Raising redline

[KristjanS9K]

Hi! Is anyone familiar with high rpm's? What needs to be changed? As much as I have found out, crank and rod's are forged on a B202 engine. Whats the maximum safe rpm range for stock rods?
Hydraulic lifters need to be changed to solid ones. Which solid lifters can I use? What will fit inside?
Stiffer springs are a must.
Are stock cams also useless above 7000 rpm?

Any info is welcome. Any links with useful info is welcome.

Engine is a turbocharged B202.

Thank you.

[KevinC]

Without a turbo optimized for higher rpms you would not get the results you want, also might need fueling upgrades.

Easiest is to gas flow head and add stronger spings, that should take you to 7k if the rest of the timing chains are in good shape. With correct boost, fuel and ignition you can make huge power, easy 400+hp w/ 7k limit.

[KristjanS9K]

I'm already at 7000. Have a BIG turbo, tubular exhaust manifold, 3" JT, custom MAF, big injectors ordered 830 cc/min. Thats yesterday already

For the moment, 10 000 rpm redline is my dream. But that needs other conrods and stronger pistons also, that would be too expensive at the moment. I'm looking for cheaper replacements rightnow. (I don't mean cheap as shi*ty work or parts)

I need to find out, which solid lifters can I use in the head. I could also make valve pockets into the pistons. Never would have the problem of pistons hitting to valves (that with having Future in my mind)
Stock conrods will definetly stretch. So you can't go very high with these.
Anything else I should know?

Oh, by the way. This research is not only to tune the car. It's also for learning. I'm not the "usual" tuning guy, who just installs parts and goes on a dyno. My main object is to make myself smarter. Just thought I'd mention it.

[Sandro]

I was thinking about doing the same thing with my N/A motor. The thing I noticed was the horsepower and torque drops right after 5000 when ever I try to get it to 6000 rpm. I'm thinking a higher flowing fuel pump (not too sure about that one) adjust timing to withstand the extra revs, and keep the ecu in mind so try reflashing it. It would be easier for an early style distributor because they had the distributors so all you would have to do is change the rotor arm to retard or advance timing but I wouldn't sugest it.

[KristjanS9K]

Yes, but I have a DI cassette. The revlimiter can easily be changed. Rightnow I'm doing the solid lifters research. Mabye some car has just the right ones. I'll let you know.

[Norman Lovie]

speak to Dave at http://www.saabflight.co.uk/
he has previously built a customer car using solid lifters from another common car - sorry can,t remember what he used - and i,m sure the rpm target was nearer 9K
other than that i,d think short stroke 2litre with a bore out to go over square could be an advantage

[KristjanS9K]

Thank's I'll do it.

E: Can't find their e-mail. My english is also NOOOOOOOT so good when speaking. Can anyone else call

[Sandro]

Originally Posted by KristjanS9K

Yes, but I have a DI cassette. The revlimiter can easily be changed. Rightnow I'm doing the solid lifters research. Mabye some car has just the right ones. I'll let you know.

I would like that thank you.

[Norman Lovie]

try info@milllaneracing.co.uk
ask for Dave Greenwood in your mail

[KristjanS9K]

Saabs hydraulic lifter weighs 57 grams (45 grams, moving parts removed), in comparison to Saab VW Golf solid lifter weighs 70 grams and hydraulic weighs 80 grams. Very big difference. Mazda MX5 has solid lifters we could use MY99+. But I don't know the size (diameter etc).

Found also a very very good page containing DIY solid lifters. The cam grinding is also a very good and cheap idea.
http://www.fordlaser.com/viewtopic.php?t=44633

I didnt want to believe it at first, but it seems that we are dealing with lightweight lifters. Unbelievable A lot of tuning shops are selling lightweight lifters (no matter solid or hydro) what weigh about 50-60 or even more grams.

[John Z Williams]

I have talked about this before, there is a shop/tuner that makes lots of race cars on the euro side of the pond that has set up motors with solid lifters and a 9500rpm rev limit making 850bhp.

I am running 7300rpm on my holset super 40 and enem 264 cams with stiffer valve springs, heat p/p.

John

[Green9kAERO]

hello John,

Since When did you buy a holset. i thought you only used BB turbos?
anyhow take care.
JP

[John Z Williams]

Well, I have been thinking about it and talking about it for a little over a year when I saw how well they were performing and how cheap they could be bought and I finally put one on my ng900 with 9k motor and it actually outspooled my gt3076wg .86ar by a good 400rpm and makes a ton more power.

For those who may not have seen here is a teaser video before it totally destroyed my spec stg 3+ clutch

http://videos.streetfire.net/video/s...-40_640075.htm

John

[Boosted9000]

To rev an engine higher than stock there are many aspects to take into consideration, depending on how far you're planning to go. Most of the aspects have already been covered by earlier replies, however I'd like to add my .50 $ to the equation.

For a really high-revving engine as you describe, the conrods would need to be considerably shorter (lighter, usually meaning shorter) in order to get the mass moving at such high speeds. Long conrods and a 'stroked' setup make more power at the bottom to mid end, but the sheer mass of the rods and pistons would make it difficult to rev past a certain point. So what you need are lightweight rods, probably shorter than stock - however, be aware that shorter rods also means you'll sacrifice bottom end power for a more 'revvy' engine. Lightweight pistons (oversquare setup, as earlier mentioned) and a lightweight flywheel will also help keeping the moving mass down.

Also, to reach 10.000 rpm safely you'd probably need to blueprint the engine and knife-edge and balance the crank. You'd also want to consider a dry-sump setup and an engine oil designed for high revs, and looking into lightweight valve train components and removing all unnecessary auxillaries to reduce parasitic drag. Other things to consider would be and an improved ignition system and aftermarket ECU, water/alcohol injection and an upgraded gear box with teflon coated internals to cope with the increased tempratures at the speeds the engine and powertrain would be moving at.

Sorry for the long post - to sum it up: Less weight to move around = higher maximum revs.


-Levi

[KristjanS9K]

Very big thanks, that made it a lot clearer. I'm still searching for OEM solid lifters BUT, all the cars seem to have Shim On Bucket type lifters. The shim can fly off at high rpm. I think thats a dead end. I (you to) have to buy aftermarket ones.

[ls six]

Originally Posted by Boosted9000

For a really high-revving engine as you describe, the conrods would need to be considerably shorter (lighter, usually meaning shorter) in order to get the mass moving at such high speeds. Long conrods and a 'stroked' setup make more power at the bottom to mid end, but the sheer mass of the rods and pistons would make it difficult to rev past a certain point. So what you need are lightweight rods, probably shorter than stock - however, be aware that shorter rods also means you'll sacrifice bottom end power for a more 'revvy' engine. Lightweight pistons (oversquare setup, as earlier mentioned) and a lightweight flywheel will also help keeping the moving mass down.


-Levi

Sory dude but you seem to be confusing several basic concepts.

#1 con rod legnth and stroke are not related. Except in that "stroking" a motor with a fixed deck height may require a shorter rod just to fit the assembly in the block.

And you have your recomendations backwards, a longer rod exibits less "angularity". A shorter rod places much more load on the bore and in some cases have been known to destroy a motor.

There is a common acceptable range for rod/stroke ratios for high perf engines and it seems to be around 1.60-1.75:1.

#2 The stroke of a motor has no reasonable impact on where the motor makes power assuming displacement and all other variables are fixed. The idea that a long stroke motor tends to make "low end" power or torque is just a myth, Basic phisics bear this out as do real world observations.

#3 The mass of the rotating assembly has little impact on the ultimate peak RPM of the motor other than the effect of "diminishing returns" seen when materials are enlarged. It will effect acceleration of said mass.


Many of the suggestions posted up are good and realistic but the theories behind them are poorly understood.

[Boosted9000]

Before I start replying to your points there are a few things you need to keep in mind:
There's something called inertia, and basic physics laws point out that the inertia in a heavier object will be higher than the inertia in a lighter object. Try swinging a light household hammer around quickly for a minute, and then do the same to a heavy sledge type hammer of the same size - you'll notice this is not quite as easy, and swinging the heavier hammer around at the same speed as the lighter hammer will require quite an increased effort, and will at a high enough speed become impossible due to the weigh, or mass, of the bigger hammer. This effect is what we call inertia.

Also, friction is an important part of high revving engine design, but this I'll leave out of this response.

Originally Posted by ls six

Sory dude but you seem to be confusing several basic concepts.

#1 con rod legnth and stroke are not related. Except in that "stroking" a motor with a fixed deck height may require a shorter rod just to fit the assembly in the block.

And you have your recomendations backwards, a longer rod exibits less "angularity". A shorter rod places much more load on the bore and in some cases have been known to destroy a motor.

#1 I haven't said anything about conrod length and stroke being related other than they share the same properties of effectively increasing power. Longer rods increases torque all over the register but the increased mass of long rods and the distance they travel (determined by the length of the stroke) may keep the engine from revving as high as an engine with shorter rods, due to the inertia of the moving parts.

However, you're forgetting the laws of physics here:
Power = Work / Time = (Force x Distance) / Time

meaning:
Horsepower = Torque x RPM

and the important part here is the way which torque is created in an engine, which is a product of the force applied to the piston, the connecting arm between the piston and crank - the conrod - and the stroke length of the crank.

A longer conrod will effectively move the crank with greater force than a shorter conrod, utilizing the force on the piston to a greater degree, meaning more torque is created at a given RPM compared to the same setup albeit with shorter rods. This is the same basic principle as adding length to a prying arm, making it easier to do the same work - ie, more torque.

This leads me to my answer to...

Originally Posted by ls six

#2 The stroke of a motor has no reasonable impact on where the motor makes power assuming displacement and all other variables are fixed. The idea that a long stroke motor tends to make "low end" power or torque is just a myth, Basic phisics bear this out as do real world observations.

A long stroke motor, all other things being equal, will have less maximum revolutions per minute, as the increased movement of the piston, rod and crank will prevent the engine from being revved higher than a certain point - maximum piston movement. A longer stroked engine will create more torque at a given rpm compared to a shorter stroke engine. What I said in my post was merely that in an engine revving to 10.000 rpm you'd need shorter stroke and probably shorter (as i said in previous post - lighter, usually meaning shorter) conrods and lighter pistons, resulting in a sacrifice of low end power for high end revvability.

I think you just misunderstood my point - being that to achieve such high revolutions you'd need to go to shorter stroke, which will sacrifice power below the desired power band, in this case what we call low end power compared to the "high end power" which will be the desired power band at a high revving engine.

Originally Posted by ls six

#3 The mass of the rotating assembly has little impact on the ultimate peak RPM of the motor other than the effect of "diminishing returns" seen when materials are enlarged. It will effect acceleration of said mass.

The mass of the rotating assembly has massive (get it?) impact on the ultimate peak rpm of the motor, as we take inertia into account. As I explained earlier - increased mass, increased inertia. Less mass, less inertia. In an engine revving to 10.000 rpm we WILL need as little mass moving as possible in order not to blow the entire engine to smitherines. The heavier mass and higher speeds, the higher the stress on all related engine components, and the less the tolerances will be - and the higher the chance of blowing something to pieces.

Of course, in a perfect world we'd have super lightweight engine parts with no friction and we'd be able to rev the engine to 20.000 rpm without any stress on the engine, but alas, we're not living in a perfect world. Stock Saab engines were never intended to rev to 10.000 rpm, and as most of us know, the engine and its parts have been designed for that low-mid end power surge we all love and cherish. This makes reaching 10.000 rpm safely with a Saab engine much more difficult (and expensive!) than for example with a Honda VTEC engine, which has been designed for high engine revs from the beginning. I'm not saying it can't be done, I'm merely saying it takes alot of work and alot of money, and more things to take into consideration - amongst these being crank stroke length, conrod weight (and ie, length) etc etc.



To the thread starter:
What you really need to ask yourself is why do I want to rev my engine to 10.000 rpm?

I'll assume it's for making power. For an N/A setup it's absolutely nescessary to increase maximum revs to achieve power past a certain point since there are limited ways of making more air enter the engine, but for a forced induction setup there are other (easier and less expensive) ways to incease power than revving your engine to 10.000 rpm.

What power numbers are you looking for?


-Levi

[KristjanS9K]

Originally Posted by Boosted9000

To the thread starter:
What you really need to ask yourself is why do I want to rev my engine to 10.000 rpm?

I'll assume it's for making power. For an N/A setup it's absolutely nescessary to increase maximum revs to achieve power past a certain point since there are limited ways of making more air enter the engine, but for a forced induction setup there are other (easier and less expensive) ways to incease power than revving your engine to 10.000 rpm.

What power numbers are you looking for?


-Levi

I'm doing it because I love high revving engine sound (who does'nt). I'm planning to use a big turbo (I mean big) and I just need more revs. Right now 1 bar comes about 4500 rpm, that leaves me only 2500 rpm for accelerating. The engine for the moment is fully stock. Thats also the cause of the big lag/spool. There is actually no HP line, just build it and see how far I can get. Fuel must be benzine/petrol/gasoline, just higher octane. No E85 or methanol or nitromethane . I know the basics of engine building. H rods have ENOUGH strenght to withstand the high rpm. If you look, at some old cars with carburettors or distributors. Most of them don't have any revlimiters. And 8500+ rpm is no problem at all and their conrods are not high performance stuff. Only the valves or the contacts in the distributor are the only revlimiters then (that was a sh*t#y comparing). With aftermarket pistons and conrods it would be no problem. Why I did ask for solid lifters? Cause I was interested in them, I hoped I could find them on some other engine. But since all seem to be shim on bucket then it's not worth searching anymore. Also the hydralic lifter mod is IMO not a good idea. It will still be heavy and with extra moving parts what can cause damadge (maybe).

Some are coating the cylinders with nickasil, even the cast iron blocks. I assume this is because of reducing friction and the coating is also harder.

Maybe I forgot something

[Norman Lovie]

Ref: shim and bucket, you,ll only risk spitting out a shim if you also run nasty cams with an aggressive lob ramp - but - shim over bucket also = weight - typical mod. that solves both is - shim under bucket with a flat top bucket - now the under bucket shims can be found in many a motorbike etc - can be home made - just make sure they are asnug fit over the valve - and "THEY do
NOT hit the collets / spring retainer

Another point ref: higher rev,s = piston the bore clearance and ring design, you may want to think about honing out to near max piston to bore clearance - and go speak to some tuners about ring profile selection

ps rod length is just a piece of metal that joins the two bits together - crank pin offset does the strokin - adding length ( say by raising the small end height = reduced rod angle offset = a good thing - however it does add weight = bad thing = compromise - its all a compromise - but your using the 2litre with the smaller crank pin offset = good thing

Another thing I just can,t quite get my head round with these engines - but forsure you want ot think about it = crankcase pumping - as std there is not a lot of crank case venting - you might want to think about adding another vent - again - where ? needs some thought to get the best out of it

and last before I go have a dram - oil pressure - too much! need to watch for this is the pressure relief man enough when the pumps doing its dinger at 10K

[Norman Lovie]

right i,ve got a dram

valves - the 9000 valves are brick ****houses - the 9-5 valves have tappered smaller shanks but they do have a suspect strength
anyway - think about a narrower stem valve = gas flow improvment to boot - less weight - smaller shims - lighter springs
so then you need new guides - phosphour bronze - no seal type.