Idea time: Extremely Canted Engines

"If only EssExTee could be so grossly incandescent" (essextee) 09/11/2014 at 19:49 • Filed to: idea time

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Now, I'm sure someone who knows more than I will explain why this is a terrible idea, but here goes: When building a transverse, FWD, I-4 car, why not cant the engine backwards at a high angle? You have more engine mass behind the front wheels for better weight distribution, you can get the wheels closer to the front end of the car, and you can fit a taller engine under a short hood than with an upright one.

The only issue I can see would be accessing the valve cover, but we already deal with that with transverse V6s so this wouldn't be much different. It could be set up so the spark plugs are on the front side of the block and going in at an angle, so they could just be pulled straight out.

Manuél Ferrari > If only EssExTee could be so grossly incandescent 09/11/2014 at 19:51

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Because the oil will fall out

AM3R > If only EssExTee could be so grossly incandescent 09/11/2014 at 19:53

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this looks like a BMW 1 series.

But yeah, oil.

Nibbles > If only EssExTee could be so grossly incandescent 09/11/2014 at 19:55

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Saab did variations on this idea by offering Slant 4 engines in the 99 and 900. The lower portion of the block was still straight up for oiling and balance reasons and the combustion chambers were canted at a pretty severe angle. They did this solely to keep the front height as minimal as possible. They got away from the issues of having the head too close to the firewall by mounting them in a reverse longitudinal layout, putting the accessories at the firewall and the clutch at the radiator

lone_liberal > If only EssExTee could be so grossly incandescent 09/11/2014 at 19:55

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I don't really know but that has never stopped me before so I'll take a stab at this one too. It could be because it makes installing the engine from below more difficult or some other packaging/manufacturing issue.

If only EssExTee could be so grossly incandescent > AM3R 09/11/2014 at 19:56

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Vee engines have tilted cylinder banks. Why would it be a problem with this?

Manuél Ferrari > AM3R 09/11/2014 at 19:57

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It does look like a 1er

Will there really be oil issues?

I made a joke about oil issues but I don't know anything so it was just a joke

Boxer_4 > If only EssExTee could be so grossly incandescent 09/11/2014 at 19:59

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The 5S-FE in the 4th gen Camry (SXV20) was like this to a degree. After 10 years, the valve cover gasket started leaking from the back edge in ours (a common issue on these Camrys). Other than that, there wasn't an issue.

It's a bit difficult to find a good picture to show how slanted they were. This is the same engine (5S-FE) in a 3rd gen Camry (SXV10).

Kailand09 > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:01

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Well in yours, the engine appears to come in a bit low and will get messed up on suspension travel.

I'm not sure, but depending on geometry and car dimensions, it would change how the frame and steering travel is designed. It may limit how far in the frame can come in order to make room for the turn angles on the tires.

It could possibly be a challenge in packaging to fit the steering rack and associated components as well, though it's definitely solve-able.

Another thing that immediately comes to mind is firewall. This could possibly move the firewall some, and limit the design for the driver and passenger's foot wells.

Now, these are simple observations. Each of these could be solved and engineered around (or most of them). The question becomes whether or not the gains in performance and weight balance outweigh the packaging compromises to accommodate that.

Disclaimer: None of this may actually be true. lol

AthomSfere > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:02

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Ah, so you mean like a slant 4... which has been done.

I think why this is not more common popular is because it lacks balance and runs rough.

claramag, Mustaco Master > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:02

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I'm no engineer, just operating off gut instinct, but it looks like a design prone to wheelhop and more than usual understeer. Something about having the driving force behind the driven wheel, like you're always driving in reverse

Few other thoughts
-oil starvation to the upper side of the engine could be an issue
-minimal exhaust header clearence if exhaust valves are rear facing, very limited intake runner space if reversed. Put em both on the front? Now you're heating up your intake runners, hello misfires.
-valve cover could get physical with the firewall under heavy load (like the FoST, but worse)

Didn't mean for this post to be such a downer. I do like the idea of an angle being used to reduce required hood clearance, but I also remember Chrystler's slant-6.

Kailand09 > claramag, Mustaco Master 09/11/2014 at 20:04

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These are some great points. Particularly header placement, I hadn't thought of that.

YSI-what can brown do for you > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:05

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There might be higher vibrations with an angled inline 4. So much so that it ruins the comfort for some people.

Takuro Spirit > Boxer_4 09/11/2014 at 20:07

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The 1MZ-FE V6 is also canted backwards, but not as extreme I don't think. That back valve cover is a bitch to get to though. The front cover almost sits horizontal.

lonestranger > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:08

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Homda does/did this. That's how their hoods were so low (think '80s / '90s).

Aaron James > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:08

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Because 4 cyl engines don't weigh enough to make enough difference to justify the added complexity. The lightest part of the engine is the aluminum head so moving it while leaving the heavy crankcase and transmission where they are wouldn't make much difference.

AM3R > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:34

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Top end oil starvation? I showed this to my brother (engineering student, but it's computer engineering so..) and he pointed that out without really explaining it.

AM3R > Manuél Ferrari 09/11/2014 at 20:35

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not 100% sure, my engineering student brother (comp. engineering though) pointed that out without explaining it. I'll ask him to elaborate I guess, but honestly I have no clue. All I can really think of myself is top end oil starvation.

Manuél Ferrari > AM3R 09/11/2014 at 20:43

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Solution: we use fighter jet engines. Fighter jets can fly upside down.

AM3R > Manuél Ferrari 09/11/2014 at 20:47

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Step 1) buy E30/E36/944 body

Step 2) install fighter jet engine

Step 3) hoon

Step 4) $$$$$$$

Manuél Ferrari > AM3R 09/11/2014 at 20:50

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Step 5) die

RallyWrench > Boxer_4 09/11/2014 at 20:52

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Several inline engines are canted to one side in longitudinal applications, including all 4 & 6 cylinder BMWs since the 60s. The Porsche 944's engine is tilted something like 30 degrees. The Toyota Previa's engine is nearly on its side. With good oiling, you can do what you want. It can work, but I think exhaust & intake plenum packaging becomes a problem at a certain point. considering that an axle has to run along the rear edge of the oil pan. I remember seeing pictures of some crazy time attack or hillclimb builds with the engines tilted way back.

Birddog > If only EssExTee could be so grossly incandescent 09/11/2014 at 20:54

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The Mopar 2.2/2.5s were canted like that.(30* like the slant six) Same for the Neon 2.0 and 2.4.

It's not uncommon in FWD cars with a low hood line.

AM3R > Manuél Ferrari 09/11/2014 at 21:38

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Die after incredible Hoonage! WOOH!!

desertdog5051 > If only EssExTee could be so grossly incandescent 09/11/2014 at 21:39

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Chrysler was working on it. Just could not figure out the FWD part. Buick and Olds would not talk.

Drakkon- Most Glorious and Upright Person of Genius > If only EssExTee could be so grossly incandescent 09/11/2014 at 21:40

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The reason I think most car makers hang the lump out front is to increase the amount of interior cabin relative to the wheelbase. More people would pay to drive a car with a larger interior than one with superior weight distribution.

Nobi > lonestranger 09/11/2014 at 21:58

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They primarily did this in the Prelude. IIRC, early ones had oil starvation issues and would spin bearings because all the oil would slosh away from the pump under hard driving.

DisplacementForDayz, ironically lusts after a Honda Grom > If only EssExTee could be so grossly incandescent 09/11/2014 at 22:55

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The dodge/plymouth slant six (inline) from the 60s/70s/early 80s is the same idea, just in a rear wheel drive layout. There's no reason why it couldn't work, even though slant sixes had problems starting warm, because the carburetor was right over the exhaust manifold (The exhaust also heated the intake air, because the intake manifold was on the same side. The only problem I see would be with a modern crossflow head design you wouldn't be able to fit a large set of headers on the side facing down, but most production cars don't need or make use of an equal length header system anyway.

Axial > AM3R 09/11/2014 at 23:00

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You can use a dry-sump oiling system to remove the need for a traditional oil pan entirely. Since it's under pressure, the effects of gravity pulling your oil away from systems are also negated.

There's no real reason why it can't work. The reason you wouldn't do it (besides accessibility) is because you'd need a longer hood to keep the passenger cabin the same size. Transverse FWD is only popular because it increases interior volume without making the car bigger; it's not actually cheaper to build a FF vehicle, because the setup is more complicated than FR. FF is only cheaper right now because of economies of scale.

benchslap > If only EssExTee could be so grossly incandescent 09/11/2014 at 23:13

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Oil isn't an issue. Porsche, Ferrari, and Subaru have had no problems making completely horizontal engines work just fine.

Atomic Buffalo > If only EssExTee could be so grossly incandescent 09/12/2014 at 04:35

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When building a transverse, FWD, I-4 car, slight adjustments to weight distribution aren't important, the wheels are further from the firewall which adds structural mass, and hoods don't generally need to be lower.