I need power estimates, both hp and trq on my 351W build. Guy on another forum is saying my goal wont be met with this setup that I would fall 50 - 70 hp short. But here is the specifications

4.030" Bore
3.50" Stroke
5.956" connecting rods
Keith Black Forged aluminum 4.030" pistons 4 valve reliefs (11cc total reliefs) 1.774" Compression distance
World Products Man-O-War aluminum heads 200cc Intake Port volume 2.02"/1.60" valves 64cc Chambers (245cfm Intake @0.500" / 175cfm Exhaust @ 0.500")
Comp Cams custom grind hydraulic roller 230*/236* @ 0.050", 0.513"/0.526" Lift , 112* LSA 2000-6000rpm (its based off the 35-425-8 cam but changed to 112 LSA for improved vacuum for aftermarket EFI, leaning back towards 110 LSA for that choppy race sounding idle)
0.020" deck clearance
9.29:1 static compression / 7.574:1 dynamic compression
Edelbrock single plane highrise manifold - Pro-Flo2 Multiport EFI 1000 CFM 4bbl throttlebody with 29lb hr injectors (was going to send the 29lb/hr ones back and get the larger ones)

I dont know if this will have any bearing on the power of the engine but there will be a remote oil cooler as well as a windage tray, crank scrapper, and baffling in the oil pan (its standard on all pans from this company)

So what power output should this engine put out? 200? 300? 400? 500? more?

Just curious cause if it doesnt reach my goal I will be asking what I can do to improve the power without stroking. As I said in the other forum I am wanting as close to a 1.7:1 rod ratio to reduce cylinder wall wear and piston side loading. Yes this is going to be a engine used on the street as well as on a road racing course but I dont want to have to pull it in 50,000 miles especially considering the final cost I have for the engine.

 

I'm getting 400HP/400TQ with a 357 wearing World SR iron heads(2.02/1.60") and the Comcams 35-450-8 in DesktopDyno, your combo is similar so the results should be too.

What motor is the 35-425-8 designed for.. I don't see it listed. (P.S.. I see its a retrofit cam..ignore that question)
And just out of curiosity what are your power goals anyway?

 

how are you going to determine if the engine does not reach your goal?

are you going to take it to an engine dyno after it is built?

are you going to take it to the drag strip and make some 1/4 mile passes, weigh the car and then calculate what it makes to the wheels?

a 454 chevy has a rod ratio of 1.53375. well maintained, most of those last far longer than 50k miles.

it amazes me how people, many people, get all wrapped up around hp and torque numbers.

sounds like you have a plan in place and have already acquired quite a few parts. Move forward and then have fun with what you have built.

best of luck, cheers, claude

 

The car will be taken to a chassis dyno for final tuning after everything is built. I will get the Edelbrock EFI as close as I can and let them finish tuning the EFI on the dyno. I could do it by feel but that doesnt always mean things are tuned right.

The car is also not really being built for 1/4 mile drag racing, or drag racing to begin with. Its being setup for a street/track car that will see some limited uses on road course tracks.

As far as my goal goes, I was shooting for 500hp. I dont know what hp I would need to obtain and maintain the track speed I am wanting I keep getting different answers from different people.One told me I would need more than 400 hp to obtain 150 mph on a road course in the straight aways and another says I would need atleast 600 hp. Which doesnt make sense because the same car this is based off of ran 180 - 190 with just a 390 hp 289 so I am not fully sure I guess 450 - 500 hp would be the min I am wanting out of the setup.

In the end if it helps the vehicle setup will be as follows

2,500 lbs vehicle weight
TKO600 5spd manual transmission with 0.62:1 overdrive gear
3.55:1 detriot gear limited slip T-bird IRS

Might even go with a 3.27:1 rear axle ratio and bump up 5th gear to the 0.82:1 overdrive but I think 3.55 with the 0.62 is ideal.



I used the compcams cam selection program camquest and with the same camshaft above with a 110* LSA which is the off the shelf camshaft (comp recomended a 112* LSA custom grind on the same camshaft) it said something like 512 HP with the Man-O-War heads. I imputed the exact flow data for each valve lift from 0.100" up to 0.700" and it came up with 512 with the flow closest to the lift listed.

But I do know that desktop dyno can over rate or under rate engines. I had one way over rated and one way under rates. so its one of those things I take with a grain of salt but I am just hoping for 500 atleast considering the price I am looking at for this and I could get a 408 windsor stroker rated at 520 hp for roughly the same price already ready to go.

 

simple answer for a efi and hp is turbo and boost level that is safe for your build. i would think that would make a 400hp motor a 500-550hp motor maybe more if it can take the boost

 

with the information you have provided, rear end gear ratio, transmission ratio, along with tire size, i would calculate engine rpm and see what kind of number you come up with for 150 mph or what ever you feel your mph limit is going to be. a good guess is the 289 is spinning way more rpms and rpms and torque is what makes horsepower.

one thing i would consider is the shape of the torque curve, you want to maximize the area under the curve over the rpm range you plan on running your engine. peak numbers may be impressive but they do not tell the whole story.

the additional money i spent to have someone design my camshaft and valve train helped me to exceed my goals.

best of luck, claude

 

From what I can gather from those that have built motors based on software predictions, DesktopDyno is considered to be relatively accurate. I mean it all depends how much info you have about a combo and the more the better, but overall it supposedly produces a pretty good guesstimate. I know it does seem to produce more conservative results than some other programs.

As for your particular combo.. any reason you selected those heads? They seem to fall well short of what can be expected from a 200cc head these days.. which is 300/200cfm give or take. I think it will take heads with that much flow potential to reach you HP goals too.

 

Correct the 289 redlined around 8000 rpm, the camquest4 program showed a smooth curve building up to 527 hp @ 6,000 rpm with the man-o-war heads

from what the gauge is showing I am figuring the following which is estimates, doesnt have hp/trq figures on the bars or rpm`s.

2,000 rpm = 300 ft lbs trq / 150 hp (the graph is off but thats what I am seeing)
3,000 rpm = 380 ft lbs trq / 225 hp
4,000 rpm = 440 ft lbs trq / 320-325 hp
5,000 rpm = 496 ft lbs trq / 440 hp
6,000 rpm = 430 ft lbs trq / 527 hp
7,000 rpm = 350 ft lbs trq / 450 hp

Camshaft is a 2,000 - 6,000 rpm operating range. I just wished I still had the desktop dyno program so I could get more accurate figures over this camquest program.

Aside from that the car is very light so gobs of trq isnt what I really need especially with 3.55:1 gearing. I need more high end hp. But on the mph this is what I am showing

MPH-----1st Gear------2nd Gear------3rd Gear------4th Gear------5th Gear
30-------4,100rpm-----2,700rpm------1,900rpm-----1,400rpm------1,000rpm
60---------------------5,300rpm------3,800rpm-----2,800rpm-----1,900rpm
90------------------------------------5,600rpm-----4,200rpm-----2,875rpm
120-------------------------------------------------5,600rpm----3,800rpm
150--------------------------------------------------------------4,750rpm
180--------------------------------------------------------------5,700rpm
205--------------------------------------------------------------6,500rpm

Now given to maintain 150 I would have to turn just under 5,000 rpm in 5th gear (higher if I went with the more common roadrace overdrive ratio of 0.82:1 over 0.68:1) Like wise 120 should be very doable at 3,800rpm especially in a light car. 150 mph is actually my goal because I have heard numerous people state the 77-79 Tbird with the 351W under the hood and the 2.50:1 rear axle ratio (same as my cougar) would turn 130-135 bone stock and the factory rating is 145bhp and 200trq.

Other than that I am not going to road race competively just for fun but I am at a loss when it comes to this. I am just going with get all the power I can and disreguard the vehicle is going to have a completed weight of 2,500 lbs and that with 400+ hp just alittle more throttle in a turn can go from understeer to oversteer.



Now if I kept everything the same but opted for 3.27:1 gears out back with the 0.82:1 overdrive unit which has a 2.87:1 first gear over the 2.92:1 first gear used in the 0.68:1 model this is what I come up with.

MPH-----1st Gear------2nd Gear------3rd Gear------4th Gear------5th Gear
30-------3,700rpm-----2,450rpm------1,700rpm-----1,300rpm------1,050rpm
60---------------------4,900rpm------3,450rpm-----2,550rpm-----2,100rpm
90------------------------------------5,200rpm-----3,850rpm-----3,150rpm
120-------------------------------------------------5,150rpm----4,250rpm
150--------------------------------------------------------------5,250rpm
180--------------------------------------------------------------6,200rpm
205----------------------------------------------------------------------

Honestly I can get longer gears in 1st - 4th but fail in 5th with the 0.82:1 overdrive. Even at highway speeds of 65 is 2,300 rpm which is just under the 2500 ideal rpm for highway useage. Problem is 65 mph on freeway will get you killed everyone runs 85 - 90 here. So I would have to turn just over 3,000 for that in 5th gear where as my daily is around 2,500 at 75-80. Not sure if I would want a 0.68:1 od with a 3.27:1 axle ratio which nets me a 2.22:1 overall drive ratio where with the 3.55:1 with the 0.68 nets me a 2.41:1 almost equal to my daily driver which is 1450 lbs heavier with 145hp and still puts down 0 to 60 mph in 6.7 seconds.

So I think the first rpm chart is the one I am going with and as one can see I need power from 2,000 on up pretty much. Being a manual its no problem I can apply more throttle and keep the car in gear longer for city driving and the 3.55`s out back should help with city driving as well.

 

YearOne Online Shopping

351W / 400 HP Carbureted Engine at FordCobraEngines.com

Somewhere between 400 and 450hp, depending.

 

I'd go with more gear - 3.73 or 3.90, why not with OD?

 

I went with these heads cause they had more cfm flow than the cast iron windsor sr which is the same 200cc intake runner/2.02"/1.60" heads. They are also aluminum which would help with the 9.1:1 to 9.29:1 compression ratio I am looking at and enabling me to run something one level below 93 octane premium.

Aside from that I think the flow is "crappy" on these heads because of the lift of the camshaft. The camshaft lift is only 0.513"/0.526" which is 245CFM Intake @ 0.500" lift and 175CFM exhaust @ 0.500" lift. The max CFM for these heads out of the box are 291CFM @ 0.800" lift Intake and 190CFM @ 0.800" lift exhaust. I could possibly increase the valve lift by going from oem standard 1.6:1 rocker arm ratio to the 1.7:1

The Windsor Sr Heads are 244 CFM Intake @ 0.500" lift and 172CFM Exhaust @ 0.500" lift with a max of 255CFM @ 0.700 - 0.800" lift intake and 177CFM exhaust @ 0.800" lift.

So comparison is as follows

0.500----245/175 CFM I/E - Man-O-War vs 244/172 CFM I/E - Windsor Sr
0.800----291/190 CFM I/E - Man-O-War vs 255/177 CFM I/E - Windsor Sr

The max flow of the windsor sr heads are only 2 cfm higher exhaust wise and only 10 cfm higher than the man-o-war at 0.500" lift.

Now I would be open to other heads but they would have to be 64cc chamber and have large valves for high rpm breathing, as well as having everything situated just like on a OEM 351W head. No raised exhaust ports, ect. I am looking at $1,200 for bare Man-O-War heads so I dont know if I can get better for less but still be backwards compatible with OEM parts. Only reason it has to is cause the headers are computer bent for a oem 351W engine.

 

I seen some people went with 3.80 gearing and they said first gear is useless with gearing that low. You would basically shift out of first around 15 mph is what one guy said. Not to mention the light nature of the car being around 2500 lbs I dont think light gears would help with traction with a high hp engine.

But I have thought of that though on the lower gearing.

On that cobra engine I saw that one already, their a vendor for FFR. Thats why I am thinking if I am only going to make 400 hp out of this engine which I am pricing around $8000 for a complete build with fuel injection I could just buy one of their prebuilt engines rated at the same for less.

This is the one I really like.

http://www.fordcobraengines.com/427w_538cobraefi.asp

Just hope I can obtain 500 hp atleast without going with a extreme stroker windsor and for under $10,000

 

like i said, rpm and torque make hp, you want hp at higher rpms then your torque curve cannot be headed south, at least at not too quick of a pace.

also remember there is a time factor involved...on a road course if you are going 65 - 70 at the beginning of the long straight away, how long does it take to get from 70 - ??.

it sounds like you have done your research. i would get some help with the cam, heads and valve train, build it and then have some fun.

i agree, you should go with larger injectors, 36 or 42s.

i've never road raced, i'm a drag racer, so take what i say with a grain of salt. how much experience do you have?

cheers, claude

 

Thats why I am doing my research before I buy anything. I sure would hate to spend money then find out I have to use something else.

The brakes I think should be good their going to be wilwood manual brake pedals with a bias bar. Front is going to be 95 Mustang brake kit Either the Superlite 6R big brake kit or the 4R. Dont want excessive brakes up front and lock them up easily being such a light car, some are running the 6 piston brakes with the 12.88" rotors up front, I can also I will just have to go with a larger bore piston on the master cylinder for the front to bleed off some of the pressure and shift the bias towards the rear. Simple trial and error. The back are going to be 99 cobra mustang disc brakes 12.88 with a wilwood single piston caliper. Hopefully I am expecting to have brakes that are as good if not better than the donor kit that FFR built. Theirs is 70 - 0 mph in 183 ft. Their 0 - 60 mph is 3.6s, 0-100 mph is 8.2s, 0-130 mph is 14.2s. This is in their 395 cid fuel injected windsor block pushing 445 bhp @ 5800 rpm and 430 lbs ft @ 4500 rpm.

But that is where my issues are. My engine upgrade experiance is mostly regulated to either drag or oem. Not something like road racing. My 63 was built up for the 1/4 mile and I figured I wanted something more street friendly but just as fast if not faster. My choice was road course racing. The nice thing about that though is its not over in under 15 seconds.

I have zero road racing experiance as far as track time. Now I have pushed my mercury on the road and did some "performance" driving but nothing to the extent of road racing.

I just did alittle look up and found out that if I downsize to the 60cc aluminum heads AFR225 (havent found them on summit yet for a price or valve size) but at 0.500" lift they outflow the Windsor sr and Man-O-War heads. 295cfm/242cfm I/E @ 0.500" That is damn good considering the others were

0.500----245/175 CFM I/E - Man-O-War vs 244/172 CFM I/E - Windsor Sr

Given the smaller chamber size with the same pistons and everything else I am looking at a new static compression ratio of 9.684:1 and dynamic of 7.885. Now based off what I read up on dynamic compression this one guy in a forum stated that it is generally accepted that dynamic compression for pump gas is 8.25 - 8.5 max for iron heads. I could even increase the deck clearance from 0.020" to 0.025" with smaller 6.40cc pistons and bump the compression up even more to 10.067:1 static and 8.189:1 dynamic and I still should be safe to run the middle grade fuel with the aluminum heads. So if thats the case then I should be looking at more compression to make the power. I am actually losing power cause the exhaust valve closes at 62* ABDC (47* ABDC @ 0.050" + 15*) means the piston is already moving up and the intake valve is still open. Which bleeds off compression and power. So I am thinking I should be looking at the 0.005" bigger deck clearance with the smaller 6.4cc valve relief pistons to obtain 10.067:1 static and 8.189:1 dynamic. That should be good for atleast 20 - 40 more hp going from 9.29:1 static to 10.067:1



~Update~

It seems I should be looking at 57cc heads. 57cc heads coupled with the specs I had for 64cc heads nets me 10.005:1 static compression and 8.140:1 dynamic compression. Hopefully theres more heads listed on the ford head flow data chart I am using for 57cc heads. Those AFR225 heads are on summit for $1000 a piece just about.

Found these heads but dont have a flow data on them at 0.500" lift. They are pricy but I dont need the assembled heads, going to be using the valve springs comp recomends and rockers and studs so I will end up with the bare heads and have a local speed shop grind the valves for it.

http://www.summitracing.com/parts/EDL-51259/



~Update Update~
I came across some heads I liked, Aluminum, standard intake/exhaust port location (assume they mean stock location) 205cc intake port volume (5cc bigger than Man-O-War) that pulls 299cfm/220cfm I/E at 0.500" lift. Also $2,000 for a pair of them, only downside is the chamber is 65cc which will result in lower compression than the 64cc Man-O-War. Not sure if it would hurt to have a engine shop deck the head to bring that 64cc chamber down to atleast 58cc. Scratch that, I forgot to look up the recomended head gasket specs, was using the Man-O-War gaskets for compression figuring. with the 0.039" compressed thick gaskets at 4.100" bore is giving me 9.879:1 static compression and 8.040:1 dynamic. Not as good as 10:1 static but better still. Thats with the smallest 4.80cc valve reliefs which might interfer with a 2.02" valve and have to be notched.

But it seems this is the head and this head should hopefully put me atleast at 450hp.
http://www.summitracing.com/parts/TFS-51400010-C02/

 

I think you should invest in a program like DesktopDyno to help you select your parts, otherwise you're guessing and I doubt you'll get the results you want. The one big thing I saw when I modeled the combo above was that the TQ curve was pretty soft at lower rpms which is directly related to your cam selection, for a road race combo I think you would want an engine with a big broad TQ curve even if that means sacrificing a few peak HP to get it, because TQ is what accelerates the vehicle and that is everything in road course racing.