nitrous on cast pistons?
Thread Starter
|
Elder User
Joined: Sep 2004
Posts: 500
Likes: 0
From: midwest
nitrous on cast pistons?
i have a 78 302 with a mild build but stock pistons and 8.5-1 compression. i was thinking about adding nitrous, maybe a 75 shot max, my motor is fresh and i have a 5 speed, will i melt the pistons?
Senior User
Joined: Jun 2003
Posts: 103
Likes: 0
With the proper tune, cast pistons will last as long as forged and can actually provide some factor of safety against detonation. The cast piston run cooler and tighter than forged. They absorb heat more easily and because of the tighter side clearance can transfer what heat is absorbed to the cylinder wall more easily than forged. They will not, however, tolerate even slight detonation for very long. To ensure safety do your homework. Learn about ignition timing in relationship to the nitrous/fuel mixture and the role that bottle pressure plays. Always jet on the rich side for the fuel, provide adequate fuel pressure and flow, and make a hobby out of reading sparkplugs and you should never have a problem. I know of a cast pistoned 302 that was sprayed with two stages of nitrous to the tune of about 250 HP worth for 2 seasons and several hundred 1/4 mile passes. I was absolutely shocked to find pistons that looked almost like new during teardown. Just be warned, nitrous is veeerrry addictive.... 
Elder User
Joined: Dec 2002
Posts: 649
Likes: 1
From: Monterey bay area
using stock cast pistons is not recommended being that detonation will destroy them quite quickly. Stock cast pistons also DONOT have the compression rings lowered in relation to the piston crown like specialty pistons do. Yes the cast pistons do tighten up better than do the forged....which is why you would built a tight toleranced engine with the forged to mitigate the difference on this factor. The forged pistons will put up with detonation alot better and THIS is what I call a Margin of safety.
Mixture as well as timing will determine how the engine runs when the NOS kicks in. Running on the rich side will keep the engine on the safe side. Just be sure to bury the gas pedal so the secondaries open up and dump plenty of fuel. Also have the secondaries jetted for that shot of NOS. I also believe that you can get a timing retard setup from MSD that has a ping sensor.
Make sure your ring material is also up to the task....Total seal makes good rings
Be sure to do your homework...
Mixture as well as timing will determine how the engine runs when the NOS kicks in. Running on the rich side will keep the engine on the safe side. Just be sure to bury the gas pedal so the secondaries open up and dump plenty of fuel. Also have the secondaries jetted for that shot of NOS. I also believe that you can get a timing retard setup from MSD that has a ping sensor.
Make sure your ring material is also up to the task....Total seal makes good rings
Be sure to do your homework...
Post Fiend
Joined: Jan 2003
Posts: 8,600
Likes: 4
From: Iowa
Make sure it's setup right, and it's getting the proper amount of fuel. If it goes lean you're done. Keep the timing set right. If you have ANY doubt about the mechanical condition of your motor avoid nitrous. If you have something not quite right in there, nitrous will make it go.
Cast pistons run significantly hotter in the center than forged. This is a well known fact. Cast and forged pistons will run the same clearances when they're warmed up. Forged pistons will run more clearace when cold though.
Cast pistons run significantly hotter in the center than forged. This is a well known fact. Cast and forged pistons will run the same clearances when they're warmed up. Forged pistons will run more clearace when cold though.
Senior User
Joined: Nov 2004
Posts: 166
Likes: 0
From: Tucson, AZ
the united engine and machine (they make keith black and silv-o-lite pistons) web site has an interesting tech article on the addition of nitrous to engines. it is pretty good, you should read it as an additional reference. good luck, garsten, tucson, az
Senior User
Joined: Apr 2004
Posts: 152
Likes: 0
From: Southeast GA
I've got a 351W in an '87 Ranger that has made maybe 5 passes out of the last 1,000+ on n2o. All on Keith Black Hypereutectic pistons..you know, the one's you can't use with nitrous. I spray 75hp off the line and a second stage, usually 125-150, comes in down-track via an NOS delay timer. There are several good rules of thumb...keep 'er rich, take out 2 degrees of timing for every 50 hp of juice, 1-2 #'s cooler on the plugs, etc. Nothing however beats the advice from the n2o system provider. I use a CompuCar kit and picked up 2 tenths in a quarter mile over my old NOS brand because "Fast Eddie", the salesman that travels to all the FFW and NMRA races knows his stuff! Give him a call and he can set you up right the first time. You get what you pay for! And for sure...run a fuel pressure cut-off switch that will shut the whole system down if the fuel pressure drops below about 5psi on a carbed motor.
Trending Topics
New User
Joined: Jan 2005
Posts: 10
Likes: 0
From: Shenadoah Valley, VA>
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
Butt-Head
Joined: Apr 2004
Posts: 9,448
Likes: 2,934
From: Reed Point, MT
Originally Posted by hotrodford87
I've got a 351W in an '87 Ranger that has made maybe 5 passes out of the last 1,000+ on n2o. All on Keith Black Hypereutectic pistons..you know, the one's you can't use with nitrous. I spray 75hp off the line and a second stage, usually 125-150, comes in down-track via an NOS delay timer.
'couse now he's running an 8-71 and 100 HP nitrous.......decided that hypers probably wouldn't take that, so he went forged.
Personally, I ran a 150 HP kit on my bone stock 460 for about a year (went through six 10 lb. bottles) before I got bored with 'the button'. Never a problem on casts, just kept it a tad rich.
Cody
Last edited by cleatus12r; Apr 13, 2005 at 07:17 AM.
Elder User
Joined: Sep 2004
Posts: 525
Likes: 0
From: Floriduh
I ran a 125 non-adjustable shot from NOS on my 302 with cast pistons for about 2 years with no problems. Then I took out the 302, put in a 351W with Kieth Black hypereutectic pop-up pistons...I've run that one for about 3 years now, and no problems...
Thread
Thread Starter
Forum
Replies
Last Post
DeckedoutF150
Supercharger, Turbocharger, Nitrous Oxide & Water/Methanol Injection
18
Feb 14, 2008 12:52 PM
46069dord
Supercharger, Turbocharger, Nitrous Oxide & Water/Methanol Injection
15
Feb 13, 2008 10:49 AM
moore89
Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W)
1
Sep 20, 2003 07:14 AM
