350 horsepower?

[350kmileford]

Do you guys reckon I could hit 350 flywheel hp with these mods?

200ci bored .040
dished pistons
Aluminum head "street/strip" headwork
Turbo'd to 15psi, intercooled
278/278 .492/.492 cam
DS II
1.65 rockers
Holley 0-80507-1 http://store.summitracing.com/partdetail.asp?part=HLY-0-80507-1&view=1&N=700+
Many other mods, these are the primary power-adders

If these mods won't do it, is there any other way to (without more boost or stroking)

Does the cam and rockers seem to match ok? Will this cam properly mate to the lifters and pushrods that come with the Yella Terra Full Roller Rocker Set?
http://classicinlines.com/proddetail.asp?prod=CSC-278-SST-10
http://classicinlines.com/proddetail.asp?prod=YTA-200-FRR

 

[Anlushac11]

Hmmm with the Aluminum head maybe.

Does 10's was hitting just past 300hp rwhp and over 500ft lbs torque with their system running 17lbs boost on their 250 I6. That was with a fully built log head. Not sure what numbers they are getting now with ported aluminum head and turbo cam.

The old setup was making about 1.2hp per cubic inch. That would equate to 240 rwhp on a 200.

Going by the 2.3L Ford turbo as a reference Im guessing you could hit about 285hp. With the aluminum head, 3" exhaust and LOTS more air and fuel (talking fuel injection or a 4bbl) you could probably hit high side of 350hp.

 

[LaGrasta]

no.

 

[Bort62]

Well, if Mraley's #'s are to be any guide, slap 15 PSI ontop of a motor making ~210 RWHP NA and you would be there easily.

That is ignoring a lot of details, of course.

There is always nitrous...

 

[Patrick66]

i think 390cfm might be kinda small.

 

[82F100]

PM Does10's with any questions. Not to dis ya' in anyway but 1st off whats is the intended main purpose of the build daily,cruiser, street/strip? They were getting about 348 hp at the tires if IIRC but that was in the upper 4k rpm range.

 

[LaGrasta]

to expand on my earlier short answer.

Torque is what you utilize with these engines. With that in mind, let hp fall where it may. As 82F100 stated, plan you chosen end result and build accordingly.

 

[MustangSix]

IMHO, the only route to go to achieve reliable, daily driver power at those boost and HP levels is to go with electronic engine management. You absolutely must control ignition and A/F ratios very carefully throughout the range. If you attempt to do it mechanically with a carburetor and a dumb distributor you will not be able to manipulate all the curves precisely enough. In order to optimize one small area, like peak power, everything else you do will be a compromise.

Yeah, you can probably build up something that will get you to the peak numbers you describe. But will it be easy to start? Will it drive as well at 1500 rpm as it does at 5000? Will it get 5mpg or 25 mpg at cruise? Will it pull hard all thru the entire band or will it have lots of lag then go off like a grenade?

EFI is not that hard and tuning it is certainly easier than tuning a carb. Using Megasquirt, its not that expensive anymore either.

 

[350kmileford]

I know about the Megasquirt kits, but what sort of kit could one obtain as far as controlled ignition goes?

 

[70stangcoupe]

to agree with lagrastas post. I dont think anyone on here is going to try to convince you that hp is the strong point of these motors. Torque is the stongpoint of the inline six and hp is just a byproduct of this torque. Torque is more fun, and useful, than hp on a street driven motor anyways.

 

[Bort62]

Torque is a measure of force, horsepower is a measure of work

You need to do work to move your car, so measuring horsepower is what makes sense.

Torque alone is a pretty useless #. Saying "X torque at Y RPM" is just saying "Z horsepower" without realizing it. It's like saying "I drove 60 miles in one hour" instead of "I drove 60 miles per hour"

If you have a motor that makes 250 Horsepower and I have a motor that makes 350 horsepower, we can get a pretty good idea of which will move the car faster without any other numbers.

However, you could have a car that makes 350 ft-lbs of torque and I could have one that makes 250 ft-lbs, but without RPM information, those two numbers don't mean anything.

These motors, and all other engines and motors of any kind, convert energy (chemical or electrical) into horsepower. (or watts for you silly metric types).

Saying you make X torque is exactly the same as saying your engine can spin to Y RPM. That information alone doesn't say anything about the POWER of the engine, which is what ultimately can be used to figure out how the car moves down the road.

 

[350kmileford]

OK let me ask this. I know that one can build their engine to have their max power be at a certain RPM. Does a 200ci favor a certain rpm? Lower rpm, mid, high?

 

[Bort62]

OK let me ask this. I know that one can build their engine to have their max power be at a certain RPM. Does a 200ci favor a certain rpm? Lower rpm, mid, high?

Here's the deal.

Horsepower is a product of Torque and RPM.

If you make X torque and Y rpm, you get Z horspower.

If you can shift your powerband up and Make X torque at Y+ Rpm, you will make Z+ horsepower.

Generally, Max Torque is the synonymous with Max VE. The two ways to make more horsepower out of an engine are to increase VE in general and to move peak VE to a higher RPM.

"Moving the powerband up" is moving Peak VE to a higher RPM. That means you make more horsepower for the same (or slightly less) torque.

There are two general factors that limit RPM. The first is the rotating assembly and valve train and their ability to stay in one piece. I don't think anyone here has ever thrown a 200 apart, so the mechanical RPM limit is probably quite high.

The other limit is the VE limit. At a certain point, there are no available parts that will allow you to push the VE peak to a higher RPM. Basically, at that point, you are maxed out.

In simplified terms, the cam generally selects where Peak VE will be. The rest (head, intake, carb, exhaust) determines how high that VE will be.

So, picking a cam that puts peak VE up at high RPM but using a restrictive head, intake, carb, or exhaust will keep that VE low, and as a result you won't make much power (over cammed).

So, basically you need to decide how much power you want to make - and then pick a Cam+Head+intake+carb+exhaust combo that has a max VE + peak RPM that satisfies that goal.

Of course, figuring out all of those values is the tricky part

Generally, the more horsepower you want to make, the higher RPM you are going to have to end up running. Once you hit around 100% VE, the only three ways to increase horsepower are 1.) More RPM 2.) More displacement 3.) More compression - pick whichever is easiest / cheapest.

Now, that is all in regards to peak #'s. What really moves your car is area under the curve, that is a more complicated discussion.

 

[falcon60]

Good post,Bort. That info is on target.

350K........The 200 engine tends to like low-mid rpm as a rule. The head is just too restrictive for high rpm use. IF you do really silly amounts of head work ($$$$$$$$$$$$) or buy the aluminum head/intake from Classic Inlines then you can raise the rpm level the engine likes,and HP will be much easier to make.
The alternate method is turbo/supercharger as you have mentioned of course. Even then a 350 HP target will be tough to hit without that aftermarket head,and a challenge even with it. If it were me I'd shoot for a 250 HP combination with a small turbo and concentrate on the 2000-4500 rpm range.That would be a real treat to drive.

Terry

 

[Bort62]

Let me paraphrase:

The only thing that "likes" a low RPM range about the 200 is the stock head.

If you get Mike's head, then that problem goes away and it is really the same as any other engine in that regard. Mike's head should support power up to and above 6,000 RPM - so it is basically a question of which cam you want to use.

 

[350kmileford]

Like I mentioned before, I will [eventually] be getting a worked aluminum head and turbo.

Now my decision is between smarter stoplight driverability or maximum rev power...

Since we are limited to intakes on the aluminum head, is there a specific RPM range that it performs best at?

 

[Bort62]

Like I mentioned before, I will [eventually] be getting a worked aluminum head and turbo.

Now my decision is between smarter stoplight driverability or maximum rev power...

Since we are limited to intakes on the aluminum head, is there a specific RPM range that it performs best at?

I don't think anyone has really nailed that down yet.

 

[350kmileford]

So I'll just keep asking questions here...

I think I have made up my mind to tune the engine for the most power to be from low rpm to midrange rpm.

I am debating between a 390 or 450 cfm 4 barrel carb. It seems like the 390 is the better choice, would you guys agree?

As far as cam goes, I will be using the 1.6 roller rockers, not the 1.65.

http://classicinlines.com/proddetail.as ... 274-HSP-10

Does that cam seem like an alright choice? Single pattern, duration isn't too high? Could I afford to go to 278 duration?

 

[Bobscoupe]

Since you want to use an intercooler you are most likely planning a "blow thru" system. Blow thru systems like smaller carbs. If you plan a "draw thru" system, not recommended with an intercooler, then use a larger carb.

I think a blow thru system with 15-20 psi, the new aluminum head, properly cammed and tuned, you will get close to the numbers you are looking for.

I don't think you can make a reliable daily driver and get those kind of numbers, unless you go with EFI as someone has already suggested.

The currently available head gaskets don't like a lot of boost but I understand Mike is working with a manufacturer to provide one to us.

 

[MustangSix]

I am debating between a 390 or 450 cfm 4 barrel carb. It seems like the 390 is the better choice, would you guys agree?.....

http://classicinlines.com/proddetail.as ... 274-HSP-10

......Does that cam seem like an alright choice? Single pattern, duration isn't too high? Could I afford to go to 278 duration?

Again, neither. I would not recommend a carb for a high horse turbo application that's shooting for 350 horses. Megasquirt controls both fuel and ignition, can give you full control over A/F at all loads and rpms, and will adjust for variations in temperature, altitude, barometric pressure, system voltage, and a host of other things. Even a TBI would be a better choice than a carb in this case.

The cam choice is ok. If you intend to turbo this thing, get a cam with a large LSA. EFI can even help a relatively hot cam feel a lot more docile since you can control the fuel even at lower idle vacuum levels. You don't get the potential puddling and fuel dropout issues that you have with carburetion at low speed.

Air inlet temps from an intercooler can vary greatly depending on boost, humidity, outside air temps, and speed. You can account for that and vary fuel and spark with EFI. With a carb you have to compromise and let it be.

No matter how you end up, the other thing you have to consider is how to get that power to the ground. If you have a manual trans, you'll definitely need to consider some sort of non-stock clutch arrangement. Maybe a dual disc. Then you need to look at the rear end. At 350 hp even an 8" is going to look puny.