3 cyl DOHC
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Author:  spade [ Wed Jul 13, 2005 2:41 am ]
Post subject:  3 cyl DOHC

I don't know if that was already discussed in the past - tried to use 'search', but to no avail.

Ok, so thats not engine swap... it probably would be head swap.

Question is absolutely theoretical, maybe even rhetoric... What about puting DOHC head on a 3 cyl block?

Correct me if if I am wrong:
G13B and G10 blocks are more or less the same, only G10 "lacks" a cylinder. So the head from G13 should fit, except for that one cylinder :), which you would have to cut off ant weld a plate instead. That sounds very hardcore, but I know that it was done a few times with motorcycle engines (can't find links now, though), or in the development of BMWs S14 engine...

Is the position of the head bolts on G13 and G10 basically the same?
What else? Intake and exhaust manifolds would have to be made, but thats a small problem compared to the project as a whole...
One big problem as I see it would be the cams... you would have to cut them too... by hand probably...

Please, don't discount the idea just because it is silly (I know that 8)), lets have a discussion. Here are a few people who have extensive knowlegde of both engines - would be nice to hear their thoughts.

Author:  Gasoline Fumes [ Wed Jul 13, 2005 4:03 am ]
Post subject:  Re: 3 cyl DOHC

spade wrote:
One big problem as I see it would be the cams... you would have to cut them too... by hand probably...

I think you'll need to make new cams, unless you plan on welding them back together. The cam timing would only be correct for one cylinder. :wink:

Author:  suprf1y [ Wed Jul 13, 2005 4:34 am ]
Post subject: 

Been discussed a million times.

Author:  spade [ Wed Jul 13, 2005 5:22 am ]
Post subject: 

suprf1y wrote:
Been discussed a million times.
Where?... As much as I was looking - I found nothing...

spt-3x1.0 wrote:
Would be nice if the head from the 657cc Suzuki Cappuccino would bolt onto the G10 block
Probably not. The bore of cappucino engine is only 68 mm... Cylinder senter spacing probably will be different.

Author:  GeoZukiGTi [ Wed Jul 13, 2005 9:04 am ]
Post subject: 

If I'm not mistaken, I think Jardamuth is experimenting with this exact thing already. It's perfectly possible, but the big problem would be oil passages, pistons(would need cutouts for valve clerance), cams, intake, and exhaust. They would alll need to be cut, and modified for a 3cyl use. I dunno if all that work and money would be worth it. Perhaps just for bragging rights of a DOHC 12v 3 banger? The big point of a 4 valve per cylinder is heavy breathing for high RPM's. A 3cyl block just isn't as capable of constant redlining as a nice forged internals GTi setup. The 3cyl 12v setup would be very promising for a turbo tho!

Author:  CMA [ Wed Jul 13, 2005 4:59 pm ]
Post subject: 

maybe you can get cara's dohc 12v I3 turbo. ( 64hp/6,500rpm and 8.7/4,000 rpm) ( average 18mpg @ 15kmh... 30 mpg @ 50kmh)

i heard that its very fast ( and somone also said that cara's frame is not good enough)

btw maybe next project will be swift ga turbo :twisted: (one problem probably hard to find that kind of enigne)

edit "oops" after read spt-3x1.0

Author:  Spydir [ Wed Jul 13, 2005 11:22 pm ]
Post subject: 

what about just swapping a Cappuccino engine/drivetrain in? that would do the job right there. I've already contemplated it, but I'd sooner just import the Cappuccino and save myself the time, energy, and extra money.

Author:  Spydir [ Wed Aug 03, 2005 3:23 am ]
Post subject: 

Well if you're set on doing something like that, you'll end up doing it regardless of the expense. If anything even a parts car/front clip off a Cappucino would work nicely.

Author:  G10 [ Tue Aug 16, 2005 5:17 am ]
Post subject:

Any1 think about the Daihatsu Charade GTti head.
Its a 3cyl DOHC turbo.
Should be easier to adapt than the gti's head.
Google it should find loads of pages.
Supposed to be a little beast to go and their tiny and lightweight.
JDM only i suspect.

Author:  Lihtan [ Tue Aug 16, 2005 5:38 am ]
Post subject: 

That would depend on how well the combustion chambers on the Daihatsu line up with the cylinders on the G10. It's already a know fact that the GTi head has compatible combustion chamber metrics with the G10.

Here's an alternate idea I had on doing a 12 valve GTi head conversion: install the entire head with the last chamber intact, and hanging off the end of the engine. Then build an adapter plate to seal off the end of the fourth combustion chamber. Now you only need reground camshafts instead of re-engineered camshafts. Oil passages are left alone, even the valve cover fits fine. I'd deal with distributor by building some kind of custom DIS-3 ignition. Then it's timing belt and engine management. Oh, and new intake and exhaust manifolds. Did I miss anything?

Author:  fordem [ Tue Aug 16, 2005 8:50 am ]
Post subject: 

Lihtan wrote:
Now you only need reground camshafts instead of re-engineered camshafts.

Just my thoughts on it -

On a 4 cylinder engine the pistons are 180 degrees apart in terms of crankshaft rotation, and on the 3 cylinder, I guess they would be 240 degrees apart (although I had a 3 cylinder Suzuki Fronte for several years, I never saw what the crank looked like)

Now the camshaft would have to have a similar separation, although I think it becomes 90 degrees for the four, and 120 degrees on the three - for certain, the distributor caps have the leads separated this way.

I'm guessing, that with a 4 cylinder head on a 3 cylinder block, the valve timing would still only be correct for one cylinder.

Author:  Lihtan [ Tue Aug 16, 2005 8:10 pm ]
Post subject: 

What I meant by reground instead of re-engineered is to save the hassle of having to make new cam journals, bearing surfaces, and modifying the oil galleys. It's just plainly easier to have the first three sets of lobes reground for 3 cylinder firing, with the last set ground down for zero lift.

Author:  fordem [ Tue Aug 16, 2005 9:50 pm ]
Post subject: 

OK - I see where you're coming from - I was looking at it from a different angle, and I could be way off here - Superf1y is the chap who knows this stuff -

When you regrind cams, isn't it a matter of reducing the base circle and reshaping the existing lobe?

I'm thinking that you can only shift the open/close points a few (at most 10 or so) degrees either side of the existing open/close point, and that to get the 30 degrees you'd need to either start with new blanks or do quite a bit of welding to build up the existing lobes.

Author:  Tim Keith [ Sat Oct 22, 2005 3:20 am ]
Post subject: 

I do not know much about G10 or G anything. I have found a
twincam G13B motor from a Swift GTi. Can the connecting rods
of the G13B swap into the G10?

Are the G13B rods the same rods as the G10 turbo used?


Author:  Lihtan [ Mon Oct 24, 2005 6:00 am ]
Post subject: 

Tim Keith wrote:
...Are the G13B rods the same rods as the G10 turbo used?



Author:  nosswiftgt [ Mon Oct 24, 2005 10:17 am ]
Post subject: 

I've got an idea. Why not use the twincam 4 cyl head and just weld an extra cylinder on your block and weld an extention on your crank shaft so it could meet up with the extra combustion chamber on your head. Then you'd just have to redesign the oil passages to incorporate the extra cylinder and redesign your crank so it would work as a four cylinder. Then you'd have not only the twincam head, but an extra cylinder as well. You could also just get your self a G13b and save a little work.

Really I don't understand what the point would be? If you really want a twincam head, just use it and the rest of the engine. Why would you go to all that trouble just to have a smaller displacement Twincam? It seems like way too much work to get an inferior engine. Most of the problems with the G13b vs the T3 engine are with the somewhat restrictive head.
I just don't understand why?

Author:  SweetGeo93 [ Mon Oct 24, 2005 1:36 pm ]
Post subject: 

Why not just swap a g13b and be done with the deal?

Author:  GeoZukiGTi [ Mon Oct 24, 2005 2:42 pm ]
Post subject: 

:stupid: :lol: . Yes. The extra 20lbs the G13B over a DOHC modded G10 is not gonna make much handling difference. BUT, the forged crank, and availability of aftermarket parts is much better for the 13B. Sounds like an uphill battle that will have not so fruitful results. Good idea, but too much effort for a small gain. If you wanna stick with a 3 legged dog, get a T3. Richard has done a couple T3 swaps, till he saw the light and did a G13B :lol:

Swap > All

Author:  t3 ragtop [ Mon Oct 24, 2005 2:47 pm ]
Post subject: 

nosswiftgt wrote:
It seems like way too much work to get an inferior engine.

....says you! :-P

there are a lot of good things about the 3 banger. granted, it'd be a lot of work to develop a twincam 3. it's the challenge of development that is the attraction. these guys aren't talking about bolting on manufactured performance parts.

what measure do you use to pronounce the g10 an "inferior" engine. i find the little 1.0 liter to be an amazingly robust piece of machinery and a very elegant bit of engineering. after all, the cars that are powered by them, even being older technology, will still beat the fuel efficiency of nearly every current day hybrid offering no matter what "trickery" is included.

Author:  GeoZukiGTi [ Tue Oct 25, 2005 12:02 pm ]
Post subject: 

Building a twincam 1.0 is going to completely destroy the gas mileage. Just like the difference in the 1.3DOHC and the 1.3SOHC. My 91 swift GT's original window sticker rates it at 29mpg, while the SOHC's are getting 35+. Between the cost, lost in gas mileage, time spent "debugging" and tuning... You could have gone turbo 1.3dohc. Originality is nice, until it becomes just plain redundant. I can see a $4000+ price tag to get a completed 3cyl DOHC engine running stable. Why cut up a G13B to make a G10? Use the G13B :lol: . That would be like Chopping 2 cylinders out of a big block, to throw a V6 in your Camaro, instead of the V8. "My V6 Camaro run's 14's!" "My V8 Camaro run's 11's :ez_pimp: ...."

Author:  suprf1y [ Tue Oct 25, 2005 12:12 pm ]
Post subject: 

Building a twincam 1.0 is going to completely destroy the gas mileage.

No it won't. It might even be better.

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