I have the 7 bolt mitsu 4g64 from the 96-99 Eclipse Spyders and 91-98 Galants(i'm not totally sure, someone can correct me or verify). It comes standard SOHC, however, mitsu did produce a few DOHC 4g64's and they came in production U.S. Galant's in 1994(once again, verification needed). The DOHC 4g64 in the Galant makes 160hp standard, as compared to the 141hp in the SOHC Spyder. But most of that power comes from the higher compression pistons(10:1, i believe) and the cams. The DOHC does have the ability to rev higher than the SOHC,and that's the main reason i did my swap. In my swap, i used a 1g 4g63 non-turbo complete cylinder head and mated it tothe 4g64 block in my Spyder. The reason i chose the N/T(non-turbo) head was because the cams are designed for naturally aspirated use and since my Spyder isn't turbocharged, there was no sense in using the head from a Turbo 4g63. To swap heads, you'd need a 1)complete cylinder head, cams on down 2)Timing belt from a DOHC 4g64(the above mentioned galant is the only US car using it) 3) intake manifold and supporting acessories(Throttlebody, tb elbow, etc.), And a list of otherpieces. There is a complete list of parts needed on the Yahoo's Group 4g64forum and also onhttp://wraithnet.net/4g64/ (http://wraithnet.net/4g64/ target=). Many thanks go out to these guys, they really are the pioneers of this engine. I was fotunate enough to have my friends 93 NT eclipse break down and got parts for free off it<IMG src=smileys/smiley17.gif border="0">. There are a few whole on the block that need to be plugged, not really a problem, but they NEED to be plugged. I will be writing up my swap procedure in another post soon, and attach it as a sticky. </P>
monkey mitsu
04-05-2004, 12:39 PM
Awesome. you should destroke it a bit and rev Super High.. thats the first N/A Head swap Ive heard of. Did it bump compression at all with eclipse Head? on the 6Bolt Hyundai version they said it did to theirs because there was alot more dish in the hyundai head than the 1G head. </P>
SpyderGS
04-05-2004, 01:34 PM
As far as i can tell, Compression is basically the same. I am using an Evo Metal head gasket though, so i'm not for sure. I was thinking of going thinner to bump compression up to maybe 9.5:1 or even 10.0:1, but since i will be going turbo(hopefully soon), i'm just preparing. Yeah, i'm not sure why many people don't do the NA head swap, the heads are basically the same except for the cams. At first i didn't want the NAhead because i was planning to go turbo soon afterwards....but that stuff takes money. Plus my friend killed his 1g NT. So free parts have a way of changing my mind. Anyways, i can gaurantee i'm not putting out more than 160hp. Perhaps, 155hp if i'm lucky(i'm talking crank by the way), and most of that is from the intake and exhaust mods. This swap probably only gave me 5-7hp total. That's along with the 60mm tb. Not much in gains, but i can now rev hard and fast<IMG src=smileys/smiley2.gif border="0">. Power comes quicker and i can run through the gears a little quicker now. Top end isn't that great, but it's better than it was with the SOHC. I also did the 2g ecu swap for the rev limit change. I'm using an Apexi SAFC to get it all leaned out, but it's still a little rich on the bottom end. I want a Greddy emanage to get it all going right, but i'm still poor. Anybody wanna donate some money? Or maybe a turbo? Anything?
Spyderman9803
04-08-2004, 10:50 PM
The turbo head would have worked just as good as the non-turbo one, just a little more aggressive cams in it pretty much. When are you planning on going turbo? I just did the conversions for DOHC and boosting the motor. What are you planning on using to tune your car? I'm still trying to decide what I want to use so I can get it and finally tune mine and get it running within good parameters. Where is everybody located anyways? I'm in SC.<IMG src=smileys/smiley1.gif border="0">
monkey mitsu
04-08-2004, 11:20 PM
Im in Louisville KY movin to Indianapolis. What turbos are you guys planning on using?
Spyderman9803
04-08-2004, 11:29 PM
I'm running a 14b until I can afford somethinga little more hefty down the road. I had to have mine rebuilt when I purchased it because I got it out of a junkyard car.
ForceFed4
04-16-2004, 03:28 PM
If you guy's are interested I can port match your turbo housings and ceramic coat themto promote less heat soak into your air intake track. I have seen asignificantdrop in engine compartment temps on my ownveh wich helped drop intake temps. Also when I ported my exhaust manifold and turbo housingiteliminated lagtremendously.</P>
Thanks Mike!</P>
1(248)249-5983 cell</P>
monkey mitsu
04-17-2004, 03:53 AM
how much do you charge for coatings?
ForceFed4
04-19-2004, 08:05 PM
Let me know what you need coated it's based on material I have to use, and that depends on the part size. It's not very expensive compared to the gain you will receive. here are some average prices for general heat reflective coatings.</P>
Give me a call or e-mail me and we can work out some deals mjsanders22@hotmail.com or 1-248-249-5983 cell</P>
Thanks! Mike</P>
SpyderGS
04-20-2004, 12:43 PM
Sorry for the late reply, but Forcefed i have a question. Will the Piston Top Coating(Gold Ceramic) make the top of the piston more resistant to detonation? I'm gonna overhaul my engine pretty soon, and the prices of forged 4g64 slugs are still sky high. So i was trying to find if there was a coating that would help the stock pistons through the rigors of forced induction.I also have a new 7cm turbine housing that will be matched to a small 16g. It doesn't need porting, but the coatings seem interesting. </P>
For spyderman, i got a pocketlogger for tuning. It's absolutely great, it can monitor everything you can imagine and logs data. Usually, i tune in second or third gear using my SAFC, depending on where i'm driving. First i set the SAFC to the best combination i think. Then i make a few runs and see how things are on the pocketlogger. If the EGT's area outta range,i'll lean things out or richen them up. I try and keep everything within the best range possibe, i'm not turbo yet so i don't really need to worry about a lot of things. I'll be going turbo probably this summer. I still have a few odds and ends to tie up. My biggest obstacle is i have a first gen exhaust manifold. I need either a 2g or evo manifold....but i spent my money on the 7cm turbine housing. Plu, i need tires right now, mine are bald....really bald. </P>
monkey mitsu
04-20-2004, 01:09 PM
So Mike doesnt have to spend all the time typing this again, This is what he emailed me today. its good stuff;
<FONT face="Courier New">There are definite benefits in all of these coatings. I work in the r+d department for Dart Machinery(dart heads) ,and we have seen great overall improvements in our prostock racing program from these coatings. The pistons by far are one of the best gains, because you reduce friction between the piston and cylinder wall under high loads which reduces heat.The ceramic base on the tops of the pistons is where the extra power starts to come into play....let me explain...
Your main goal in creating high horse power is to produce high dynamic cylinder pressures in the cylinder .This is the main reason your running a turbo. Now pressure is produced in any engine by hot rapidly expanding gases in the cylinder which you apply to the top of the piston creating reciprocating motion into rotary motion at the crankshaft.
One thing that I have found is that you get some heat soak through different parts in the motor one being the piston and one being the cylinder head. when you ceramic coat the tops with this coating it helps retain heat in the cylinder by reflecting it back into the chamber of the head creating higher dynamic cylinder pressures which = Torq and torq is the building block for horsepower.Also one more advantage to the ceramic tops is if by chance you run into detonation it reduces the chances of melting the pistons you just spent good money for...remember heads can be welded and repaired, and pistons you throw away....just a thought.
Now when I coated my exh manifold , turbo housing , swing valve and lower plenum of my intake manifold it reduced heat under the hood temps tremendously ,and reduced intake temps by 20 deg after putting 20 psi through it. If you have any more questions call me on my cell 1(248)249-5983
I can explain more aboutthese coatings in less time. Call anytime.
Thanks Mike! </FONT>
Spyderman9803
04-20-2004, 02:24 PM
SpyderGS....I had the same tire problem about a month ago. I just barely afforded new ones. That and a few other purchases made me broke for about the next 3-4 months. How much did you pay for your pocketlogger? </P>
ForceFed4
04-20-2004, 07:03 PM
Thanks monkey mitsu </P>
If anyone needs these coatings done e-mail me or call me and we can work somthing out. It is about a week turnaround time.</P>
</P>
Thanks! Mike</P>
mjsanders22@hotmail.com</P>
</P>
SpyderGS
04-21-2004, 01:52 AM
Awesome, i think i'll get some stuff coated then. </P>
My pocketlogger costed $175. My Palm m100 costed $20 on ebay. For under $200 you can have an awesome datalogger. The good thing is that it works through the OBD2 port, so you can use it on any car 1996 and up. Well, ISO cars atleast...but who needs ford or chevy anyways....<IMG src=smileys/smiley17.gif border="0"></P>