Cleavage upgrade.

[PRO250 1,506]

 

 

why would it matter what stroke it has to make hp? :S torque yes but not horsepower.

430hp was in the high end, well setup motor, dialed in cam, all top quality componentry etc etc, this motor definitely wasn't just slapped together, Dave at AFD has seen similar figures with that cam and his heads also that cams coming out of that motor now apparently anyway, just sold him my camtech hyd roller very curious to see how that goes!!! (if it pulls what it should pull, im buying another one lol)

as for MPH and time slips, unless your perfect you wont get anywhere near the slide rule.... weight, tyres etc all come into it as well.... btw if you're making 320hp at the tyres, thats at least 400hp at the crank.... most drivelines will see a 25% loss of power. especially ancient technology drivelines like ours....

agreed, stock cast heads would not make 430hp, should still crack close to 400hp i reckon.
either way, stick a nitrous plate on it and have some fun!

btw definitely agree, should see a big kick up the ass from the old cam to this one!

How does a bigger engine not make more HP as well?
a slide rule will tell you heaps. pocket dyno and for 8 bucks its worth looking at

Mine would not make 400 at the crank no way just looked on a racing calculator it has about 360 370 hp for 3000 pound car running high 11s and 118.8mph its funny my ETs a real slow for the MPH it runs but its geared for the road not the track

A real 400 hose in a corty would see much faster times . i go racing with a bloke thats now in the 10s with a 4k slapper engine and only 302 cubes and makes 385 on the engine dyno his car weighs less then mine but is very well setup, mines a street car not a full track toy like his. for a idea stu my engine went 12.6 in a full body falcon with a FMX and 3.5 9inch on street tyres never seen a set of rollers but has been around a while and you work out what works and what dont by seat of the pants feel.

Im not in NSW stu but good track the creek i lived there most of my life even old enough to say i raced on the old track, i remember the dip at the top of the track buzzing over that at 180+kmh can scare you if you dont know its there. take some pictures when your there and tell us how you went

[Stu5766 394]

No worries mate, it's just the drag strip I'm going to, not the full track. But I'll defiantly give you done feed back. Might takes done dizzy springs, timming tight and jet kit with me.

[Trev Vaa 1,185]

How does a bigger engine not make more HP as well?

a slide rule will tell you heaps. pocket dyno and for 8 bucks its worth looking at

 

increasing stroke (from 3.5" to 4"") does not increase horsepower, it increases torque, if you went from a 4" bore to a 4.5" bore you would see an increase in both HP and TQ.

 

this is why changing diff gears from 3.25:1 - 4.11:1 changes the quarter mile time, it increases the torque going to the wheels, torque = ability to pull weight, this is the same theory as increasing stroke on an engine.

 

agree the slide rule is a good tool, and if you can get perfect shifts, perfect launch and perfect traction, it will be accurate

its VERY handy, don't get me wrong, i have one myself (somewhere, need to find it actually and see what the XY should be pulling)

 

definitely take a tuning kit with you Stu, never go down empty handed when you plan on improving the car, you would be amazed how much a bit of tinkering to change the setup, i remember watching Ronny go from running a 11.2 in his BB XE to a 10.5 the same day, he spent most of the day tuning in between runs, got the results thats for sure!

[FORD_MAN 1,026]

trev just saying, a 302c makes the 20hp less than a 351c and a 200 xflow makes 20hp less than a 250 xflow.

I'm sure that has nothing to do with the stroke.

and 3.25 to 4.11 diff gears is more a fact of total of the gear multiplication since a C10 is 1st 2.46:1 2nd 1.46:1 3rd 1:1

so total final gearing

3.25:1 diff 1st 5.71 2nd 4.71 3rd 3.25

4.11:1 diff 1st 6.57 2nd 5.57 3rd 4.11

[Trev Vaa 1,185]

what i am saying, is if you put 2 engines back to back, exactly the same with different strokes, the one with the longer stroke will actually show LESS hp but a shitload more torque.

torque = rotating weight

crank is bigger (longer stroke, will increase torque) and heavier (will also increase torque due to rotating mass) = heavier rotating assembly = less hp but more torque.

 

its maths & physics. very simple physics and yes, 302s and 351s ran different carbies as well as a bunch of other differences from the factory. so yes there is a HP difference. they didn't just switch the bottom ends over. it has nothing to do with the stroke of the motor.

 

stroke does not gain HP, torque yes, but no HP.

 

ask any engine builder, mechanic or engineer if increasing stroke will increase HP, the answer will be no. ask Chaise or Thom.

 

yes changing the diff gears changes the final ratio, it increases the amount of turns it takes the driveshaft to turn the wheels one rotation, this acts as a torque multiplier. you just said the exact same thing i did.... changing diff gears, changes the amount of torque going to the wheels. if you went for 2.75:1 you would lower the torque at the wheels. if you went 4.11:1 you would increase the torque at the wheels. this does not effect how much torque the engine has, only the torque at the wheels. (which is where i think you are confused FORD_MAN)

 

this is why trucks, 4WDs etc have low range, because they need the torque in certain circumstances.

[gerg 10,871]

Power is torque times rpm.

 

Two engines of same design but different displacement, at a given rpm: smaller one makes 350 Nm, bigger one makes 450. Guess which one makes more power? Sure you can spin the smaller one to higher rpm to make more power, but up to that point the torque has been less. Also, the faster you spin an engine, the less efficient it becomes due to friction and many other factors, so power is lost there too.

 

I think too much emphasis is put on peak power and not average power and torque curves. This is the reason why the Engine Masters competition uses a formula that shows an engine's efficiency and not it's peak power.

 

A saying by Cosworth Engineering:

"Horsepower sells engines, torque wins races"

[bear351c 10,270]

A saying by Cosworth Engineering:

"Horsepower sells engines, torque wins races"

 

Love that.

[PRO250 1,506]

what i am saying, is if you put 2 engines back to back, exactly the same with different strokes, the one with the longer stroke will actually show LESS hp but a shitload more torque.

torque = rotating weight

crank is bigger (longer stroke, will increase torque) and heavier (will also increase torque due to rotating mass) = heavier rotating assembly = less hp but more torque.

 

its maths & physics. very simple physics and yes, 302s and 351s ran different carbies as well as a bunch of other differences from the factory. so yes there is a HP difference. they didn't just switch the bottom ends over. it has nothing to do with the stroke of the motor.

 

stroke does not gain HP, torque yes, but no HP.

 

ask any engine builder, mechanic or engineer if increasing stroke will increase HP, the answer will be no. ask Chaise or Thom.

 

yes changing the diff gears changes the final ratio, it increases the amount of turns it takes the driveshaft to turn the wheels one rotation, this acts as a torque multiplier. you just said the exact same thing i did.... changing diff gears, changes the amount of torque going to the wheels. if you went for 2.75:1 you would lower the torque at the wheels. if you went 4.11:1 you would increase the torque at the wheels. this does not effect how much torque the engine has, only the torque at the wheels. (which is where i think you are confused FORD_MAN)

 

this is why trucks, 4WDs etc have low range, because they need the torque in certain circumstances.

i go racing with a guy that went from a very tough 351 to a 393 it makes 50hp and a heap more tq then the 351 combo this was, this was back to back engine same engine diffrent bottom ends and bigger carby on the stroker it makes more hp as well cause its a bigger engine

 

 

If what you said was th case all the ford engines would have made the same hp and just more torque but they dont  

[Trev Vaa 1,185]

what you described is physically impossible, argue it all you want, but you are arguing with physics and mathematics, increasing stroke will not increase HP, it will however show a gain of torque, by the way, doubt he used the same cam when going from 351 to 393 cube, that would be poor use of either the 351 or 393, one of them had to suffer to achieve efficiency of the other.

 

and no, because it wasn't just the stroke that differed, but you wouldn't know that, because you didn't work with people who worked on the production line at the time these things were built, unlike myself, who has worked for multiple including guys who worked for FSV and some of the RnD team, also the HP figures were a marketing ploy.

[XPT 673]

Say you took a Boss 302 , ripped the top end off and bolted it onto a 351W bottom end with the same CR and cam etc. It would not make 1 more HP than the 302?

[Trev Vaa 1,185]

nope, but it would make a shitload more torque. which is what you feel.

a 302 and 351 rebuilt with the same components will make the same HP, but nowhere near the same torque.

[gerg 10,871]

Two labourers on a job site: Laurie, a short Maltese bloke, can carry 8 bricks at a time. His mate, Shane, is a tall beefy Aussie bloke. He can carry 12 at a time. This is torque.

 

Laurie however, is quite athletic and nimble, and is able to shift those 8 bricks from one pile to another 3 times a minute. So he can move 24 bricks in that time. Shane is a bit slower, at only 2 trips, but each load contains more bricks. So Shane can actually move 24 bricks in the same time that Laurie can move 24. This is power.

 

I think we all need to be on the same page when having a discussion about torque and power. XC I think you're referring to two engines of different stroke but with everything completely optimised for their corresponding size. I think everyone else is comparing two engines that are identical in every way except for stroke.

 

The physics dictate that, RPM for RPM, more torque will make more power. In fact, at 5252 rpm, both hp and lb-ft are always identical. So if torque at this rpm is more, so will be the horsepower. So in order for a smaller engine to make the same hp as a bigger one, it must spin faster.

 

The Boss 302, in race form, could put out around 500hp. However it had to rev upwards of 8000 rpm to achieve it. This kind of rpm dictates serious engine prep, an expensive valve train with solid lifters, and an engine that's off its tits.

 

A 393 stroker Clevo could reach this number without cracking 6000 rpm, even using a near-stock valve train and hydraulic lifters. A much easier engine to live with, more mild-mannered and longer-lived.

 

So everybody's right in regard to what they're talking about, but we're not talking about the same thing.

[bear351c 10,270]

So, if I left the train station at 11:45 am, with 297 people on board, how many oranges will I have if I dont stand perpendicular to the earth's crust?

[MNTL.XD 3,831]

So, if I left the train station at 11:45 am, with 297 people on board, how many oranges will I have if I dont stand perpendicular to the earth's crust?

  F@ck all and none. Fact is 2 of them 297 people were Islamic extremists. 

[XPT 673]

This is turning into a stroke-fest.

[wagoon 2,429]

I like torque cause torque is pull and a good pull feels grouse

[bear351c 10,270]

  F@ck all and none. Fact is 2 of them 297 people were Islamic extremists. 

 

Aaah.....I see.

 

Waiting for Godwins Law.

[gerg 10,871]

So, if I left the train station at 11:45 am, with 297 people on board, how many oranges will I have if I dont stand perpendicular to the earth's crust?

 

42.... I'd have thought that was an easy one to work out

[PRO250 1,506]

HEHE shit just got funny

drove mine to the shops today lacks TQ but not HP  
 

[dougie77 789]

42.... I'd have thought that was an easy one to work out

no it will only be 7 cause you forgot to divide it by the number of spanners in a sidchrome tool set

[wagoon 2,429]

I dont mean to bring this conversation back to being serious cause we have gone well away from the OP's original topic but, I had a stand up argument near punch on with a mate about which is better carby or fuel injection. Both sides were valid and made sense and were correct from the direction we were coming from which. I wont get into each argument here ( held over for another topic that can be destroyed by discussion) cause it was 15 year ago and I couldn't give a shit anymore but I think this is where greg is coming from, context is everything.

[Stu5766 394]

Hey guys, heading to the street meet this Sunday, 9th Febuary. Should be a good day. If your down there, I'm running a red XD with shakers and B45 Simons on it. Cheers stu.

[Stu5766 394]

Hey guys, just letting you all know, I'm gunna hold off running the XD this weekend. It's gunna be over 35 degrees at the creek and I don't wanna push the old girl too hard in those temps.