1145 replies to this topic

[Acidpopstar]

Can these saab engines (with mods) really rev to 8k safely and consistently? That's astonishing if so

[Kieran McC]

Mine revs up to the limiter at 7600

[ArticMonkey]

Can these saab engines (with mods) really rev to 8k safely and consistently? That's astonishing if so

Speaking to Vocky, with head work and valve springs, yes. They have sodium filled valves which can take much more than stock z22se ones. I doubt I'd continually rev it that high, might start at 7500 and see how I go. Easily changeable with the Dutch software.

Edited by ArticMonkey, 07 July 2015 - 04:56 PM.

[CHILL Gone DUTCH]

i rev mine to 7500 (2.2 saab ) without any issues i have reved it to 8000 but he gear change is awful so i have the limiter set to 7800 but dont rev it much past 7500

 

[fezzasus]

 

Can these saab engines (with mods) really rev to 8k safely and consistently? That's astonishing if so

Speaking to Vocky, with head work and valve springs, yes. They have sodium filled valves which can take much more than stock z22se ones. I doubt I'd continually rev it that high, might start at 7500 and see how I go. Easily changeable with the Dutch software.

 

 

The sodium filled valves don't really make a difference to the speed you can run an engine to, they're there to help with cooling so you don't need to run the engine as rich. This in turn helps with emissions (the reason they're in there) and gets a better fuel burn to generate more power.

 

The main benefit is moving to 2.0 L. So most people who have converted to 2.2 L have lost this. It's simple physics - the piston has to move faster the more you rev the engine. It gets to a point where the force at piston reversal is too great and will stretch the con rod. Moving to aftermarket con rods helps, but they add more mass, which adds more force at piston reversal. This just transfers the damage elsewhere.

 

Once you've got the piston speed controlled/managed, the next issue is valve bounce, dual springs help, but again add mass.

 

In theory dual springs should allow 8000 rpm, and uprated single springs top out about 7600 rpm. Personally, i'd set a limit 200 rpm under that.

[ArticMonkey]

 

Can these saab engines (with mods) really rev to 8k safely and consistently? That's astonishing if so

Speaking to Vocky, with head work and valve springs, yes. They have sodium filled valves which can take much more than stock z22se ones. I doubt I'd continually rev it that high, might start at 7500 and see how I go. Easily changeable with the Dutch software.  

  The sodium filled valves don't really make a difference to the speed you can run an engine to, they're there to help with cooling so you don't need to run the engine as rich. This in turn helps with emissions (the reason they're in there) and gets a better fuel burn to generate more power.   The main benefit is moving to 2.0 L. So most people who have converted to 2.2 L have lost this. It's simple physics - the piston has to move faster the more you rev the engine. It gets to a point where the force at piston reversal is too great and will stretch the con rod. Moving to aftermarket con rods helps, but they add more mass, which adds more force at piston reversal. This just transfers the damage elsewhere.   Once you've got the piston speed controlled/managed, the next issue is valve bounce, dual springs help, but again add mass.   In theory dual springs should allow 8000 rpm, and uprated single springs top out about 7600 rpm. Personally, i'd set a limit 200 rpm under that.

I doubt with a screaming harrop I'd need to see 7600, let alone 8000. I'd be happy that if ever entering that range it will still be ok on the engine. My main issue will be finding the sweat spot for power and risk with the stock internals. Some say 330, others say 350+. Both easily made with a harrop and pulley under 2.9".

[Nev]

Valve spring poundage and oil pump design are the 2 things that will limit that engine's revs. You usually have to dry sump from "around" 7750 RPM onwards with those 2 Litre oil pumps or you risk oil cavitation. Thickness of oil and oil temps obviously are a variable factor too. Nipper may have suffered from oil cavitation as I had an unusual big end failure and used to rev and sustain circa 8000 RPM. I have now programmed my hard limit to 7750 and soft limit to 7500 for this very reason.

Edited by Nev, 07 July 2015 - 05:41 PM.

[fezzasus]

I had an unusual big end

 

 

You're right highlighting oil viscosity. The OEMs are finding cavitation issues with 0W-20 fluids in standard tune. That said, they're using variable vain pumps so the ECU is changing the pump volume to a target oil pressure, so drop the oil viscosity and that target pressure needs a higher flow rate.

 

with the dumb pumps in these engines, it's a much less complicated story. I would say you would want to go the other way and thin the fluid, as too high a viscosity and you'll see too high a pressure, which will cause cavitation in the bearings.

[fezzasus]

 

 

 

Can these saab engines (with mods) really rev to 8k safely and consistently? That's astonishing if so

Speaking to Vocky, with head work and valve springs, yes. They have sodium filled valves which can take much more than stock z22se ones. I doubt I'd continually rev it that high, might start at 7500 and see how I go. Easily changeable with the Dutch software.  

  The sodium filled valves don't really make a difference to the speed you can run an engine to, they're there to help with cooling so you don't need to run the engine as rich. This in turn helps with emissions (the reason they're in there) and gets a better fuel burn to generate more power.   The main benefit is moving to 2.0 L. So most people who have converted to 2.2 L have lost this. It's simple physics - the piston has to move faster the more you rev the engine. It gets to a point where the force at piston reversal is too great and will stretch the con rod. Moving to aftermarket con rods helps, but they add more mass, which adds more force at piston reversal. This just transfers the damage elsewhere.   Once you've got the piston speed controlled/managed, the next issue is valve bounce, dual springs help, but again add mass.   In theory dual springs should allow 8000 rpm, and uprated single springs top out about 7600 rpm. Personally, i'd set a limit 200 rpm under that.

I doubt with a screaming harrop I'd need to see 7600, let alone 8000. I'd be happy that if ever entering that range it will still be ok on the engine. My main issue will be finding the sweat spot for power and risk with the stock internals. Some say 330, others say 350+. Both easily made with a harrop and pulley under 2.9".

 

 

and the GM build book says 300, but that's without under piston oil jets, which take away about 30-40 % of the piston heat. Factor those in and i'm treating 350 bhp as the hard limit, but aiming to be around 280-300 with my build, might be slightly ambitious, but we'll see.

[ArticMonkey]

I think you'll see that with no issue and a small pulley on the m62. Especially with the full 3" system and cams.

[fezzasus]

Hopefully, if events stop conspiring against me. after 12 months of faffing around with a house build, the cam belt tensioner in my vectra failed on the way back from collecting the exhaust.

 

Working cars = zero.

[ArticMonkey]

Hopefully, if events stop conspiring against me. after 12 months of faffing around with a house build, the cam belt tensioner in my vectra failed on the way back from collecting the exhaust.   Working cars = zero.

Same boat. Spent 6 months last year on my new house and have a wedding in 4weeks. Time is few and far between at the moment. It didn't help me having to send a major part of my car build back for refund. Putting me 4 weeks behind and counting.

Edited by ArticMonkey, 07 July 2015 - 06:56 PM.

[Graeme Lambert]

Hopefully, if events stop conspiring against me. after 12 months of faffing around with a house build, the cam belt tensioner in my vectra failed on the way back from collecting the exhaust.   Working cars = zero.

Same boat. Spent 6 months last year on my new house and have a wedding in 4weeks. Time is few and far between at the moment. It didn't help me having to send a major part of my car build back for refund. Putting me 4 weeks behind and counting.

4 weeks? Pffft

[ArticMonkey]

Hopefully, if events stop conspiring against me. after 12 months of faffing around with a house build, the cam belt tensioner in my vectra failed on the way back from collecting the exhaust.   Working cars = zero.

Same boat. Spent 6 months last year on my new house and have a wedding in 4weeks. Time is few and far between at the moment. It didn't help me having to send a major part of my car build back for refund. Putting me 4 weeks behind and counting.

4 weeks? Pffft

If you could spanner quicker, you would of saved 4 weeks.

[ArticMonkey]

Anyway, power figures please. Graphs can come later.

[Graeme Lambert]

Hopefully, if events stop conspiring against me. after 12 months of faffing around with a house build, the cam belt tensioner in my vectra failed on the way back from collecting the exhaust.   Working cars = zero.

Same boat. Spent 6 months last year on my new house and have a wedding in 4weeks. Time is few and far between at the moment. It didn't help me having to send a major part of my car build back for refund. Putting me 4 weeks behind and counting.

4 weeks? Pffft

If you could spanner quicker, you would of saved 4 weeks.

I won't bother disagreeing with that one. I will mention I haven't laid a spanner on it since August. 2014...

[Graeme Lambert]

Anyway, power figures please. Graphs can come later.

Ok, I still don't have my graphs or an idea what they revved it to but power at the crank was 325... So Vocky was right. No surprise there. I'm happy with that and excited about finally moving onto the next chapter of the build finally - bodywork

[gingerjon]

Nice one G, you must be well happy with that!!

 

GJ

[leevx2.2]

Well I've been told it was more G 😜

[Graeme Lambert]

Well I've been told it was more G �

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