Engine build - ideas, general knowledge, motor basics/physics

Discussion in 'General' started by Stancer, Aug 2, 2019.

  1. Stancer

    Stancer New Member

    More a technical discussion than anything else , did copy paste to an engine discussion board hence why it's so vague about Lancers lmao but I feel this is a good place to post also

    Wanted to get kinda a general discussion going about engine sizing and outputs etc more than about my actual car so it's not limited to people with knowledge of specific cars etc

    Ignore my ignorance as I'm asking because I wanna learn not because I know, i may ask stupid questions etc

    I'm fairly technically minded, was a mechanic for a couple years..but never built a motor, pulled a couple down etc and am wanting to experiment with them (obviously not gonna jump into some crazy motor but food for thought I guess)

    I have a fairly low power front wheel drive car, and am toying with a couple motor choices
    It's a 2000 Mitsubishi Lancer / mirage in some countries

    Factory its a 1.8L sohc (86kw) and had previously swapped to a 2L of the same architecture

    Am onto a new shell and it's a stock motor again, i still have my 2L but want quite a bit more out of it

    Wanting to keep it n/a

    Also wanting it to be fairly light as it's a hillclimb/circuit car so straight line speed is great but I don't want a big 3.8 boat anchor hanging out of the front of it even if it does make way more power than any of these options do....

    But I've kinda got a choice of putting a small or big 4 cylinder in, options are

    Standard 124kw ish (all according to spec sheets)
    2.4L sohc mivec motor out of a newer Lancer

    1.6L dohc mivec (with extra lift like VTEC motor from the ck4a/JDM Lancers and mirages

    2.0L sohc motor (what I have sitting, is low KMs and good condition)

    2.0L V6 mivec from an fto

    Or something completely different, most of Mitsubishi's stuff is "Universal parts bin" for the same motor family so heads can be swapped etc so I could use the mivec lift head on the 2L block and people have seen 150kw at the wheels with a fair amount of work done to them

    The V6 is an easy swap and makes decent power but probably not quite what I'm after, with a e85 etc I'm sure theres more in it but it takes away from the *poo*ty 4 cylinder aspect that makes me like the car

    But am I better off with a small engine and it's ability to rev, would a 'square' motor be better and just ring the neck of it all day long

    Or would a bigger displacement motor be better for torque and overall grunt?

    In an ideal world what's the best way to make power from what would normally not be a powerful motor

    Can a sohc motor with a good flowing head and we'll suited cam size compare to a dohc engine?

    What is the limit of what we can rev a 4 cylinder too? And around what parameters?

    Tight ring gaps etc how much different would it make? I know with F1 cars etc they'd basically lock up if started cold?

    What compression ratios can be achieved on a n/a car, is there a limit where you'll start losing power with more compression because you can't have the timing as advanced?

    Individual throttle bodys? I know they sound cool, but from what I've found they are kinda old tech and don't give a huge advantage anymore compared to a well designed intake and plenum...plus space is a constraint because the intake is at the back of the engine bay and the exhaust is near the front

    Semi plan is e85 as it's readily available near me, high compression, high rev limit, big cam

    But at the same time I want it to be drivable at lower rpm hence why I was thinking of mivec heads but they are expensive and hard for find near me and performance parts are the same being expensive etc

    Obviously it's going to be a timely and costly project and am in no huge rush to get it done or even start etc, I don't wanna dump $100,000 into the car, but at the same time do plan on keeping it for a while and like that it's different etc

    Realistic goal is around 150kw at the wheels, which is way more than double stock power, more would be great but it gets to a point where it'd be so much easier to turbo it to make big numbers and that's not really what I'm after, I want a lightweight responsive car thats got a bit of power to back it up

    Reliability would be nice, no point making a motor that's gonna last 3 track days so I've gotta be kinda sensible and walk the edge of the line for pushing it further than some have

    Also interested to see what 4 cylinders people have and what power etc, I'm sure I've missed heaps but that's what's floating around on my mind

    Happy for any input within reason, turbo not on the menu, have a much more powerful turbo car and I see no need for 2, would rather 2 completely different cars

    Thanks for reading this far lmao!
  2. wagonmaster

    wagonmaster Active Member Lifetime Premium Member

    Someone that might know from personal experience with conversions is Hornunga, on this site, has had plenty of experience with conversions on lancer/mirages with 2lt and 2.4 lt plus other mods, give him a shout, he may be able to answer some of your questions?
  3. Jimmib

    Jimmib Member

    I have been in a few FTO V6 swapped mirages and the power is great but they lose something in the corners from the extra front end weight still fun but if you want to be serious about the track with it go a 4 cylinder and more than anything power your track times will come more from lack of weight and suspension/tyres than outright power. I have been to track days with guys who have big power "street GTRs" and my bog stock GTR with its R888's ran circles around them because I wasn't struggling to go around a corner!

    I am sure someone will counter my point and that's fine :) but I would just get a 4G93 or 4G94 good set of extractors and good smooth intake aka even a mild polish, not even a port and some form of CAI (let the stock box with a "hollow filter" to seal breathe from the wheel well) haha budget as and just pop the exhaust off at the cat (if the noise isn't a problem some tracks have noise limits) spend some $$$$ on some coils or a good shock and spring and some chassis bracing/stiffening and tyres and BOOM :)
  4. SDate42

    SDate42 Active Member Lifetime Premium Member

    “The better the base, the better the gains will be” is a good way to look at this. Decide based on weight and parts availability as to which motor you will build. If it’s easy to add 20% power to any motor, why not add 20% of 140hp instead of 20% of 100hp you know.

    Personal choice : 4G69 with aftermarket ECU.

    You can rebuild the bottom end fresh with standard components at home (except pressing wrist pins). Quick hone of the bore, and you have a strong base for an N/A build.

    Get a spare head, skim it down* and raise the comp ratio. A solid port and polish, re-cut 3 angle and HAND LAPPED valve seats. Cam of your choice w/mivec. Get manifolds to match the head.

    Water/Meth injection kit.

    Follow with the basic CAI and tuned length single cat exhaust. Possible P/S and A/C delete.

    You may also want to build a spare gearbox with different ratio’s to suit your application.

    * I have forgotten, but its easy to calculate the amount to be removed to bring it up to 11:1 without too much risk of damaging anything.
  5. donki

    donki Administrator Forum Administrator

    Fuarrr so much to answer/opinion to lol.

    Nothing wrong with this, even better that its in public view, because these exact questions will be asked 1000 again,

    20k+ rpm. F1 cars do this day in day out, though rebuild between days lol. On a production engine the limit is still well above 10k (honda's in particular). Better bottom end bearings, stiffer valve springs, valves, and a couple other little bits and pieces and you can take a 4g93 up to 9k without too many issues.

    3/5ths of fk all. F1 engines are at the extreme end of performance, and on a streetable car it wouldnt matter. Even on a high end build, it would do nothing except reliability, and even then its barely worth the effort.

    The Mazda developed Skyactiv engine runs between 14 and 16:1 compression. The Ferarri 458 also runs 14:1 without many issues. Timing isnt directly relatable to compression, theyre similar but not the same - e.g. you can run a lot of boost with very retarded timing and still make no power despite the massive boost. Add timing and power goes up exponentially. A fundamental rule with timing is to use as little advanced as possible, and let the engine do the rest of the work.

    Sound bonus, but the difficulty in syncing them and tuning them is an absolute nightmare, and almost never dialed in correctly (unless its from factory such as the Skyline GTR).

    For an N/A build, doubling stock power is pretty much the top end limit of the home-mechanic. Adding boost is a very easy way to achieve this on the other hand.

    Im running a 4g93 in a Mirage. Added a turbo, custom grind cam, turbo, tiny bit of DIY head work, e85, and my custom tuning, and the virtual dyno reckons a peak of 198kw/349nm. NA imo you'll struggle to hit 100kw atw from a g93 without a hell of a lot of work and dollars, which would have a better ROI on other parts.
    Stancer likes this.
  6. pLethora

    pLethora Active Member Lifetime Premium Member

    I see you finally hit the forums Elijah haha. Welcome to decent opinion/knowledge town.
    Stancer likes this.
  7. unclepaulie

    unclepaulie Well-Known Member Lifetime Premium Member

    hullo *waves*

    Magna/outlander/nimbus 2.4l head, reco'd, skimmed a pinch
    thin headgasket
    CH lancer 2.4L bottom end
    evo 4-6 fuel rail
    evo intake and TB or magna TB
    big ass cam and adjustable cam gear
    ported / smoothed intake manifold and intake chambers of head, gasket matched
    gasket match exhaust side
    4g93 loom
    4g93 ecu, tune to suit
    CH lancer box and shafts

    its simple
    its easy
    no mivec f**kery
    easy to source loom and ecu
    lump cam idle + it'll rev

    OR just do 4g69 and leave it as is. but if youre considering a cam....think of it as a Mivec killer cam
    Stancer likes this.
  8. supern0va

    supern0va Member


    Sounds like your quite on learning some things about engines and what you can put in the lancer/mirage so i thought I would reply. Alot of what your asking has been done over the years by various people, its just hard to find it all/most being deleted.

    It usually depends on time vs cost. Time like if your studying, working alot, have the right friends or accessible wreckers to get to. Cost in if you have the money to do it all, budget, your expectations on how much to spend etc.

    I personally did a 1.8L swap in a mirage with bolt on's and tune - did a 14.7 down the 1.4 mile and also a 4g69 swap best time of 13.4@105 mph.

    The V6 Swap and 1.6L Mivec swaps never really measured up to what looked like a fast package on paper. your looking at low 14's down the 1/4 mile for these two swaps and thats about the limit with basic mods.

    generally the limitation is in your mind of what you can do and what you can achieve.

    Here are a few videos to check out
    - 4g93 mivec
    - 4g93 sohc

    nafwdmitsu - my channel with some vids from 2013
    ARC likes this.
  9. Stancer

    Stancer New Member

    Thanks for all the reply's guys! I kinda forgot I posted to the forum's as I haven't used forums in years lol

    For reference

    My car already has coilovers, suspension mods, wheels, tyres etc and morealess power is the limiting factor now

    While the 4g94 I have is good, it just didn't quite do what I wanted out of it, and I have extractors, a cold air intake, never did tune it etc, but even still it wasn't close to the mark

    When I had my r33 gtst I had a rb30 bottom end with an rb25neo head and kept it n/a trying to make a faster n/a car even though everyone went tUrBo iS bEtTeR ..which is fine, but not what I wanted for the car, same goes for the Lancer, it'll never compare to the my GTR so there's no point trying, but I do think the 2.4 will be the go, just unsure what sort of cam spec to go with and compression ratio etc etc, especially confused by gearbox choices with a 4g69

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