How much HP and Torque?

[AzCoupe]

How much HP and Torque can I get out of a 200ci, naturally aspirated? How about a 250ci? Which is better? What would you do? How would you build it?

I am quized on these questions every single day. And they are rather difficult questions to answer. I usually answer with one or two questions of my own. First and foremost, do you have a budget in mind? And, do you want it to be streetable, or is it going to be a trailer queen?

The reasons are varied, but the answers are usually the same. Money is something they "work hard for", and a trailer is what "other people use" to pull their weekend toys. Keeping that in mind, just how much HP can be made? Will it be Reliable? Economical? Practical?

A few years back, 200-225 seemed like a fairly reasonable answer, and most were happy with that. But now days the big number seems to be the magical 300. Is it possible to build a 300 horse, N/A, 200ci, that will pound the blacktop day in and day out?

I know what I think, but I'm interested in what you think? How would you answer?

 

[xctasy]

Really easy.


Basic lower modification details abound in the forum, but to explore the wilder envelope, look no further than Super Sedan and Super Street engines in Australia.


Holden 202 I6 and Falcon 250 guys in Australia have done it all before, and the details on power curves are included in some of my posts.

Basically, for a 200 cube engine, Stage 3 would be 215 hp at 5800 to 225 hp at 6200 rpm is the practical limit for a streetable, non turbo engine. Your came could be 280 degrees total , or 215 at 50 thou. 4 or 5 speed gearbox, can't have a C4 past this level because it become impratical for the street.

Stage 4 245 hp is available at 6200 to 6500 rpm, if you use EFI or triple carbs, best head around and a bigger 290 degree cam with about 220 degrees duration at 50 thou lift. Four or five speed manual gearbox required

Stage 5 If you use Weber DCOE 45's and a 300 to 310 degree cam, 295 hp at 7000 rpm is possible with ease. 4 or 5 speed manual gearbox needed

If its 250, you only get 10 to 15% more power, because the engine can't rev as highly as the 200 without damage. Remember, its a big heavy crank with short rods and long, slender valve gear.


So Stage 3 250 becomes 245 to 260 hp at 5500 to 6000 rpm.


Stage 4 250 becomes 275hp at 6000 to 6200 rpm.

Stage 5 250 becomes 330 hp at 6800 rpm.


When you add turbo's, it gets very easy to get great power with low revs

 

[Leddemo]

Thats a good question. I've kinda been getting annoyed a little bit with how many times I've seen that question, because as you said, it really depends on soooo many variables.

300hp? I don't think that too far out of reach with a good CR and cammed out a little (for a 250 at least)

I rigged a 250 - 6 cylinder engine on a desktop dyno (I know, most accurate thing ever..) and I'm making just a hair over 250 with a moderately low cam, 252 int - 262 exhaust : .425/.450 : 112 lobe center : 112 centerline. With the flow #'s from the stickied thread up top, Chevy 305 piston dia., and picked a 600cfm - tuned port injection as the fuel delivery type (which maybe a little high?), 9:1 compression, Timing advanced 7°.

Switching that exact setup to the 200 crank throw it actually doesn't kill much of the HP off ~220-235 - it ate the torque curve alive though...

Can it be done? I think if you camed it right you could and upped the CR juuust a hair, it might not be the most streetable, but will probably do allright. Besides, there's still room to port it more

of course everything i've posted is computer generated, so don't take anything I've posted too seriously, there's no "real" data behind it.

*edit: Torque was at 306 Ft Lbs @ 2000RPM - 300 @ 4000 - ~245 @ 5500
^250ci

Torque was at 245 @ 2000 - 255 @ 4000 - 225 @ 5500, so a little flatter, but much less overall
^200ci

 

[Anonymous]

Is it possible to build a 300 horse, N/A, 200ci, that will pound the blacktop day in and day out?

To get 1.5 HP per cube from a 2 valve per cylinder, NA engine, you had better have you game on.

That's like building a streetable, 450-HP 302. I haven't seen vary many that could do that and be considered streetable. Less cubes to work with would be even worse!!

300 HP 200....Can it be done? Sure, but it won't be easy, and I wouldn't expect the average joe to tune it to that level. That would require the best flowing parts you could get and a serious dedication to getting it right on the dyno.

^ all this = a lot of $$$$$$

To be REALISTIC I would shoot for lower numbers.


Also...tell people to stop thinking HP numbers all the time and start thinking torque. A high HP car with no torque is not fun to drive. Torque makes a car fun to drive.

 

[69Falcon]

Also...tell people to stop thinking HP numbers all the time and start thinking torque. A high HP car with no torque is not fun to drive. Torque makes a car fun to drive.

Dang, Linc! You stole my thunder! I really don't care if it *only* has 200hp peak, if it *does* have a nice flat torque curve. I'd like to see a minimum of 200ft-lbs from 2000rpm to 4500rpm with a max of 250ft-lbs on the lower side of 3000rpm. Then match the top tranny gear, final drive gear and tire size so that peak torque rpm=75mph. Cruising with power and efficiency is what I'm after.

 

[Mustang Boy]

i would say no with the stock log head but with the aluminum head anything is possible

 

[AzCoupe]

You guys gave some great answers, but stopped a little short of what I was looking for.

stop thinking HP numbers all the time and start thinking torque. A high HP car with no torque is not fun to drive. Torque makes a car fun to drive.

Linc made a great point, and it's usually the first thing I cover. Which is why I ask if they are building a street machine, or a racecar. The two are very different animals, and require very different answers.

69Falcon did a great job by taking the above quote a step father, defining the true goal they should be seeking. Mid range power with a reasonably flat torque curve that peaks around 3000rpm.

a minimum of 200ft-lbs from 2000rpm to 4500rpm with a max of 250ft-lbs on the lower side of 3000rpm. Then match the top tranny gear, final drive gear and tire size so that peak torque rpm=75mph. Cruising with power and efficiency

The idea, is to build a motor based on usage, not simply how much HP can be obtain. And to build it as a cpmplete system to obtain the desired results.

Just about everyone agrees it will be difficult, but possible, and it will be expensive. However, some important question are still unanswered.

First, how expensive is expensive? Up to $2000, 2000-3000, 3000-4000, 4000-5000, over 5K, or more?

Next, and probably just as important. Will it be reliable, or a maintenance nightmare? Which also brings up another point. Why are so many set on keeping their sixes N/A? Are they just old school and leary of stepping up to better technology, or is it something else? And to some, N/A rules out EFI? To them, N/A = carburation.

Which is better for street use, a 200 or a 250. Or does it really matter? Can the differences be compensated for during the build?

What system would be the most reliable? Which would be the most economical (MPG)? Which would be the least expensive, ruling out boost?

I'm just tossing out questions, as food for thought. I know the answers I would give, but I'm interested in the opinion of others and what they think. Sometimes when your inside the box looking out, you don't see things the same way as someone outside the box looking in.

Our goals over the next several months, will be to seek out definative answers to these questions. We plan to build both, a 200 and a 250, with fairly mild blocks (keeping them main stream rather than exotic). Cast pistons, ARP bits and pieces, a good balance job, etc. Then test the various induction and cam packages, seeking that which 69Falcon so clearly defined.

The end result, will be similar to what Xctasy posted. Phased systems that are defined by usage, power, and price. Our goal is to remove all the guess work by, defining the various builds in detail, the resultant power expectations, and the approximated cost, for each individual system or phase. Its a lofty goal, but should be lots of fun.

 

[woodbutcher]

Very nice thread with good common sense questions and answers.
Leo

 

[69Falcon]

Thanks Mike, and I'll try to give a few more answers, at least for how I use my own car.

I prefer naturally aspirated. I've played with boost (see my website for my '88 RX-7 with a Paxton blower), and while fun, it is somewhat more tempermental. Which seques into...

I need my car to be streetable, dependable and at least semi-fuel efficient (20mpg highway). Its pretty much my daily driver, and riding my motorcycle to work in the winter flat out bites.

I would prefer to swap my existing 200 for a 250, because I sense, but have no real hard core data, that transmission options/swaps will be somewhat easier. Also the extra cubes and their related torque/hp are always welcome.

As far as a budget goes, pure guestimating on my part:
Long block (minus the head) - $1000
New head & intake - $1500
Fuel injection setup - $1500
Budget total - $4000

Yes, I'd like fuel injection. I'm thinking a single throttle body on a side mounted plenum with runners to the head. (On my Falcon, that would allow me to put a K&N style cone filter up near the radiator support, which has a few slits in it to allow cool air in.) Single tb would be easier to program/tune yet still yield good all around performance and mileage.

 

[LaGrasta]

My personal answer would be for a healthy daily driver. I'd want a 200 with as much hp/tq as I could get for around $3000 or less.
A small turbo is easy hp/tq, even with a less-than-200. So for me, it's a money thing. Where do I get the most bang for the buck?

Personally, I don't want to build an entire motor. That leaves me with the option of a standard rebuilt with some nice add-ons. My other preferable option is call Mike, tell him my goal and pay a fair price for a fair product. I get in return, a motor I know is built correctly and designed for my basic goals.

 

[jahearne]

I'm along the same lines as LaGrasta. I'd spend $3k and would want a reliable motor, streetable, one I can drive to LA and back with no issues. Sure I'd expect a tune-up to be more expensive and more frequent.

I would think $5k and over would be on expensive side of things and what I would expect to pay for a ~300hp inline six, but I'd imagine that motor as a package job not something we could put together in a month's worth of weekends. However, if someone just purchased a $24k Mustang off of eBay I doubt $6k for a unique motor wouldn't be an issue and that I feel would be a market segment that you would want to include.

200 vs 250. I'd go 250 naturally if it was for the lack of... let me put it this way, the 200 has more hi-perf parts readily available.

Once I finish my project, I'll get dyno tests, mileage, etc. I've kept all my reciepts, taken pics and what have you, but at the moment I can't help with more detailed answers.

 

[xctasy]

According to the Australians (care of StreetMachine's Hot 302's and 351's, and Hot 308's and 350's), there are three things to master when you do your engine up for more power



1) Be realistic. Tell the truth about the rev range you'r looking for. Know what you are aiming for. How much you spend is defined by how well you identify the final use of your 200 or 250. You must be able to say how many days a year your are auto racing, drag racing, or solely street driving it, or if its a mixuture of all three. Is it going to see trafic jams, or is it just a Sunday or weekend adrenaline pumper? Mixture cars which are supposed to be all things to different conditions are at best sad compromises. You'll find a 150 hp street car will be a better lasting enjoyment than a 330 hp street and strip car if your going to have to drive it to the drags.


2) The 'general gearing' must match the engine power and torque characteristics. V8 Engine builders in Australia say that over 1.5 hp per cube, a 3-stage auto car is impossible to drive daily, and you have to go to a 4 or prefereably 5 speed auto.

3) There are three tests to run on gearing calculations. Firstly, the diff ratio must be matched to ensure the automatic streeter has no 'hole' off idle to stall speed. If its manual, the overall first gear must suit the conditions of vehicle use. If its a race car, a close ratio Toploader will be perfect, on the street, a wide ratio T5 would be far better.
Secondly, the weight to cubic inches ratio defines the overall first gear required. Lastly, the final test is that the 2nd gear on a 3stage auto, and the 3 rd or 4th gear on a manual gearbox must reach maximum engine revs at the end of a quarter mile.

You can deal with anything else, if the car is geared right.



A. If the above three items are as close to prefect as possible, you'll find a 200 is more economical on the street than a 250 in most smaller cars. Cross over point is at the 3000 pound weight level. If the stock weight is over 3000 pounds, go the 250 every time. It will use less gas when its in a 3000 pound car than a 200. The 250 is easier and cheaper to get good gearboxes than a 200, and any 5.0 AOD or T5 25% over drive will ensure the open road fuel economy is 9% better than with a C4 or 1:1 4 speed Toploader.


B. The longievity of a 250 is longer than a 200, matching apples with apples. If it has to work 25% harder or rev 25% more to keep up, the 200 will wear more.

C. 200's in cars below 3000 pounds are the most economical (MPG)


D. The 200 is always the least expensive, (ruling out boost). Their are far more 200's than 250's, and you can puts stuff on a 200 which won't fit on a 250 because the height of the block and the engine bay limits having a great carburetor system. Any time your engine makes more torque, the whole drivelane must be rebuilt to transfer the power. Over 3000 pounds, a 7.25 or 7.5 or 7.625" diff will break if its got a strong 250, but it will last a long time if your 200 has an 8" diff.

 

[Anlushac11]

8) I drive a Fox body so my thoughts compare my car to other Foxes.

The 1985 Mustang GT had 210hp and 270ft lbs of torque.

The 1986 Mustang SVO had 205hp and 248 ft lbs of torque

The later 1993 Mustang GT had 205hp and 275 ft lbs of torque


If I go with normally aspirated I would be happy to hit over 200hp and 245 ft lbs of torque.

If I go turbo Im looking for 300hp and over 270ft lbs of torque.

 

[Profkirby]

When I had my 02 WRX it was rated 217 HP and 230 #'s ft. The car weighed around 3300 #'s. I believe most of these were around 175 wheel HP and as far as most people are concerned these cars are fast. That being said a 200 with an honest to goodness 200HP and 225ft lbs at a fairly low rpm in a relatively light car say 2700 to 2800 pounds will be downright exhilarating to drive. With fairly tall overall gearing milage should also be excellent. As for a turbo or blower, while it would be great it's cost may be prohibitive. You can build a nice bottom end for the money and headwork too. (I can't wait to see some results from the FSPP alloy head and what modern combustion chambers can do).
Fuel injection, also would be great. With modern head designs, ie; fast burn chambers, higher compressions, and proper fuel injection 1 HP or more can be wonderfully streetable with great fuel economy.... but, budget depending, a well set up carburation system can do amazing things. I do like an equal length intake runners though to keep A/F ratios as close as posible in each cylinder. This is one of the benefits of having an injector at each port.
My two cents, worth much less than that.

Tim

 

[Stubby]

That question brings to mind twenty other questions. I used to dread answering these questions.

1. Auto or standard?
2. Cruise rpm?
3. Auto, how much converter can you stand? Directly relates to cruise.
4. How much does the car weigh?
5. If we push this thing into the upper rpms will we lose too much torque?
6. This will require more than just the engine. Is the guy gonna buy the ignition and fuel system to support it?
7. Pump gas? I would say yes. (streetable)

I like the combo idea. We used to build what we called an RV motor.
Flat tops, ARP bolts, moly rings, mild cam with the block decked and honed with trq plates. From this base short block you could add just about anything within reason.

I had a Pure street combo that worked along the same lines. It was a short block, head package, assemble for extra with pans and other options. Track champion had one, so it was easy to sell. Also had a loner engine. The loner engine was loned to the competition more than once and it brought more customers.

After the dyno sesions with various combos I would install them and get some real world measurements. Or better yet, after you get some real world measurements with the combos that are being tested with the prototype heads, dyno these. I think the torque will show itself. I would even consider building a rental car for the big shows, with a nice drivable combo that could be used for the day.

 

[addo]

Much as people like to talk numbers, a little relativity would possibly help, too.

A good benchmark would be to outpower a factory spec K code 289 - with reliable (video if possible) dyno evidence. And dyno a bone stock six, too.

 

[Anonymous]

Which also brings up another point. Why are so many set on keeping their sixes N/A? Are they just old school and leary of stepping up to better technology, or is it something else? And to some, N/A rules out EFI? To them, N/A = carburation.

In my case, because there is no kits...just a hodgepodge of parts you either have to find in a junkyard (none in my area) or score off ebay or pay through the nose new...whereever you can buy them?

Then judging from other guys trials and tribulations you have to spend 3-6 months to get them built and dialed in and when you live in the midwest you only have 6-8 months of good driving weather anyways.

I like to drive my car in the Summer

As far as a N/A 200 goes talk to "Cometguy". He's ran a best of 15.30 @ 86 mph out of a totally stock 1 bbl carb engine.

In summary, the 2006 season was fairly satisfying. We ran a best of 15.30 at 86mph under ideal atmosheric conditions in October.

http://fordsix.com/forum/viewtopic.php?t=33499

Thats gotta be over 200 hp IMO. I ran a best of 16.30 @ 83 which puts my highly expensive and highly modified 200 in the 167-175 hp catagory.

I'd be happy if Mikes head and 4 Bbl would make mine run a low 15 high 14 second qtr mile!

Most everyone would be happy if there 6 could bust a 14.99 or slightly better in the qtr so shoot for that.....lotsa 60's-70's-80's cars running street brackets in the 14's and its a very respectable time to run.

 

[AzCoupe]

Much food for thought, and some great comments. Thanks for the awesome replies. Keep them coming.

2007 is going to be a banner year for us, with a lot of lofty goals. How much we actually get done is dependant on two things, cash flow and planning. Two of our primary goals, are improving the website (in progress), and setting up a shop/showroom. The shop will include an assembly room for building crate motors, and a service area to work on our company project cars. Eventually, we want to add a dyno room and purchase some basic equipment for in house machining, but that will be highly dependant on cash flow.

The new website is centered on educating our fellow inliners. The primary goal is to expand the tech section. This will be accomplished by adding numerous tech articles, as well as new sections for dyno testing & results, trouble shooting & servicing, performance tips, and Q&A. This is going to take assistance from forum members who are willing to assit in writting the various articles, or submitting information (such as dyno results). There are volumes of information in the forum, which needs to be condensed into useful tech articles. But that's going to take hours of hard work and good writing skills. However, the new website has a login feature, so contributing members will be able to log in for special pricing, as will previous customers. I won't go into the details, but basically there are five levels, which are based on previous purchases, and/or website contributions. The higher the level, the bigger the discounts.

We also want to add a photo gallery and free space for personal websites where members can feature their rides. I'm still looking into the various options, but it should be pretty cool.

Anyway, thanks for all the awesome replies. You guys are great.

 

[Mustang Boy]

wow looks like 07 is gonna be a big year for u guys and i cant wait to see it all come into effect cause this is really gonna help our cause of making the I6 a respectable motor


and it sounds like u guys r gonna have quite a shop over there i can only hope to be able to stop by one day when its done and have a look around

 

[ludwig]

Sounds like you are working on a performance 'kit' or stepped upgrades. Or maybe I can lobby for stepped upgrade packages, since you are talking that way. 1) bolt ons; 2) cam, valves, whatever; 3) full-on wow.

Have you thought of a F6 crate engine? I mean, people are still paying big bux for those Clifford milled performance heads. You have the start with your new head.