NOS Question Jim V
 

Am considering NOS for a quick blast at kelo
runs. Engines are 600 ci with intercoolers and 1471's. I think I am makeing about all the hp I can with iron Merlin heads unless i add NOS. They now make 1065 with 12 pounds.
Ideas and help appreciated
Thanks Loy :)

Bruce I would appreciate your ideas also.
Thanks Loy

youa re gonna haev toi prop it to run under teh NOS. If it was propped for max speed withjout NOS when you hit the button at full tilt your rpms are gonna go through teh roof. I have heard taht NOS is good on blower motors becasue it casues the fuel/air charge to be lower so with more boost you are ok. You will also need to jet richer. The NOS will allow you to burn more fuel so you need to supply it. Talk to dustin whipple he does alot of drag engines. SO i woudl assume he has experience setting up blown NOS engines.

Of course you can only lead a horse to water....

I'll be glad when this forum has a spell checker!

grammar is totally out of the question.

LMAO :eek: :D :D :D

What rpm are you making 1065 HP, where is peak torque, what is WOT rpm now, how well is the exhaust side of the heads ported and what castings are they, what exhaust are you running in the boat, what is the camshaft duration/lift @ .050, what is the static compression ratio of the engine, what ignition system, and are you willing to dyno tune the experiment. The iron heads really concern me. My first instinct says replacement carburetors and alchohol for fuel. You could get much more controllable horesepower, but NOS could probably be made to work. I'm getting a headache already. :D

They make 1065 @ 6200 rpm, peak torque is 990
@ 4600 rpm. WOT rpm is 5900 to 6000. Heads were done by Inovation, don't remember the castings. Cam specs-685in. 692ex. duration is
269in. 276ex. Compression is 8.5, ignitions are FirePower by Nutek that are one the last sets made before Holly bought them. Exaust are CMI Sport Tubes and dyno is a yes.
Thanks again
Loy

bruce was i close with my comments? That is what i have gathered from what I have seen here and posted on other sites.

Blown1100,
1100hp is a very respectable number for iron heads. You may want to take a closer look at them, (iron heads) if your going to keep them. At 600 inches you need big airflow to feed the motor. Pressurizing the intake helps the 345cc intake runner, its the exhaust I would be conserned with. Are the chambers ported to the bore size? This is critical on the exhaust side for optimal airflow. The exhaust ports should flow 300 cfm at .700 lift. Also important is exhaust port volume. What size valves are in the motor? What is the header primary tube diameter? At 6200 is the torque falling fast? Does the boost increase at higher rpm? I dont think 12 lbs intercooled on racing fuel is too much. The NOS will definatly make the power but if the cam is too small, or the exhaust is restricted, you will see more power in the mid range and not so much on the top end. The easy answer is to change to Big Chief heads. I plan to run nitrous this year also. Im using two 175hp plates. I will dyno problaby in march. If your intrested I can keep you posted. And if you would, keep us informed on your project.

Blown 1100, you have a nice combination right now. Thanks for the data. My instinct tells me your limited by exhaust flow from making more power with your present components. I agree with Jim, the nitrous will probably add more torque mid range than top end. To fully utilize the nitrous addition you will probably have to prop up and keep the WOT rpm about the same as it is now. I feel the exhaust just really won't support much more rpm. Jim can help you with port work, it will also improve your existing power. It's your call whether your driveline can handle that much torque. Ideally you would use the nitrous to carry torque further up the rpm range without spiking up at the lower rpm. I just question whether the heads will allow breathing above 6000 rpm at larger power levels. Any good nitrous installation will add fuel and spray. I'd suggest a plate under each carburetor for distribution. It can be done, I question if the driveline can take it. Puder, your right, fuel must be added with the NOS shot. You can't do it with jetting, the spray plate has a fuel nozzle also.

so when you hi the NOS button it also spray more fuel too (in addition to what flows through the carb??

yes NOS systems have a fuel side and a nitrous side. nitrous bottle feeds line to selenoid and then thru plate or nozzle in intake if fogger setup. fuel side is tapped into your fuel system which runs to its own selenoid then to plate or nozzle in intake. when you activate NOS system both selenoids open at the same time giving you nitrous injected into the intake charge along with additional fuel charge. with the basic( low HP) bolt on systems there is no need to change your carb jetting only retard timing accordingly.

Yes Puder ,YOu normally run a second fuel system (lines ,pump ,and filter)to supply the NOS system. NOS needs a alot of exhaust flow ! I have used it on everything you can think of ,diesels ,boats ,cars motor cycles, snow mobiles . You need to realy open your exhaust and have the right cam to also flow the exhaust .You would also gain from a multi stage ignition retard switch. It will retard your ignition to pre set amounts when it senses boost or you spray NOS. I used to race lots of people that blew motor after motor by running a lean NOS system and too much timing . You could hear them popping and see flames out the exhaust as they go by . THere was one guy used to blow his carb off his car every week because he didn't have the NOS hooked up right and it puddled in the intake .After he shut it off ,you could almost count to 10 and it would blow ski high ! Sometimes just the air filter but a couple times the hole carb ! I ran out of gas one time with the "juice" on and took all the spark plugs off with the threads like a saw ! You could pull the plugs out with your fingers ! Didn't hert the motor . I don't know how ! NOS is great when hooked up right . And I have seen NOS (the company ) make some bad recomendations . I always run about 2 jet sizes richer then what they say in the fuel system for the NOS kit. Just like a carb ,better to start rich then lean . Lean goes BOOM ! Good luck Blown 1100 ! Sounds cool ! ;)

I think you guys have hit on the problem with the exaust because from 9 to 12 pounds boost top rpm and speed does not improve but it sure gets there quicker. We are going to do some testing in a few weeks I will keep everone informed. Thanks for the info. guys. Jim keep me posted on dyno results, that should put you well ouer triple digets.

Now you see why I was getting a headache at the start of this thread, I didn't want to be responsible for you gernading some nice engines!! NOS will make more power but the potential must be in the engine components to start with. I suspect exhaust flow improvements will help you make more power, your camshaft is certainly big enough. Now, back to my original recommendation of Methanol, that would make some power for you and your blower is big enough to be turned up. I can visualize about 22 lbs of boost and 1450 HP pretty easily. The fuel curve would be fairly tricky but it can be done. :D

22lbs of boost!!! are you kidding?

Methanol baby, it's a whole new world! Yes I'm serious. Puder don't try this at home, you need more experience than a computer will allow. :D

i run CAM2 in my 1986 200cc honda fortrax quad, it runs fine and teh smell is go so wonderful I could sniff that **** all day long :D

Bruce
I am intrested in Methanal but that is something I know nothing about.Is 1400 plus possible with the iron heads. A friend of mine will be dynoing his 658ci in about two weeks, It made 1300 plus on pump gas now he is adding a 300hp fogger system. He is the red 25 Daytona in Hot Boat that ran 122 at the ShootOut. Things may get exciteing next year. I will let you all know what happens on the dyno.
Loy :D

Blown 1100, go find a drag race guy and talk about alchohol. It is very possible with your combination, you may need to disable the intercoolers. Alcohol is a very different fuel, it burns slower and cooler, it will cool down as it goes through the blower and your exhaust gas temps under full load will be around 850-900 degrees F. I can do it for you, but the geography is a bit of a deterent. I'm sure you can find someone local, look for a guy running Pro Street Outlaw or building engines for tube frame level drag cars. They will be knowledgable in both NOS and alchohol. Or feel free to call or email me directly.