When does an engine become a performance engine?

[gjm 3191]

I was doing some research on oil pumps. An interesting topic, for many reasons, and it crosses over into dry sumps, scavenging, aeration, emulsifying, reservoirs, multi-staging, and so much more.

One of discussion points was about when to use a better-than-stock oil pump, and the consensus was that the huge majority of stock, or mild performance engines, were fine with a stock oil pump under normal conditions. It went on to qualify 'mild performance' as "up to 550hp".

I suspect that as this was a US-based site I was reading at the time, that the writer was talking about 305ci (5.0 litre) V8 engines. (Or larger.)

By extension, this suggests that anything producing less than 100hp per litre is little more than a 'mild' performance engine, and there's perhaps some truth in that - high performance NA engines typically do have higher specific power outputs.

That said, it is only relatively recently that a NA engine producing over 100hp per litre has been sold in a production car. (I think BMW may have been the first to do this? In mass production, anyway.)

What thoughts do folks have? When does an engine become a performance engine? Is the absolute power produced (or torque) make any engine a performance one, or is it the case that specific power output - hp per litre - is the yardstick? Does forced induction move the line?

 

Edited December 14, 2016 by gjm

[M3AN 4015]

Yes, it was BMW with the S50B32.

Performance is relative to range. There a 'R' Suzuki Swift that matches none of the above criteria but it's still the "performance" model (and is quite fun actually).

But of course compared to any Ferrari the Swift would hardly be considered a "performance" car.

 

[KwS 2372]

3 hours ago, M3AN said:

Yes, it was BMW with the S50B32.

The B18CR Honda engine was a 1.8L making 200HP in 1996

[KwS 2372]

I think the Mitsubishi 4G92 Mivec pre-dated that too with 170hp from a 1.6L, somewhere about 1992.

[gjm 3191]

12 minutes ago, KwS said:

I think the Mitsubishi 4G92 Mivec pre-dated that too with 170hp from a 1.6L, somewhere about 1992.

Good call. 168bhp from 1597cc in 1993.

[M3AN 4015]

20 minutes ago, KwS said:

The B18CR Honda engine was a 1.8L making 200HP in 1996

Perhaps but that was after the S50B32.

14 minutes ago, KwS said:

I think the Mitsubishi 4G92 Mivec pre-dated that too with 170hp from a 1.6L, somewhere about 1992.

Well the BMW engine is recognised as reaching that milestone first. Is the 4G93 (GSR engine?) NA? 

Edited December 14, 2016 by M3AN

[M3AN 4015]

Can't see 100bhb/l here in NA form? 

https://en.m.wikipedia.org/wiki/Mitsubishi_4G9_engine

[gjm 3191]

2 minutes ago, M3AN said:

Can't see 100bhb/l here in NA form? 

https://en.m.wikipedia.org/wiki/Mitsubishi_4G9_engine

Under 4G92 - " Power output raised as high as 168 hp "

[BreakMyWindow 1870]

4G93 was the baby brother to the 4G63. Liked to throw a leg out with above 'mild' tuning. The 4g92 was the NA Honda B16a rival, the B16a which was released in 89' had an output of 99hp/litre. (Sorry Ron)

[M3AN 4015]

I was seeing 93 not 92,

That MIVEC looks interesting, I need to read more about it now.

[Allanw 1051]

Sorry... got you all beat:

 

Introduced July 1970: Daihatsu Max 360 SS - 40PS (39,5HP) from 360cc... of course it's 2 stroke :-) It was also detuned very early in it's production life, but it still was just over 100hp/l

I had 2 non-SS models, which were a bit less powerful.

 

[M3AN 4015]

This is actually quite interesting... Ferrari 355, for example, claimed 109 bhp / litre in 1994. But that's "claimed" and so were:

Honda : 175PS = 172bhp from 1590cc = 108.1bhp/l @7500rpm
Mitsu : 170PS = 167bhp from 1580cc = 105.7bhp/l @7800rpm

Both "claimed" (as far as I can determine) and there's much conjecture about their real specific power output (i.e. a lot of people say these claims are BS or that in testing the torque was so appalling it made the engines effectively unusable).

Apparently the S50B32 was "proven" to have >100 bhp / litre but it was (apparently) BMW themselves that "proved" this on a dyno to a UK publication. I can't find that publication or article.

Certainly I'd say the S50B32 is the most acclaimed and useable of all the engines that claimed >100 bhp / litre in the early days.

[Palazzo 427]

4th Gen 4aGE was quoted at 160hp from 1587cc in '91. 

'91 B16A Vtec, 125kw/166hp from 1.6 also.

[Michael. 2312]

I think it's also crucial to what chassis the engine is fitted into. 

Any high performance engine is going to be wasted if the car is too heavy! 

I think you need at least 150hp per tonne for something to start feeling brisk.

200hp-220hp per tonne is an excellent bench mark (Ie E46 M3 / E39 M5)

Anything over 250hp-300hp+ per tonne is getting crazy fast (especially if its a road car), but that seems to be what most performance cars are now days. 

[Michael. 2312]

Bike performance! Now you're really digressing  

[gjm 3191]

That's why I cited the engine originally...   My original thinking being along the lines of considering what are the requirements of, from or for a performance engine, rather than what contributes to a good power-to-weight ratio or a performance vehicle. (My wife's first car, an Opel Kadett C2 coupe with the 12S engine - 44kW, 1196cc - was sporty and great fun, but hardly performance.)

[aja540i 1896]

100Hp/ litre seems about right to me, but a performance engine alone is useless, 500 hp in my 1900 Kg M5 gives good performance, 215 hp in a 650Kg Fraser clubman also gives excellent performance , but a 215 Hp 2 litre Iitre in my M5 would be rubbish!

500 hp in a 650kg Fraser on the other hand.....

[hotwire 352]

Now we've got Ron quoting in old school measurements

[BreakMyWindow 1870]

10 minutes ago, hotwire said:

Now we've got Ron quoting in old school measurements

 

Oops.

 

Oh well, even monkeys fall from trees.

[Herbmiester 909]

I find the hp/L a bit of a of red herring especially in road cars. A performance car by default is all about power to weight. (Ignoring chassis for the sake of this discussion). So this is really only relevant if you are racing in a class that has a cc restriction. A performance engine could be considered any engine that elevates your cars performance without unduly affecting the weight?   Better power to weight yes sure I'll take that

If you pull up to the traffic light drag strip give it a go and lose, do you say to your mate "yes well I won because I make more HP per litre than him"? No I dont think so.

The measure should be HP per KG and HP per external volume. 

The classic NA engine for me is the GM LS series, specifically the alloy block versions. They are compact  engines so if the measure was hp per cc of external volume they beat the Euro V8s. The BMW's have more HP per litre but not necessarily more HP. What about HP per kg? Again the OHV LS engines do very well here? What About torque per kg. Hard for a smaller NA engine to win that race. The OHV design will reach its limitation when it comes to revs. 7000 is an upper limit for sure while a OHC design can add 1000-1500 rpm to that level and continue making power. The reality is that in road cars that RPM difference is more like 500 rpm. BMW made a 5l V10 that made 500 HP, GM made a 7lt V8 that did the same. The GM engine is smaller and lighter. (65-75lbs) with a lower centre of gravity. So I think that HP in itself can be the measure and as for turbos well that changes everything. 

There is a saying in sales; "We buy on emotion and justify with logic" Never is this truer than when arguing about engines. 

Armour bolted on flame proof suit fitted. 

Edited December 16, 2016 by Herbmiester

[coop 261]

6 hours ago, Herbmiester said:

I find the hp/L a bit of a of red herring especially in road cars. A performance car by default is all about power to weight. (Ignoring chassis for the sake of this discussion). So this is really only relevant if you are racing in a class that has a cc restriction. A performance engine could be considered any engine that elevates your cars performance without unduly affecting the weight?   Better power to weight yes sure I'll take that

If you pull up to the traffic light drag strip give it a go and lose, do you say to your mate "yes well I won because I make more HP per litre than him"? No I dont think so.

The measure should be HP per KG and HP per external volume. 

The classic NA engine for me is the GM LS series, specifically the alloy block versions. They are compact  engines so if the measure was hp per cc of external volume they beat the Euro V8s. The BMW's have more HP per litre but not necessarily more HP. What about HP per kg? Again the OHV LS engines do very well here? What About torque per kg. Hard for a smaller NA engine to win that race. The OHV design will reach its limitation when it comes to revs. 7000 is an upper limit for sure while a OHC design can add 1000-1500 rpm to that level and continue making power. The reality is that in road cars that RPM difference is more like 500 rpm. BMW made a 5l V10 that made 500 HP, GM made a 7lt V8 that did the same. The GM engine is smaller and lighter. (65-75lbs) with a lower centre of gravity. So I think that HP in itself can be the measure and as for turbos well that changes everything. 

There is a saying in sales; "We buy on emotion and justify with logic" Never is this truer than when arguing about engines. 

Armour bolted on flame proof suit fitted. 

No need for flame suit, valid arguement.

GM LS deliver in the real world with the added benefit of great torque, under stressed - longevity, and decent fuel economy. This is relevant to application of course but last time I drove a 6.0 Caprice down the Hume Highway it returned 8.2 l/100km average speed of 99kmh. 

high hp/l great to talk and admire over but no relevance in the real world apart from ringing the neck out of it from low torque peaky power delivery.  

 

[Herbmiester 909]

On 12/14/2016 at 2:21 PM, gjm said:

What thoughts do folks have? When does an engine become a performance engine? Is the absolute power produced (or torque) make any engine a performance one, or is it the case that specific power output - hp per litre - is the yardstick? Does forced induction move the line?

Actually Ron I think my dissertation answers the original question correctly. 

[E30 325i Rag-Top 2914]

Why use power? Torque is what makes the difference in terms of acceleration.

 

[Herbmiester 909]

Yes torque is what road cars need, always has been. As to KW/L yes it does indicate engine efficiency but not necessarily fuel economy, which by the way was not originally part of this discussion. I will say though HP/L in an NA engine is as much an indication as to how high an engine can rev, more revs more power but less driveability. In a road car gearing and low RPM torque have just as much if not more of a bearing. That said the Chevrolet Camaro with its 6.2L engine gets marginally better economy than a BMW M4 and it weighs 80kg more that the M4 and makes more power and torque. Performance wise they are almost identical. 

 

Edited December 16, 2016 by Herbmiester

[aja540i 1896]

So by this line of thinking a 1 litre engine making 150 hp at 10, 000 rpm is considered a performance engine , but a 2 litre engine making 150 hp at 5000 rpm is not? All of the factors need to be considered for a reasonable benchmark to be set.