Nitro And Superchargers!

[Jack Gifford]

I'm afraid I have to echo what others are saying about nitro being too big a "leap" at this point.

To add yet another viewpoint to all the others: why not develop a comfort level of burning methanol, then up the boost as needed for your goal? Simply switching to one of the modern twin-screw blowers offers huge gains in blower efficiency.

[38flattie]

  Just a few basic parameters:  I built my 496 Dart BBC to run on 30% max Nitro (unblown) using 12 1/4 to 1 Compression which is as far as I feel is safe for 30% (okay, what the hell,  lets make it 35%)!
  Basicly, I used a Dart Big M tall deck block with billet main caps, ARP main studs, Callies Crank, Carrillo rods ($2200 a set),   . . .

Buddy, you've got 40% fewer main bearings than Bob, and you want to run Blown on Nitro? 

I understand that Colorado just legalized pot, but DUDE, you don't have to advertise it . . .

SHHHHH! They're watching....... lol!



Interesting responses, er...warnings! Lol!

Out of curiosity, how many of you have actually run nitro? I mean no disrespect, I'm just curious.

Here's my biased, and probably warped view on it. I don't think the engine knows if the extra cylinder pressure comes from added boost, or nitro- cylinder pressure is cylinder pressure! I believe the only way I can achieve my goals is with added HP, and alcohol alone won't get me there.

Of course, as pointed out, the engine may not survive. I'd rather give my everything to achieve this goal, than look back at a failure, and wonder if I could have somehow been successful, if only I had....

So, please help me make this engine survive, using this volatile stuff- feed me some useful info to keep me from unnecessarily grenading the engine!

  Just a few basic parameters:  I built my 496 Dart BBC to run on 30% max Nitro (unblown) using 12 1/4 to 1 Compression which is as far as I feel is safe for 30% (okay, what the hell,  lets make it 35%)!
  Basicly, I used a Dart Big M tall deck block with billet main caps, ARP main studs, Callies Crank, Carrillo rods ($2200 a set), JE pistons, Barnes six stage Dry Sump oil pump, external JK water pump, Donavan Gear Drive, front driven Mallory Mag IV, Comp Cams Cam and Roller Lifters, Jessel shaft rockers and 7/16" pushrods on Dart Heads, using ARP head studs, Cometic Head Gaskets (MLS), and NO O-Rings head to deck. I use a Edelbrock tunnel ram with a Enderle hat and a front drive Enderle pump.
  Now add up the cost of those parts and keep in mind that every four runs I get to remove the $700. pan to replace the rod bearings and now you are in the ballpark........
NOT INCLUDING THE BLOWER which you better be ready to restrip every four or so passes.
  Add in a new blower belt every few runs, and don't forget that the oil in the engine (I run eight gallons) must be changed every pass because of dillution.
  Now if you have the ball's to fire it up, try to remember to back the motor down first or your new blower and hat will be in your neghbors yard or living room, and you will never hear clearly again.
  Oh, once it fires, you are doomed................. nothing (except maybe Beer and Sex) will ever be of interest to you except....................... NITROOOOOOOOOOOOOOO!
                                                                                                                           One Run Bob (maybe 32% should be where I stop) 

Bob, Interestingly enough, I run many of the same parts as you- billet main caps and girdle, ARP main studs, Crower crank, Crower rods ($2200 set), Venolia pistons, Barnes dry sump, external water pump, Donavan gear drive, front driven mag, Elgin cams cam and custom roller lifters, ARP head studs, and new Cometic head gaskets. The Elgin cam, rollers, and Cometic head gaskets are new this year. I also run a 6-71 stripped blower, with Enderle bugcatcher and front drive Hilborn pump.

[SPARKY]

I read sometime ago that to double the horsepower N/A you increase the stress by 350% + or - 50%  to double the HP with turbos it only adds about 20% more stress on components.  Buddy I would sure look at Blow through Carbs, Turbos, Intercoolers, and Methonol---much higher knowledge base--- much more forgiving --- the alky broadens your tuning window and is much more forgiving! 

IF you were to CHOOSE to TRY do it on race gas --- all you have to do is break the seal or run 70-30 with you water injectors to be in the fuel class.

[Dean Los Angeles]

The amount of blown nitro grenaded motors can be weighed in the tons. Only because it's easier to do then on gas. But grenaded blown gas motors are out there too.

There is no end to the amount of horsepower you can create. Think 90 psi, 80 percent nitro AND nitrous!

The limitation is all in the metal components. Somewhere between running 100% methanol and the explosion is an answer.

If you think you have a target horsepower number then start with 10% on the dyno and tune for that. The result will point you in the right direction.

[jimmy six]

The people I would talk to is John Beck and Fred Dannenfelzer. They know how to make them live. My experience is 75% unblown and with that knowledge I can say a few things:

#1. Get a bigger gear and tire. Nitro makes a ton of torque, burns slower, and doesn't need RPM to do the work. That blown Caddie should do everything you need under 5000 (probably 4500)

#2. Don't let it unload. Learn to drive with that egg under your shoe. If you do get out of it go back in slow.

#3. Your car will never smell that good again............Good Luck

[Dynoroom]

I've run a couple of small blocks on the dyno with nitro. A "C" motor with 10% N/A picks up about 75 hp. No muss or fuss, kinda easy or no big deal. 12.5:1, no timing change, didn't delute the oil right away. Just a simple way to get 75 ponies.
The problem comes when you start pushing. After about 25% the details to keep making more power started to take the "fun" out of it. And as I'm sure you know or at least have heard it said.......... "we need just a bit more, lets tip the can".

Buddy, I know you have a big car, and it sure ain't very aero........ But 850 hp for 200?

[Bob Drury]

  Just to add to my previous post, when I stated that I built the motor for Nitro, it has to this date only made one pass (with 25%) burning Nitro and was shut off at the 4 mile at 225 mph.
  We have spent the last three years running straight Methanol trying to see how close we can get to the 250.5 class record (A/CFALT) on Alky alone before we start back on the Nitro program.  This is the only way I can afford (like hell!) to learn what the motor likes.
  So far we have gone 238+ which isn't too bad for a 12 to l motor (Alky likes 14 to l or higher) but I specificaly built this motor for the low dosage of Nitro (for my own sexual gratification)!
  When I (hopefully) restart the Nitro effort it will be on 20% and then gradually build back up 5% at a time.
  Nitro takes no hostages, you either treat it with respect or it will bite you right in the wallet.......................................  One Run, out.....................

[jl222]

 
 Buddy..just estimating on these numbers with the Bville pro computer program

  30 sq ft frontal area
  .4 CD
  3300 lbs
  510 hp =167 mph

  856 hp =200.7 mph

  Takes a bunch of hp to push a brick.

  If I knew your frontal area-weight and speed at Bville, Bville pro could calculate the CD and HP.

                   JL222

[38flattie]

Thanks JD, Bob, and Dean! That's good info! John Beck will do our tune on the dyno.

Yea Mike, it takes a lot of HP to push this brick!

John, Thanks! Frontal area is about 29 sq.ft, weight was 4400lbs, and speed was 166 mph. You were as close as you can get!

[desotoman]

Out of curiosity, how many of you have actually run nitro? I mean no disrespect, I'm just curious.

I helped a guy back in 1969 and 1970 run a Jr. Fuel car, so I will not be any help. We ran 85-90% at the time, and the one thing I do remember is running rich was way easier on the parts in the motor.

Here's my biased, and probably warped view on it. I don't think the engine knows if the extra cylinder pressure comes from added boost, or nitro- cylinder pressure is cylinder pressure! I believe the only way I can achieve my goals is with added HP, and alcohol alone won't get me there.

Why not alcohol and added Boost? Just curious. Another question. Is there a reason why this goal of 200 has to be met in 2013 ?  Sorry I am not any help, but as I said in my previous post I wish you the best.

Tom G.

[38flattie]

Out of curiosity, how many of you have actually run nitro? I mean no disrespect, I'm just curious.

I helped a guy back in 1969 and 1970 run a Jr. Fuel car, so I will not be any help. We ran 85-90% at the time, and the one thing I do remember is running rich was way easier on the parts in the motor.

Here's my biased, and probably warped view on it. I don't think the engine knows if the extra cylinder pressure comes from added boost, or nitro- cylinder pressure is cylinder pressure! I believe the only way I can achieve my goals is with added HP, and alcohol alone won't get me there.

Why not alcohol and added Boost? Just curious. Another question. Is there a reason why this goal of 200 has to be met in 2013 ?  Sorry I am not any help, but as I said in my previous post I wish you the best.

Tom G.

Tom, we will try alky and more boost on the dyno, but do you think that will be any different than nitro, in the fact that both ways I have more cylinder pressure? I do realize it would be a LOT easier to tune, if it will build the needed HP.

As for does it need to be this year- I wanted to take 2013 off, and get the engine ready for a special construction car- turbos, EFI,different intercooler, etc.. In fact, Sparky lent me most of the stuff for the conversion!

At the end of B'ville last year, I told the team this, and they weren't happy, so we held a team vote- I was the only vote for jumping right to special construction. Since everyone on the team does soooo much to make it possible for us to do this, I respect their collective opinion.

So, this year is for me to see just what the engine can really handle. 200 mph seemed a worthwhile goal to push the engine, and it's a one shot deal.

Ultimately, I want to follow in Jimmy Stevens and Ron Main's footsteps, and push over 300 mph. This engine with turbos and fuel will already make as much or more HP as Main did, but for how long I don't know. I also figure I'll need more HP than he did, because finding and fitting it in a car like the Speed Demon probably won't happen!

I know it sounds a lot easier than it will be, but I have time!

[stay`tee]

i ran a injected blown fuel bike (970cc Z based Kawasaki, Hilborne in frount of a 60c" Magnusson) back in the earlie 80`s, this was the begining of my nitro experience, but a divorce soon put a stop to that, ,,, over the last cuppla years i have been messing with the stuff in my inline n/a four (Kawasaki ZX12) and have seen a real gain at the wheel on the dyno and out on course at 20*,,
ive had zip experience with flathead chamber design, but have found that what works in a hemi head dose not necessarly work in a pent roof,,
keep a "real close" eye on A/F, every percentage change, along with temperature (both fuel and ambient) will "affect" A/F, the jimmy`s going to complicate this, but moniter "everything" and err to rich,  ,,
imho the biggest problem with "juice" is the naysayers, the WOW factor based on nothing else than seeing what it dose when people do not have a clue,, ,, if more folks started ignoreing this and had a go at small doses the information shared would be priceless, not to mention performance gained,,

[racergeo]

   Freud's post#3921 ranks number ONE for wit and wisdom! Some where in my extensive hot rod book collection is an issue with one of the first articles on running NITRO. It got into all aspects of what was known about the stuff at the time. Technical type stuff. How to modify your Stromburg 97 and the like. One of the pictures used was a pile of Ford V8 flatheads that had  given there all at Bonneville. If I can find the book and send you the picture you'll be able to superimpose your engine in the picture and make a cool T shirt to sell and try and recoup some of your losses. No thanks to Freud, I'm going to go and change my undies.

[JasonS]

I myself would love to build a nitro-burner but can't afford it. I say go for it . Going lean is when things go boom, and you need a healthy fuel system to keep LOTS of nitro packed in the cylinders. Here is some inspiration!

http://www.youtube.com/watch?v=WLFTO0Bx9-E
http://www.youtube.com/watch?v=NfQUc5F_JMs
http://www.youtube.com/watch?v=5dfTktM4JzI

[Dean Los Angeles]

Gasoline runs at 14.7:1. Very stable, well known properties.
Methanol runs at 6.4:1. Also very stable, and you do need twice as much.

Nitromethane at 1.7:1 requires massive amounts of fuel compared to gasoline. Trying to pour that amount through a carburetor is a tough deal. Injection is the only way to go.

So yeah, it makes a bunch of heat and pressure. It's much harder to reach the mechanical limits with gas or alky. Not so hard with dial-a-percentage nitro. Tipping the can is so gratifying! And the smell is sooooooo good. I love the smell of nitromethane in the morning. 

These days with sensors and data logging and dyno runs you have a much better handle on what the engine is telling you. Having a good dyno baseline will save you parts on the salt.

both ways I have more cylinder pressure?

True enough. Cranking boost allows you to stuff more fuel in, gas, alky or nitro. The only question you can't answer, and really don't want to answer, is what is going to break first.