[Guest]

The engine (E6 TM) now contains:
HKS forged pistons
Crower con-rods
264 cams, HKS GT 3040 turbine
HKS Steel cranck shaft
We removed the balancers from the engine. Engine capacity is standard.
We are planning to rev the engine up to 9500 rpm.
Anybody had experience with such settings of RPM? what do you think is the max safe limit (consideing the steel cranck shafts and so)?

 

[Guest]

No probs with yr bottom end using those parts , but there r two issues at 9500 rpm , lubrication system and valve gear.
Have u uprated the valve springs and retainers , replaced the hydraulic lifters with solids ?
Wise 2 check the lube system 4 scavenge problems at those revs , and u definately need a breather/overflow tank.

 

[Guest]

Original Post:
Crower con-rods

Have you got specs / temp ratings for these?

 

[Guest]

Claudo,
C the Crower web site 4 details , they offer a titanium version also ,very expensive but appropriate 2 a man of yr means

 

[Guest]

Why do you want to rev it that high ?? the power will have long gone by then. IMHO you are better off building large torque at low revs, this will be much quicker for general use.

 

[Guest]

orrrgh Kevin , I knew that , I just wanted 2 c wot it looked like when it blew up

Seriously tho , I agree , this is at turbo engine not an atmo so 9500 rpm is not needed.

 

[Guest]

C'mon, u are all low end rpm pussies as Claudius?
He drives his evo from 2000 to 6000rpm, do not want a bigger turbo because even if it gets 200 more bhp it will loose low end, and do not use his gearbox!!!

If u want to go fast u just keep the rpm at 7000, and if u don't who cares about low end?

 

[Guest]

Of course 9500rpm is needed.

If you want the huge power figures it is the only way to go.

2 bar boost at 9500 rpm will be much more powerful than 2 bar at 7000.

There is only 2 litres to play with after all. (OK - maybe 2.2 with a stroker kit)

If you set out to build an engine such as this then every day driveability is not what it's about.

 

[Guest]

Thanks for the replies.
Evoboy-
I have changed the valve springs and retainers. Do you know anyone who makes solid valve lifters? is that really needed? And what shall I check on the lube system?
T27...-
As much as I know, more rev mean more power. Especially with a big turbine, it will enable to spread the usable rpm range. I think an engine reving at 9500 rpm will produce more power then an engine reving at 7000 rpm.
Lightspeed-
The problem with the 2.2 stroker kit is that at this revs the pistons speed gets too high, so 8,500 rpm will be the max. I agree with you that huge power you need high rpm. it also spread the power band.

 

[Guest]

RoyBoy,
Hope u didn't mind my bit of fun

I don't know of any 9500 rpm redline motors 2 give direct advice , but 2000 rpm over the stock redline is substantial so the crankcase breathing will require attention 2 avoid excessive pressure , so a larger bore breather and a good sized catch tank , but also the oil scavenge might become a problem because of aireation of the oil caused by the much faster crank speed , this is an unknown until u try it.
Solid lifters arn't a problem , I'll post a source l8r.
Who is building the motor ?

 

[Guest]

I'd have thought there must be some maths/engineering involved to calculate max possible revs.
Increasing the revs on an engine must be a pretty common thing to do, there should be something knocking about somewhere that will put a bit more of a technical slant on things.

it should be ok for 9500 rpm wouldn't fill me with confidence if it was my engine we were talking about. Not that anyone here has said that, but often that is peoples response to these things.

 

[Guest]

Lots of Maths/Engineering (computer) analysis is possible – but very time consuming and expensive to do it properly. Probably cheaper to blow a few engines on the dyno than to calculate the all stresses in the pistons/rods/block/valvetrain etc.

 

[Guest]

Lightspeed,

I couldn't see royboy using your suggestion http://www.lancerregister.com/graphics/Wilk.gif border|EQU| 0 align|EQU| middle >
I wasn't talking about computer simulation and analysis, just something that takes into account piston speed, weight of pistons, crankshaft calcs etc, put them into a few equations or model and there you go. Something along the same lines as the spreadsheet you can use to calculate 1/4mile times.

There should be some documentation or book out there on engines that could be read without needing a degree.

 

[Guest]

I understand what you’re saying but in my oppinion it’s too complicated a subject.
I have a Masters Degree in Mechanical Engineering and my work involves predicting structural failures using computer analysis. There simply are too many variables for a quick *** packet type approach to be more accurate than gut feeling. For instance – Roy has new pistons, rods and crank. Without a complete laboratory analysis of the metallurgy of these components – ie. alloy, heat treatment etc. and a knowledge of their working conditions (ie. piston crown temperature) it is impossible to even begin an accurate calculation of the failure stresses. Modern car manufacturers spend millions on analysis and testing of new engines – tuners often have to work off gut feeling and blind luck. (Maybe that’s a little unfair!).

The Bosch Automotive Handbook is a bible (or koran for Moses) which has a lot of info including basic engine equations. Well worth investing in.

 

[Guest]

Lightspeed,
Hear wot u say , 2 much math spoils the fun

AnEvoGuy,
U mean things like calculating inertial loads (loads r proportional to the rpm of the engine squared , basically) then comparing those against say the tensile strength of the conrod, mean piston speed etc . I think u will find that most engine and component designers work with certain accepted mean values which r industry accepted then factor in some safety headroom. Unless they work in F1 where they do not accept ANY excess life at all , I know an F1 piston designer who if given a brief for a piston life of say 4 hours and supplies 1 that lasts 4.5 hours it will b rejected because it will also b 2 heavy !
Wot I can't understand with RoyBoy is why the question about the redline , the engine builder shud have pre-determined the suitability of the spec used.

 

[Guest]

Roy,

If you want to rev the engine to 9500rpm without a drop off in power at this high engine speed, why are you using 264 cams and not 272's.
Also have you modified the cylinder head so it is capable of flowing the air required. What about a different inlet manifold with shorter runners? Bigger inlet valves?

 

[Guest]

Evoboy
The engine is built by Prospeed from Sweden. They can not tell what is the absolute safe red line becuase they dont know. But, HKS in Japan run a similar spec engine, and did some tests (using several engines I guess). They claim that 9,500 rpm is ok to run. But I guess that until we try we will not know.
Clive
I use a modified inlet manifold, and the head has been ported. Valves have been grinded. Could not find bigger ones. Maybe I will visit Japan and come back with a suitcase full of goodies soon! you are right about the cam shafts, but we wish to try first with the 264 so the low end will be good. If on the dyno we see a major drop in power at high rev I guess we will take another try with 272.

 

[Guest]

Roy,
Wll Prospeed have a good rep , so it's a case of running up the motor gradually 2 c if there r any signs of distress from the valve gear , and any signs of trouble from the crankcase breathing system and lube system. Check oil and water temps carefully , but remember that if the checks r made with the engine out of the car , u need 2 check again when it is used on the road due 2 more variables.

 

[Guest]

It will not be safe to use 9500Rpm as the piston speed will be over 28 metres per second which will
give major long term reliability problems. We use 8000 Rpm max on the JUN Stroker kit which is the
safe limit and piston speed is only 25 Metres per second.

Also to give good power at this rpm you will need much wilder camshafts and bigger valve size.
I would suggest getting some stainless valves made and fitted for very high Rpm use.

Cheers and amp; goodluck

Simon

 

[Evolution]

Simon,
So what do you think will be the max safe RPM? I mean this is a 2.0 engine, with a shorter stroke then yours. So 9200 at least should be OK, as HKS Japan has noted, or? Thanks.