Team MightyBoy

Hi guys, I've got a stripped out project Mightyboy that I tried to sell a while ago without any interest, so I've decided to keep it and finish it myself as time and money allows.

Currently, it is engineless although it came within F6A in need of a rebuild and I wanted your opinions on what I should actually do as far as engine goes:

Option 1: rebuild the f6a turbo engine that has munched a few valves, and put that in.

Negs - it's some unusual variant of the F6A and the valves available on eBay to not fit. The valves have shorter and fatter stems and will need to be custom made (need 2 intake and 1 exhaust). I am unsure whether the Pistons are standard f6A or a variant also.

Given the cost to get the parts mad to rebuild this motor, I'm not sure the cost vs performance increase maths adds up.

Option 2: an F8B, mated to the fuel injection and turbo setup from the F6A.

There are a few ways I could go about this. I could
A: try and find a second hand engine & gearbox from an Alto, which has probably been beaten half to death

Or

B: order a brand new "Kazuma Mammoth" engine either from Alibaba or a western Kazuma distributor. Unsure of the build quality, and everything Chinese I have owned in the past while well made, has needed all bolts replaced immediately as for some reason they use the softest steel known to man for their fasteners. Which means new head bolts at the least before turboing.

Would still need to source a gearbox.

Option 3: I also have a swift GTI, while the engine has done over 300,000k it was rebuilt 40,000km ago. I already own the car so I have everything I need for an install, but the body would need modification (possibly a custom subframe too?) that I am unable to do myself and would need to be properly certified which = $$$.
Plus, the G13b is pretty heft compared to the little f5a, would the extra weight at the front end negatively effect handling? Would I need to put some ballast at the rear or would stiffer/ stronger suspension at the front sort it out?


Option 3 appeals the most to me, mainly cos it's the most powerful and I already own a suitable donor. But there is additional engineering required to make it work.

Option 2 would be my second choice

Option 1.... Just doesn't seem worth the effort for the minor increase in performance.

Pls give me your opinions on what I should do,
I'm especially interested in hearing about previous G13B conversions or from anyone who has gone the Chinese engine route.

I'm sure a lot of us MB owners would love to see it GTI powered, but due to size, there is quite a bit involved to fit a much bigger motor. The F8B with F6A manifolds is an option (if it's from a SOHC that is) which you can then convert to EFI and has been done a few times. Although finding an f8b can be hard, it's the most common engine conversion as its a direct bolt in replacement. The F6A would be a great motor to put in too because you would be gaining a great amount of power over a stock engine, especially being turbo. Going with an aftermarket ecu would be a wise choice to get the most out of it too.  

If the car already has an F6A in it, then the easiest option is to rebuild or replace it. If the engine conversion is already certified then rebuild, or if it isn't then just buy another F6A and slot it in. There's two for sale on the forum at the moment.

If the idea of extra displacement appeals to you then there is also the option of the F8C from a Daewoo Matiz, which is already fuel injected, making the install a bit easier. The only reason you would use an F8B is if your current F6A was a SOHC (but you haven't mentioned that).

I'd say go for the G13B if you have money to burn, but the alternative swaps/repairs are much easier to achieve.

Thanks Brayden, yes my F6A is a SOHC so the turbo stuff should bolt on with a minimum of fuss, yes?

I've picked up an F8B however it was out of a carry so has the incorrect mounts for a Mightyboy, any idea where I can get some? I am also planning to use the F6A gearbox, it is my understanding that the SOHC F6A bell housing should just bolt on and I will need to use the flywheel clutch and starter from the F6A.

Carry models were never fitted with an F8B. They had F8A four cylinder motors.

You are correct about the F6A/F8B compatibility though.