[74Xr7302]

i have a 71 302 looking to put a supercharger in top i have been suggested to go with the Weiand 77-174FSB-1. my question is if i run around 5-6 lb of boost on a stock engine will it be alright to run this set up i seen a post of someone running 15psi? on stock components, but idk about that, something doesnt sound right to me. im new to the whole supercharger thing, have a basic understanding of how they work, but thats about it.

here is a the info on the 1971 ford boat engine which is in my 1974 xr7.

holly 750cfm carb holly 0-33105 (4160)
edlebrock rpm performer heads 2.02 int 1.60exh 60cc Chamber, 170cc Intake Runner
edlebrock performer 289/302 intake
crane cam Duration 268/276, Lift .448/.464,
1.6 roller rockers
HV oil pump
stock fuel pump
3/8 rubber fuel line
ford racing tall valve covers
long tube headers 1 3/4 - 3" collector
MSD 6a ignition module
MSD coil
MSD plug wires
NGK plugs .50 gap
HEI pro comp dizzy conversion
c4 trans stock converter stall unknown
stock 74 cougar drive shaft and rear end. i believe its the 9" just not sure of the spline
14 X 10 cragar SS W/ Hoosier Racing Tire 17030QT
14 X 7 craggar SS in front
and adjustable air shocks in the back.

think thats about it lol.

 

[68xr7gt4spd]

i would not mess around without forged pistons. also check compression ratio.

 

[mopardon]

I ran a Paxton on a 91 Mustang GT. The kit went on easy and it ran real strong. No experiece with the Weiand.

 

[Bad69cat]

Do you know what the comp' ratio is? I doubt you could go 15 PSI on it as is if the rest of it is truly stock....the sealing between the block/head is a critical spot for one thing, depending on boost.

 

[cougarshaman]

5 lb is not a significant amount of boost. Not enough to warrant the expenditure for the blower setup, the tuning, and all the rest of the time and install, relative to the hp return.

Cubic inches are basically what superchargers add.
Take a shortcut and ditch the smallblock for cubes.
I'm not bagging on your choices either. It's just math.
Torque is what makes things happen in drag racing. The more cubes, the more torque.
An object at rest tends to stay at rest (starting line) The more mass (74 Cougar) to move, the more torque to overcome that and get off the line, then you have to accelerate. Once you start doing some quick times with a small block, you'll need an aftermarket block to make the kind of power that the vehicle weight and frontal area require to accelerate past, say, speeds of 130 or so.
When you do the math, that's more power than a stock Ford block can take and remain reliable. Boosted, even less durability. Too much stress and Ford windsor blocks will split right down the mains, taking nearly everything with them.
Also, if you want to hit the 13's or so with that car, you can do it cheaper with a 460, have a stock idle, and get OK mileage. A 302 with enough beans to launch that car near the twelves will be twitchy and need race fuel and a good tuner. You've already mentioned you're going to take it to someone to tune, so that's another good reason to choose good ole' torque over the lil' 302. The more mellow, the less you have to fiddle with it.

 

[cougarshaman]

A few years ago, CarCraft built a budget 460 that ran on pump 87 octane (!!!!) and made nearly 500 ft/lb of torque and almost 430 hp.
http://www.carcraft.com/techarticles/116_0008_87_octane_ford_460/index.html

Something to consider.

 

[74Xr7302]

not too sure on the comp ratio. i know stock for the 71 is 9.5-1 but my heads change that a little bit. and yes more cubic in is better due to less work, but the right 302 set up can perform very well, my buddy have a 347 roller motor, with over 650hp, blown,. im not close to that, but this if first round build, i want to grow with my car as it gets faster and faster, unlike some ppl i've seen race daddys car and crash the thing on the first pass. and hell im only 24 so i have quite a long time to reach goals with this car. im the 2nd owner!!! and it had 65k original when i got it. ive had it since 2003 and was my daily driver until last winter, when i decided to start making it the real deal. problem with the 460 is the only part i have for it is a crank. and a complete and functional 302 lol. so starting over on a new block before i get to enjoy this motor is not an option. ill build this one until there is nothing left to do to it, then take it out put it in something else, then start with a bb platform in the 74 cougar. and its not stock weight anymore. heavy weight reduction!!!!! only a hand full of wires left, only whats necessary to run the ignition. no alt, electric fan, even took out all of the bolts, screws, etc... that are not being used. bumpers gutted, shortned. anything i could think of, except fiberglass, cause i haven't found it yet. but as i digress i really thank ya'll for the great info, you guys never fail to impress, i have much to learn, and through trial and error, and a few good men, and parts, this 74 xr7 drag car in the making, will be tearing up the track in no time

 

[cougarshaman]

OK then.
My best advice for you is to build an anvil short block. Meaning: buy the best bottom end components you can so if the driveshaft blows, the trans pukes, or the converter balloons and fails, an overrev condition won't kill it immediately since you won't have a bunch of lesser parts barely hanging together at your shift rpm.
What that will do for you is give you a solid short block that will allow you to swap heads, cam, intake, whatever, as you want to increase power levels and get more cash to do that.
Using cheap parts and watching them barf onto a track because you wanted to save some money is a mistake we all make sometime. If you're on a budget and want to build in stages, you can't afford to buy cheap parts for the block.
Cheaply built 302 engines will blow to pieces just like anything else. In fact, they do it regularly.
Carnage and cautionary pics: http://www.yellowbullet.com/forum/showthread.php?t=275635 (caution: swearing and juvenile posts)

 

[Bad69cat]

X 2 to Andy's thoughts...I like the 460 thought myself. They aren't hard to come by and a $ for $ basis fugetabout it - the big block is the only way to go. Building a bullet proof SBF takes a bunch of work and dough.

 

[Smith Brother]

That Car Craft story tells again, WHY so many Chevy's have/are being used. Look at the statement under, DYNO-TEST.

I understand the Coyote isn't the first effort by Ford to attract more serious car guys/gals, I have been seeing more and more ads from Ford with other crate engines that spell, "WE ARE GETTING THE MESSAGE".

Dale in Indy

 

[cougarshaman]

Very true, Dale. Very true.

 

[mopardon]

With my 91 GT with Z code axle I had no durability problems and ran high 12s. Other mods were Headman Shorty headers and Hypertech Chip for supercharged 5.0s. Car was still running stong when I sold it to buy my 04 Cobra !

 

[mickp]

up to 6 psi boost would be the absoulute max limit on cast pistons. it is to easy to start detonation and crack them.
same goes for the hyperyoucrackedit pistons. (turbo owners name for them.)

i have and old original ray-jay draw through carb turbo that was mounted on a 351m.
this gave it good power considering the big vehical that it was in. and it was used to tow a big camper trailer as well.
it needed a water/alk injection system to help control detonation @4psi up to 6psi max.

if you are going to use this on a track or just like to step on it and let er run hard at boost then forged piston is a must.
in a blown app, build a good bottom and that will make the best foundation for anything that comes up in the future. you might change your mind and go without the blower but you would still have a solid foundation.

i like to push air under pressure in to small motors , it is a good power adder. but you need it set up for a blown app and it is not the same as a n/a engine.

for example: a cam shaft with alot of lobe seperation that would be the nuts on a n/a app would just allow all the air to be blown right out through the exaust on a blown app.
you need to be able to control timing advance so that when boost comes on the timing retards instead of advancing like it would in a n/a engine.

theres no replacement for displacement but you should see the look on there faces when i am door to door with half their sized engine.