4G63 DOHC N/A build

[Tj.]

I have just acquired a bent Hyundai Sonata off eBay with the intention of tearing the 4G63 DOHC N/A motor out of it and swapping it into my GC Galant Coupe.

So, what do you suggest I do to the motor mod wise? (don't say turbo, I don't want to go down that road in this car)
I'm looking to build it up as a warm N/A motor. Nothing too wild as it's a daily driver but I would like to squeeze a few more neddies out of it.

I figured the way to go would be something along the lines of:

• A bigger throttle body (easy done as it's gotta be cut and shut onto the opposite end of the plenum, same as an Astron EFI setup)
  
  Up the compression (is this a matter of swapping to Flat Top pistons or would it involve head work?)
  
  Hotter cams (are there off the shelf items for 4G63 N/A or would it be custom, There's millions for the Turbo motor but I assume they wont work, right?)

is there anything else that i haven't mentioned? or is anything i've mentioned not going to work?
There's so much info out there for the turbo motors as there's a huge following for them, but it seems not many people go the N/A option.


Oh and I'll try my best to document the conversion on here as much as possible.


I'm not looking for a nut and bolt how-to, just a pointer in which direction I should head.

[Superscan811]

I'm in a similar situation. Just bought a '91 GSR Galant with a 2.0L Twincam N/A motor for $600 off EBay.
Had a "Faulty gearbox TCU" which turned out to be $5 worth of Electrolytic capacitors and about 1-hour of my time to repair the corroded tracks.

It too is going to be a daily ride and the wife may drive it every now and then, so I don't want it much more than "WARM".

This is what I am planing to do...

1. Freshen the head up with 1mm Oversize Stainless Steel valves, new valve stems and 3rd gen lifters.

2. A little bit of port work just to clean up the casting marks.

3. Quad 42mm Throttle bodies which will give much better throttle response than a single large throttle body but would be equivalent to a single 84mm throttle body.

4. Better exhaust system.

After that I hope it will just be regular maintenance.

Hope this helps.

Cheers.

[shuggy]

is it possible to get a carby manifold for these babys?
im keen on mucking around with one in this coupe if i get it but i dont want any silly electrics shit, i wana try make it carb.
anyone know if the 4g63 SOHC intake manifold would fit it? coz even if i get an engine from the wreckers and muck around, even if it dont work im sure i could sell it off n not lose too much eh..

[Superscan811]

is it possible to get a carby manifold for these babys?..

Not as far as I know. Someone on the site has a Twincam with carbies but I think think the manifoldwas fabricated.

im keen on mucking around with one in this coupe if i get it but i dont want any silly electrics shit, i wana try make it carb...

It wouldn't be that difficult to modify a standard single runner (per cylinder) manifold to accept some carbies. There would be a bit of fabricating, but not much.

anyone know if the 4g63 SOHC intake manifold would fit it? coz even if i get an engine from the wreckers and muck around, even if it dont work im sure i could sell it off n not lose too much eh..

The SOHC inlets are different.

Cheers.

[tandanus]

I agree with Superscan811 on this.
Ive seen twin carbs on these, (once considered it myself), but unless you cant live without the sound of Webers, why would you? (youve got the EFI stuff already).
T.

[woops]

Actually I saw on the weekend at the Classic Jap Show and Shine at Brisbane a GC Coupe with the 4g63 DOHC with a toyota quad throttle bodies adapted to it. Might be a good option as it's already got the EFI gear on them and all you would need is an aftermarket computer for it to run easily.

[Tj.]

Ooooo the quad TB idea sounds sweet. The toyota setup sounds the buisiness.
I was quite interested in doing that too but the $$$ put me off a little. For the time being anyway.
The poor old 4G32 is on it's last legs, it's been getting around with a blown head gasket that's been bodgied up with some Chemiweld. It's done the trick but it hate to think what will happen when that lets go

My main aim is to get it running before the current engine carks it. So I'd like to do a few things that are easier to do in the build stage of the engine and worry about diddly little bits and bolt on stuff later.

Is there any bottom end stuff worth doing? Like crank or rods? Or is that only necissary for HiPo turbo motors.
What about lightening the bottom end? Can anything be gained there?

[panda]

Actually I saw on the weekend at the Classic Jap Show and Shine at Brisbane a GC Coupe with the 4g63 DOHC with a toyota quad throttle bodies adapted to it. Might be a good option as it's already got the EFI gear on them and all you would need is an aftermarket computer for it to run easily.

One of our car club members has fitted quad throttle bodies to his rally car. He used a set from a Toyota Corolla 4AG 20 valve mounted on a custom inlet manifold. Is one of the quickest 2WD rally cars in SA.

[woops]

I have more pics in the thread for the show but here is what his set up looked like. He just had about a 5 to 10mm plate fabricated which changed the stud pattern to suit the different manifold. And he had a very nice setup for the engine too. He managed to retain the original heater as well and only massaged the firewall a bit for the crank angle sensor. He was also saying that the coupe's use a nippon denso heater tap because they were built in japan which is easier to change about then the aussie built versions and there are a few jap cars about which are similiar. The one he used was a suziki sierra one. The car had pretty clean body too.

[Superscan811]

Ooooo the quad TB idea sounds sweet. The toyota setup sounds the buisiness. I was quite interested in doing that too but the $$$ put me off a little. For the time being anyway.

I made a set of Quads for the Magna heads a while ago.



The Throttle bodies are off a 2001 Suzuki GSXR1000 and are 42mm ID.
You need to space them out, but it's easy to do even with basic tools.
The throttle bodies cost about $200 - $250 (EBAY, from the US) but you have to wait for the bargains otherwise you will pay up to $400.
I used a standard TR inlet manifold, cut off the runners close to the flange and got Cheater to relocate the thermostat housing and weld on a few pipes.
It was about 90% done when I decided to go about making a different style of manifold, so I still haven't put these on an engine yet.

Hope that gets you a bit more enthused Tj.

Cheers.

[Tj.]

That'll be for future Tj to get frothy over. Present day Tj doesn't have the dosch and will have to make do with the standard set up.

I wonder how they'd affect torque. Would it put peak power way up in the high rev ranges?? My understanding of how it works is minimal at best.

[shuggy]

mmm im definatle keen on the carby supercharged 4g64 dohc fab'd
but thats money so not for a year or two haha

[cheaterparts]

I used a standard TR inlet manifold, cut off the runners close to the flange and got Cheater to relocate the thermostat housing and weld on a few pipes.


Cheers.

If I remember I think the std magna manifoid was machined off leaving about
25 mm inlet stubs then the new runners had some groves machined to the out side ends
so the rubber hoses would not slip - then the whole thing was glued up with the
aluminium TIG glue gun
just looking there are no fuel rail mounts was I slack at the time




cheaters 50 mm quads - using magna TBs the whole manifold is custom with the runners
machined with a 3 deg taper from the 50 mm tb end to 43 mm head end
end plates were hand made and again welded up

[dwlee]

TJ, has the motor got a 6bolt or 7bolt crank?

I'm putting a 4g63 DOHC N/A into a GTO at the moment. I'm using a DOHC 6bolt block with a 4g61 head and using piston from a AMG 4g63 giving a compression ratio of approx 10.6. It is running Kelford 264 camshafts. I initially was going to run quads, but decided to keep things simple to start with so I'm using an Evo4 inlet manifold with adapter plate. The reason I'm using the 4g61 head is for the smaller ports as the ports in the 4g63 6bolt head (same as VR4 head) are far to big. The stock bottom end is fine (same as VR4) unless you want super high rpm. I'm also using the 4g61 oil pump and no balance shafts.

Issues that I ran into with a dohc swap into a GTO are
a] firewall clearance for cas and water outlet (engine and gearbox in standard position). I'm running a custom cas (Haltech S3 halleffect) off the inlet camgear and the water flow has been redirected to exit out the front of the head.
b] bonnet stiffener clearance of the camgear cover (if engine is in the standard position with standard 4g63 rwd mounts). The stiffener in the video below has been cut.
c] sump clearance with steering link if the 6bolt block with bridged caps is used (all factory 6bolt engines with dohc head). Easy fix with gentle use of a hammer. This is not an issue if using a sohc 6bolt block or a dohc 7bolt block.
d] The battery tray (left side for a GTO when looking from the front towards the back) and have the motor in the standard position the alternator hits the tray support.

Note that the all the above may not apply to a GC, but the GC is very close to the GTO.

Here's video of a GTO with quads.
http://www.youtube.com/v/ahggc7c0SW0

[Superscan811]

just looking there are no fuel rail mounts was I slack at the time

The standard mounting points were removed so I modified a standard TR fuel rail to fit.
One end also had to be cut otherwise it would have hit the thermostat housing.


Cheers.

[Tj.]

So after striping the engine out of Koreas finest I began to look at the electronics and I'm starting to wonder if the quads are still the unjustifyable expense I thought they were.

My plan is just to take it to an auto sparky and get them to sort the original ecu and wiring out proper. I managed to remove the loom including the fuse panel and a short section of the loom leading to the steering column but there's a lot of crap that's not needed and it's begining to look like a mess.

I'm sure it would be quicker, easier and therefore cheaper to run an aftermarket setup offsetting the cost of buying such a setup... In theory anyway.

But realistically how much would that cost??

I'm just thinking out loud a little here.

[Superscan811]

I'm sure it would be quicker, easier and therefore cheaper to run an aftermarket setup offsetting the cost of buying such a setup...In theory anyway.

But realistically how much would that cost??

The last quote i have is around $500 to wire up and $500 to tune. I was to supply the ECU.
He did have a package deal for a bit over $2300 which INCLUDED the EMS4860, install and tune.

Cheers