RB30 engine conversion (lots of pics)

[whoflungdung]

all looking good Andy

the shineyer the better

just waiting for my new amp from Japan, will let u know when its ready(if ever)

[shanef]

whats the reasoning behind coating the piston? and why did u fell the need to change from the acl (also named ross lol) to the wiesco?

P.S u running with gapless rings?

[R32 Combat]

No, I'm not running gapless rings.

ACL(ROSS) are of a lesser quality than wiseco. As can be seen in the pics. The piston failure wasn't the pistons fault, but I think that wiseco are a better piston. The design is certainly better and the piston/bore clearance is much less.

There does seem to be an engineering issue with some RB30's running massive piston/bore clearance. Oil comsumption is crap and they are noisy. Mine has 0.006" some have even more. I think the guy's in Oz/Nz like this. Personally, I think it's sh1t. I'm runing 0.003" in the wisecos. The ACL's were causing the engine to use 1L of oil every 700miles. Oil in the combustion area caused DET. So, all RB's with big clearance will be more susceptible to DET. This is a contributing factor to my failure.

Coating is just a protective barrier, helping eliminate hotspots and increasing the surface hardness.

[kingsley]

Originally Posted by gtr1987

In this formula, you can clearly see that Manifold Absolute Pressure is inversely proportional to the engine displacement. So, in this case, if you set the twin GTSS turbos to produce 1 bar boost in the 2.6 litre engine, when you use the turbos with the 4.5 litre engine, it will not hold 1 bar boost. Is this true? What are the effects on the horsepower output on the engine? (Assume that turbine restriction doesn't exist)

Not wishing to hijack Andy's thread, but ...

... I would agree that the GT-SS would struggle to hold boost on a 4.5 litre engine compared to a 2.6 litre. They'd have to flow far more air and they'd run out of puff. I would, however, expect a larger engine to still make a BIT more power with the same turbos than a smaller one (within reasonable bounds). I'm sure there are many reasons I'm not aware of but thinking back to steam engines, the following seems to make sense (to me):

Imagine a steam engine. The intake valve opens at approx TDC but is closed before BDC. The reason for this is that when the valve closes there is still high cylinder pressure, therefore useful energy. Though the intake valve is closed, because there is still high cylinder pressure the steam continues to drive the piston down. This way, you get more mpg out of the steam. As the piston continues to descend, cylinder pressure now drops as no more steam is coming in. I guess the max mpg you'd get from the steam would be if you open the exhaust valve just when the cylinder pressure has dropped to nothing (ie same as outside). Clearly, you'd get more power from the steam if you left the inlet valve open for the whole stroke but you'd waste a lot of steam, therefore waste a lot of energy.

Now applying that thought to the RB26/RB30, for the same mixture flow in and the same rpm, I would expect an RB26 to still have greater residual cylinder pressure when the exhaust valves open than would an RB30. Therefore, I would have expected the RB30 to have in effect extracted more mechanical energy from the fuel than the RB26 would have done. For that reason, I would expect an RB30 to produce more power at the same flow rates than an RB26 once you're at a decent throttle opening. Obviously the dynamics of a fuel mixture burning in the cylinders are rather different from what happens in a steam engine so the similarity may not be as close as I might have liked in this instance.

I'm just guessing and this could all be completely wrong. Also, I'd expect the RB30 to possibly have slightly higher internal losses due to the longer stroke, which would count against you a bit.

That said, I did see dyno plots of a GT-SS equipped RB26 vs an RB28 of more or less idendical spec aside from the capacity. The RB28 made about 20bhp more, which seems to back the theory. Importantly, the RB28 made max bhp earlier in the rev range and the area under the curve was much greater.


PS. pistons are looking great, Andy

[R32 Combat]

Crank position snesor setup mockup.

[Asim R32GTR]

oh yeah! thats nice!

Did you make the bracket yourself?

But i still dont understand how you can use that triggerwheel without any missing tooth?

Asim..

[shanef]

looks good mate.

1 suggestion, is there only that one bolt holding it in place? reason i ask, if it came lose and the sensor wiggled loose, would that affect the reading? i.e the distance between the sensor and the teeth varied

[Asim R32GTR]

Originally Posted by shanef

looks good mate.

1 suggestion, is there only that one bolt holding it in place? reason i ask, if it came lose and the sensor wiggled loose, would that affect the reading? i.e the distance between the sensor and the teeth varied

If you look at the first pic, you can se both bolts

[mambastu]

Originally Posted by R32 Combat

No, I'm not running gapless rings.

ACL(ROSS) are of a lesser quality than wiseco. As can be seen in the pics. The piston failure wasn't the pistons fault, but I think that wiseco are a better piston. The design is certainly better and the piston/bore clearance is much less.

There does seem to be an engineering issue with some RB30's running massive piston/bore clearance. Oil comsumption is crap and they are noisy. Mine has 0.006" some have even more. I think the guy's in Oz/Nz like this. Personally, I think it's sh1t. I'm runing 0.003" in the wisecos. The ACL's were causing the engine to use 1L of oil every 700miles. Oil in the combustion area caused DET. So, all RB's with big clearance will be more susceptible to DET. This is a contributing factor to my failure.

Coating is just a protective barrier, helping eliminate hotspots and increasing the surface hardness.

6 thou clearance, thats pretty large isn't it ? I thought most forged pistons were in the 3 to 4 thou range ?

I was looking at a set of Wiseco RB26 pistons a couple of weeks ago and they had the same skirt coating as yours. I assume its a dry film lubricant of some sort ?

[R32 Combat]

The skirt coating is indeed a lub coating put on by Wiseco


The trigger disc doesn't need a missing tooth because I'll be using the CAS as a #1TDC sensor. The trigger disc then knows the position for the TDC on all 6 pistons.

The CAS will be set up to reset the disc counter between a rising edge and a falling edge of a tooth, so the ECU will know exactly when #1TDC is by calculating the time required using the engine speed, it just counts from there for the 720degs. It then resets and starts over.

[bobstuart]

do you know for sure that your ecu can read your trigger disc

[R32 Combat]

Yes, my ECU can be configured to run a disc with any number of teeth.

[Asim R32GTR]

Originally Posted by R32 Combat

The skirt coating is indeed a lub coating put on by Wiseco


The trigger disc doesn't need a missing tooth because I'll be using the CAS as a #1TDC sensor. The trigger disc then knows the position for the TDC on all 6 pistons.

The CAS will be set up to reset the disc counter between a rising edge and a falling edge of a tooth, so the ECU will know exactly when #1TDC is by calculating the time required using the engine speed, it just counts from there for the 720degs. It then resets and starts over.

Ok, every other ecu that i have worked on needs some sort of missing tooth, to let the ecu know when cylinder 1 is at TDC. And then combine it with a signal from the cam usually 6-180 degrees before firing of cylinder 1... then it uses the info and starts counting...

Hope you understood this hehe... damn the language barrier

Asim...

[Madden]

This is some clever shit.

[shanef]

Originally Posted by Asim R32GTR

If you look at the first pic, you can se both bolts

oh dear...i must be going blind