chicksdigmiatas

Hi, I would say a handful of you all know me from other Miata forums. But incase you don't...


Hi, I'm Myles, I am in the Air Force, like long walks on the beach, I am married (to a woman) and I drive a Miata.


Said Miata has a built 1.9 VVT with a 6 speed, 3.63, 2871, and runs on corn juice sprayed through 1000cc/min garden hoses.


I am also tired of having a BP in said Miata. I would like to have a reliable 300ish WHP NA motor under the hood. Obviously, a BP isn't going to do that. I'm not sure what the highest NA BP makes, but I'm sure it drives like crap, doesn't make the power, and is not reliable.


I also know at said power level, the Miata drivetrain isn't the most reliable. It would be a real shame to grenade my nice, low mileage, meticulously built drivetrain just to have to upgrade it anyways. That would rob a fellow Miata owner the joy of utilizing my fantastic driveline, and leave me with less money, money which could have been spent to buy something that won't break. That being said, I have taken swaps that utilize the OE drivetrain off the table.


I don't want another 4 cylinder. What would the point be. While I love my car, it has a sentimental value to it (I have had it since 2002, when I was 17). However, I am also not willing to spend 20k sticking an LSx in it. Now, I am left with 2 options. 5.0 or LFX.


I am leaning more and more heavily toward the 5.0 everyday. It seems like a bad ***, cammed 5.0 would be tons of fun. They are inexpensive, easy to work on, and the swap has been done hundreds of times. While I can fabricate, I now have a family, and can't have my car flung across my garage for a year when I can get orders at any time. Therefore, I can spend a paltry 4k for the kit once I get the engine built the way I want to and have it done pretty quick. I may be wrong, but I am pretty sure if I'm selective in what I buy, and look for good deals, I can build the engine I want for 4-5k.


Now you know why I'm here.

Flavaquero

I have had the opportunity to ride in the V8 Roadsters V6 test mule. It is truly impressive. All the way to its Borla exhaust system.

MRM331

I've built 5 Ford 5.0 conversions and am now looking seriously into building a LFX. The 5.0 and the LFX are pretty much a match on total cost, complexity of the swap, and even total horsepower. The LFX has the advantage of being a 50 year newer design and therefor more efficient and light. The 5.0 will always have more torque although the LFX spreads out the torque it has better due to its VVT. The 5.0 has an awesome aftermarket that the LFX can't touch. The LFX kit gives you better ground clearance than the Monster Miata kit unless you get creative with the header design. The LFX can be made OBD2 compliant, the 5.0 can not. The 5.0 sounds better (subjective) and is a V8. The LFX clutch situation is annoying (dual Mass). With a 5.0 build you start by building an engine, with the LFX you can buy a 5000 mile donor driveline for under $3000 and never have to remove a valve cover.

I'm going with a LFX this time around because I see it as the future of this level of swap. I've built the wire harnesses for over 60 5.0 conversions at this point and see developing the processes to build a harness for a LFX as the next logical step.

Hope that helps,
-Jason

SupaDupaSteve

Only potential problem I see with the LFX is lifespan of parts production. Didn't they already stop using it in camaros and such? So how many years we're they produced? 5.0s and LSs have been made for quite some time and both have huge aftermarket support.

MRM331

I've looked into this by doing a cross search on RockAuto for most major engine components (pistons, gaskets, waterpumps, electronics, timing chains, etc), and found that most of it was or is used on a number of other GM vehicles spanning over 15 years. GM is very good about diving into their parts bin; there are some components in the engine that go back to 2002. The only real difference between the LFX and its predecessor the LLT is the heads and intake manifold. That connection alone takes the bottom end back to 2010.

There is also the fact that the kit really could be used to mount any GM "High Feature" or "Alloytec" V6 into the Miata and you substantially increase the engine donor years.

The Ford 5.0 as used in most V8 Miatas only existed from 1987-1993.

I'm really interested in the new Duratec kit in England right now but will more than likely come back to the LFX once my initial excitement wears down. I also need to build a garage (keeping house now, building a garage behind it).

-Jason

Flavaquero

btw I did four years in USAF and I have two kids in now. So you will understand when I say I really don't care where you like to walk and there is a don't ask don't tell policy in effect. Lol Sorry couldn't resist. I see San Antonio, what is your job?

paNX2K&SE-R

The LFX block is the same across all platforms (rwd/fwd/awd) that used it so when you include all the impalas/malibus/traverses/acadias/cadillacs etc there were incredible amounts of them produced and they are going to be dirt cheap in junkyards. I paid $2600 for my dropout from a '12 Camaro complete top to bottom and front to back with 44k miles on it. If I ever need to replace the longblock in the future I'd anticipate it would be more like $400-500.

V8MiataMike

If it costs the same... 5.0

NASCAR used to have the what is now the Xfinity series cars using V6s and it sounded like a giant bee hive! Now that is my subjective opinion at the moment. I could be swayed if it is lighter, better overall fit in the engine bay, has enough torque to pull hard enough through the gears, and (subjectively) sounds decent... someone give me a ride in one!

paNX2K&SE-R

I drove the V8R demo car at MATG in 2015 and it sounded great (and that was before the magical kooks exhaust was put on last year). These engines are rated at 323/278 with a weight around 345# and the '87 5.0 was rated at 225/300 and weighs around 411#. I'd expect V8R to have the car at MATG again this year and I'm sure Shandelle would give you a tour!

paNX2K&SE-R

I just found this:



The audio doesn't do it proper justice, sounds even better in person.