2016 Pentastar engine... worth considering?

Discussion in 'General Auto Conversion Discussion' started by pfarber, Jan 14, 2020.

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  1. Jan 14, 2020 #1

    pfarber

    pfarber

    pfarber

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    Since I have not bought a engine, I am still open to suggestions.

    I see that the 2016 Pentastar engine is a pretty good candidate:

    All aluminum
    60deg V6 (no balance shaft!)
    In 'car form' is 326lbs (I'd say less than 300 when put in 'aircraft mode')
    200hp at slightly over 4000rpm (out of 290hp avail at 6800)
    Tuning/ECU mods is a thing
    multiport, not direct injection
    engines are fairly cheap (ebay < $1200)

    Downsides:

    Most PSRUs seem to only come with Ford/Chevy adapters
    new engine, might have issues

    I don't think this is a huge difference from the LV3 other than not having direct injection. The Pentastar would have more HP at higher RPM, but my sweet spot is 200hp at less than 4500RPM.

    Any thoughts?

    An IO-360-A1A at 180HP is 258 dry (according to wiki) so to see a car engine at 200hp for about 350lbs installed at less than $8k is interesting.
     
  2. Jan 15, 2020 #2

    Chris Matheny

    Chris Matheny

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    They are also using them in the front wheel drive commercial vans used as service and vending trucks. My neighbor drives with close to 300k miles on it. That's a pretty heavy industrial usage and it apparently holds up well. I had one in my 2011 Challenger, never had any direct engine problems but a ton of electrical issues with the chassis. I'd definitely do an aftermarket ecu and harness.
     
  3. Jan 15, 2020 #3

    Doggzilla

    Doggzilla

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    Ya, dont ever trust stock electronics and wiring. There is a reason Tesla is creating an entirely new wiring architecture for its next generation of cars. Because the quality of wiring from the major suppliers is absolutely horrific.

    The wiring on my truck is starting to fall apart after 5 years. Its absolute garbage.

    You dont want to play Russian roulette with your wiring.
     
  4. Jan 15, 2020 #4

    pfarber

    pfarber

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    Custom ECU programming would require the removal of unused circuits, and that would mean unwrap and re-wrap the harness and also reroute some things.

    I have no issue with OEM wiring. Its fine. Its not like they spend millions to R&D the motor and then just throw garbage on top and call it a harness. If there are flaws, then a sharp eye on the specific forums would give tips.

    And without know what issues there were (BCM? ECU? VATS?) the expense of a new harness without significant proof is just not gonna happen.

    I like the low weight and the 60deg layout of the Pentastar. The cast in steel sleeves may be an issue if there is no cheap way to remove/repair them. But at $1200 for a motor you could just buy another in spec block.
     
  5. Jan 15, 2020 #5

    ScaleBirdsScott

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    I've had my eye on these as well for future reference but don't know much about the details. Would be interesting if they were being sold brand new in volume and not just scouring rebuilders for a used one.
     
  6. Jan 16, 2020 #6

    Doggzilla

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    The rate of "serious" defects is about 15% right now, with an industry average of 12%. That is not good enough for aviation.

    The problem is how they are made in the factory. It may perform fine as a prototype which has the wiring constructed to a high standard, but the quality of the cheap factory wiring is often horrendous.

    When I used to work for a large corporation we often had entire lots of defective work vehicles delivered. We once had a lot of 60 $130,000 commercial trucks delivered with defective electronics that made the trucks near useless.
     
  7. Jan 17, 2020 #7

    pfarber

    pfarber

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    You have to know that I'm gonna ask were you got this 15 and 12 number from.

    What defects? connector? ECU? bad routing? You just can't say 'they suck' and not have something more than 'I once knew a fella' story.
     
  8. Jan 18, 2020 #8

    crusty old aviator

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    Replace the stock EFI and ignition electronics with a SDS system and be done with it, unless you’re wicked handy with electronics and computer programming, then try MegaSquirt. Both work with the stock or upgraded hardware, plus add-ons like Hall sensors, etc.
     
  9. Jan 18, 2020 #9

    Hephaestus

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    There is a middle ground as well of course. Part of the delay in my briggs right now, got a custom engine harness made up for it.

    Wasn't that expensive, local company supplied and built to spec - connectors of my choice at my location with my wiring schematic. Warrantied for 5yrs, all high grade parts and pieces, built specifically to my needs. Cost was on par with filling up the Mooney.
     
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  10. Jan 19, 2020 #10

    pfarber

    pfarber

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    I get that a harness will have to have unused wires removes, but you can easily remove the wires from the connector.

    Why do people see a need to throw away the OEM harness? The ONLY upgrade I can see is MAYBE soldering the wires to the terminal ends.. but they might not fit back into the connector due to the solder. But again, is there a large % of mechanical crimp failures? Maybe a new harness to improve wire routing is a valid reason?

    I am not seeing the need for $300-500 harness when failures just don't seem to be thing.
     
  11. Jan 19, 2020 #11

    BJC

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    My beef with Toyota / Lexus engine wiring harnesses is that the insulation contains a material that rodents love to eat. When squirrels chew it off at the injectors, it really messes up the engine.


    BJC
     
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  12. Jan 19, 2020 #12

    Hephaestus

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    Generally it's turned the wrong way has dozens of wires that are totally incorrect, often could be run better for maintenance. There's a lot of reasons to just swap it to a custom build.
     
  13. Jan 19, 2020 #13

    pfarber

    pfarber

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    Ok I see. But after reading a few dozen harness articles I don't see the value for the cost. An LV3 harness for $800? +$500 seems to be the going rate. No way I see the value in that.

    If you're smart enough to put a car motor in an airplane, which YOU BUILT, reading some connector pinouts and removing unneeded wires should not be a difficult task.
     
  14. Jan 19, 2020 #14

    Hephaestus

    Hephaestus

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    But also a good way to introduce problems. Wires and connectors are cheap - chasing corroded wires bad connectors and failing splices isn't.

    For me it was a non starter, I've built more than a few harnesses over the years for car projects, some were great some sucked. I'd rather build/have a new harness built than chase problems in old wiring.
     
  15. Jan 19, 2020 #15

    pfarber

    pfarber

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    Well it seems that the Pentastar is firming up. It still unclear if they mean the China only 3.0l, the 3.2 or 3.6 liter engine

    "Fully dressed with fluids, the new engine tips the scales at 332 lbs. (151 kg), Gorgas says. In some applications, the Pentastar will weigh as little as 326 lbs. (148 kg)."

    Consider that the SPG-5 from Airtrikes is 30lbs I think that a 200hp motor/PSRU/radiator setup could be done for less than 375lbs.

    You are seeing a car motor for what a TIO-360 @ 200hp weighs.

    Quick ebay prices show the 3.6l over $2k but the 3.2l about $1000-$1200. I'm sure you could get one used for < $1000 from other than ebay sources.
     
  16. Jan 19, 2020 #16

    Himat

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    I don’t know the Pentastar engine, but car manufacturer usually integrate more than the engine management in the ECU. Then, the engine wiring plug into the main harness with one ore more plugs. (The engine is installed later than the wiring harness in the car body.) The easy way out to wire up the engine is then a custom wiring harness and ECU that just manage the engine.
     
  17. Jan 20, 2020 #17

    pfarber

    pfarber

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    The ECU will typically only do engine and tranny.

    The BCM does all the interior stuff (lights/dash/power accessories/security) and there are usually specific ABS/Traction Control and other models. Finding the pinouts for the ECM is easy, and programmers are out there that can modify 2014 an newer ECUs.

    The Pentastar engine is BIG in jeeps and off roading so while its a new-ish engine, its already had chips and tuners available, and a few people have already moved the 3.8l (300hp) motor into stand alone units so retro fit into older cars. Replacing a cast iron 300hp V8 with a light weight V6 is the ticket to some free power.

    So it looks like there is an active aftermarket for the 3.8l.. and the 3.2l is the same motor. The only real difference other than power is the 3.8's are north of $2k used while 3.2ls are easily found for about a grand.

    One think I like about the pentastar is the exhaust manifold is already cast into the engine.. so all you do is bole up a straight pipe down and exhaust is done. No snaking 6 tubes all over the mount. Two pipes (muffler optional) and done. All that weight saved!
     
  18. Jan 23, 2020 #18

    Chris Matheny

    Chris Matheny

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    Any particular measurements or anything you'd like off a pentastar? I have one currently in the shop for repairs. I can say undoubtedly in no way would I reuse this wiring harness. Any small movement and it was making noises that had me nervous about reliability even in automotive service.
     

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  19. Jan 24, 2020 #19

    pfarber

    pfarber

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    Making a new harness is really not an issue. I've done harness work on my 42 Ford and 43 Chevvy (I even have a braiding machine) so if OEM is bad, new wires are just not a problem.

    Is it a 3.2 or 3.8? I think the 3.8 is a no go because it has some really wonky water cooled EGR setup due to the insane compression ratio, I'm hoping its not on the 3.2.

    I'm super interested in the water pump. I am 100% pro electric water pump. I don't think the Jeep engines would have off the shelf electric water pumps like the V8s.. so a few photos of the water pump, how it connects to the heads, etc.

    And maybe just one of each side/front/back/top if you could swing it.

    Any other thoughts you have on the motor (are the mounts in a good spot for a cradle type engine mount? Does the intake plenum look solid? The oil filter is on the top of the motor and is just a paper element like on some Toyota's... does that look like it will last?)

    Looking forward to your reply.
     
  20. Jan 24, 2020 #20

    Chris Matheny

    Chris Matheny

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    The oil filter on top is connected to the oil cooler plate system. This is a 3.6 Pentastar. This one is apart for the leaky filter housing/ oil cooler setup. Bad design with what looks like plastic epoxied plugs in the passages that fail with time and i'm sure petroleum contact like most epoxy. This is in a 2014 Charger awd vehicle. It's outside in the rain at the moment but tomorrow when its parts come and its back inside i'll put it on the lift and snap a few shots.
     

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