Accurate weight anyone?

[Anonymous]

Has anyone here ever weighed there car for an accurate measurement? I'm trying to find out how much my '69 Mustang 250 w/ c4 weighs.

Also, any guesses on the horsepower numbers for my setup?

250 ci
D8 head w/ 3 angle valve job
CR is 9.5:1
Holley 350 cfm on Clifford Adaptor
6-2-1 headers ( http://mustangsunlimited.com/itemdy00.asp?T1=BA55+01 )
2 1/4" dual exhaust
Duraspark II conversion
Manual brakes and steering

Thanks all!!

 

[xctasy]

Has anyone here ever weighed there car for an accurate measurement? I'm trying to find out how much my '69 Mustang 250 w/ c4 weighs.

Also, any guesses on the horsepower numbers for my setup?

250 ci
D8 head w/ 3 angle valve job
CR is 9.5:1
Holley 350 cfm on Clifford Adaptor
6-2-1 headers ( http://mustangsunlimited.com/itemdy00.asp?T1=BA55+01 )
2 1/4" dual exhaust
Duraspark II conversion
Manual brakes and steering

Thanks all!!

About 3100 pounds. Engine was rated as 155 hp gross. In the later 66 variants, the 200 had 125 hp gross. In the gross rating, all engines are tuned to maximum power without the full exhast, air cleaner element, and a real cool, high pressure air conditions. If a 125 hp 200 has 67 rear wheel hp (85 hp net at flywheel) at the back wheels, then a 155 250 should have 83 rear wheel hp (105 hp net at flywheel).

1) electronic ignition improves drivability and low end torque, (0% less power)
2)headers add power (18% more at the very least),
3) especially with the low restriction exhast (6% more power by halfing the back pressure if the carb and ignition are tuned),
4) the later head gives a much higher peak power at lower rpm because the internal manifold profiles are actually very good (another 10%).
5) Bumping the compression ratio up from 8.5:1 to 9.5:1 (makes about 6% more power).
5) Finally, adding a better carb really helps all the above make a huge amount of extra power and torque.

The 250 now has all the fuel and air in the right places.

If each of these items are ideal in there settings (very unlikely unless its dyno tuned), then you'll go to 153 hp net.

Taht is about 121 rear wheel hp. We are find the little 350 cfm Holley is really able to give lots of power because the engine can make lots of vaccum through the carb.

Only thing is the engine is very undercammed. There is a super mild factory stock 256 degree camshaft with a small amount of lift. A set of aftermarket 1.6:1 rockers would wake it up, so would a FSPP 264 cam.

 

[Anonymous]

Wow, thanks for the in-depth reply!

How much more could I expect with the camshaft and 1.6:1 roller-rockers for my engine? And, I have NO clue when it comes to camshafts. Which one of Mike's should I look into? The car is a daily driver, but I still want as much HP as I can get! (I dont mind losing smooth idle and such) Oh, ya and its a stock converter and c4.

 

[xctasy]

One guy on this forum Mraley has a 200 cube Mustang that has been dynoed at 120 rear wheel hp with just a 350 cfm carb and well cleaned up D8 log head. It does run a split duration 260/270 cam.


The 264 cam is about it for the street with no modification to your transmission. There are other more savage items around, but the Does10's runs this little Turbo 250 Falcon which has about 300 hp.

The 250 could possibly handle a 500 cfm carb and a 272 or 280 degree cam, but there would be a mileage and low speed driveablity issues unless you spent about a grand on a torque converter, shift kit, and the bigger 4412 500 cfm carb. With your current transmission and carb, some kind of 264 cam and maybee a set of really good 1.6:1 roller rockers is the best choice. You won't believe how much low end torque there is in a 250.

(Torque is the twisting force felt every time you floor the throttle. Power is the rate or speed of change. The Peterbuilt truck verses the Ferrari. One luggs any load at any time with slow but sure increase. The Ferrari is gear sensitive, and the driver has to concentrate on having the car in the right gear. Americans generally need lugging ability for traffic jams and highway driving. Aiming for power will mean yu have to spend extra money on good gearing so you can exploit the extra power. On the street, a cam too big will up set you)


Just a note. The 250 is a long stroke engine, you can run a wilder cam on a 250 than a 200.


There is always 25% more torque with 25% more capacity if everything else is equal. With the power, the restriction is street gearing, stall rating and carburettors air cleaner. You can get 140 rear wheel hp with a 350 cfm carb if you have the right air intake and tuning. The difference is the cost of doing timing chain, sprockets, balancer, front cover gaskets, lifters, and an extra 1 k of work when its all tuned up.

The amount of power on a 250 is never 25% more than the same 200 cube engine. The peak power is 3500 rpm with the stock cam, 4500 rpm with the 264 cam, and 4500 to 5000 rpm with the 272 to 280 degree cam. Peak torque is about 1800rpm at the moment, 2800 rpm with the 264 cam, and about 3000-3200 rpm with the 272/280 cam. Each time you go up a cam profile, you loose that free and easy low end grunt, and gain heaps more higher up.


The existing combination should yield good mid to low 16 second quarter miles with no effort.

 

[Anonymous]

Ok, thanks for the help!

I think I'm going to go with Mike's "extended cam package" with the 264 cam with 1.6:1 rockers. But unfortunatly this is going to have to be sometime after the holidays :x and after getting the car painted :x and after buying some wheels :x and after finishing the upholstery :x this thing is never ending !!!!!!!!!!!!!!!!!!!!!!