Rb25-26/30's And Reliability?

[bubbabooga]

giday all

well iv currentlly got a shagged 25/30 in my cefiro which had been running for no more than 1000k's. After destroying a gearbox, tailshaft and trans tunnel i had the car sit in a mates shed slowlly getting repaired for around 9 months. Now the day i got the driveline drama's sorted and the car back on the road i stupidlly got a bit too keen driving it and managed to toast all 6 cp piston's. my guess is the fuel in the tank loosing some octane over the 9month or so period it was sitting their. every piston has major detonation on the intake side only.

Now iv gone to speak with a well known builder about replacing the pistons and told him its going to be for a track only car.

He seemed certain id be much better off building a 26 or 25 for a track car cause no matter what i done i would just keep f**king balancer's and oil pumps due to the rb30's stroke and crank harmonic's and their was no cure for it,

Im curious to know how many people on here are running 300kw+ rb30 hybrids in track only car's, wether it be circuit or drift and doing so reliablly?

im hoping i can keep the 30 bottom end as the cars already set up for it, but moreso i want reliabillity in the thing..

cheeers a heap

tom

[Zorro]

You could speak to Darren from Lewis Engines, hes just out of Adelaide & knows RB30's well! ph 85385154 or google his webpage.

Also, check out what RIPS has done with a standard'ish rb30 & the HighOctane time attack car!

Edited November 9, 2011 by Zorro

[JonnoHR31]

your builder doesnt know what hes talking about. find another one

[bubbabooga]

I wasnt to keen on naming names but darren at lewis is who i have spoken with as his shop is 10 minutes down the road from my place.

he assured me theirs nothing we could do to fix the rb30 problem, as when their coupled with a big turbo they rise threw the rev range to quicklly and have problems spinning balancers and oil pumps all the time.

my motor is currentlly running a twin scroll t04z but i had plans that once my motor was back on track to downsize to a smaller gtx turbo.

[Zorro]

hmm i dont think your getting the full story from Darren?

[bubbabooga]

Hmm what do ya mean? Like something he's not telling me? I thought maybe he might have been trying to get him self more work by having me start from scratch with a used 26 block off him? He was positive I would keep having dramas staying with the 30 bottom end...

[Zorro]

what are you using the car for, drifts, burnouts, circuit etc? What is your max rpm? limiter bashing? I believe the power curve ramp up is where some of the dramas are, as in a sudden vertical power graph (ie: gaining 200kw in under 1000rpm) can cause problems wth the oil pumps, but so long as everything is within tolerance, balanced correctly & your using a good balancer (ATI or ROSS & done up properly), with a quality oil pump, i cant see you having too many issues really, considering what other have done with rb30's! You could even use a block girdle to further reinforce it further (platinum racing offers these)! The problem with the oil pumps is common to all rb's really! Not sure how you managed to spin a balancer if it was done up right?

Darren is a very competant engine builder & is helping me with my rb30/25, we've discussed alot of these issues, it just seems strange that hes talking you out of the 30.

[The Bogan]

Balanced motor, Tomei pump, and Ross balancer, mine is limited to 7500 but I shift at 7200, the only problems Ive had was restricting the oil to the head, thats fixed now and Im loving the car, the down low power from the 30 makes up for the lack of high end revs I feel.

I am also running a TO4Z and making 355, 25/30, I must admit that Ive only had I day at the creek so far but it was run in for 400Ks then went to the drags on the SAU drag day which seen it have about 30 runs.

From what I understand you dont want to rev the 30 past 7500 if you want it to last.

Im loving the 30

Thoughts...

[jas/slo32]

RB26/30 9000rpm low 9's high 8's 5 year old oil pump (jun)5 year old ati balancer,stock girdle,stock crank with collar,arp main studs,good machinist & engine builder.

[bubbabooga]

ah good good just what i wanted to read..

at the time being the car is still road registerable so my plans where to fix the motor and drive it sensiblly on the road for a couple months or untill its defected then will be track only, for drift that is. maybe a dash of grip.

and just to note, i havent spun a balancer, thats just what darren was saying will inevidably happen if i stick with the 30.

alright sweet, i currently have a nitto pump to go on and ill get darren to organise and fit a ross drift balancer and a good sump.

im gooona cap power at 300kw till i learn to drive it at that level and the limiter will be set at 7500.

cheers guys

[D_Stirls]

Go speak to Rhemac

[r33_racer]

I would go to a different workshop. Its not going to spin a balancer or destroy a pump if the engine is built correctly.

If you are going drift/track work mainly I would definitely invest in a good harmonic damper and probs go external oil pump. Two main critical things since limiter bashing is no doubt what will be happening. Good tune too!

[bubbabooga]

alright sweet

when i went to see darren it was to have a bit of a look at the sump design he offers in the external oil pump kit's he sells.

he said even using that belt driven pump setup i would still have dramas. lol

might have a chat with rhemac's then.

cheeers

[bubbabooga]

yeah when i went to see darren it was to have a look at the sump design that he offers with the external oil pump setup which i was going to have put on also, but yeah then he tells me it wont fix the rb30's problems.. lol

think ill have a speak with rhemac's and see what they can offer in the wet sump external oil pump department.

cheeers

[bubbabooga]

whoops double post

[wads66]

One of the local drifters here in the west (borneo) runs a rb30det ceffy and has done for a while (gets thrashed sits on limiter all day). I asked about the build he said he went through a couple motors at the start all to do with oil issues but most of them still lasting a season or so. the latest motor has been in there for a few years with no problems, he said the only difference between the last motors and this was a dry sump setup. I would say for your street car no problems running standard gear but for a track car it might be worth the initial investment in a good dry sump setup or even a jun/nitto after market pump that way you can push your car hard without the thought in the back of your head that if you push too hard it will break.

[T04GTR]

speak to ross. he has a external pump setup in the pipeline. smash the limmiter all you want

[jangles]

the 3l shouldnt need to be revved as hard for the same results because of extra capacity obviously.

There are more non hybrid engines failed due to oil pump failure than RB30 harmonics. (obviously not as many about either, but enough)

as said, if it is built well, harmonics should not be an issue, especially for a 300kw motor, and up to 400kw because the revs are not (should not) be required anyway.

if the whole lot is all balanced, harmonics should not come into play. but that all depends on the budget also.

so many builders with great results as mentioned

[DYNOBUSTER]

Sorry but the harmonics have little to do with the crans balance.. the harmonics are caused by the defection in the crank when you make big power each firing stroke torques up the crank and then springs back.. The crank is a stiff mofo but it still twists and at some points in the rev range it hits a resonant frequency and the amount of angular displacement multiply s... It's still only a degree or two but it smashes oilpumps throws off belts and breaks balancers the point at which this happens is dependant on the mass of your rotating assembly the problem in our rb30's is the third order vibration with the node near the center bearing there are other modes of vibration but I believe that this vibration would cause the most angular displacement at the front end of the crank it happens at the flywheel too hence the loose flywheel there has been published journals by bmw loong a their straight sixes and they have gone all through it and aircraft in the old v 12(two straight sixes joined together) and ship engines all have thes e problems... And in ships and aircraft they just avoid those engine speeds bit hard in a car.. But I know for a fact that my rb in it's current form is resonant at 6800 or so because I have a solid center twinplate and the gearbox is hating life there did this on my phone so my writing is a bit retarded

Edited November 27, 2011 by DYNOBUSTER

[zebra]

The way i read that (had to do it more than once lol)

Is not so much harmonics, but simply bulk horsepower twisting the crank and causing failures (hence big $$ V8 race cars running $10k worth of billet crank)

I have always known harmonics to be related to Bore x stroke x rod length x pin height yadda yadda yadda

which at certain revs and load causes the harmonics.

As you say with aircraft engines, particularly some of the pratt and Whitney radials weren't to be operated between 1200-1750 rpm at low load (i.e on the ground) because without a heap of load on them the could and would shake themselves to bits.