V6 DOHC Headswap

[Stewi]

I know this has been talked about before thats its not possible using the 3kGT heads, however I have another idea. Now, im not sure if this is anything new, being that I mostly focus on 4 cylinder related tech info. I was checking out a 05 Hyundai Sonata GLS today, and I got to spend a good 20 mins poking thru the engine bay and it definetly looks like you can swap those heads, if not swap the whole motor. The mounts are all in the same spots. Anyone have any more info about this? Im not sure the performance gain would superceed the cost of doing it, but again this is just an idea at best for now.

[DOHCstunr]

whats the engine code for the sonata?

edit

i foudn that the 3.3l is a 6GDB
hmmmm
very close indeed.

[ChikagoGTZ]

I like my Sloppy Over Head Valves!!!

[Jet Black]

Intresting find Stewi. Though how abundant are these motors?

[DryBear]

From a discussion on inkate manifolds on Club3G:
http://www.club3g.com/forum/showthread.php?t=59446

<div class='quotetop'>QUOTE(Mitsiman)</div><div class='quotemain'>Word of warning on the tibby 2.7 DOHC engines - there bolt pattern is definitly different to the Mitsubishi engines. Mitsubishi and Hyundai do cross over a lot but the 2.5 / 2.7 engines in the tiburon are not mitsubishi. The sonata engines are because they are based on an old Mitsubishi Galant platform.

I have trouble keeping up with it all I tell you.</div>

<div class='quotetop'>QUOTE(Mitsiman)</div><div class='quotemain'>No the tiburon V6 engine manifold won't fit onto the Mitsubishi engines. We bought a Tib V6 superhcagrer kit and no way it woudl fit onto the mitsubish V6 engine. The only Hyundai manifold that will be fit must be off teh Sonata 300 / 350 engine because it at least uses a Mitsubishi 100% engine, if not in a format we normally see</div>

Mitsiman is from RPW, by the way. Maybe someone can contact him for more info?

[gtx]

I always wondered about some hyundai engines that supposed to be based on mitsu 6g72/74s for the same reason (dohc head), and frankly, I can't follow or find anyhing solid on them. I still would like to take a look at the '01 XG300 (3.L DOHC Sigma engine, G6CT?) or even the XG350 and the '93-98 v6 Sonata (old 6g72 24v DOHC)

As far as the whole enigne, the new 3.3 "Lambda" has a 10.4 cr, the Hyundai UK site says 10.5, the block is alu. Also, what tranny could we use with it? The V6 Sonata seems to be only coming with an automatic... deja-vu

[Stewi]

<div class='quotetop'>QUOTE(gtx)</div><div class='quotemain'>I always wondered about some hyundai engines that supposed to be based on mitsu 6g72/74s for the same reason (dohc head), and frankly, I can't follow or find anyhing solid on them. I still would like to take a look at the '01 XG300 (3.L DOHC Sigma engine, G6CT?) or even the XG350 and the '93-98 v6 Sonata (old 6g72 24v DOHC) Â*

As far as the whole enigne, the new 3.3 "Lambda" has a 10.4 cr, the Hyundai UK site says 10.5, the block is alu. Also, what tranny could we use with it? The V6 Sonata seems to be only coming with an automatic... deja-vu Â*</div>

you would use a stock auto trans or do a 5 speed swap.

[mysticj]

grave digging? yes!

the engines in the XG300 and XG350 are 6g72 and 6g74 with DOHC heads. They are the same Sigma engines as Mitsu.

[WarmAndSCSI]

Yes, very interesting, but it makes me wonder if there is any potential at all since the Hyundai version of the 6G72 only puts out 190 bhp with that DOHC setup AND an increased CR of 10:1.

[Fishboy55]

Yes, very interesting, but it makes me wonder if there is any potential at all since the Hyundai version of the 6G72 only puts out 190 bhp with that DOHC setup AND an increased CR of 10:1.

Sorry to hijack this old assed thread, but where have you been hiding my friend?? and Welcome Back!!

[WarmAndSCSI]

I've just been hella busy helping out over on Galant Forums. They gave me the opportunity to fix the site up and run with it, so I did.

I hadn't posted on TGC for quite some period... I'm not holding any grudges, but this is what happens when my honest opinions get swept under the rug and I get banned for no damn reason.

[Fishboy55]

I've just been hella busy helping out over on Galant Forums. They gave me the opportunity to fix the site up and run with it, so I did.

I hadn't posted on TGC for quite some period... I'm not holding any grudges, but this is what happens when my honest opinions get swept under the rug and I get banned for no damn reason.

Well, I for one am glad you're back. I been having some fun since you've been gone with your little friend the electronics wizard, fagflogger or fluffndouche or flatulance or whatever the fuck his name is...so get your ass back over here!

[DOHCstunr]

Please stay on topic, as this has nothing to do with v6 dohc.

[WarmAndSCSI]

Kiss my ass, he was just asking a question. This thread is old as hell any way. God forbid I come back in a few weeks and post about how I actually did the swap

[RedGalant2k1]

I'd actually like to see details on a V6 DOHC headswap...may be a great changeover when my G isn't a daily driver anymore. Keep this thread updated!

[WarmAndSCSI]

I did a quick junkyard search yesterday and there are a few XG300 engines available for about $600. I might take the chance and make this my alternative to spending almost $1500 on cams and springs.

If I end up taking the plunge, I'm sure I'll post about it. It would be really nice to see some modded XG300's just to see if the engine has potential, but I really can't find any.

edit: And this would just be swapping the heads after rebuilding them. The block would be up for grabs lol

[krispy03]

better wait till after mod to try it!

[mysticj]

6g74 DOHC(G6AU)
==========
V - type, DOHC
93.0 mm (3.661 in.)
85.8 mm (3.3779 in.)
3497 cc
10.0 cr
1 - 2 - 3 - 4 - 5 - 6
218mm deck height
152mm rod length

I. o: 11.5&#176;
I. c: 60.5&#176;
E. o: 43.5&#176;
E. c: 20.5&#176;
Overlap: 32&#176;
Int Dur: 252&#176;
Ext Dur: 244&#176;

Int. Cam Height: 35.098-35.298mm
Ext. Cam Height: 34.81-35.01mm

---------------------------------

6g72 DOHC(G6AT)
==========
V - type, DOHC
91.1 mm (3.587 in.)
76.0 mm (2.9921 in.)
2972 cc
10.0 cr
1 - 2 - 3 - 4 - 5 - 6
210.5mm deck height
140mm rod length

I. o: 16.5&#176;
I. c: 55.5&#176;
E. o: 48.5&#176;
E. c: 15.5&#176;
Overlap: 32&#176;
Int Dur: 252&#176;
Ext Dur: 244&#176;

Int. Cam Height: 34.805-35.005mm
Ext. Cam Height: 34.81-35.01mm


As you can tell, they use the same cams as for the 3.5, the degree is change by 5 because of the taller deck height. The same will happen if using a 4g63 cam in a 4g64. The cam profiles are very close to the 95-99 NA 3Si.

The hyundai engines were tuned to run on 'regular' gasoline so that would explain the power output.

A JDM 6G74 DOHC produce 256hp@6000 with 10:1cr while the 94-96 Montero SR produce 215hp with 9.5cr. Both engines used the same cams, but right now I don't have the specs on those cams. So it safe to say that the ecu controls the output of the engine. The 6g72 DOHC produce 218-222hp.

If there is rom or log for the NA 3000GT available, if can be use to reflash the ecu for the 6g74 DOHC. Weird thing is that the 98-99 NA 3000GT ecu has a very similar and close pinout as the 99-2003 Galant V6.

[gtx]

Yes, the 99 is as close as it gets, but IIRC it has the same problem as our 2000 ECUs -> not flashable yet.

[mysticj]

The cams for Hyundai 3.5 are the same specs as the Montero SR/Debonair while the cams for the Hyundai 3.0 are the same specs as the 95-99 NA 3000GT. The only cams that are different are the exhaust ones for the 95-99 VR4.