The 2.4L G4CS can be found in 89-91 Hyundai Sonota SOHC engines in cars with the eighth digit of the vin being 'S'.

q: Why is this engine of any interest to a DSM'er?
a: Beacause it's basically a 6 bolt 4g63 with an extra 20% displacement, a more favorable rod ration than a 2.3 stroker, and it's stealthy as hell.

The engine has a nitrided crank (a good thing, trust me) with 100mm of stroke (a 4G63 crank = 88mm stroke), 86.5 mm cylinder bores, and 235.1 mm deck height (the 4G63 = 229 mm deck). It is of critical importance to note that the extra 6mm of deck height is entirely at the top of the block, above the provision for the top most bolt for the water pump and motor mount bracket.

The main caps are not bridged like a 4G63, but they are physically larger and it has been said that they are actually stronger than the bridged 4G63 caps. This motor will have no more occasion for walking than a 6 bolt 4G63, end of discussion.

The G4CS engine has no oil squirters (unlike the 4G63), and does have balance shafts (like the 4G63). Lets' keep discussion about both of these features out of the thread as they've been beaten to hell numerous times.

The rods are the same as 1g big rods and the pistons yeild a higher compression ratio (CR) and do not have reliefs for a DOHC (again, the G4CS is SOHC 8 Valve). The rods are interchangeable, but the pistons are not reusable. having noted the similarity in rods, it should be recommended that they be replaced with Eagle rods at the least as rods are cheap insurance for your engine. You're already getting aftermarket pistons, why stick with the stock rods? Besides, the lord thy dsm-demigod, David Buschur has publicly stated that he thinks crowers are a good idea in any stroker motor and he is only offering stroker motors with eagles to be competetive with other shops. Thus he has spoken, and so shall it be written.

So what will be needed from the G4CS engine in order to swap into a 6 bolt or 7 bolt DSM? I'll cover the 6 bolt only, as the same concepts will apply with the addition of all the 6bolt in a 7bolt swap basics covered here.

You'll need the following:
G4CS block
G4CS crank
custom pistons (wiseco p/n: K564M865 ; stock G4CS bore)
87mm head gasket (mitsu p/n: MD189436; aftermarket hg's also available)
'94 Galant GS DOHC Timing Belt (mitsu p/n: MD182292)
'94 Galant GS DOHC Cam Gears (mitsu p/n: MD189399; 2 required)

Everything else bolts right up with the exception of the intake manifold brace and the stock knock sensor. I repeat, everything else used will be from a 4G63, no other parts from the Hyundai Sonota G4CS are needed. For the third time, that means your 4g63 (or aftermarket eagle or crower, etc.) rods will work, the 6 bolt 4g63 oil pan, the front case, oil pickup tube, dipstick, motor mount, water pump, pulleys and timing tensioners, etc. will all fit this new block. You can order the same bearings for the rods and mains as a 6 bolt 4G63.

Here are some considerations:

1. The deck is 6mm taller, which does mean that the valve cover will be 6mm closer to the hood. Stock hoods will clear, but aftermarket hoods have been shown to perhaps have problems.

2. Again, the deck is 6mm taller (which is less than 1/4 inch) so the downpipe and oil drain tube may have clearance issues on the oil pan. Remember, the turbo is essentially bolted to the head, not the block, so it is now 6mm higher.

3. For the third time, the deck is 6mm taller, so the timing belt cover will have a slight gap where the upper most cover meets the lower cover right at the level of the engine mount. This is not a huge issue and can be remedied with some sort of a dust shield or skirt if desired.

Take Note: This thread is intended to be a resource to others who intend to perform this upgrade. All talk of 4G64's, G64B's, 2.3 strokers, which is deemed irrelevent or repetetive will be removed from the thread. There are numerous other threads where this information is also available, but if you don't like sorting through 20 pages of non-value adding content, this thread will be better.

If anyone is interested, I have a spare (that means in addition to the one I purchased for my own build) G4CS shortblock in verified near-mint condition that I will also be able to build for a potential 4G63 swap. If you are seriously interested, pm me for more information.

I will document my own 2.4 buildup(s) in this thread, there will be more to follow, but I'm not in any big hurry, so it may take a while between updates.

pics of one of the engines in all it's SOHC glory as well as the blocks ready to be taken to the machine shop.

Good compilation of information Kris.

As far as the timing belt dust cover goes, there may not be a gap to close between it and the timing cover. The gap was not visible on my 2.4 by anyone but myself when I first installed it.

Also, because the deck height is 6mm taller the upper mounting holes for the timing cover at the cylinder head level will not line up without modification. This is not a big deal and I have just left my upper bolts out and no one has been the wiser.

On the '94 Galant GS DOHC Cam Gears (mitsu p/n: MD189399), Kris is recommending two exhaust cam gears because the Intake gear is ugly as it is made for an additional bolt on piece. I have this gear if anyone wants to see it's ugliness. The only thing needed when using two of the same gears is to paint or at least recognize that the timing mark on the oposite side of one of these gears will have to be used. They will come with the same side timing mark painted.


Marcus

the link listed here is no longer valid... is there an update for this link???

Look up the '1G in a 2G' pdf link here

Obviously not in a big hurry at all.

Haha.. Yeah, Ben is going to have to finish this write-up since he bought Kris' Sonata 2.4 block off of me.