Build me a Small block

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I just sent my Eddy heads, M1 intake, and hyd. roller cam to RyanJ a month ago, and they are on their way back now. I have a Magnum 408, in a 68 notch. I put the top rings in backwards before I disassembled the engine(my stupid mistake) and it still went 11.9 @113 with MASSIVE blowby. I tore it down, discovered my mistake, and thought, well, I might as well go for the gold. Sent everything to RyanJ and he did a stage 2 port, 5 angle valve job, milled the heads, and intake, port matched the intake, and reground the roller cam. There is a guy who goes by Flyfish here and on Moparts that pretty much has what I have, except he has a solid cam, and he went 7.17 in the 1/8th. Mind you this is a fresh combo and I think he is still tuning. A 408 can be built to be a very nasty little combo.
 
my 2 cents

Don't get caught up in the hype around magazine or the engine master builds and related aura of those doing them.

I've just seen one of the biggest disasters of a build I've ever seen in my 30+ years of doing this stuff. The builder was a participant in those challenges and basically screwed the buyer... BAD! Total mismatch of parts, bad choice of bore/stroke combo for intended use, poor machining, you name it, it was in this engine. We're talking a 5 figure build here!

Talk to the locals that run hard, find a machinist that has a car that runs well. Proofs in what they actually do not what they all learned in a book. Some of the best education is the "School of Hard Knocks"! Some things in the books are flat WRONG. Look at some of the info in the Mopar books.

Something to think about... some guys sell heads based on flow numbers and promoting the big numbers. Sometimes those big numbers are detrimental to the intended end use. There's more to a good cylinder head than the flow numbers.

Figure what you want the engine to do for you and build it for the intended application. You'll save money in the long run using that approach. Some think a 560hp solid cammed SB is a streetable piece, others don't. Got to find your happy place. :-D
 
Heres my 2c -

To be honest, it doesnt fuss me if you take on board what guys like Mopaer have told you - you may have some shortcuts and you might save some pennies on the deal -

But I DO worry when I read this........

Ryans build was VERY simple just a hyd flat tappet off the shelf cam with about .525" of lift and 9.5-1 compression. RPM airgap intake and some cheap roller rockers. Keep in mind this was for his daily driver so he was also looking for reliability when he built this. it ran 113mph in a 3550 lb. car with 3.55 gears.
Sorry to disappoint - but theres no way that MPH and weight = 500HP. PERIOD

113 mph at 3600lbs = a flat 12, and appx 400 FWHP.

Rule 1 - gears don't effect the trap speed that much, so it doesn't matter if he was running 4.11s or 3.23s- the MPH/weight tells the story -

I don't know if thats what RYan told you, or you got the MPH and used one of these on-line calculators, MOST of which are wrong.

Big statement I know, but read on..........

Rule 2 - Most of the on line calculators are based on the Moroso slide rule -

(Without getting too antsy - A lot of guys out there like to think its RWHP because they can then say that their engines are making X+ more HP than they actually are).

But here's the reasons why its not RW hp:

Rule 3 -
The reality is the Moroso (and therefore the Mopar charts in the books) deal in FWHP -

How do we know? Well,

1st / Mainly and most obviously because to deal in RWHP, there are far too many losses and variables to be sure and arrive at a constant formula. (losses through converters, tyre size, etc) make it impossible to arrive at a predictable Rear Wheel output....

In summary - the Moroso does not take into account "20% drivetrain losses" for one car, and "25%" for another. How can it ?- Its a simple tool based on a set of known constants and trialled data.

So - the Moroso has to be FWHP - and therefore the Tech charts also.

To prove this case further - Lets take an example:

The chart says for a 3600lb car - its making 400 "RW" HP :bootysha: to run 113mph.

Why do we know this is false?

Well, if we reverse the situation, that means that it takes 500 FWHP to run the same flat 12 sec qtr. (assuming 20% losses)

I'm sure most experienced racers will agree with me that a 500FWHP car which is well set up will be in the flat 11s and running appx 121 mph..... NOT the 12s at 113.

- In fact Im sure there's plenty on here who've dynoed their engines and fit this equation almost perfectly.

Id even go so far as to say take any KNOWN engine thats been on an engine dyno and see what times the car subsequently runs - 99% of the time the Moroso will agree with the engine Dyno and reveal that the "RWHP" assumption is incorrect.
Click to expand...


Moving on - the purpose of this post is not to "can" what Ryan has said - I dont know how the quoted 113/500HP figure was arrived at - But there's a lot of folks out there who still don't realise the HP calculators are not RWHP.

Most of the time, when the car runs a full second slower than the "HP" they THINK the engine should be making (Cos its never dynoed) , they look at other areas - without understanding how the Moroso calculator was invented.

Another example - The car in the vid is a full weight appx 500 FWHP 360, No big arm, NO gas, 3600lbs, sorted over a period of 7 years , no traction issues, J heads (yep Js....) that flow appx 280 CFM, rear leaf sprung etc. Basically its as "sorted" as you'll ever see for the fairly straight fwd engine combo it is.

Its best was 10.89 at 123 mph through the Magnaflos- Yep - thats 500HP for a consistent 123 mph.

This was an earlier run in its build as far as I recall......476 FWHP - 118@3600lbs = 11.18

No way no how is 113mph making 500FWHP. :-D

http://www.youtube.com/watch?v=YLt-YmaJuJk
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Moparmal said:
Heres my 2c -

To be honest, it doesnt fuss me if you take on board what guys like Mopaer have told you - you may have some shortcuts and you might save some pennies on the deal -

But I DO worry when I read this........

Ryans build was VERY simple just a hyd flat tappet off the shelf cam with about .525" of lift and 9.5-1 compression. RPM airgap intake and some cheap roller rockers. Keep in mind this was for his daily driver so he was also looking for reliability when he built this. it ran 113mph in a 3550 lb. car with 3.55 gears.
Sorry to disappoint - but theres no way that MPH and weight = 500HP. PERIOD

113 mph at 3600lbs = a flat 12, and appx 400 FWHP.

Rule 1 - gears don't effect the trap speed that much, so it doesn't matter if he was running 4.11s or 3.23s- the MPH/weight tells the story -

I don't know if thats what RYan told you, or you got the MPH and used one of these on-line calculators, MOST of which are wrong.

Big statement I know, but read on..........

Rule 2 - Most of the on line calculators are based on the Moroso slide rule -

(Without getting too antsy - A lot of guys out there like to think its RWHP because they can then say that their engines are making X+ more HP than they actually are).

But here's the reasons why its not RW hp:

Rule 3 -


Moving on - the purpose of this post is not to "can" what Ryan has said - I dont know how the quoted 113/500HP figure was arrived at - But there's a lot of folks out there who still don't realise the HP calculators are not RWHP.

Most of the time, when the car runs a full second slower than the "HP" they THINK the engine should be making (Cos its never dynoed) , they look at other areas - without understanding how the Moroso calculator was invented.

Another example - The car in the vid is a full weight appx 500 FWHP 360, No big arm, NO gas, 3600lbs, sorted over a period of 7 years , no traction issues, J heads (yep Js....) that flow appx 280 CFM, rear leaf sprung etc. Basically its as "sorted" as you'll ever see for the fairly straight fwd engine combo it is.

Its best was 10.89 at 123 mph through the Magnaflos- Yep - thats 500HP for a consistent 123 mph.

This was an earlier run in its build as far as I recall......476 FWHP - 118@3600lbs = 11.18

No way no how is 113mph making 500FWHP. :-D

http://www.youtube.com/watch?v=YLt-YmaJuJk
Click to expand...

I NEVER said 500hp to the REAR wheels. I dont know what drivetrain was in his car...I however did run the HP calculations BEFORE I posted it and yes it was around 400 at the rear wheels figure in 50 horse loss in the drivetrain and you are around 450hp at the crank...and keep in mind he used a SMALL cam shaft and only 9.5-1 compression. my point was for a street strip car NOT a daily driver you could up the compression and install a little more lift and probably pick up that 50 horse. I just had one of the best small block mopar guys in the country tell me it was possible to do for around 5K and you are still doubting it.
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72, The last small block I built was a customers and a member here, albeit ususally too busy to hang around. The build was simple. 4" arm, 340 block (which is not a big difference at this level over a 360), on a budget, and startign with nothing but a core block and 587 heads. I charged him about $1200 in assembly, sonic testing, and head prting work. All the other work was paid to a machine shop I work closely with. They are not the cheapest around, but they have the best equipment and sharp guys working with it. In fact, it's a 1.5hr drive for me to get there and I pas a whole bunch of cheaper shops enroute. But this guy does the best work, period. The car this engine is in is an Ebody that weighed in at a portly 3800lbs with driver and runs a 3.23 8 3/4. I The engine is iron heads with "stage 2" porting, around 265cfm intake (ready to bolt on were $1500), cast crank, stock rods with good bolts, and Diamond dished pistons. Internally balanced to .1/gram, main studs, and basic good assembly. It pulls mid 12 at 109 and gets 17mpg on pump unleaded (89 or 90 as I recall). It's a hydraulic cam with roughly the same specs as Ryans. 508/528, 308/318 hydraulic with sintered iron. A 4" arm needs a big carb to make power and I use 870 Street Avengers for base builds. So the 3310 off the shelf (or even the 800cfm 4150 DP) aint enough. This package makes between 450-470hp depending on your math. Very basic. The total cost (and I'm sure there's more I overlooked) was $7K. That was a year ago and parts were bought two years ago. Do I think you can build a 4" arm for $5K, sure. Do I think Ryan can? Hell yes. Do I think yours will be the same as his in terms of parts and quality? Nope. Do I think it's reasonable to get 500hp from a budget build? Nope. Why don't you try and do it, track every dime, and run the car when it's done, and let us know how you did? What's funny is Ryan's livlihood is based on his getting your money. And he says "sure no problem" to $5K. What happens if it goes over? He make shis profit, and your engine sits until you can pay for it. If I tell you "sure, no problem" to your $5K my life is totally unaffected. Yet I say it's not doable. Why? I've done it, and I do it for fun. My house gets paid for by my job, which has nothing to do with cars. I've gotten paid to do it for others for (ugh..) 22 years now. I can tell you it cant be done AS YOU ARE ENVISIONING it. Not because you're stupid or your Dad's out of it, but because I think what you have listed is leaving a ton of stuff out that Ryan and others do know about, or perhaps you haven't discovered yet. It's like a road map from my house to Montreal that doesnt show any road smaller than the 4 lane interstates. Sure, you can see the big distances and the basic path, but you can't see what happens off the main road. And when you need to get to the first highway you're lost, and when you get off the last one you're lost. We're not trying to diss you, just trying to nicely point those small bits out. The small bits always either equal cash spent, or power left out. 2800lbs needs 350hp at the crank to run low 12s if it's set up to drag race . 400hp with street gearing and a street convertor. :D
 
- we got two discussions now - one is the cost, the other is about HP.

thats my fault - so Ill explain and leave it on the table -

but theres no way that MPH and weight = 500HP.
Click to expand...

72, see?

I didn't say Rear wheel.....

Here's the deal - The whole point of the "Moroso" stuff was to point out that 500 FLY WHEEL hp makes WAY more than 113mph. So if Ryan's driver makes 113mph - its making 400 NOT 500.

So mate, Take a slow breath and read whats being written and be cool - don't assume we're all coming down on you , OK?

Now the next thing - read what you wrote....

and I was told building a 500 horse 360 based 408 for 5K is fairly simple and reliable as he built one for his daily driver.
Click to expand...

it ran 113mph in a 3550 lb. car with 3.55 gears.
Click to expand...

..so I put the two things together...maybe I got it wrong? Doesn't matter 8)

My only concern was that you thought 113mph = 500 FLY HP - Be sure champ, it doesn't - its way less......or we'd all be running 10s with Hydraulic flat tappet cams... :toothy10:!

Anyhow - 113 mph is appx 400 FLY HP for a flat 12 in a 3600 car - keep that in mind .


----------------

Part 2


Please don't get all twisted up over this discussion - you obviously want to do it right -

FWIW, I think its great that you want tuf lil SB - but to be honest, Moper obviously wouldn't waste his time posting IF he thought you had it "cold".

He's just saying there's always traps in engine building. So have a solid review of everyone's posts and "have at it"...but take on board everything thats been written..thats the cool thing to do.

So what do you want to know?........there's some clued in racers and builders on this board....why are you wasting time arguing with me? ;-)
 
I would listen to what Moper has to say. I just finished my stroker motor a few weeks ago and can tell you that his numbers $$$ are pretty much right on. For instance, I already had my Edelbrock heads, pro magnum rockers, Air-gap intake, carb, ARP studs, converter, distributer & electronics and all accessories from a previous build. My block needed minimal machining because I had a pretty healthy combo before I rebuilt it. I sent my heads to Ryan @ shadydell for stage 2 port work and assembled the entire engine myself…I still spent over 5k. Not trying to bash, just trying to give a fellow Mopar guy a heads up; there are a lot of little things that add up quick…like custom push rods, valve springs, machining the heads to accept those larger valve springs, 10° locks, retainers, lots of specialty tools. Not to mention that once you have that power you will probably want to get it to the ground (rebuild trans, sticky tires, gears, bigger axles, better brakes)…I could go on and on, but I think you get the point.
My engine combo is on the first page of this thread if you’re interested.

BTW, Ryans port work is AWESOME!! He is THE man when it comes to small block head work.
 
Ok one final thought. correct me if I'm wrong which I may be.

As far as Ryans daily driver he made note to. None of us know if the chassis was setup for drag racing or how efficient the converter was for his engine application. It very well could of been just some stuff he had laying around and wasnt worried about every single mph and et out of a daily driver.

I'm still undecided on what engine this car will have. I may just get the schumacker kit and drop a 440 in and build a custom set of fenderwells for it or it might get a stock stroke 360 with stock type heads (home ported) with a turbo.

On a better note I will be picking the car up today and was just told that I get a fresh small block 727 with it for free.
 
Ok one final thought. correct me if I'm wrong which I may be.

As far as Ryans daily driver he made note to. None of us know if the chassis was setup for drag racing or how efficient the converter was for his engine application. It very well could of been just some stuff he had laying around and wasnt worried about every single mph and et out of a daily driver.
Click to expand...

Chassis will hardly effect MPH is a street car - converter will - a bit.

That is why MPH tells you engine improvements

- ET tells you chassis, tyre engine and gears........But not which one ;)
 
Moparmal said:
Chassis will hardly effect MPH is a street car - converter will - a bit.

That is why MPH tells you engine improvements

- ET tells you chassis, tyre engine and gears........But not which one ;)
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Thanks for the correction. I knew HP was a factor of MPH but wasnt sure how much HP a converter (thats not matched to your application) can suck up
 
72swgnr said:
For $6500 bucks you can buy a crate engine with a 30month/50,000 mile warranty that puts out 455HP/510TQ ...(or at least is supposed to put out those numbers) I respect the replys that I have gotten but im still skeptical that it will cost that much for 500hp if you do your homework and find some good deals on parts. But you guys have obviously been there done that many times so I wont argue anymore :)
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Is that the Blueprint motor? Eddy heads and all? If so I cruised with a guy this weekend that has one in his 68 'cuda and it goes 103mph or so in the 1/4 mile.

I have the motor that Moper built, there were a few unforeseen problems that no one could predict that caused the price to go so high, but his numbers also reflect the costs of the accessories as well. If I were to do it again I'd go with the Al heads for a little more. Intake,carb, double springs, custom pistons,pushrods, balancing with mallory, adj rockers, carb accys, oils, filters, etc. I think an extra block too....LOL I try not to keep all the reciepts in one place since the Wife may find them....:snakeman:

Also, the HP slide rules are a good tool. Not sure how they can figure Engine HP since all combos are different(drivetrain losses) it would seem that rwhp is an easier # to come too since it will take a given net hp to move a certain weight over a given/known distance. I'm not a rocket scientist though. I think most factory E-body Hemi cars ran under 110mph in the 1/4 and they were hopefully more than 400 Engine hp.

My e-body goes 109+ and this is with a slippy tq converter in the 8-9% range on the top end. I just tell everyone it has 400 horse since thats what everyone else has....:cheers: I need to work on my launches with my 3.23's I can only pull a 1.92 60' time going to a 12.7. Too much tq for the smallish Drag radials(235/60/15's) it will spin through 1st gear if I get too excited, I need to roll out 15-20' for any hook.

The Budget deal will vary on many things,

Good Luck and keep us posted.

Tom:mrgreen:
 
72challorange said:
I have the motor that Moper built, there were a few unforeseen problems that no one could predict that caused the price to go so high, but his numbers also reflect the costs of the accessories as well. If I were to do it again I'd go with the Al heads for a little more. Intake,carb, double springs, custom pistons,pushrods, balancing with mallory, adj rockers, carb accys, oils, filters, etc. I think an extra block too....LOL I try not to keep all the reciepts in one place since the Wife may find them....:snakeman:
:
Click to expand...

Tom, you DO have all the parts but aftermarket rods and aluminum heads. And.... you HAD a spare block, remember? I threw out the first block when that crack showed up ;) . And yes, my intention was to show everything to get it together and running in the car.
 
Tom - I’m sorry to sound like a know it all - but your post proves my point about folks not understanding that Moroso is an approximate FLY wheel HP reference tool – There are three basic parts to the proof of what Im saying.

To be specific:

First part –

Knowing how it works and what data it uses –

The main thing to be aware of is – the essential information for the slide rule are derived from experiential analysis - NOT physics.

History - the FLY wheel HP from factory engine dynos, MPH, weight and ET coefficients were all gathered by a guy named Huntington - from data collection on thousands of qtr mile runs – where the only known hp output was fly wheel., sourced from factory stats and engine dynos.

Go here if you want the full history -

http://www.stealth316.com/2-calc-hp-et-mph.htm

He accumulated all this data and created a ‘constant”, and arrived at a general formula to align ETs and Fly wheel HP from MPH and Weight etc.

So in summary - The Moroso uses a constant derived from averaging data – it simply draws a average from the inputs – weight/MPH and known Fly wheel HP in each case…depending on what you want to know.


Part 2

You said - .
“Not sure how they can figure Engine HP since all combos are different(drivetrain losses) it would seem that REAR WHP is an easier calculation.”
Click to expand...

I’m afraid this thinking is backwards – Here’s why:

1 - The fact is that drivetrain losses occur mainly through the transmission and the differential – agreed?

2 – You also agree and are correct in saying the Moroso can’t calculate drivetrain (Trans/diff) losses from car to car,

Conclusion - Therefore, this makes it logical that the Moroso calculates FWHP, using known weight, FLY WHP and MPH coefficients as I explained above.

I think that’s pretty logical.

Part 2B :D

Now here’s another IMPORTANT (and complicated) point –

Why are the Moroso readings "low" for FW HP?

OK, so we now know - that the Moroso calls upon a data bank of verified factory or dynoed FLY wheel HP and uses a constant to cross reference against best case ETs, weights and MPH etc.. But here’s the kicker –

1 - Factory / engine dyno HP ratings that were used to create the Math constant were without alternator, air con, fuel pump etc –

BUT –

2 – The MPH/Weight coefficients were taken from cars running drivetrain- so losses had an effect on the formula -

So what’s the result?

Conclusion – Using the two different sources of experiential data corrupts the formula, and the end product is that the Moroso provides very conservative FW HP estimates.

This is why the “lowish” Moroso readings make people THINK its RWHP –

BUT, it is not – it is still a cross referenced FLY wheel read out, as that was what was used to genrate the formula to begin with!

Read on for the proof –


Part 3

– For example –your car ran 109mph

1 - Moroso says appx 385 Fly wheel for a 3900lb car (including driver) at 109 mph

2 - Truth is, that’s pretty close to what your average factory Hemi was probably putting out if you consider air-con, mechanical pumps etc.

.......so the “claimed” 425 was more than a bit unrealistic by the time the engine is in the car and driving the generator, fuel pump etc..

Now on to your second point –

“I'm not a rocket scientist though. I think most factory E-body Hemi cars ran under 110mph in the 1/4 and they were hopefully more than 400 Engine hp.”
Click to expand...

OK, I’ll play along, and prove how we know that the Moroso IS FWHP – just so you can tell others LOL! –

How? - We simply do the math in reverse:

Lets assume Moroso says its Rear wheel HP –

1/ It says for 385 "RWHP" – you should be running 109 mph

2/ Using 20% losses through trans and stall - 385 RWHP = appx 480 FWHP. (and probably more as 20% is very conservative for a 727 trans and stall – rule of thumb for most racers is add 120 HP)

Conclusion - If we assume the Moroso is REAR wheel, we have to agree that factory Hemis produce 480 – 500HP HP at the fly……I hope we both know that just isn’t the case? - Because we both know that 480 FWHP engines are good for low 11 ETs.

Soooooooo,

The only way the calculator can work correctly is if its understood that it is a very CONSERVATIVE FWHP calculator.

I agree - there are plenty of situations where the Moroso doesn’t check out perfectly on FWHP – Ive explained why in part 2B-

BUT - you only have to reverse the equation to realise there is no way on earth it can be REAR WHP.

Here’s another example –

Fact - My car is 3600 with me in it (had it on a weigh bridge),
Fact - Runs a flat 13 at 103 mph.
Fact - Rear Wheel dynoed at appx 265 RWHP.

Using the Moroso, it says at weight/MPH I’m making around 310-325 FLY HP.

20% losses from 320 = 270 REAR WHEEL almost exactly what the RW Dyno said. – so I’ve now verified that the Moroso deals in FWHP.

Lastly – and just a note - Don’t confuse Gross HP (without alternator, fuel pump etc) and Net SAE (with alternator etc) with RW and FLY HP. These terms mean different things to RW and FLYwheel HP.

FWIW, Gross and Net are BOTH taken at the flywheel

(Apologies if you already know this - but I thought I betetr clear it up)
 
i built a 408 with 9.8 comp eddy heads no porting, hyd cam, air gap, pretty much what you are describing, and I am right at $5,000 and already had the oil pan, and of course my engine has not been run at the strip yet, but I can already tell it is not going to make anywhere near 500 hp, I like the others would love to see how fast your car goes and how much you really spend.
 
tblotske said:
i have well over $8000 in an smallblock build to get over 550 hp good luck!
Click to expand...

I am currently at $7500 for a 416 that should be just over 550hp at the rear wheels. These small block strokers are awesome but not cheap. Only $600 is in assembly. LaPouttre Racing in Bay City, Michigan has proven results. I will let you know how this works out for me.
 
Moparmal said:
Tom - I’m sorry to sound like a know it all - but your post proves my point about folks not understanding that Moroso is an approximate FLY wheel HP reference tool – There are three basic parts to the proof of what Im saying.

To be specific:

First part –

Knowing how it works and what data it uses –

The main thing to be aware of is – the essential information for the slide rule are derived from experiential analysis - NOT physics.

History - the FLY wheel HP from factory engine dynos, MPH, weight and ET coefficients were all gathered by a guy named Huntington - from data collection on thousands of qtr mile runs – where the only known hp output was fly wheel., sourced from factory stats and engine dynos.

Go here if you want the full history -

http://www.stealth316.com/2-calc-hp-et-mph.htm

He accumulated all this data and created a ‘constant”, and arrived at a general formula to align ETs and Fly wheel HP from MPH and Weight etc.

So in summary - The Moroso uses a constant derived from averaging data – it simply draws a average from the inputs – weight/MPH and known Fly wheel HP in each case…depending on what you want to know.


Part 2

You said - .

I’m afraid this thinking is backwards – Here’s why:

1 - The fact is that drivetrain losses occur mainly through the transmission and the differential – agreed?

2 – You also agree and are correct in saying the Moroso can’t calculate drivetrain (Trans/diff) losses from car to car,

Conclusion - Therefore, this makes it logical that the Moroso calculates FWHP, using known weight, FLY WHP and MPH coefficients as I explained above.

I think that’s pretty logical.

Part 2B :D

Now here’s another IMPORTANT (and complicated) point –

Why are the Moroso readings "low" for FW HP?

OK, so we now know - that the Moroso calls upon a data bank of verified factory or dynoed FLY wheel HP and uses a constant to cross reference against best case ETs, weights and MPH etc.. But here’s the kicker –

1 - Factory / engine dyno HP ratings that were used to create the Math constant were without alternator, air con, fuel pump etc –

BUT –

2 – The MPH/Weight coefficients were taken from cars running drivetrain- so losses had an effect on the formula -

So what’s the result?

Conclusion – Using the two different sources of experiential data corrupts the formula, and the end product is that the Moroso provides very conservative FW HP estimates.

This is why the “lowish” Moroso readings make people THINK its RWHP –

BUT, it is not – it is still a cross referenced FLY wheel read out, as that was what was used to genrate the formula to begin with!

Read on for the proof –


Part 3

– For example –your car ran 109mph

1 - Moroso says appx 385 Fly wheel for a 3900lb car (including driver) at 109 mph

2 - Truth is, that’s pretty close to what your average factory Hemi was probably putting out if you consider air-con, mechanical pumps etc.

.......so the “claimed” 425 was more than a bit unrealistic by the time the engine is in the car and driving the generator, fuel pump etc..

Now on to your second point –



OK, I’ll play along, and prove how we know that the Moroso IS FWHP – just so you can tell others LOL! –

How? - We simply do the math in reverse:

Lets assume Moroso says its Rear wheel HP –

1/ It says for 385 "RWHP" – you should be running 109 mph

2/ Using 20% losses through trans and stall - 385 RWHP = appx 480 FWHP. (and probably more as 20% is very conservative for a 727 trans and stall – rule of thumb for most racers is add 120 HP)

Conclusion - If we assume the Moroso is REAR wheel, we have to agree that factory Hemis produce 480 – 500HP HP at the fly……I hope we both know that just isn’t the case? - Because we both know that 480 FWHP engines are good for low 11 ETs.

Soooooooo,

The only way the calculator can work correctly is if its understood that it is a very CONSERVATIVE FWHP calculator.

I agree - there are plenty of situations where the Moroso doesn’t check out perfectly on FWHP – Ive explained why in part 2B-

BUT - you only have to reverse the equation to realise there is no way on earth it can be REAR WHP.

Here’s another example –

Fact - My car is 3600 with me in it (had it on a weigh bridge),
Fact - Runs a flat 13 at 103 mph.
Fact - Rear Wheel dynoed at appx 265 RWHP.

Using the Moroso, it says at weight/MPH I’m making around 310-325 FLY HP.

20% losses from 320 = 270 REAR WHEEL almost exactly what the RW Dyno said. – so I’ve now verified that the Moroso deals in FWHP.

Lastly – and just a note - Don’t confuse Gross HP (without alternator, fuel pump etc) and Net SAE (with alternator etc) with RW and FLY HP. These terms mean different things to RW and FLYwheel HP.

FWIW, Gross and Net are BOTH taken at the flywheel

(Apologies if you already know this - but I thought I betetr clear it up)
Click to expand...

I never stated the Moroso Slide Rule was rwhp. It also seems to use at the "clutch" power using "factors". The factors for a 727(which uses lots)vs a 904 vs a 833 would be very different, nevermind unsprung weight(rotational masses). It is a tool that's all. It would seem to me that rwhp would be easier to predict, but again I'm not a rocket scientist.lol


Unfortunately I did a search online to "learn" but there were many arguments for both with dyno #'s and mphs to back them up. The only thing I see is that with your link the moroso slide rule is the most innacurate? Either way no sweat to me.

Tom
 
72challorange said:
I never stated the Moroso Slide Rule was rwhp. It also seems to use at the "clutch" power using "factors". The factors for a 727(which uses lots)vs a 904 vs a 833 would be very different, nevermind unsprung weight(rotational masses). It is a tool that's all. It would seem to me that rwhp would be easier to predict, but again I'm not a rocket scientist.lol


Unfortunately I did a search online to "learn" but there were many arguments for both with dyno #'s and mphs to back them up. The only thing I see is that with your link the moroso slide rule is the most innacurate? Either way no sweat to me.

Tom
Click to expand...

Just a thought on the percentage loss. A trans and differential will take a certain hp to turn no matter what engine is in front of them. There are other inefficiencies through the drivetrain such as brake drags and bearing drags that you can not get exactly right. Force is a factor of mass times acceleration not including drag/heat efficiency losses so I agree that if you spin them up faster they will take more hp but it is not proportional. A 165hp 318 will still overcome the same losses as a 600hp one. Maybe I am wrong but I think any percentage loss is just a SWAG.
 
michformulaS said:
Just a thought on the percentage loss. A trans and differential will take a certain hp to turn no matter what engine is in front of them. There are other inefficiencies through the drivetrain such as brake drags and bearing drags that you can not get exactly right. Force is a factor of mass times acceleration not including drag/heat efficiency losses so I agree that if you spin them up faster they will take more hp but it is not proportional. A 165hp 318 will still overcome the same losses as a 600hp one. Maybe I am wrong but I think any percentage loss is just a SWAG.
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I agree it's a SWAG. Seems that Flywheel hp is a tougher measurement to reverse engineer due to these things. Effective or Wheel hp would seem to remove these things.

Tom
 
Tom - Fair enough - I thought you were arguing it was - and fwiw I agree its not the most accurate of guides.

You'll note I used the word "guide" instead of "calculator" ?

I guess the main problem i see is that some folks think the slide rules perform some "Physics" type calculation where losses are "magically" assessed etc.

So back on the soap box :read2:- Truth be told they are far simpler tools than that - and in reality rely on pre-assigned data and use a common constant simply to arrive at an arithmetical sum......

Quote from the link -

"MPH" is the terminal speed (trap speed),
"ET" is the elapsed time,
"224" is the empirically determined coefficient that includes the necessary unit conversion factors,
"hp" is the peak engine horsepower output at the clutch (net power), and
"weight" is the the total weight of the vehicle (with driver) in pounds.
Click to expand...


Its as simple as "Raw Data > Constant > Result" - Where the Raw data and the result are measured in the same units.

.......so it stands to reason that when MPH and weight is used to determine HP, it arrives at FLY HP as a result of the equation.


FWIW - The the bottom of the linked page, there are three different calculators using a slightly different Constant in each - the LRT calculator seems to be the most accurate for street type cars - but the "Hale formula" one supports the 400HP=12sec=3600lbs FLY benchmark ive always gone by.......


MichformulaS- Im no Physicist , and I agree with this part -
so I agree that if you spin them up faster they will take more hp but it is not proportional
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. - because rotational and inertial friction increases as more energy gets put in, and each drivetrain combination has different losses, its not 1:1....another reason why they couldn't use RWHP to calculate a reliable "Constant" for a reference tool.

Re the SWAG thing - most of the gun builders I know assume a 120 HP loss for a 727 and a 8.75/ford 9" diff.

JUst an observation - That would mean that the factory Hemi is producing appx 300 Rear wheel HP - the Moroso gives them way more than that - more proof if anyone needs it. LOL!! :-D
 
Well I just got the first peiece of the puzzle. I found a cam speced out by Dwayne Porter for a stroker. It will be pretty radical but it's not going to be a daily driver

Comp Cams CRS 7262/7263 S 110.0 Valve adjustment: intake= .026 exhaust= .026 Gross lift .577 intake .585 exhaust Duration @ .050 tappet lift intake= 262 exhaust= 266 Valve timing @ .050 intake open 25 BTDC close 57 ABDC Exhaust open 67 BBDC close 19 ATDC These specs are for cam installed @ 106 center line. Duration @ .050 intake 262 exhaust 266 Lobe lift intake .3850 exhaust .3900 lobe separation 110.0.
 
Question is how long do you want your 500 HP to last? Stock rebuilt 360 with good pistons (Hypers will do for now), nothin' fancy cam cam ( like Comp XE285XL),fresh j heads, used intake of some sort ($75 Torker) and $500 Nitrous kit (NOS or Zex or whoever)will get you there for cheap but who knows how long it will last. Ever watch Pinks? Or build it to last with forged-everything stroker stuff, modified Eddies, etc. and hang on to it for awhile. Motors are kinda like some woman I know. Cheap and fast or costly but good for the long run.
 
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