I have a .040 over 350. Forged flat top pistons, and stock rods and crank in a Mexican block. My plan was to get some forged rods and have the rotating assembly balanced by a good shop. The top end of my motor is 882 heads that were partially ported (from what I see), 1.6 roller rockers, cam with ".510" lift(as told by previous owner), victor jr intake, 850 demon carb, stock hei distributor, accel super coil, longtube headers into true duals with cutouts and flowmaster 40's. I would like to spray a 200shot(possibly in a dual stage 100/100 or a progressive shot). I was also planning to have main studs installed aswell as ARP head studs. The vehicle will mostly be used to cruise around town, but I would like to be able to keep up with some pretty stout big blocks and LS1's in my town. Any help or advice would be greatly appreciated.

 

with spraying 200 shot its critical you have good fuel supply and correct tuning. i would say with forged pistons and rods that a 200 dual stage or progressive should be ok, you may want to invest in a dedicated fuel system for the nitrous witha 110 octane as well. Make sure you bump you timing back (retard). the rule of thumb is 2* per 50 HP for a baseline. you may want to make some dyno pulls to get your A/F ratios or invest in a wideband before you just go spraying away. Another thing is plugs, with that large of a shot go 2 steps colder and run about .35 gap on them, i suggest autolite 103's or NGK tr-6's (thats what i run) If you plan on running 200 consistantly and you're going to be putting forged pistons, you might want to put a little extra gap in the rings so the ends dont meet...that would be very bad.....

 

Get some better heads

 

Are the 882's not up to the task? I was going to buy some aftermarket heads, but I figured I could make up for the lack of head flow by shooting a 200 shot rather than just a 100shot or 150. Does that make any sense?

 

As mentioned above do a dedicated fuel system for the nitrous.
1gallon fuel cell mounted up front with a good electric fuel pump.

If you deff. plan to run 200 or more Watch the ring gap as said above also.
You should be fine. for what you want.

 

Stock 882's are good for around 400bhp with everything else well matched, assuming whatever grinding that was done on them didn't screw anything up.

 

Stock 882's won't even make 300hp.

A simple swap to a set of vortec heads will get you no less than 80hp and a ton of torque over 882's.
You will literly think you are "on the bottle" all the time. You'll be much further ahead.

 

You are joking, right???

 

No. its the real deal.

 

Yea, 882's are pretty hurtin' brutal. You *could* get 400BHP out of it, but we're talking on an engine dyno, with a big solid roller cam and electric water pump and no accessories. Like flat out magic.
They're not great heads.

You surely won't look back if you go vortec.
Gap the rings big, like .030" for the top ring. You'll be fine then.

 

No, 882’s are not great heads but they will make 400bhp with the right combination of parts, and swapping to a set of vortecs will not give you an automatic 80hp, maybe 10 if you’re lucky over that combination optimized for the 882’s. Hell, there is only about 15cfm difference in peak intake port airflow which is less the 30hp in a perfect world…

There’s a bigger airflow difference going from most post ’85 f-body heads to 882’s than there is going from 882’s to vortecs.

 

What?
I'm gonna have to go find some flow data on 882's, last I checked they barely squeaked past 200cfm at .500" lift on intake, and I mean barely. Vortecs run in the 230-240cfm range out of the box. Then the superior swirl, and even more important, the low lift flow - which kicks the the 882's in the rocks.

post '85 F-body heads are inferior to the 882's? Que?

 

those stock rods wont handle the sudden diiference in the combustion. they will break very quickly and will ruin your whole engine.

 

lmao....

 

Do I really need great heads to spray a big shot of nitrous? I figured good heads were better, but not really needed if you were on the bottle. What if I was to only shoot 125 instead? Would the 882's handle it? Thanks.

 

More importantly will the fuel system handle it.

 

Good point. I plan on adding a good mechanical pump(not a fan of electric pumps).

 

882’s are usually good for 203-210 cfm in the .450-.550” range.

I’ve never seen a set of stock vortec heads flow more then 225, and you’re not going to get .500” out of stock vortec heads anyway.

Confused sums this up pretty well.

 

Could you rattle off which particular casting numbers you are referring to when you say post '85 F-body heads? 416's were still used then, so were 081's. 187 enter the mix as well.

I think you are the only member i've seen touting the 882 cylinder heads. Are you saying that 882's will compare near to Vortecs? I am saying the vortecs will far surpass them, do you disagree with me there?

https://www.thirdgen.org/forums/tech...882+flow+chart

https://www.thirdgen.org/forums/tech...882+flow+chart

Most members will agree that our 305 heads can be ported up very nicely, where 882 heads would have the tendancy to crack, and still flow poorly. Since he has ported 882 heads, and plans on using nitrous, I think ported 416's would work better.

 

Crossfire: I can tell ya first hand that 882 heads will not make power in stock conditions. I don't care what you read in a hot rod book about what they flow.

A stock 882 head without tons of porting has a real hard time making 300hp on a street 350.
I've had on the same 350 short block in the same car stock 882's and stock vortecs. Trust me, there is no less than 80hp and a ton of torque actual difference. There is 1 full second quarter mile difference. About 5mph difference in the traps.
My ported large valve 305 heads are right there with (almost as good) the vortecs and smoke any stockor ported 882 heads short of a full superstock welded port workup.
The exhaust ports are a mess. The combustion chamber is the worst ever of any SBC head.
the vortec heads are way way better. there is way more to these head performance than the raw peak flow numbers.
Vortec heads flow more air at .300" and .400" than any other out of the box 170cc port head and more than many larger race heads.

Swirl, tumble Air fuel mix quality and combustion speed, are detonation resistance are way way better. We won't evn get into fuel mileage while cruising or emissions levels.

If you want a 14 sec hot rod, use 882's. if you want to go fast your first best move would be to ditch them. They are that bad. Somewhere I have the dyno test that proves tha the vortecs add 80hp over stock 882's. This was on a mild typical 350ci sbc. No tricks, nothing special.

 

Its not a matter of wether 882 heads will handle it. They are not going to melt. They are just junk frickin heads.
They do not flow. No flow= no power. The popular "cylinder head flow data base" that everyone uses to compare cylinder head flow is full of ****. They flow less than 200cfm with stock 1.94" valves and no porting. Even when ya port them they suck. the 882 heads in that magazine article had been worked over a bit. They are not stock.
Instead of trying to make up for junk heads with a ton of NOS. Buy some good heads. You'll go fast ALL THE TIME.
Then add a moderate safe amount of NOS (150-180hp)to that motor with the good heads and go faster than you will ever need to go. It will be cheaper and better overall.
You'll trash the motor trying to make up the difference in performance between stock 882s and any good head like a vortec or....(insert favorite brand performance head here)
using more NOS.
if you want a turd, use the 882's. if you want to go fast, nitrous or no nitrous, get better heads.

 

Before ya get yer guns a blazin' and all NOS-ed up with no where to go. You had best get your fuel system worked out.

For a powerful street nitrous system that will not let you down you need a dedicated fuel system with an electric pump and a regulator for the Nitrous. A Carter #P4594 is a very reliable 72GPH 7psi, OEM/Military spec electric fuel pump that will outlive you. The price is hard to beat. Its perfect for a N2O system up to 250+hp. Use a holley regulator. Install a small 1 gallon fuel cell and the carter P4594 pump and regulator under the hood Use 3/8" braided line to the regulator near the fuel solenoid.

If you want a reliable easy cheap fuel system for the motor, use two Carter P4594 pumps at the back of the car feeding off the fuel tank and run two 3/8" fuel lines to the carb. At 7psi pressure, no regulator is required. Thats 144GPH. Good enough for a 10sec car. They last forever unlike other pumps. If one happens to crap out they are dirt cheap to replace and available everywhere. When properly rubber mounted they are not very noisey. A mechanical fuel pump on a third gen tends to pick up a lot of heat. A hot pump cannot move the fuel. It cannot move air bubbles in the hot fuel. (vapour lock). You do not want to get into a vapour lock condition ona NOS feed motor. Instant blown motor.
These Carter electric fuel pumps were origionally designed as a OEM/Military quality full duty cycle pump.
many of the electric pumps were not designed for constant use. Like the blue Holley pump.

 

If you want a 14 second hot rod pull one or 2 plug wires on a stock TPI 3rd gen and you’re there.

One of us is obviously doing something wrong…

No, I’m not saying that 882’s compare to vortecs, but I am saying that they’re not as far apart as you make them out to be. The biggest issue with 882’s is that by the time you make some power with them you’re most likely to see their tendency to crack, so I wouldn’t waste much money doing any real work to them.

Ok, lets get real here… the question was can he spray a 200shot and will this keep up with the LS1’s and big blocks floating around town.

200 shot- depends more on tuning and bottom end and how sanely you use it. If you make mile long runs spraying (I know someone that amazingly managed to do that on the street), you will blow headgaskets, crack heads, break rings/ringlands, pound the bearings out of your bottom end… If you use it sanely it will be fine, though I’d step up slowly with the spray till you know things are right.

Ported 882’s, cam lift numbers with no duration, vague engine specs… could be anything from a 150 to 450hp engine, depends on the details/tuning. Add 200hp even to the bottom end of that and you’ll have a 12second car, possibly MUCH faster, and if it will beat the big blocks and LS1’s tooling around town is more up to your tuning and driving than anything else.

To be blunt, most of the hairy 10second big bocks run 13’s when they finally go to the track, and most LS1’s run high 13’s/low 14’s when they finally go to the track. A well tuned, stock bolt on 3rd gen with a driver that knows what they’re doing can go hunting for most of that prey successfully, start throwing hundreds of HP on top of that and I’ll know for sure that the car will be able to do it…

 

Yea, that's the cold hard truth, they're not that great without a good driver and a good suspension setup, etc etc.


And yea, I certainly wouldn't spend any more $ on them now. If the porter before hogged the crap out of them, you've got even more tendancy to crack under high cylinder pressure (nitrous).

Anyway, it seems like we're all on the same page now, so the original poster can make up his mind with where he wants to drop his paychecks now.

 

"One of us is obviously doing something wrong"

Well here is the car. Have been "doing" it for over 35 years.

One of us has actually tried 882's and vortecs on the same motor, in the same car. The other, has not.

The other, reads too many Hot Rod mags and takes every bit as gospel.

 

Heh, it’s taken you >35 years to get a burnout picture of yourself??? ****… I’m not even that old and I’ve had 4 different pictures of me doing a burnout or launching in 3 different magazines. 4 cars that I’ve built for others have had magazine articles written about them, as has a custom supercharger setup that I was involved with building and that car gets invited to a major magazine’s tuner event regularly. One of the cars was “best cars that didn’t make it” WRT to the first pump gas drags… Please, quit wasting everyone’s time, idiot.

Enjoy:

(though I’m not sure what having a picture of me at the dragstrip proves besides that I’ve been to a drag strip, at least this one was at an event an in a magazine…)

 

Well, I've decided to put the spray on hold and address the heads issue. So far my options look like some ported 416heads with bigger valves or some junkyard vortecs with fresh hardware.

 

THEN DO AS THE OTHERS HAVE STATED - ADRESS THE FUEL DELIVERY SITUATION, AND FOR SAFETY GET A HOBBS SWITCH JUST IN CASE

 

Hobbs switch....good idea. I'm gonna add an electric pump to help out the mechanical pump. Will that cover the fuel side of things?

 

that depends on the supply line from the tank and your filter setup - start out small - 200 is a big shot not to have a dedicated fuel source for, that is why a hobbs is critical if the fp isnt there it wont let the nitrous solenoid energize ( if you have it wired correctly)

 

The draw back with a engine mounted mechanical pump on these cars is heat soak. They can flow enough fuel but not when the fuel is hot. Because the pump sucks the fuel from the back of the car, it creates a low(ered) pressure situation on the feed line from the tank to the pump. Any time you lower the acting pressure on a (liquid)fuel and add heat, it boils way too easy. Much easier than if the line as pressurelized or even at atmospheric pressure.
When it does boil in the fuel line, even a little, the mechanical pump cannot move the fuel.
(vapour lock) Then your fuel pressure takes a dive.
If you want to run hard with nitrous (200hp shot) I highly recomend you eliminate the mechanical pump altogether and use a electric pump at the back to move the fuel to the carb with the least amount of heat soak. That way you will get a much more reliable rock steady fuel pressure, even on a very hot day.
Then run a seperate fuel system (pump lines, regulator) dedicated to the nitrous system. The nitous system requires a specific, adjustable rock steady fuel pressure.
that is different that what the carb needs.

With the milder 100-150 N20 shots you can get away with a lot of evils. When ya get to a 200hp nitrous shot, when things like fuel pressure are not 100%, $$$$$bad things happen in a big big hurray$$$$$.
I prefer to run a mechanical fuel pump on a street motor as well but on these cars with their cramped engine compartment etc etc the things are real hard to keep cool enough on hot days to ensure a rock steady fuel delivery.

You will also need a ignition timing retard box that you can trigger when you engage the N2O. For a 200hp shot on pump gas I would retard the timing to 24degBTC and work up little by little, from there.
I perfer to run a front mounted 1 to 2 gallon fuel cell+ electric pump under hood for the nitrous. That way I can fill it with high octane racing gas. Cheap insurance against busted pistons.

You have a lot of good choices as far as cylinder heads go. I just wanted to help ya by showing you the real limitations of the 882's. Haveing been
in the same boat.....
With facts, not magazine bull..... The newer design LS series small
blocks run pretty hard, especially when modded and tweeked. So if you want to run with them you're going to need to bring all the ammo ya can. Spend the $$$ where it will do the most good.
Nitrous or no nitrous you're going to need a good high flowing cylinder head that has a good combustion chamber (like the LS1/Ls6 heads do). The 882's just don't cut it on either account. In the long run you'll run faster, a lot longer by investing in a true modern high performance head now and using a milder N2O shot. Buy the best head you can afford.
It costs money just to fill the bottle. And that adds up fast.

 

I'm checking out some vortecs now and I'm looking into a good cam/stall/intake combo at the moment. I will probably only shoot a 100 shot to keep it safe and less expensive. Thanks for you help guys.