14
Nov

How Much Nitrous Can a Stock Engine Take? – Engine Masters Ep. 13


– Bye bye, little buddy. (rock music) (gears clicking) (motor whirring) (dramatic music) How much nitrous oxide can a bone stock short block take? That’s what we’re going to find out on this episode of Engine Masters, presented by AMSOI and supported by Mr.
Gasket and Earl’s Plumbing. Here’s the thing. Nitrous does not blow up engines. People blow up engines. And we’re going to show
you how to not be that guy. We’re going to take
steps along the way here as we make more and
more nitrous oxide power to show you how you can tune to actually prevent an explosion. But let’s be honest, there’s no entertaining in not exploding and there’s no chance
that that sucker lives. This is a stock Chevy small block. It’s a 305, so it’s no loss. No crying, dry your tears. ‘Cause that sucker is going to go. With it’s cast cranks, stock rods, stock bolts, cast pistons. It’s junk. But we have hopped it up a little bit. It’s got a Comp XE268
hydraulic flat tappet cam. That is an Engine Quest Vortec head. It has aluminum roller
rockers also from Comp. Big hankin’ single plane intake manifold. Big hankin’ 850 double pumper and of course, the precious. The two stage NOS Cheater, capable of 500 horsepower. But is that motor capable of a 500 shot? No. But we’re going to find
out how much it will take. First, we’re going to run into the Dyno and baseline this thing. And find out how much power this pooch makes naturally aspirated. AMSOIL knew that we were
going to splatter the guts of this thing all over
the Dyno cell walls. And they said, “You know
what, when that happens “it’s not going to be the oil’s fault.” Because, bam. DOMINATOR racing oil. They’ve recommended this
every time that we’ve gone with a super charge or
a nitrous application. Because it has a really
tough film strength, so the oil doesn’t squirt out from between the bearing and the rod
under that heavy pressure. But what’s interesting is
that they went this time with the SAE 60 weight oil
for the 305’s final meal. This is the equivalent of going to the chair for an engine. Yeah. (dramatic music) (engine revving I feel really guilty now. – [Voiceover] Yeah. – I feel like we’re
about to shoot a puppy. That thing runs pretty good.
(laughter) What did this thing make? 358 horsepower and 323
pound feet of torque. And look at the torque curve. – No, it’s good. It really is good. If this thing were in a guy’s Camaro with a 150 shot on it,
which we know we can do. This would be good. – Ready? – [Voiceover] Yup, ready. – Okay, nitrous time. With N O S nitrous. You can’t say nos. You can’t say noz. It’s clown shoes, just don’t do it. Here’s how nitrous oxide works. Stored here in this bottle, it’s liquid. You inject it into the
engine, it’s a vapor. And you’ve got all these little molecules that have one atom of
oxygen and two of nitrogen. And because you’ve got oxygen in there and you’re injecting it into the engine, you’re bringing more air into the engine. Which means that you can burn more fuel. When you burn more fuel and more air all smashed into the combustion chamber, you make a bigger
explosion and more power. Here’s how you do that. You inject the nitrous and
the supplemental gasoline into your engine with some
kind of a plates system. This happens to be a plate that goes underneath a Holley carburetor. It is an NOS Cheater two stage set up capable of 500 horsepower of additional nitrous into your engine. As I said, nitrous doesn’t blow up motors. People do. So people can take steps to make sure that doesn’t happen. And here’s what we’re going to do. You must control detonation when you’re on nitrous oxide. The first thing that we’re
going to do with that is run Rocket brand 118 octane gas. That will just control that detonation, help the thing survive
a little bit longer. Next thing you have to do with nitrous. Because that explosion happens so much faster than it
does naturally aspirated, you have to retard the ignition timing. Otherwise, the cylinder pressure is fighting the piston coming up. And that is just disastrous. What we’re going to do to prevent that is use an MSD power grid ignition system, which is pretty advanced. MSD also makes a bunch
of other lower end boxes that are designed to
retard ignition timing right when you hit your
nitrous oxide button. So you always want to do that. Spark plugs. When you’re running nitrous, you need to run a colder spark plug range. Now remember, that doesn’t mean anything about the power
of the spark itself. Instead, it is the temperature of the center electrode there, because of the length of the path to the cooling passage. So that is a very cold
spark plug right there. Also in your tune up, you really need to pay attention to your air fuel ration. You could hurt your engine
whether it’s too lean, meaning not enough gas,
or if it’s too rich. A lot of people say fat and happy. That is not necessarily true. You go too rich, you can
hurt your engine on nitrous. I highly recommend you get
an oxygen sensor like this and a reader to power it, and either a data logger or a gauge or something so that you know that you’re in a range of, say, 12 and a half to one, that wide open throttle on your nitrous. Remember. The air fuel ratio that makes the most power naturally
aspirated on your engine is the same air fuel ratio that will make the most
power on the nitrous. Now, that’s all a bunch of tuning steps that you can largely take care of with this chingadera right here. This is a nitrous controller. It happens to be an NOS launcher. This is a really advanced controller that can do a lot of things. It can shut off your nitrous if you’re too rich or too lean. It can read our nitrous bottle pressure. It can activate your nitrous in a whole bunch of different ways. Throttle switch, whatever
you want it to do. But most importantly, it can control the behavior of how you’re applying
the nitrous to the engine. Because you’ll hurt an engine if you just hit it with
the nitrous really hard. What you’d rather do, instead of hitting it like this, is give it a nice push. Put the nitrous into the
engine in a delay over time. And that’s what this can do. We can ramp the nitrous from say, 50%, to 100% power delivery over a period of time that we select. You’ll see that as we move on today. Now, the last thing that
we didn’t control at all in this test is the fact that you want your engine to have good internal parts. Forged pistons, rods, crank. Our 305 has none of that. Here’s what the problem with that is. Not only can the pistons be fragile and just fail under the power, but a big deal is piston ring end gap. Of course, the piston ring goes in here. Seals the piston to the cylinder. Now the end gap right there, of course, gets much smaller when you put
this thing inside the engine. The problem is, if you are gapped for just a regular street engine, when the ring heats up under nitrous, that gap can close up. When it does, it breaks the piston. That’s probably what we’re
going to see here today. And it could lead to catastrophic failure. The smart thing to do is to take any engine apart that
you’re going to run with a power adder and just file
those rings further open. Did we do that? No. But I bet you this thing will
live through the 150 shot of nitrous that we’re going
to start with right now. We’re going to spray it? – [Voiceover] Yep. – Yeah. – Got all the wiring
tidied up and everything. (chuckles) – [Voiceover] Sweet. – Okay, we have this
thing set up right now just on one stage, it’s 150 horsepower. We already have it jetted. We’ve already verified when it’s running naturally aspirated that the MSD is pulling the timing out like we want to. It’s got 35 degrees
total naturally aspirated and as soon as we hit the nitrous, it drops to 29 for the
150 horsepower level. This is the handheld controller
for the NOS launcher. You can go through the menu
here and do all the settings. I’m not going to ramp the nitorus in on the 150 horsepower set up. We’re just going to hit the button, boom. 150 horsepower, later on you’ll see it’s tuning more with this. So the last thing we have to do is hook up the hose to the nitrous bottle. We are monitoring pressure
very carefully here. You want, like, 950
pounds of bottle pressure, and we need that to be
stable through all our tests. Just because that’s a way
to maintain a consistency and to make sure that you’re delivering enough nitrous to the engine. If the pressure is down, it’ll go lean. What we’ve got here is a hot water bath for the nitrous bottle. We’ll throw it in right here. And the perfect temperature
for it is 92 degrees. Look at that. As if by magic, it is at 93, 92. So that bottle is set. Going to hook up a line directly
to the nitrous solenoids. And bam. Got it fired up, bottle’s open. 150 horsepower ready to go. Are you going to purge it? (speaking indistinctly) Is this going to blip it? (motor whirring) (engine revving) Our 350 horsepower 305 is making 537 horsepower, no. – 557. – 557 horsepower.
(chuckles) (laughter) 200. That happens a lot, actually. We notice that… The factory jetting
ends up delivering more. Ho are we looking on air fuel ration? – Well, I have to tell you. Part of that is because
when the system is optimized and you’ve looked at everything as far as air fuel ratio and timing. And it’s all doing… What it’s supposed to do. It’s not unusual to make a little more power than they’re actually rated. – So what’s our call right now? – I’m already impressed. I say we just put it to bed. – I know it’s pretty happy. – Put a blanket over it and say we– – [Voiceover] That was good. – So, this is a good setup. Right? – It is. – Yeah. Let’s step it up. – What would be better? More power. – Yeah. – [Voiceover] Using your wrench. – Just leading the pressure
(air hissing) out of the line so it
doesn’t seep into the engine. Always a good precaution. What we’re doing here is changing the jets
in the nitrous system. – [Voiceover] There’s your jet. – And these are very much like jets in a carburetor. They’re just a metered orifice. This thing has a whole in it. It is a fixed size. This one, I believe, we just ran was 63 on the nitrous, 59 on the fuel. – You never want to put more nitrous in it without getting the right
amount of extra fuel in. Or you might just burn
the whole thing down. – Now that we’re stepping
up the power levels, I don’t want to smack the motor as hard. So instead of going
all the nitrous all in, I am going to ramp it
up so that when Steve hits the button, it gives
us 50% of the nitrous hit. And then goes up to 100% over one second. Now we’ve got it jetted to 250. I think we’re finally going to
see that 305 crest 600, right? – [Voiceover] That’s the idea. – Unless you pulled out too much tining. – [Voiceover] Wow. – [Voiceover] That would be awesome. – [Voiceover] Just trying
to be conservative. – Yeah. (dramatic music) (engine starting) (engine revving) (yelling) Two horsepower per cubic inch. – Whoa. That is awesome. – That is awesome. We’ve just made 620
horsepower with a 305 Chevy. Exactly two horsepower per cube. – [Voiceover] Wow. – That’s hilarious. I’ve gone through the
emotional roller coaster. – Really? – Because at first I was
like, this is a junk 305. We’re going to scatter
it against the floor in Steve’s Dyno cell.
(chuckling) And then I was like, I love that warm and cuddly 305
that’s making good power. And now, I want it to make 700 and live. I don’t want to blow it up anymore. – Well, you figure if
anything pays you back that high of a dividend,
then it deserves to go back. – You can’t put it down. It’s no longer like Old Yeller. – [Voiceover] No. – Yeah, it’s not.
(laughter) So next step, two systems, 150 each. And I’m going to go into the control room and we’re going to ramp both
of them from 50% to 100%. – [Voiceover] Right. – [Voiceover] That’s the thing,
I’ll get the bottle ready. (suspenseful music) (engine starting) (engine revving) (groaning) (engine sputtering) – [Voiceover] Wow. – There we go. I’m going to call that
head gasket, how about you? – No, it slipped out the… That was blow by. – I let off the butt. – I didn’t like that,
something went wrong. Lot of smoke out the valve covers. Okay, I think we owe it to the 305 to tear the heads off
and see what went wrong. I want to see how hurt it is. – It’s not catastrophic, though. It’s still in one piece for the most part. – Yeah, rods aren’t hanging
out of the bottom of it. – That’s positive. (laughter) – Okay, and… This one’s hurt bad. – [Voiceover] What do you see? – Piston on it. This is out of the number two cylinder. And look how it’s got silver all over it. In fact, it’s filled up the crevice there between the porcelain and the metal here. That is aluminum off the piston. And there’s some oil in there too. This is the number four cylinder, and you can see that it’s
got some of that also. And it was a little wet
when we first pulled it out. So our guess is that it
just killed a head gasket between the number two and four cylinders. But what we really want to do is putt it apart and find
out how dead that piston is. – When you melt your piston and completely fill up your spark plug, that’s usually not good. – [Voiceover] Right. (light music) – What are those little
chunky metallic bits? (laughter) – [Voiceover] That’s piston. – [Voiceover] Yeah. – [Voiceover] Piston sand. (drill whirring) – We gather here, not to mourn the death of the 305. But to celebrate the nitrous
horsepower in the 305. – That’s right. This is not a funeral, this
is a celebration of life. – That’s right. (groaning) – Yep, it pinched a ring. What you can see here really clearly is just classic nitrous failure with an engine that is not nitrous ready. Right here, the whole top
of this piston is missing. Just fractured, and it’s beat up here from the pieces flying into the
chamber and getting smashed. What happens is that the piston ring, which I can see the
end gap is right there. It butts together and
then lifts like this. Because it’s a circle,
it’s got nowhere to go. It’s got to expand somewhere. It cracks the piston, and then the piston just destroys itself. We are lucky that the
piston didn’t shatter. And then the connecting rod swings around, just saws the block in half and you end up throwing away everything
underneath the carburetor. This thing’s actually saveable. The cylinder wall’s not even that bad. Poor baby. (soft music) We made two horsepower per cubic inch out of a 305 Chevy. – And then we blew it up. – You know, this was the completely textbook, predictable result
of what we were doing here. But I think the real lesson is if you want to do this, take the engine apart. File that ring end gap wide open. Just let it be junk. And then you can spray
a lot more than we did, because the failure was
nothing more than that. – You’re changing your tune, now. It was a blown head
gasket in the Dyno cell. – [Voiceover] It did blow the head gasket. – [Voiceover] Yeah. – [Voiceover] After that happened. (laughter) – I guess you’re right. So we were both right on that. But it did pretty well,
I’m proud of the 305. – You know, can you really
call us engine masters when this happens? You can’t, and that’s
a wrap until next time on Engine Masters, presented by AMSOIL and supported by Mr.
Gasket and Earl’s plumbing. (gentle music) You got to make sure not to touch the nitrous when it’s coming out. It will literally burn you. – [Voiceover] Wow. That was dangerous for our burner. – I know. You know what this 305 is like right now? – [Voiceover] What’s that? – It’s like a puppy on your farm. – Oh no. – Yeah, it’s a nice,
cute little warm puppy. You like with it and it’s a good doggie. But you know it’s not going to last long. (laughter) – What are you saying? Now I’m a puppy killer? – It’s true. Well, we kind of know what went wrong. But now we’ve got to tear it apart and actually see what
the level of death is. ‘Cause death on an engine is not really a black and white situation. – Unlike a puppy, which
is either alive or dead. (laughter) – [Voiceover] Here we go with the puppy. – More definitive… When you’re talking puppies. 305s, there’s more gray area.

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