How are you going to get 200hp? Forced induction ?
With 2.1 liters, your only real avenue to 200 HP is revving the piss out of it (and having enough I/H/E flow to support it).
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How are you going to get 200hp? Forced induction ?
With 2.1 liters, your only real avenue to 200 HP is revving the piss out of it (and having enough I/H/E flow to support it).
I just assumed that he was going to bore it to 92 mm based on his question.
With 2.1 liters, your only real avenue to 200 HP is revving the piss out of it (and having enough I/H/E flow to support it).
It would certainly make it easier to make a fun-er-er engine..Moar Torax.
but not significantly change things I would suggest..i just don't get too fixated on XXX.z HP
And i don't fixate on motor alone...I say you can't talk motor without referencing gear-set and final drive, since we don't drive engines around, we drive cars.
The torque you can make with normal aspiration is limited, all you can do is get closer to a theoretical maximum. Room for improvement, but not a doubling or tripling like you can do with boost. Since you can't make a bunch more boost, you just have to improve on the other part of the HP equation, RPM. Torque is nice, torque at double the RPM is twice as nice.
And yeah, I'd say well north of 7000 rpm. Like the Honda S2K engines that have a 9000 rpm redline. You're probably not going to get a square(r) Volvo motor to rev like that (for long), but the higher the better.
I/H/E - Intake/Head/Exhaust. It gets increasingly difficult and technical to make it all flow effectively at higher RPM's.
I think we all get somewhat spoiled with how turbo cars make HP (just up the booooosts!), it's hard to get a really significant increase in HP out of a normally aspirated engine.
True - cars are systems. No point mating 200 hp to a 2.90 final drive if you were thinking of having fun!
What car is this B20 going in? What are you using it for? Enquiring minds want to know!
Since the OP is MIA and I'm familiar with the project I'll try to answer.
He has an early 142 that he's using for 'vintage rallies' that involve spirited driving on paved and gravel roads. It has a 4.30 rear end with a Tru-Trac LSD and he plans on using a T5 trans when the DeeWorks adapters are available.
The engine will be bored .100" over to 3.6" (2100cc) using forged pistons and rods. The F head will get oversized valves, hardened exhaust seats, dual valve springs, a mild port job and be milled to increase compression to 10.5-11:1. He's looking at cams with either .480"/280? or .510"/300?. He has dual DCOE's (45's I think) for induction. I'm not sure what the plans are for exhaust.
I told him to expect 160-175 hp realistically. 200 is a bit optimistic.
I was subtly saying the same thing. Peak HP is all about pushing the torque band higher and higher, and unless you can do the New(!) Improved(!) fancy fun things with cams like modern engines can (the Honda VTEC two cams-in-one, or variable cam timing, or variable intake timing separately from variable exhaust timing), like you said, it comes with tradeoff lower in the RPM range.Agree 100% we get spoilt by boost...but boost is about same volume engining making moare toque and by difinition more hp...the definintion of hp is torque x time --how BIG is the BAND= torque..How many BANGS in a unit of time= HP..Up the first and you up the second...
FLOW is nearly always talked about in PEAK terms and linked to "ability to rev" commonly.
But valves aren't instantaneous at full lift. Nor are engines run at 100% wide open...
The increasingly difficult part is also the increasingly 'spensive part...I've often just shaken my head when people fixate on peak flow at some max lift ---often way beyond what can affordably be pulled off in left and brag about another 5-8cfm at "14mm lift" when you see the flow flatten out at say 11.5mm lift... What % is 5 out of 175? Under 3%...
So is it worth $2000 more for 3% more?
Is it worth $2000 more in a head for 3% more peak---if the car still has a gearbox with canyons between the gears and a 2 car-length 1st gear that'll fall 40-50% revs on a gearchange Like WHAAAaaaaaaaaaaaaaaaaaaaaaaa(cruch!) DUHhhhhhhhhhhh
That is a big problem so little point in having a fap-fest about MAX anything...
(and that's why I look mainly at upping torque to make it so the motor acn "pull' the gearchanges without falling flat on its face. And peak HP be damned to some degree.)
Do what we can do and see how it feels and maybe that's all the guy really wants in the end.
I don't think 7000 is revving the piss outta sumpin..8000 yeah
And whats I/H/E? for us nervous novices??
What car is this B20 going in? What are you using it for? Enquiring minds want to know!
Since the OP is MIA and I'm familiar with the project I'll try to answer.
He has an early 142 that he's using for 'vintage rallies' that involve spirited driving on paved and gravel roads. It has a 4.30 rear end with a Tru-Trac LSD and he plans on using a T5 trans when the DeeWorks adapters are available.
The engine will be bored .100" over to 3.6" (2100cc) using forged pistons and rods. The F head will get oversized valves, hardened exhaust seats, dual valve springs, a mild port job and be milled to increase compression to 10.5-11:1. He's looking at cams with either .480"/280? or .510"/300?. He has dual DCOE's (45's I think) for induction. I'm not sure what the plans are for exhaust.
I told him to expect 160-175 hp realistically. 200 is a bit optimistic.
I had an S cam in the PV's motor for a while (until a lobe got chewed off, as happens occasionally with these things).
It was pretty fun, nice 'on cam' feel at 3200 rpm or so, pulled pretty well up past 7500. I have an Isky VV81 in it now, which is pretty similar to the S.
There is a noticeable (relative) lack of power under 3000 rpm though, but in use, that's really just a brief moment or two when starting out in 1st, from there on when you shift to a higher gear (when you're at least trying to accelerate quickly, anyhow), you're already over 3K in the next higher gear. That's with an M41's stock ratios, at least, but still, you're never in a dead spot unless you're just puttering along on purpose.
T5's usually have a sky high 5th gear. Trying to coax some EPA mpg's out of a lazy V8.