Too Fast to Race

[Adam]

HP/L is useful for determining how un-streetable an engine is. An N/A engine with 100 HP/L is street able but one with 150 is less so. One with 200 HP/L is a race engine or impossible. Forced induction works the same way, but the thresholds are higher. I will site examples when I have a better keyboard than my phone.

[Adam]

My "streetability" rating is mostly made up, but here are some examples for comparison. It can also be used as a durability indicator to some extent as in many cases high-strung, high HP/L engines generally don't have the service life of engines which aren't built as crazily. These numbers need to be looked at during a similar time frame for context. The threshold for "streetable" in the 60's is different from that of the 2000's. I would argue that for recent power plants, 80-90 HP/L is about the point where you start making tradeoffs in streetability in the name of performance, although that bar is on its way up in the past couple of years.

Rounded to nearest HP/L:

Chevrolet L05 9C1 engine - 205HP(?), 5.7L = 36 HP/L
- Not a very stressed engine. Lots of low end torque, runs forever.
Chevrolet LT1 (2nd gen, cast iron heads) - 260HP, 5.7L = 46 HP/L
- Great street engine in stock form, lots of low end torque, GM stated 200K mile service life in a 9C1. Pushed the streetable bar up in its day (10:1 compression!).
Saturn LL0 (DOHC) - 124 HP, 1.9L = 65 HP/L
- Reasonable low end performance for a small engine (somehow). Runs forever. Terrible NVH.
Honda D16Y7 - 106HP, 1.6L = 66 HP/L
- Reliable for the most part, powers millions of normal Civics. Terrible NVH.
Chevy LS3 - 430HP, 6.2L = 69 HP/L
- Go to Chevy performance V8. Very streetable. Go-to crate engine for resto-mods.
Chevrolet LS7 (LS engine, not BBC) - 505HP, 7.0L = 72 HP/L
- Amazing engine. Not as streetable as other Chevrolet offerings from the same era, but moving the streetability bar up. Designed to run on racetracks at WOT.
Chevrolet ZZ572/720R (crate motor) - 720HP, 572ci (9.37 L) = 77 HP/L
- Designed as a drag racing engine, not too extreme to be in a street car, just. Modern take on old timey engine design.
Ford Coyote V8 (1st gen) - 412 HP, 5L = 82 HP/L
- OK street engine, requires revving for excitement. Lack of bottom end power make top end power more exciting.
Chevrolet LFX (as shipped in 2012+ Camaro) - 323 HP, 3.6L = 90HP/L
- This is really new so its moving the streetability bar up with direct injection and such. Very streetable.
Toyota 2ZZ-GE (Elise trim) - 190HP, 1.8L = 106 HP/L
- Works well in the Elise due to light weight, would feel pretty sluggish on the bottom end in a heavier car. Needs lots of revving for awesomeness.
Honda B18C5 - 195HP, 1.8L = 108 HP/L
- Barely a street engine, though it was a great race engine (if you keep it in VTEC range)
Honda F20C (S2000 engine) - 240HP, 2.0L - 120 HP/L
- The holy grail of "engine efficiency" idiots. Such a terrible street engine that Honda made it bigger and revised other parts of it to make it more streetable for Americans (same peak power at a lower RPM with 10% more displacement)
Chevrolet SB2 (NASCAR!!) - ~800HP, 340ci (5.57L) = ~144 HP/L
- 2015 rules will reduce the HP some to slow cars down. Hardly a street motor.
Formula 1 (pre-2014 V8) - ~750 HP, 2,4L = 313 HP/L
- They moved turbo V6's for 2014 (1.6L). These represent the least streetable N/A engines in the modern era. Or perhaps ever.

[kevm14]

Chevrolet LT1 (2nd gen, cast iron heads) - 260HP, 5.7L = 46 HP/L
- Great street engine in stock form, lots of low end torque, GM stated 200K mile service life in a 9C1. Pushed the streetable bar up in its day (10:1 compression!).

The F/Y-body version had 10.5. The LT5 was also very streetable but that came with a significant bill and complexity. 405HP, 5.7L = 71 HP/L. 11:1 compression.

Chevy LS3 - 430HP, 6.2L = 69 HP/L
- Go to Chevy performance V8. Very streetable. Go-to crate engine for resto-mods.

10.7:1 compression on these. As a note the 2005 LS2 also had 10.9. 400HP, 6.0L = 66.6 HP/L. These were far from racing spec engines. Aside from the CTS-V (06-07), GM also put them in the SSR and Trailblazer SS, complete with nearly 7000lb tow rating.

Chevrolet LS7 (LS engine, not BBC) - 505HP, 7.0L = 72 HP/L
- Amazing engine. Not as streetable as other Chevrolet offerings from the same era, but moving the streetability bar up. Designed to run on racetracks at WOT.

Actually, these do have one weakness: valve springs. The rpm combined with the valve lift is just a challenge for OHV. I don't know if this is solved or what the deal is.

[Adam]

Chevrolet LT1 (2nd gen, cast iron heads) - 260HP, 5.7L = 46 HP/L
- Great street engine in stock form, lots of low end torque, GM stated 200K mile service life in a 9C1. Pushed the streetable bar up in its day (10:1 compression!).

The F/Y-body version had 10.5. The LT5 was also very streetable but that came with a significant bill and complexity. 405HP, 5.7L = 71 HP/L. 11:1 compression.

Chevy LS3 - 430HP, 6.2L = 69 HP/L
- Go to Chevy performance V8. Very streetable. Go-to crate engine for resto-mods.

10.7:1 compression on these. As a note the 2005 LS2 also had 10.9. 400HP, 6.0L = 66.6 HP/L. These were far from racing spec engines. Aside from the CTS-V (06-07), GM also put them in the SSR and Trailblazer SS, complete with nearly 7000lb tow rating.

Chevrolet LS7 (LS engine, not BBC) - 505HP, 7.0L = 72 HP/L
- Amazing engine. Not as streetable as other Chevrolet offerings from the same era, but moving the streetability bar up. Designed to run on racetracks at WOT.

Actually, these do have one weakness: valve springs. The rpm combined with the valve lift is just a challenge for OHV. I don't know if this is solved or what the deal is.

I would say the street able threshold in the '90s was a little lower, around 70-80 HP/L. The LT5 would have been right at the edge. I should put in more engines from that era to see how things looked. The LS2 falls right in line with the LS3. As you creep over 70HP/L, the LS7 may have some adverse durability characteristics. Maybe the 2000's threshold should be a little lower.

To add in something more exotic, the Ferarri 458 makes 562 HP from 4.5 L for 125 HP/L. With its 9000 RPM redline, it has driving characteristics similar to the B18C5 above, although it is much newer. Pretty much a racecar.

Just to be clear, I love the idea of a racecar on the street and would totally drive any of the things listed above that are in the more "race car" category. Some people here do not share my opinion, which is fine. That just works out to be less people bidding against me in the event that I buy any of this stuff.