Jaw dropping Evo engine build...

[Pistol Pete]

http://forums.bimmerforums.com/forum/showthread.php?t=1575817

Enjoy!

[Cle]

WOW :eek:

[Spudly]

Holy crap, i wanna see vids though lol

[Bubba]

O_O


fap



ah :)

[Edd]

And since a factory 4G63 block probably wouldn't hold up, just CNC machine your own from billet aluminum

loved that statement lol

[bazil]

fook me a rebuild every 120 hours!!!

scrap that read it wrong lol

[Bubba]

If you want a turbo, they'll build whatever you want, and their quad BB center sections are damn strong. GM's 1400whp Ecotec project used one of their 80mm turbos:

now your talking :d

[MK999]

Serious engineering, Be interesting to see what it revs to though, those conrods are obviously not made for seriously high RPM, yet the turbo is gonna need massive amounts of exhaust to spool up to 2000whp at 100psi

edit: doh, power graph on there duh. 8500, so not high enough to warrant beefy big ends on the rods.

[L14MNP]

Sad face.

[wwmnw]

Something was said about 12,000rpm, not sure if it will be taken that far but surely it wont be far off.

[MK999]

That was their NA motor. The conrods pictured I very much doubt would cope with 12k RPM, they appear to be built for massive compressive stress but very little tension. As edited in above though, 8500 seems to be it, just wind up the boost from there to hit their 2000 aim.

[Adam]

Very very nice.


LOL @ size of this turbo lol
http://img714.imageshack.us/img714/1755/dragcosworth3.jpg
That would suck up probably anybody in its path smaller than about 5ft 8 lol lol

[dhdev (Oli)]

Just read the full 30 page thread, they aim to make power by 11500rpm. Although it gets confusing as there are several builds being discussed in broken English :tard:
The engineering being employed is a joy to see, he's not just engine building, but engine engineering. I'm particularly enjoying his taste in expensive alloys :cool:

[MK999]

I'm loving the exhaust

"we seem to have an issue with bulkhead clearance"

"No problem :cool:"

edit: Just seen what Oli posted, 11,000 RPM on those rods is nuts! The big ends are way too thin for that surely, my 1.6 8v has thicker big ends I think Oo

[dhdev (Oli)]

That was their NA motor. The conrods pictured I very much doubt would cope with 12k RPM, they appear to be built for massive compressive stress but very little tension. As edited in above though, 8500 seems to be it, just wind up the boost from there to hit their 2000 aim.

Apparently they had problems with the MMC rods and they are set back by 6 months whilst they get a suitable material.

[dhdev (Oli)]

I'm loving the exhaust

"we seem to have an issue with bulkhead clearance"

"No problem :cool:"

edit: Just seen what Oli posted, 11,000 RPM on those rods is nuts! The big ends are way too thin for that surely, my 1.6 8v has thicker big ends I think Oo

They have extremely light pistons though, so the forces in tension are significantly reduced enabling higher RPMs.

[MK999]

Hmmm, why not just make them thicker to deal with the stresses, they do appear to me to be overengineered in between the ends, although I've never seen a set of 2000+ BHP rods before so it's hard to say just how much material you need to cope with that.

But the bottom of the big ends are where it will fail at high RPM, I realise they're running stupidly light pistons but it still looks a tad on the skinny side, unless it's degrading under heat it looks like a design rather than material issue to my lightly educated eyes.

edit, just seen oli#s post again :p and yeah as said above they still look a bit thin to me, stroke is also quite long still, so piston speeds are going to be relatively high.

[Bubba]

so...who would like to try and fuel this now :p

[dhdev (Oli)]

Hmmm, why not just make them thicker to deal with the stresses, they do appear to me to be overengineered in between the ends, although I've never seen a set of 2000+ BHP rods before so it's hard to say just how much material you need to cope with that.

But the bottom of the big ends are where it will fail at high RPM, I realise they're running stupidly light pistons but it still looks a tad on the skinny side, unless it's degrading under heat it looks like a design rather than material issue to my lightly educated eyes.

edit, just seen oli#s post again :p and yeah as said above they still look a bit thin to me, stroke is also quite long still, so piston speeds are going to be relatively high.

Where on the rod do you see as a potential fail point? I appreciate you say big end, but which part is the cause of concern, as surely the big-ends strength is largely based on the pre-loading of the joint with the bolt and the section away from the shank of the bolt seems beefy (technical term) enough to me.

[MK999]

High RPM engines normally fail snapping the 'caps' as the piston is thrown upwards on the exhaust stroke, and to look at it's possibly thinner in both directions than the standard rod. Extra material you mention may help prevent it splaying outwards.

Like so:
http://www.hrengineering.co.uk/conrod.jpg

I'm assuming the split right in the centre of the big end cap is your 'cause of death' if you like, crank has then come round after the piston rebounds off the valves etc and bent it back inwards, also bend the LHS bolt in that rather extreme fashion, snapping the upper side of the big end (there's not a lot of stress in that component otherwise) And you can also see the big end is elongated from the tension. So yeah, basically just like that lol

[burgo]

mark they are pretty much copys of cosworth F1 v10 rods which go to 18'000rpm so 12k should be a doddle. also that graph is of another evo which "only" makes about 1500bhp

[MK999]

Interesting, I'd love to see an FEA plot on them at TDC at 12k, I'm obviously missing something lol

[dhdev (Oli)]

Interesting, I'd love to see an FEA plot on them at TDC at 12k, I'm obviously missing something lol

He did actually post an FEA plot in the 30page thread, god knows what page on though!

You say that 'High RPM engines normally fail snapping the 'caps'', I'm surprised by this, I wouldn't have thought that the loads through that section would be that high. With the case photo you have shown, I'd have imagined the failure would've been instigated by failure of the rod bolt that is shown missing, with the ensuing opening of the big-end causing the bending of the remaining rod-bolt and fracture above it, with the cap fracture caused by the crankcoming back down on the splayed open cap. (hard to put into words a theoretical rod failure PMSL)

[MK999]

Remaining bolt is bent the wrong way for that though, and the whole rod is elongated, and both sides of the middle break are bent up but elongated as if it's been impacted after being elongated. So your theory doesn't account for all of the damage :p

All depends how thick the other sections are as to where the highest stresses are, can quite easily pass to that bottom section if it's the weak link in the chain around the bottom of the big end. I'd knock up a solidworks model to play with in FEA but this machine is due for some parts to be RMA'd so I wouldn't have time to finish it properly before its in bits for a while, and the laptop won't cope lol

edit: found the FEA, pure pot luck, pg11. It's just a generic rod though, but you can see in that the next highest stress to the are around the bolts is the bottom of the big end, and it's much beefier in relation to the bolt points than the other rods pictured.

[dhdev (Oli)]

Remaining bolt is bent the wrong way for that though, and the whole rod is elongated, and both sides of the middle break are bent up but elongated as if it's been impacted after being elongated. So your theory doesn't account for all of the damage :p

The bolt could quite easily have turned, I'm not sure how you can diagnose the elongation in the cap from the angle/quality of the photo and without knowing any dimensions, the bent up ends could easily have been produced post failure during the decel of the rotating lump that is the crank/rods etc etc



All depends how thick the other sections are as to where the highest stresses are
Hence why I was very careful to say 'loads' not stresses ;) I don't think the loads would be that great and hence (IMO) the section being thick enough that the stresses wouldn't be excessive.

All IMO obviously and I must say I am enjoying this informed exchange, certainly beats doing revision :thumb:

[dhdev (Oli)]

edit: found the FEA, pure pot luck, pg11. It's just a generic rod though, but you can see in that the next highest stress to the are around the bolts is the bottom of the big end, and it's much beefier in relation to the bolt points than the other rods pictured.
Good find and you're right, it does seem to be a generic/standard rod.

I'm gonna have to go girly and relate to colours as I can't make out the scaling on the stress plot:- the cap has regions of green (mildly stressed) and blue (minimal stress) I agree that in relation to the shank it is more highly stressed, but it still seems that the joint is the weak link to me with more yellowy/orange/red regions.

[MK999]

The bolt could quite easily have turned, I'm not sure how you can diagnose the elongation in the cap from the angle/quality of the photo and without knowing any dimensions, the bent up ends could easily have been produced post failure during the decel of the rotating lump that is the crank/rods etc etc

I'm assuming it pinging around around in the crank case and dropping into the sump wouldn't cause it to bend, and that it's impacted with the crank as it dropped back down in once piece still. like you say it's impossible to tell though, I'm just going for best guess from what I can see. By elongation I mean it's obvious 'ovalled' shape across the big end rather than any necking in the material etc



Hence why I was very careful to say 'loads' not stresses ;) I don't think the loads would be that great and hence (IMO) the section being thick enough that the stresses wouldn't be excessive.

All IMO obviously and I must say I am enjoying this informed exchange, certainly beats doing revision :thumb:

The loads aren't the highest but they are certainly high in that area, if you neglect to 'beef it up' at the same time as the area around the bolts it could well cause a failure. It does follow a "T beam" sort of shape so it's definitely designed to deal with stresses, I just wonder how well it actually does.

It does indeed, it's nice to have such an exchange with a fellow engineer rather than someone that finishes the first part of an exchange with "why do you always have to be right?!" lol


I'm gonna have to go girly and relate to colours as I can't make out the scaling on the stress plot:- the cap has regions of green (mildly stressed) and blue (minimal stress) I agree that in relation to the shank it is more highly stressed, but it still seems that the joint is the weak link to me with more yellowy/orange/red regions.

Indeed, but compare that to the very wide and shallow rods from first page of the thread on the BMW forum, it's a much less even shape that would pass a lot more stress into the very base of the big end.

[dhdev (Oli)]

Indeed, but compare that to the very wide and shallow rods from first page of the thread on the BMW forum, it's a much less even shape that would pass a lot more stress into the very base of the big end.

You're right that the ratio of cross sections does seem to be 'worse' in the upgrade rod, however, if the FEA is a standard rod to be used with standard weight piston, and the other rod is the upgrade to be used with lighter weight piston, then if the tensile forces are reduced the need for cap CSA is reduced and there is then the chance to save some weight.
Obviously this is all dependant on doing some maths to determine whether the decrease in mass offsets the increase in RPM, which I'm sure Spyros has done :)

[MK999]

You're right that the ratio of cross sections does seem to be 'worse' in the upgrade rod, however, if the FEA is a standard rod to be used with standard weight piston, and the other rod is the upgrade to be used with lighter weight piston, then if the tensile forces are reduced the need for cap CSA is reduced and there is then the chance to save some weight.
Obviously this is all dependant on doing some maths to determine whether the decrease in mass offsets the increase in RPM, which I'm sure Spyros has done :)

As you say it does all depend on the factors involved, after reading the thread he definitely appears to know what he's doing, I'd love to see the stress plots for the upgraded rods though :d

[dhdev (Oli)]

As you say it does all depend on the factors involved, after reading the thread he definitely appears to know what he's doing, I'd love to see the stress plots for the upgraded rods though :d
Just emailed him on his personal email and asked for a stress plot lol Did it from my uni account so that it is more likely to get a response ;) You don't ask, you don't get :thumb:

[MK999]

Nice one lol Do post it up if you get anything :d

[shed-on-wheels]

looks mint that does i cant believe what can be achieved when you have no object in your way but for many of us there will always bee somthing stoping us

[peester]

would ya look at that

[dj_wudgey]

thats mental!! loving teh vid off teh escort cossie aswell thats fast as fook!!

[NOV4_SPORT]

WOW thats proper amazing, can only imagine how good it sounds when it comes on boost, iam thinking a jet fighter lol.

Wouldnt it be nice to build cars with endless money

iain

[Jonesyboy]

might get them to build me and engine for my nova .....lol

[dj_wudgey]

would be ace if i ha the money to send them a nova and a let lol

[Pistol Pete]

lol they'd more than likely look at it, ask WTF and send it back lol

[dj_wudgey]

yea they probs would lol

[Danny s-p]

link to there you tube page ( look like they like a bit of street racing to lol)

http://www.youtube.com/user/ExtremeTuners#p/u/9/aMJA4W3VQmQ