[Skip Fix]

Actually Half Inch a 12 sec furlong(1/8th mile) is a pretty good clip for a thoroughbred, good ones can keep it up for a mile. Quarter horses at a 1/4 mile run 20-21s.

[uneasyrider]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by motor-daddy:
My point is that people always call low rpm power "torque", and high rpm HP. In all actuality it is Horsepower at 500 rpm or 5,000 rpm. Diesels still make HP, they just generally do it at a lower RPM! A longer stroke is just a longer bar, and we all know what happens when you use a longer bar. It is in effect a built in gear reduction! </div></BLOCKQUOTE>

Ah, ok. Thank you for that brilliant and insightful explanation. Had I only understood it from that perspective. That was WAY better than my totally uninformed one. I had know idea! My god! Diesels produce hp! You must be the ONLY person on here that TRULY understands the physics behined this thing! Ahh (grunt, drool, drool) longer stroke mean longer bar more torque.

P.S. The thermodynamics of the combustion cycle of the diesel engine are different than a gas engine. That makes for very different hp and torque curves.

Thanks,

[Tom Vaught]

A runner with a taper (larger at the plenum vs the manifold gasket location) will act like a shorter runner because the pulse wave energy will be dissipating as it travel up the runner.

Getting the right ration of runner length vs the
correct taper angles is an exercise in tuning.

Having the max torque of the engine occur close
to 1000 rpm from the max hp of the engine is something that a lot of engine builders would
like to achieve.

This doesn't mean lowering the HP point but actually raising the max torque point in the rpm scale.

Food for thought.

I was surprised that Lynn's engine torque vs Hp points were that far apart.

Tom V.

[bmpmdf]

Thank You Lynn for lunch / bench racing time Friday ! Always a great time to learn. I have been as Ponchoshop thinking of new ideas on the entire shape of the runners from carb to valve. I have also seen some recent Pro Stock heads, and the set I just got to inspect up close today was very interesting !!! (that'll cause a flood of new ideas!) I look at things we have now, and wonder, why build some of the combos when we could be more efficient. Even with inline valves. BTW, the heads I got to see and inspect today, went 6.67 recently. And the team has a better set on now.

[NHRASuperStock455SD]

Thanks for all the responses and kind words. Good responses!

Well they are all good ideas in modifying the runner lengths. We spent two years doing Victor runner length modifications unsuccessfully. We made all the various modifications suggested here, and more. None worked.

I believe it is the flaw in the casting design itself. It is way better than we have ever had, but the runner length is too long. We need a casting with a shorter runner with the same cross sectional area as the Victor.

Tom, you are right on the money with your "taper" comment. Oh, and never stop telling those stories, real life examples are the best way to learn! To achieve the distribution we need, we must extend the dividers under the carb into the plenum. This gives us an extended runner lengths. We simply cannot get around this, and it is responsible for the lower peak numbers combined with the longer runner lengths to start.

I believe we need to shorten the casting itself and develop a "Victor" style intake with a shorter runner and maintain the same plenum.

I would do sheet metal, but I believe it would take 5 or six different ones to determine the proper intake tuning.

The Victor is a great with cross sectional area and taper improvement (as Tom pointed out), however, I believe with a lot of evidence, its runner length is suppressing peak horsepower in racing applications.

Tom, we have subsequently done other things to boost RPM. Larger header sizes, bigger collector, 110 lobe separation (installed at 110, and going out to 112). All these things have gotten us up, but we havent been back on the dyno with it.

I believe 300RPM could be had if we can find the same intake tuning efficiency with a shorter runner.

I believe it is worth a 5% gain with everything else being equal, and that is 30-35 HP.

In any event, HP not torque is the key in making power here.

Lynn

[NHRASuperStock455SD]

A word about the HP and torque issue.

HP factors in the additional time and gearing potential of the torque produced at the higher RPM's.

Why would my brother's friend who is head mechanic for Newman/Haas racing run a 16,000 RPM Toyota?

Why build a motor that has 220 ft-lbs of torque at 16,000 RPM?

Gear Multiplication. There is a reason they dont run Caterpiller diesels at Indy.

Lynn

[Half-Inch Stud]

Vaught said: ""Getting the right ration of runner length vs the correct taper angles is an exercise in tuning.""

Nozzles are a fascinating engineering study: Oil funnels = bad, worst we could do.
Trans Fluid funnel = better
Vacuum cleaner parts = mostly poor
Venturis = good
Exhaust tips: bad, silly decor, an opportunity.
Thruster, (Rocket) nozzles = optimized

Q-Jet carb venturis = approximated thruster shape on underside. We can apply the parabolized shape for intake runner taper. Wider taper: yields less signal for increasing length. Indeed, Taper RATE is a tune item. Even up to the condition of no-apparent-taper (constant cross-area runners). I'm not a fan of constant cross-area runners in Intake & Head. Taper must be either increasing (silly) or decreasing from Airhorn or Carb plates to Valve seat. Enter Plenum:

Plenums volume is a real monkey wrench in the tune. Pulses get integrated to constant flow (muffler) or uniformed flow at the carb baseplate. Really bad AND really good Runner designs need huge//or right-sized plenums to perform at excellence. I suggest the 4-tube HEADER's Collector is an example of how an optimized Plenum floor could look.

Single-Plane intakes (Torker I, II, Tomahawk) are eye candy in the tuned-runner design regard. I ponder why the Dual-Plane has not been developed into a straight-runner manifold.

Overall, a Dual-Quad with Dual-Plane feed seems optimal.

HIS

[Motor Daddy]

uneasyrider, you said "A friend (Diesel Performance Unlimited is the name of his buisness) of mine has a diesel dragster that will run 150mph in the ¼ and all that thing does is make torque. Just put tall gears in the rear and the torque does the rest."

Maybe you should have worded that a little different. What did you mean then? Did you mean that your friends deisel makes a ton of HP at low RPM? That's what I thought!

[Motor Daddy]

Last time I looked for one, I couldn't find a 1/4 mile "torque" calculator!

[Region Warrior]

My Victors runners are about .25" unequal length's. Not to bad considering Pontiacs staggered port layout i guess. I'm planning to extend the dividers, tapering down to center of floor. A modified turtle. I just dont like a big flat floor. What we need is a carb with about 3" more spacing between front & rear throttle shafts.

[fasteddy]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">3" more spacing between front & rear throttle shafts </div></BLOCKQUOTE>
How about 2 Holley 500 2 bbls in line?

[Region Warrior]

You guys in your horsepower vs torque I cant believe none of you electricians havent jumped on this one. I'm going to get slapped for this. Horsepower has to do with units of power(watts)in electrical motors to create mechanical power How many ft lbs per second. Torque is a measurement on how much force it takes to overcome a rotating resistance. US auto makers like HP #'s for advertizing. HP has higher #'s when converted from torque All i really know is the more power(torque and or horse), which ever you like to go by, you can make at a higher rotating mass, the more total power you are going to produce. Dont even get me started on wieght vs gearing OK, now i have to go mow my lawn with my 14HP(at 3500rpm,s) rider that produces 24 ft lb,s torque at 3200 rpm,s

[Region Warrior]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by fasteddy:
<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">3" more spacing between front & rear throttle shafts </div></BLOCKQUOTE>
How about 2 Holley 500 2 bbls in line? </div></BLOCKQUOTE> Not only thought about that, but would love to have a Victor tripower with 3 500cfm's on top of RAV heads & 2.25 primary exh.

[johnta1]

I'm not for sure but the Holley 2 bbl's would be rated at 2 bbl specs, wo they would make less than 500cfm rated like a 4 bbl.

So, a set of split Dominators would be cool!

Possibly do like Strauss did with the old Torker and use 2 back halves with split Dominators?

[bmpmdf]

You got the engine to handle the split Dominators, I want a ride!

[455-4+1]

johnta1

I am with you on that one

The back halves of and old Torker with the short runners and a long "rectangular" plenum with a split big dominator at either end

Sounds cool

Maybe some interesting work with a turtle etc to reduce or alter plenum volume

Would you build up the underside of the plenum and lower the floor as per the old Pete McCarthry / John Angeles book or add material to the top of the runners near the plenum and raise the port roof there ???

[455-4+1]

Ok, having never seen one of the "2x back 1/2" torkers so I cobbled one together on my "cybermill" and it appears the basic plenum shape would be be more of a rhombus than a rectangle ??

Plenty of possibility for different plenum configurations and carb mounting options with a new top

Comments ?????

[Half-Inch Stud]

455-4+1, adapter plate.
Marsha, Marsha, Marsha

Tomahawk does this(now).

[455-4+1]

Half-inch Stud

What is the average runner length of the new Tomahawk???. I havent seen any published data but maybe I havent been looking hard enough

If it delivers the shorter runner length some people are after this is all great


The yellow circle shown were to represent the location of a pair of 2" throttle bores (carb or DFI throttle body ??)

Not sure what you mean by "adapter plate" ????
Please elaborate

Obviously a new spacer/adapter would be needed to finish off the intake. Is this what you meant ???

[sdbob]

Thanks Lynn and one and all this gives a lot to digest.Someone does have a different way of connecting piston to crank.It is being used by the armed services in those spy planes to stay aloft for extended periods of time as fuel mileage is better.This was developed by a mechanic playing with a childs toy.The 'rod' length can be adjusted.Tom Vaught Did you find anything out about that device? interesting Lynn about the M40 and the 200.GM did make a 2spd M40 in65.Would that reduce rotating weight?