if I need to get the crank machined and balanced as well or should it be ok as is?

Cheers Matt

[GTRgeoff]

Greg, sad to hear. The 25 has one weak point, and that is any lean running so as suggested look long and hard at the fuel system.

Without a rising rate reg and upgraded pump you are close to the limit there (190-200rwkw) anyway on stock injectors so if a minor problem did arise there is little margin for safety.

Go with the specs Duncan suggested, and for more detail call me, I'll send you a Pm with my number.

[blind_elk]

ECU = Wolf 3D 4+

Pump = Bosch motorsport

FPR = standard

Speed Tech said engine has definitely been running lean, but no-one really understands why, when Wolf was tuned rich. Although they reckon a "5" NGK Iridium (NGK catalogue) was a bit hot for the engine. (should have been at least a "6", and probably a "7" would have been even better)

Nulon sounded like a good idea at the time, but I really don't think it played any part in this. The engine survived Wakefield Park at Easter and Morwell Hillclimb a couple of weeks ago, and nothing has changed in that time.

I did notice an unexpected "tinkling" during an overtaking move on the way up to Winton, so I'm beginning to suspect a crook batch of BP Ultimate may have played a part. But maybe someting stupid like the fuel filter starting to block up, who knows?

Anyway, will start stripping it down this weekend and have a good look at what happened. Plan to do a balance job on it while it's apart also.

Duncan, thanks the info. Do they have a website?

[ferni]

Greg, sad to hear. The 25 has one weak point, and that is any lean running so as suggested look long and hard at the fuel system.

Without a rising rate reg and upgraded pump you are close to the limit there (190-200rwkw) anyway on stock injectors so if a minor problem did arise there is little margin for safety.

Go with the specs Duncan suggested, and for more detail call  me, I'll send you a Pm with my number.

I've got friends running 230-250rwkw on stock injectors in thier RB25 - upgraded fuel pump and turbo however.

[Bobjones]

Matt,

So it was you that blew up at the start line last night.

Sorry to here bro, but I would be going forgies. I wish I did now, however I am not making the line a fast car...its a whale at that is the way it will stay...

Cheers

Neill

[GTRgeoff]

Greg, certainly at the limit of safety with the standard FPR. Also so easy to get a gutload of bad fuel and clog the filter. Try here though http://www.rocketindustries.com.au/

Andrew, they would need both pump and turbo, and the FPR to make the flow on the injectors. 250 is a pretty good number though.

The non RB26 nissan pumps are becoming an increasing concern for me in my research of engine failures. I have not yet heard of a 26 pump failing, but that may be due to smaller numbers and reporting. Can you double check it for me Greg?

[GTRgeoff]

Greg, certainly at the limit of safety with the standard FPR. Also so easy to get a gutload of bad fuel and clog the filter. Try here though http://www.rocketindustries.com.au/

Andrew, they would need both pump and turbo, and the FPR to make the flow on the injectors. 250 is a pretty good number though.

The non RB26 nissan pumps are becoming an increasing concern for me in my research of engine failures. I have not yet heard of a 26 pump failing, but that may be due to smaller numbers and reporting. Can you double check it for me Greg (I know you have a bosch)? Looking for the flow past the filter if it is blocked and flow rate.

[Al]

Greg if you suspect it could be a bad batch of BP fuel, can't you get a sample tested and if proven take it up with the BP servo? I have previous heard of ppl being financially compensated, when it was proven that the fuel caused the failure. Of course you would require the fuel receipt to prove time and date of purchase.

A little off topic (sorry Greg):

I have a 2lt surge tank/swirl pot with an external Bosch 044 pump and the std in-tank pump filling the surge tank. Just had a thought; is it worth moving my fuel filter to the line feeding the surge tank? This idea came to me while reading the previous posts. If my filter was to temporarily get blocked the bosch pump will still have 2ltrs of fuel to draw from, by which time the blockage may pass. In the current set-up, if the filter becomes blocked, the engine will run learn till the blockage clears.

[GTRgeoff]

Al, this is a good idea but I'd recommend an alarm attached to a sensor in the pot to advise on low fuel, then you could be aware of any blockage problems and pull over.

[blind_elk]

Greg if you suspect it could be a bad batch of BP fuel, can't you get a sample tested and if proven take it up with the BP servo?  I have previous heard of ppl being financially compensated, when it was proven that the fuel caused the failure.  Of course you would require the fuel receipt to prove time and date of purchase.

Unfortunately, didn't think of it at the time, and it now has a nice tankful of Synergy 8000 sitting on top of what was left of 2 separate servo's BP Ultimate. (But I think it would have to have been the first servo's, since the second was as a top-up - maybe 1/4 tank - on the way up to Winton)

Geoff, OK to call you over the weekend?

[GTRgeoff]

Greg, call anytime, even today.

[Roy]

Bugger!!!

Id go for a set of CP/Aries pistons, approx $1100-1350 depending on how good a shopper you are (or so im told) If you want to save the cash as you don think you will ever be making the number to justify forgies, then what are a set of new GTR pistons worth from Nissan? I can speak to a friend who can get Nissan gear a tad cheaper, GTR pistons much better then RB25.

Will have to check what that does to you compression though, you may need to GTR Rods as well which is another few hundred:(

[Al]

Al, this is a good idea but I'd recommend an alarm attached to a sensor in the pot to advise on low fuel, then you could be aware of any blockage problems and pull over.

The surge tank is already constructed/sealed how can i rig up a sensor/alarm?