g13a crank in g13bb?

[BadGoat]

Has anyone ever tried to swap a g13a crank and Vitara pistons into a g13bb? I saw the idea discussed on this forum. I'm hoping to find out if its possible. If it is possible, what kind of compression I might see?

I swapped a g13bb into my US Suzuki Samurai and ran it with Megasquirt. But the motor is burning oil. I know the best option would be putting in a g16, but I don’t want to do that…

viewtopic.php?f=13&t=7371&hilit=swift+G ... e&start=10

[Anton]

Most 1.3 litre Suzukis after about 1996 have 13bb engines - are they very rare stateside? Maruti Suzuki still builds bb's in India.

The G13a crank should fit, although it will slightly alter the stroke of he engine (G13a is 1325cc, G13ba/bb is 1298cc, slightly shorter stroke but the same bore). You would probably need G13a rods, not sure. What that'll do to your compression, I don't know.

Vitara pistons wont fit a G13a/ba/bb. They only fit G16, G15 and G13c blocks. You need bb pistons for a bb engine. G13a/ba pistons may fit, but might have valve clearance issues.

Honestly, I would recommend finding another bb to pull pitons/crank from, although are you certain that you don't just need fresh rings? Are you certain that your gaskets are all fine? Your valve stem seals? Bad pistons are not the only way to burn oil. I had a G13a burn big oil because of a warped head. I literally hid a bus with smoke when I revved it, so I swapped in a G13ba.

[BadGoat]

G13bb are common and pretty cheap here.

I've seen thr DOHC 1.3 bored to fit vitara pistons, it was done to lower the compression. I was hoping i could add a little displacement to my g13bb. But if i can't find anyone who has done something similar I'll probably just do what you said and rebuild the g13bb.

I am burning oil because of a bad ring, but i can see some scratches in the cylinder 1 wall when i stick a camera down the spark plug hole, I'll need to bore the cylinders some. Everywhere i've tired is out +1mm pistons, but i can still find +0.5mm g13bb pistons.

[Anton]

If there's a lot of damage to the walls, a new block might be a good idea - they're not expensive (at least, not this side of the pond). Be aware that if you get one from a FWD car, the sump and pickup pipe will be wrong, and you'll have to swap over your current ones. Otherwise your axle can hit the sump.

If the damage is minor, then a hone and rebuild sounds good to me - you won't add much displacement by going to 75mm pistons over 74mm, so I'd question what the return on time investment would be in doing that.

Your 1298cc would become (if my maths is correct) 1334cc. If you swapped in a G13a crank too, then you'd be looking at 1360cc. 62cc - 4.7% more displacement, and you'd have to be certain that the pistons you used wouldn't hit, and gave you a decent compression ratio.

I doubt you'd feel 4.7% more power either.

Honestly, unless it falls foul of some regulations over there, you'd probably be better spending that time getting a J20 in there, or just sticking with the 13bb as is. It's a lot of work for not that much gain, and the G16 isn't *that* much better than the 13bb that it's worth all the effort - I'd skip it and go for the 2.0 if it were me. Or maybe a G13b DOHC out of a Swift GTI if you can get your hands on one.

[BadGoat]

thanks