Worst engine in KSP

[ImmaStegosaurus!]

I'm going to say Reliant is pretty much best stock engine in early career and thrust vectoring is overrated. I wish more engines had a lighter, more powerful and cheaper variant without gimballing.

I've never understood how to use Juno. That thing is next to useless.

[magnemoe]

6 hours ago, GoSlash27 said:

In defense of the LV-T30:

 It's an engine that's so underrated, I consider it to be a secret weapon, especially in career mode. There are very few LFO engines that can beat it in terms of cost/ tonne to transstage burn, and those engines are way too big for early "caveman" style missions, where mass on the pad, part count, and price tag matter.

 I probably use the LV-T30 more than any other engine in the game in career mode.

Best,
-Slashy

Yes, fins works well for control under launch. my standard for smaller payloads even in late career. 

[storm_soldier2377]

1 hour ago, magnemoe said:

Yes, fins works well for control under launch. my standard for smaller payloads even in late career. 

It is better to use an LVT-45 with thrust vectoring than and LVT-30 with fins for small payloads because vectoring works in a vacuum and thin upper atmosphere. Regardless, both engines are rendered obsolete in late game by spaceplanes.

[KerikBalm]

6 hours ago, ImmaStegosaurus! said:

I've never understood how to use Juno. That thing is next to useless.

I'd say its more useful than the goliath. Its got a higher top speed, and does a little better at altitude, making juno based SSTOs barely possible

But... aside from micro SSTOs (which would have to land in the water by KSC because they lack gear, and I think putting on a chute big enough to let it land on the runway prevents it from making orbit).

IMO, this is the real use of the Juno:

 

The Junos advantage is that its small. Small is good for the payload, not the booster. If I want to send something of its type to a destination, its best to send something small - so the Juno gets picked when I want to send something of "its type" to a destination. Since its an airbreather, that means laythe is the only destination. I don't just use it for aircraft, but also small laythe watercraft. My laythe based has some "fuel trucks" to take fuel from an ISRU to a vessel.If that vessel is in the water, the fuel truck needs to be amphibious, and I use a juno or two to let it putter out to the ship or seaplane just offshore - then fuel it up (via claw), and then putter back to shore where its wheels can be useful again. Rockets would consume way too much fuel, and 1.25m engines would be much bigger than needed, but I guess a wheesely would be ok. I've also considered 0.625m based laythe SSTOs. I'm not sure if they could take a kerbal in an external command seat - but laythe is much easier to SSTO from, so a Juno SSTO should have enough of a margin to mount some science equipment.

FYI, plots of the fixed points in the thrust curves (to be more accurate, I'd need to use the tangents)

Its not super high speed, but it can produce useful thrust at higher machs than the wheesely/goliath (about +0.4 mach). Its not as good as the Panther in dry mode - which may seem weak at first, but if your craft is designed right, it can go over 600 m/s surface velocity on kerbin in dry mode:

Which gives very good range (just based on that picture, 43.5 min at 627 m/s means 1,637 km range, which is enough to reach any point on laythe from any starting point laythe, but not quite enough for kerbin... it would do even better on laythe thanks to the lower gravity meaning that AoA and drag can be lower as it doesnt need to produce as much lift)

However, its got another advantage, and that is its better high altitude performance, Whereas the panther in dry mode, or the goliath barely have 1/10th of their sea level thrust at 1/10th of an atmosphere, the Juno has nearly 1/6th of its sea level thrust at 1/10th of an atmosphere.... so it can climb higher, or travel at higher speeds up high than you would expect based on comparing its performance with the wheesley and dry panther at sea level.

Sure, its still clearly not even close to the utility of the panther-wet/whiplash/rapier for SSTO applications... as those three engines have stats off the chart for that first chart... and 2 of those threee way outclass the juno as shown in the 2nd chart. But its better for high speed/altitude/spaceflight applications than the goliath and wheesley, as long as you tolerate its mediochre Isp and lack of a thrust reverser.

The stat difference between the goliath and wheesley is so small, that I just don't bother with the goliath.

Even when I want to send big stuff to laythe... I don't use it

Its got a pair of turboramjets for electrical generation (since rapiers don't have alternators), and it can fly with just the pair of truboramjets (not very fast though) getting 4,000 Isp... which is enough. Past a certain distance, its more efficient to go suborbital than to putter around in the low atmosphere even with a fairly high Isp.

And if I want something big that has good range, and can putter around for a while in the low atmosphere with a good TWR, I still don't take the goliath... I take the panther because 9000 Isp is good enough, and then I can still light the burners and get a good surobital trajectory going... and I can even get orbital with a rapier "module" in the cargobay.

- there's the panther one(also a sea plane) in the background, with an early version of the rapier+turoboramjet SSTO transport in the foreground)

Also, the 1.25m profile of the panther pairs well with Wheesely on the front... usin thrust reversers to get even more forward thrust for only a 1.25m profile (yes the reversed engine + thrust reverser thing is a bit exploity). So the reversed wheesley + inline intake+ panther give a lot of thrust for minimal drag ... beating the goliath, it gives useable reverse thrust (but stopping reverse thrust on the wheesleys and stopping the panthers)... it gives a good atmospheric cruising speed, suborbital capabilities, and orbital capabilities at the cost of any payload capacity:

Why would I use the goliath?

[Sereneti]

the juno is a good engine.
if you have to go to a place of kerbin, and make some experiments, you dont need an kerbal for that.
a small drone, with the needed EQ do the same job. better.

a small probe dont need a lot of fuel, and can be reused for another contract at the same place...

 

[GoSlash27]

I use the Juno for 2 things in career:

Science carts for gathering science from around KSC...

... and small planes for gathering science from other Kerbin biomes. Very useful little engine.

Best,
-Slashy

[Hotel26]

One more upvote for the Puff.  Two of them in the xenon/monoprop craft pictured (Gossamer Albatross) is enough to achieve 300 m/sec cruise and then slow to land so I have no doubt it could even make it into Mun orbit.  Weight and endurance were critical factors and carrying more than 2 kinds of fuel was not feasible.

Edited July 27, 2016 by Hotel26
rationale

[magnemoe]

5 hours ago, storm_soldier2377 said:

It is better to use an LVT-45 with thrust vectoring than and LVT-30 with fins for small payloads because vectoring works in a vacuum and thin upper atmosphere. Regardless, both engines are rendered obsolete in late game by spaceplanes.

LTV-45 is more expensive and have lower trust, you would often also need the fins anyway for stability with an wider payload. Spaceplanes has cargo size restrictions too and require recovery to be economical. 
 

[storm_soldier2377]

7 hours ago, magnemoe said:

LTV-45 is more expensive and have lower trust, you would often also need the fins anyway for stability with an wider payload. Spaceplanes has cargo size restrictions too and require recovery to be economical. 
 

While the LVT-45 does have slightly less thrust, it works out more economical by not needing to pay for fins. You don't need fins if you know how to fly your rocket. While yes, a spaceplane does have cargo size limitations, they do replace the LVT-30/45 engined rockets for the small cargo niche later in my game.

Edited July 27, 2016 by storm_soldier2377

[magnemoe]

11 minutes ago, storm_soldier2377 said:

While the LVT-45 does have slightly less thrust, it works out more economical by not needing to pay for fins. You don't need fins if you know how to fly your rocket. While yes, a spaceplane does have cargo size limitations, they do replace the LVT-30/45 engined rockets for the small cargo niche later in my game.

Most of my cargo is oversize at this time so it would still need fins., my two last 1.25 meter missions was an scan probe to dock to an mothership and an 2.5 meter heatshield for and module brought back from duna, 
And yes I'm switching to and 2.5 meter rocket ssto with two aerospikes now, its based on my 8 kerbal passanger ssto but with an fairing instead of crew module.
Not an pure ssto as I eject fins before circulation. without 4 basic fins the fairly stubby rocket tend to tumble at 20 km, this however mess up reentry, my only lost kerbal was under renetry of my one kerbal ssto, I thought the open service bay below pod was enough to stabilize. but it tumbled at 30 km and everything blew up 

[Tweeker]

The Poodle,

       This thing has never been intuitive to use. At it's best it is a good second choice. But it rarely ever the first choice.

Edited July 29, 2016 by Tweeker

[magnemoe]

7 hours ago, Tweeker said:

The Poodle,

       This thing has never been intuitive to use. At it's best it is a good second choice. But it rarely ever the first choice.

Poodle is good but an niche engine, its nice for an medium upper stage or landing engine for heavier stuff like bases or miners because its so short. 
think of it as an 2.5 meter 909. 
 

[mk1980]

kinda hard to say. there are several engines that i wouldn't miss if they were completely removed from the game.

i guess the most useless is probably the Goliath. not because the engine itself is bad. it's just designed for a niche that is pretty much non-existent in the ...let's say "core game". there's no real use for atmospheric airliners or cargo planes, and even if there were, chances are that you'd probably use supersonic/hypersonic engines.

 

the puff monoprop engine is a real contender for most useless engine. it would be useful if LF/O engines could only ignite a limited number of times or something. this limitation doesn't exist in the game, though. which means it's just a low thrust engine with horrible Isp. and it even requires a special fuel type to work.

[kiwi1960]

IMHO, all engines are good, and all are bad... depending on the job you want done. If you need an engine to get to the Mun, then the "Skipper" is overkill and therefore bad... but put a small thrust engine on that rocket, and it would still be bad... the selection of choices means you can pick the best one for the job at hand.

Therefore, there is no such thing as a bad engine.

We are spoilt for choice, if there was only two engines in the game, you'd be complaining about that, rather than which is the worst engine. Rejoice the fact that you can pick and choose... and lets face it, the minute you call a particular engine like the "thud" bad.... is probably the day you have a job for it as its the best engine for the job.

Just keep that in mind.

 

3 minutes ago, mk1980 said:

kinda hard to say. there are several engines that i wouldn't miss if they were completely removed from the game.

i guess the most useless is probably the Goliath. not because the engine itself is bad. it's just designed for a niche that is pretty much non-existent in the ...let's say "core game". there's no real use for atmospheric airliners or cargo planes, and even if there were, chances are that you'd probably use supersonic/hypersonic engines.

 

the puff monoprop engine is a real contender for most useless engine. it would be useful if LF/O engines could only ignite a limited number of times or something. this limitation doesn't exist in the game, though. which means it's just a low thrust engine with horrible Isp. and it even requires a special fuel type to work.

The Goliath is the best engine for a cargo plane if, like me, you want to set up a base at the North pole... one man's meat is another's poison. Just because you do not use them doesn't mean others don't, and its selfish to suggest they be removed form the game, or rather, that you wouldn't miss them... I would.

[KerikBalm]

If I was going to the north pole, I'ld use panthers or whiplashes... Surborbtial trajectories beat slugging through the air.

Its rather hard to make a turbofan powered craft that can circumnavigate the globe in KSP... I get about halfway there with most designs I make (not that I've tried to build one for that purpose, just from wahtever design I put together, then looking at the cruising speed and the fuel consumption at that speed).

With whiplashes, its not hard to get to a trajectory that take you halfway around the world without even using half your fuel. If kerbin wasn't so small, this would change

I still prefer panthers and reversed wheeseley necelles to a goliath... about 2/3 thr thrust for 1/4 the frontal area, about equal thrust with afterburner, and it can go fast enough to get suborbital trajectories that can actually get some significantly fuel savings... while the normal sustained aerodynamic flight averages out to abut 9,500 Isp which is competitive withthe goliath's Isp when you factor in the benefits you get for long distance travel.

[Tweeker]

15 hours ago, magnemoe said:

Poodle is good but an niche engine, its nice for an medium upper stage or landing engine for heavier stuff like bases or miners because its so short. 
think of it as an 2.5 meter 909. 
 

On paper it is superior to the 909, but  loses out to the 909 in actual practice.

The 909 is shorter, even with an adapter.

If you are landing bases, then attaching the 909s radially adds width, and stability

 

 

But what really hurts it is how it relates to other parts in it's size range.

The smallest tank in the 1.25m range is 1.125x heavier than the 909

The smallest tank in the 2.5m range is  2.57x heavier than the poodle

The same is true for every other part, command pods, lander cans, ect. The blocks that you build with are much larger relatively speaking for the Poodle than the 909, so you loose precision in your build.

 

 

[Bev7787]

I've never used the LV-N. If I want high efficiency, I use LV-909s.

Edited July 30, 2016 by Bev7787

[Hotel26]

2 hours ago, Bev7787 said:

I've never used the LV-N. If I want high efficiency, I use LV-909s, the LV-N just outputs too little thrust and has worse efficiency then the LV-909.

KSP Parts lists the LV-N Isp (specific impulse) as 800 in a vacuum, the highest rating in the table and higher than the 345 cited for the LV-909.

Quoting the KSP definition of Isp: "The specific impulse (usually abbreviated as ISP) defines the efficiency of an engine. It is linked to the thrust and fuel consumption."

Clusters of a dozen LV-N are standard for my interplanetary missions and I have a GP booster designed around them.  Only disadvantages are burns take longer, overheating has to be mitigated and there are restrictions on how LV-N are mounted (not directly under an orange tank).

[Alshain]

On 7/27/2016 at 3:08 AM, storm_soldier2377 said:

It is better to use an LVT-45 with thrust vectoring than and LVT-30 with fins for small payloads because vectoring works in a vacuum and thin upper atmosphere. Regardless, both engines are rendered obsolete in late game by spaceplanes.

Unless you are using it on the lower stage of a two stage rocket, in which case space an low atmosphere are irrelevant.  You will be discarding it before that point.  Pair it with an LV-909 upper stage and you don't need it to have gimbal.  If you are doing a gravity turn ascent, you only need control right off the launchpad anyway.  A couple of fins will do that.

Edited July 30, 2016 by Alshain

[Bev7787]

1 hour ago, Hotel26 said:

KSP Parts lists the LV-N Isp (specific impulse) as 800 in a vacuum, the highest rating in the table and higher than the 345 cited for the LV-909.

Quoting the KSP definition of Isp: "The specific impulse (usually abbreviated as ISP) defines the efficiency of an engine. It is linked to the thrust and fuel consumption."

Clusters of a dozen LV-N are standard for my interplanetary missions and I have a GP booster designed around them.  Only disadvantages are burns take longer, overheating has to be mitigated and there are restrictions on how LV-N are mounted (not directly under an orange tank).

Whoops, well I'm not a patient person, so it's the best I can find for me. Just my opinion

[Hotel26]

16 minutes ago, Bev7787 said:

Whoops, well I'm not a patient person, so it's the best I can find for me. Just my opinion

I hear you.  However, fuel load is make-or-break on interplanetary missions.  Nukes can minimize the total departure mass of your vehicle and maximize the amount of surplus fuel at arrival.

When I discovered nukes, I had just sent a fuel tanker to Duna and it arrived on fumes.  Design invalidated?  Nope: I added nukes and the next load arrived weighing in with 33K units of liquid fuel.  That's the difference nukes can make.

Edited July 30, 2016 by Hotel26
clarification

[magnemoe]

1 hour ago, Alshain said:

Unless you are using it on the lower stage of a two stage rocket, in which case space an low atmosphere are irrelevant.  You will be discarding it before that point.  Pair it with an LV-909 upper stage and you don't need it to have gimbal.  If you are doing a gravity turn ascent, you only need control right off the launchpad anyway.  A couple of fins will do that.

My take on it too, second stage tend to be payload as in satellite or probe who uses part of it fuel to finalize burn. 

[magnemoe]

9 minutes ago, Hotel26 said:

I hear you.  However, fuel load is make-or-break on interplanetary missions.  Nukes can minimize the total departure mass of your vehicle and maximize the amount of surplus fuel at arrival.

When I discovered nukes, I had just sent a fuel tanker to Duna and it arrived on fumes.  Design invalidated?  I added nukes and the next load arrived weighing in with 33K units of liquid fuel.  That's the difference it can make.

This, using multiple LV-N will also increase TWR to decent levels, yes it will reduce the dV however getting an TWR of 0.5 is no big deal, using the slanted 1.25 nose cone is perfect for attaching 1.25 meter engines radially, put them around an MK3 liquid fuel tank and you tend to solve problems.. 

[GoSlash27]

On 7/29/2016 at 5:58 AM, kiwi1960 said:

IMHO, all engines are good, and all are bad... depending on the job you want done. If you need an engine to get to the Mun, then the "Skipper" is overkill and therefore bad... but put a small thrust engine on that rocket, and it would still be bad... the selection of choices means you can pick the best one for the job at hand.

Therefore, there is no such thing as a bad engine.

kiwi1960,

 I understand where you're coming from, but I disagree. Not all jobs are of equal importance to the player (particularly in stock career) and not all engines have a scenario where they are the best option. I would consider these engines to be "bad".

Best,
-Slashy

[The_Rocketeer]

8 minutes ago, GoSlash27 said:

not all engines have a scenario where they are the best option

I have to disagree with this statement. Mathematically there may be absolute scenarios in which a 'best' engine can be said to exist, but any engineering process is a matter of compromises - thrust for mass, drag for stability - and in some cases a runner-up engine in a specific application may be the best compromise in practice for multiple applications or in situ.