Close the idle a bit and lean the LSN (in tiny increments) as necessary...

rb blast v12
 

Dose anyone know the bearings size for rb blast v12 engine front and rear bearings
thanks

Check Amain hobbies, I think they are the RB distributors.

7x19x6 front. 14x25.8x6 rear

Hope you guys don't mind me giving you the "story" of my engine so hopefully some people can make suggestions of what to try next! It is the same engine I was asking about in the previous page!

It is an RB SLS5 that went into the car brand new during qualifying at Neo with just a quick box break in. Carb was setup by the rb factory guys and it ran the rest of Neo fine with a smooth steady idle, clearly rich but clean running, about 6 min tanks. Neo of course being a cool English low altitude spring.

Next to a club meeting in PA, didn't touch a thing, ran fine all day but still only 6 minutes runtime.

Through these meetings there was a slight tendency on track for the motor to stay on power a little as I came off the throttle, but nothing bad.

Next AMS, again even in the totally different atmosphere ran fine for MOST of the meeting...but as it had about a gallon through it by now was beginning to feel it may be time to chase performance, it was still definitely revving low and losing out on top end, smoke everywhere and in final qualifying sounded a bit unclean when flat on the straight. I leaned hsn an hour for the final and it felt a bit better but I lost a servo 4 laps in.

When I got back from AMS I decided to put a tank through on the box to check it all and then store how I normally would...and the idle would stay up high, 2 stage but even second stage being higher than before. (I live at sea level in VA).

I played around and richened lsn about 2 hours and slightly increased idle screw and got a nice clean low idle very quickly and an idle that could sit for a long time without stalling.

Have just done another meeting in a different car with a more compact manifold in the high heat of southern Virginia, engine now has over a gallon through it, and top end is not bad but still struggling for even 6 minutes run time. I also blew a plug. I tried reducing throttle EPA but it runs dirty at top as soon as I do (I set to just see the carb slider even at full throttle using a 7mm Venturi. I played with a slightly richer bottom too (1 hour) as I temped up at 245 after a qualifier (8 minute qualifier). In the final today I then kept getting lean full tank bog at pitstops, had one flame out coming off pitlane turning downhill right into turn 1 and another where it ran but at walking speed from the pitspot for about 15-20 seconds, then a bit dirty for a lap then back to good. Tends to be nice and smokey certainly on low to mid throttle...I don't naturally blip but at times was struggling a little to get a snappy corner exit and found mid corner blips helped this.

So, basically now what to do!?

Specifically:

1. I need more runtime, at least another couple of minutes, I am getting 5 - 6 minutes where my competition gets 8 - 9 (and the experts even more)..my brain says that it MUST have been set rich hsn to break in, and leaning hsn would be the best way of reducing fuel use age too... But I am weary about that high temp and risking the engine.

2. It's not particularly crisp off corners, would like a touch more zip.

3. Why would the full tank bog only occur today!? I was pitting in qualifying due to runtime issues and it didn't occur at all!? I run a quite steep down loop on the gas like out of the tank, should I keep it high? Run a bigger gas line?

4. If as I suspect I need to get brave with the hsn and keep leaning an hour a run whilst checking temp and chasing runtime, should I make counter adjustments to lsn (richen) to offset? I assume idle adjust comes last?

5. Slightly random but it often bogs if you hold the car at say vertical by the wing while waiting to put it down (bogs but doesn't stall)...but it's fine on track, eg even when nose down off jumps or if upside down waiting to Marshall!? Not bothered by it but a bit odd!

Any help much appreciated!

Tune
 

[QUOTE=DaveG28;13399598]Hope you guys don't mind me giving you the "story" of my engine so hopefully some people can make suggestions of what to try next! It is the same engine I was asking about in the previous page!

It is an RB SLS5 that went into the car brand new during qualifying at Neo with just a quick box break in. Carb was setup by the rb factory guys and it ran the rest of Neo fine with a smooth steady idle, clearly rich but clean running, about 6 min tanks. Neo of course being a cool English low altitude spring.

Next to a club meeting in PA, didn't touch a thing, ran fine all day but still only 6 minutes runtime.

Through these meetings there was a slight tendency on track for the motor to stay on power a little as I came off the throttle, but nothing bad.

Next AMS, again even in the totally different atmosphere ran fine for MOST of the meeting...but as it had about a gallon through it by now was beginning to feel it may be time to chase performance, it was still definitely revving low and losing out on top end, smoke everywhere and in final qualifying sounded a bit unclean when flat on the straight. I leaned hsn an hour for the final and it felt a bit better but I lost a servo 4 laps in.

When I got back from AMS I decided to put a tank through on the box to check it all and then store how I normally would...and the idle would stay up high, 2 stage but even second stage being higher than before. (I live at sea level in VA).

I played around and richened lsn about 2 hours and slightly increased idle screw and got a nice clean low idle very quickly and an idle that could sit for a long time without stalling.

Have just done another meeting in a different car with a more compact manifold in the high heat of southern Virginia, engine now has over a gallon through it, and top end is not bad but still struggling for even 6 minutes run time. I also blew a plug. I tried reducing throttle EPA but it runs dirty at top as soon as I do (I set to just see the carb slider even at full throttle using a 7mm Venturi. I played with a slightly richer bottom too (1 hour) as I temped up at 245 after a qualifier (8 minute qualifier). In the final today I then kept getting lean full tank bog at pitstops, had one flame out coming off pitlane turning downhill right into turn 1 and another where it ran but at walking speed from the pitspot for about 15-20 seconds, then a bit dirty for a lap then back to good. Tends to be nice and smokey certainly on low to mid throttle...I don't naturally blip but at times was struggling a little to get a snappy corner exit and found mid corner blips helped this.

So, basically now what to do!?

Specifically:

1. I need more runtime, at least another couple of minutes, I am getting 5 - 6 minutes where my competition gets 8 - 9 (and the experts even more)..my brain says that it MUST have been set rich hsn to break in, and leaning hsn would be the best way of reducing fuel use age too... But I am weary about that high temp and risking the engine.

2. It's not particularly crisp off corners, would like a touch more zip.

3. Why would the full tank bog only occur today!? I was pitting in qualifying due to runtime issues and it didn't occur at all!? I run a quite steep down loop on the gas like out of the tank, should I keep it high? Run a bigger gas line?

4. If as I suspect I need to get brave with the hsn and keep leaning an hour a run whilst checking temp and chasing runtime, should I make counter adjustments to lsn (richen) to offset? I assume idle adjust comes last?

5. Slightly random but it often bogs if you hold the car at say vertical by the wing while waiting to put it down (bogs but doesn't stall)...but it's fine on track, eg even when nose down off jumps or if upside down waiting to Marshall!? Not bothered by it but a bit odd!

Any help much appreciated![/QUOTE

Throw the temp gun back in the bag and tune for sound , smoke, performance. I see far to many people tune to get a certain temp. I never check mine after break-in.

a 2 stage idle is usually a rich low speed needle and would kill your runtime

DaveG28 , I know this does not resolve your problem but I have had the following experience here.
I started sponsoring one of our front running racers with a 2013 BX with ceramic bearings (note not the BXR with rossi ceramic) whilst waiting for the new engines SLS DI5 and SLS 5 to arrive.
To start with he loved the BX and said it’s an improvement everywhere over the smoking gun that he was using.(I leave that upto you to decide which engine it is, popular here and the UK)
I then handed him the new range SLS DI5 and SLS5 same piston and liner but different crank. Response has been " pls give me back my old engine" though the new one screams they don’t produce more punch in fact I’m told less!!But are really quick on the long sections but races are not won on the straights so it means little, and fuel consumption is less.
Though perhaps European tracks are longer with less jumps so this is a better option but here the racing is done at 2000m above sea level and probably a mixture of US and European style tracks would be my guess.
We also had one carb issue and one bearing issue .It must be said that RB's response to any issue I have have had has been excellent and I don’t think any manufacture out there will respond they way they do .If something is wrong they take my word for it and they replace.
In the pursuit to move forward and this coming weekend will be the first to do so we will now run the BXR SLS DI5 with the SLS3 piston and liner in the pursuit of fuel consumption and to try and get back the torque that has been lost. If this does not work out to be any better than the 2013 BX with ceramics I will then change all my imports to the BXR LS5 which is in fact last years BX and listed as the entry level engine for this year .
Also the kind of consumption you are getting with the SLS5 is the same as we experienced and the consumption with the older BX(2013) was in the region of 9min at the altitude mentioned .
All engines were and will be run on the 2097 with medium header with 7mm restrictor,i have only ever had problems running a 6mm.

I will give feedback on our findings 18th of this month after the 3 national .
Also the above is my opinion and is formed probably under different conditions to what you would experience in Europe.

DaveG28 , I know this does not resolve your problem but I have had the following experience here.
I started sponsoring one of our front running racers with a 2013 BX with ceramic bearings (note not the BXR with rossi ceramic) whilst waiting for the new engines SLS DI5 and SLS 5 to arrive.
To start with he loved the BX and said it’s an improvement everywhere over the smoking gun that he was using.(I leave that upto you to decide which engine it is, popular here and the UK)
I then handed him the new range SLS DI5 and SLS5 same piston and liner but different crank. Response has been " pls give me back my old engine" though the new one screams they don’t produce more punch in fact I’m told less!!But are really quick on the long sections but races are not won on the straights so it means little, and fuel consumption is less.
Though perhaps European tracks are longer with less jumps so this is a better option but here the racing is done at 2000m above sea level and probably a mixture of US and European style tracks would be my guess.
We also had one carb issue and one bearing issue .It must be said that RB's response to any issue I have have had has been excellent and I don’t think any manufacture out there will respond they way they do .If something is wrong they take my word for it and they replace.
In the pursuit to move forward and this coming weekend will be the first to do so we will now run the BXR SLS DI5 with the SLS3 piston and liner in the pursuit of fuel consumption and to try and get back the torque that has been lost. If this does not work out to be any better than the 2013 BX with ceramics I will then change all my imports to the BXR LS5 which is in fact last years BX and listed as the entry level engine for this year .
Also the kind of consumption you are getting with the SLS5 is the same as we experienced and the consumption with the older BX(2013) was in the region of 9min at the altitude mentioned .
All engines were and will be run on the 2097 with medium header with 7mm restrictor,i have only ever had problems running a 6mm.

I will give feedback on our findings 18th of this month after the 3 national .
Also the above is my opinion and is formed probably under different conditions to what you would experience in Europe.

Are any of the RB plugs identical to the Novarossi C6TGC?

As far as im aware they are repackaged Novarossi plugs ,but I cant say im 100% on this.

I figured I would throw my hat into the ring after reading all negative on the stock BXRSLSDI5, as my modified version of it is possibly the fastest most powerful offroad .21 I have ever come across...This is the first engine I have seen where its so much faster then everything else that it can make a clean pass on our straightaway...It is nothing short of awesome.... has insane amounts of bottom punch end and then pulls like a freight train all the way to 42 000 RPM and somehow manages to get awesome mileage doing it.It is a fairly substantial amount of work to get these results that involves lowering the exhaust timing and raising the intake timing thus lowering the overall blowdown timing which gives the engine much better power and mileage..... Anyways I have been doing these engines for many years and this SLSDI5 is something special in its modified form...it is truly an awesome engine with crazy amounts of potential....

+ YouTube Video

Not convinced till I see quad single on back section... ;)

we are working on it ! :blush:

Hi Neil, pls don’t view my criticism as negative it’s really just the experience we had this side of the pond and to make the criticism cost me a shit load of money because I buy engines and give them away(to my driver) so every time the result is not satisfactory I feel it on my pocket 
I am glad you have found the sweet spot and have put the effort into the engine but I am comparing STD engines when making my critique. I am also not surprised you changed exhaust port timing as it looked aggressive but that’s only looking not measuring.
I still feel that after this weekend I’m probably going to come back here and say we going SLS3 or we going back to LS5 effectively last years BX.

Also the other stumbling block I have here is by the time the engine lands it retails for about the same as its competitors (os speed,Bullit 219 Reds) so having say you mod it before hand would kill the price.