

I think that they make out in such conditions and start having hot steamy s*x.

Based off what we saw in PROMETHEUS, especially how the Engineer just ignored being hit by a shotgun at least once, and possibly twice...as well as the strength displayed...
My money's on the Predator, BUT I'd sneak some covering bets with a side-bookie on the Engineer.
That said, it'd be one epic brawl :)
IN SPACE THERE IS NO WARNING

Engineer crush Predator easily.
Engineer→Alien→Predator→Human.

I am talking about the robed ones, not the biomechanical Mr. Clean ones.

My heart says Predator, but I think a warrior Engineer would win in hand to hand combat. Yautja are tough SOBs but they rely pretty heavily on their tech, especially against more formidable opponents

My money is on the Engineers, they seem more physically capable than a Yaut'ja.
@Dk It shouldn't matter which type of engineer: Otherwise it would be like if your asking who would win in a fight, a Predator vs a human child

Honestly, I very much doubt that the robed Engineer class would fight anyone. They're all about sacrifice & religious order.
Pretty sure they would leave the fighting to the pressure suited dudes. In which case...look out Yautja, prepare to be ripped apart!
"Let The Cosmic Incubation Begin" ~ H.R. Giger

I think an Engineer in a robe, barefoot, and hungover would paint the surrounding walls, rocks, and/or octagon green with glow-in-the dark blood. And not get his robe torn off.
Lone has a point though. Anyone wearing a robe would prefer the hardened pressure suit Engineer to handle the issue.

"I am talking about the robed ones, not the biomechanical Mr. Clean ones. "
Ive just Realized something.......................
Those Robed Engineers did not seem as AWE Inspiring as those in Prometheus, we dont know how Strong they are, but David must have Overpowered the Survivors (i have a theory on that).
So let me ask you a QUESTION?
Predator vs Superman
First on Earth....
Then on Planet Krypton
Ha ha... maybe thats why those Engineers are weaker, as they are on their home world, but on other Worlds they become Super Human ;)
Does that mean the Green Crystal is Kryptonite?
R.I.P Sox 01/01/2006 - 11/10/2017

But being Serious, its hard to tell with our Planet 4 Guys.
They are Genetically related to Humans, and they appear to be 20% Taller Than a Human. But that does not mean they are just 20% Stronger.
The LV-223 Engineers it appeared they are protected by that Bio-Mechanical Suit thats attached to their bodies and this Acts as Strong Armour.
They appear to be 25-30% Taller than a Human, but they are much much stronger, like 8-10X Stronger.
So in a Straight up Fight LV-223 Engineers vs Predator then i think Unarmed a Engineer would Win, with not to much Difficulty.
It would be like a Human vs Predator.
However i think those LV-223 Engineers are Genetically Altered Engineers, and so a more Fair Match up would be the LV-223 Engineers vs the Genetically Altered Super Predator in The Predator
R.I.P Sox 01/01/2006 - 11/10/2017

Regarding a Predator vs Planet 4 Engineer.
Looking at those Engineers they appear to be slightly Smaller than a Predator, but we dont know HOW strong those guys are, could they possesses Super Human Strength like the Godlike LV-223 Engineers?
I think those LV-223 Engineers are Genetically Enhanced, maybe Technologically Too (makes them strong) so i am going to say a Planet 4 Engineer vs Predator would be interesting but i think the Predator would Win, not easy but should Win, i would even say it would not be a Even Contest... more like a 65/35 in Favor of a Predator.
R.I.P Sox 01/01/2006 - 11/10/2017

@BigDave
That makes sense, we don't really know much about the planet 4 engineers.

The Engineers in Prometheus are very strong so they could win. If we are talking about those at the plaza then I guess that the Predator would win. My point is that it depends on what kind of Engineer that we are talking about.
I agree with Lone that they would probably let the pressure suit guys handle it since they seem to be better prepared for the task.

Thoughts_Dreams It sounds like the plaza Engineers would defer to the Prometheus Engineers then? That would mean using technology for a proxy fight which also means losing to a bare knuckle brawl and violating the terms of the OP. Predator for the win!

Robed or biomechanical suite - no difference. Engineers crush Predator like tomato.

Yep, Engineers all day. They're a superior being, by far. The Predator is like your juiced up bodybuilder who relies on brute force and intimidation while the Engineer is the naturally large, 7 foot monster from Iceland who happens to have a martial arts background. Lol Engineer for the win.

Its open for Debate as we have not seen the Planet 4 Engineers in any encounter with a Human, it appears some of them were Folly for David to experiment on yet must have survived the Bombardment but there are maybe logical reasons for this (Emaciated/Drained/Injured)
I do get the impression our LV-223 Engineers are genetically Altered Engineers and so are like Replicants to Humans or even the Big Mutha Predator in the Predators movie compared to our regular Predators.
So i am going to say Planet 4 vs Predator, i will assume it may be a close Fight, because i assume a Predator is more Tougher/Stronger/Agile than a 7ft Human, but i also think those Planet 4 Engineers are Stronger/Tougher than a 7ft Human but i am inclined to think that the Predators seem to be that little larger and i would assume are Stronger 7ft beings than the 7ft Planet 4 Engineers.
Planet 4 Engineer vs Predator Odds.. i assume 30/70 in favor of Predators.
LV-223 Engineers vs Predator Odds.. i would say 70/30 in favor of the Engineers.
R.I.P Sox 01/01/2006 - 11/10/2017

Im not sure, it could go either way due to the fact that Predators are stronger than they are displayed. They dnt need tech, they have observed warriors for centuries on earth, & their dna gives birth to Yautja's that have over the top strength and agility. Just depends on the Yautja.