2.4 Engine build for low RPM torque and reliability

Robert Venable · Post by **Robert Venable** » Mon Oct 02, 2006 8:42 pm

I have a 1990 MMM, 2.4L 4G64 FI, with 208,000 miles on it and it is leaking oil from what I believe is the front case gasket.

Since I would have to take this off anyway and I currently have a freind's left over motor from an AWD 2g Eclipse for parts I was thinking about swapping heads and completely rebuilding the motor. What kind of problems will I run into with swapping this newer 7 bolt head on my 6 bolt block?

Now I've searched back threw all of the pages on here and it seems that most people who do this swap go for the 1g head. I did some research and found that this is mostlikely due to the larger ports. Large ports that I don't think I want.

I am more than likely gonna keep this motor NA, so I think the 2G's smaller ports will allow me to keep my velocity up for increased torque. And from what I've read the combustion chamber is alittle more efficient on the 2g. Does anyone know for sure that this is due to a head design change and not the higher compression ratio in the 2g's pistons?????

Also, it seems that removal of the balance shafts is a very popular mod for reliablilty and to allow the motor to rev up quicker. Considering that I am going for increased lower RPM torque, wouldn't removal of this extra rotating mass hurt my performance that I am currently going for??? If so I think maybe replacing the bearings with coated ones might be a better setup for me.

And as for the rest of the motor, I would like to have my stock crank nitrided, Block Bored to 87mm (0.020" over) for Wiseco pistons, either Scat or Eagle rods (any oppinions????), nitrided cams, adjustable timming gears (to advance cam timing), full ARP studs and bolts, POSSIBLY upgraded main caps, and I'm gonna try to get the motor completely coated in anyway I can think of.

Any other suggestions????

BTW: I know this is probally going way over kill on the motor, but thats what I want.

jeffball610 · Post by **jeffball610** » Tue Oct 03, 2006 2:33 am

For a low reving NA motor, your setup is WAY overkill. That's not a bad thing, but in NA form and low revving, stock parts will hold up fine. The stock rods are good for about 400hp. Stock pistons aren't that great, but with the 4G63 head, will bump compression to about 11:1. Not sure what will happen at that level.

It is true the 2G head flows better. It has an improved intake runner angle and the smaller ports are good for most applications. The 1G head starts with larger runners, so it needs little porting for high revving fun. The 2G will likely outflow the 1G head with porting work, but should not be attempted without a flow bench. However, the 2G head is not equiped with the CAS (cam angle sensor) that is on the 1G head. I don't know how you'll adjust timing or have the ECU read timing without this. Most people put a 1G head on a 2G motor and use the CAS wired into the 2G wiring. I'm sure there's a way, but I don't know of one. The 2G head also has smaller head bolt holes. Not a big deal, but be careful when installing it, as the head will likely lose some shavings to the head stud threads on the tight fit. (1G motors have 12mm bolts, 2G motors have 11mm)

Removing the balance shafts is good for a couple reasons. First it removes the balance shaft belt that is the culprut of most timing belt breaks. Second, removing rotating mass from the crank is the best place. Typical power increases are in the area of 5-15hp just by removing these. Also, removing these will increase your oil pressure slightly. Not necessarily a reason to do it, but low RPM oil flow is always good.

I really doubt you'll want to nitride the crank as it is pretty stout as is. And in NA form, you won't be pushing it's limits at all unless it a full race motor running extreme compression and alcohol or something. As far as I know, there are no nitrided cams available. There is no need. You will want to upgrade the lifters (hydraulic lash adjusters) in either head you choose and going with upgraded springs and retainers is good, but you won't be pushing the limits of the stock springs unless you have a pretty steep cam profile. ARP head studs are always recomened, mostly cause the stock pieces cost about the same and the ARP units are far superior. Adjustable timing gears are probably good on an NA motor, but not so much on the turbo. Basically this is because most cams are designed well from the manufacturer and need no adjustment. Not to say there isn't any room for additional power.

In short, yes, you are REALLY overbuilding the motor. With all the parts you want to add, you should be good for about 600hp. I seriously doubt you'll make more than 300hp, but not many people try this route. Dare to be different, but realize that for the money, forced induction will almost always reap more power.

Post by **DJpowerHaus** » Tue Oct 03, 2006 9:51 am

Is E85 readily available in your area? A motor with stock pistons and a 1G head would probably love 11:1 compression running 110oct E85.

I think you'll be fine with stock rods, bearings, etc. If you dont want to use the stock pistons, I'm not sure what your options are for a middle of the road compression ratio. Maybe you could get OEM mitsubishi 1994 Galant DOHC 2.4L pistons and find out how to get the wrist pin size right for 6 bolt rods.

Or you could just do the mods you want to do, get the redily available 8.7:1 Wiseco pistons and turbo it. You wont regret it!

You might gain some info about your head swap from http://www.roadraceengineering.com/1gcasin2g.htm . People from www.mightyd50.com might also be able to help. DSM sites have way more info on the longblock than we do. Check out the big DSM sites for help there.

Project Zero G mainly focuses on the details of making it RWD (water pipes, IC pipes, etc). Most long block stuff is the same on DSM stuff (other than plugging holes on heads for RWD cooling).

Robert Venable · Post by **Robert Venable** » Tue Oct 03, 2006 10:54 am

jeffball610 wrote:For a low reving NA motor, your setup is WAY overkill. That's not a bad thing, but in NA form and low revving, stock parts will hold up fine. The stock rods are good for about 400hp. Stock pistons aren't that great, but with the 4G63 head, will bump compression to about 11:1. Not sure what will happen at that level.

I'm aware of the compression ratio, thats a big reason for going with the aftermarket pistons, not comfortable with going more than about 10:1 on any motor w/o a good bit of overlap. As for the rods, I'm gonna search on e-bay for the pistons and rods and that will probally determine which I go with. I'll probally never see 400 hp, but I'm building this motor to take any changes I might make in the future. A power adder is not out of the question, just not likely at this point (I've got a BIG Small block powered S-10 in the works for that). As we all know, plans NEVER CHANGE.

It is true the 2G head flows better. It has an improved intake runner angle and the smaller ports are good for most applications. The 1G head starts with larger runners, so it needs little porting for high revving fun. The 2G will likely outflow the 1G head with porting work, but should not be attempted without a flow bench. However, the 2G head is not equiped with the CAS (cam angle sensor) that is on the 1G head. I don't know how you'll adjust timing or have the ECU read timing without this. Most people put a 1G head on a 2G motor and use the CAS wired into the 2G wiring. I'm sure there's a way, but I don't know of one. The 2G head also has smaller head bolt holes. Not a big deal, but be careful when installing it, as the head will likely lose some shavings to the head stud threads on the tight fit. (1G motors have 12mm bolts, 2G motors have 11mm)

When you say timing are I assume you are reffering to to ignition. If I do this swap I'm gonna move to coil-on/per-plug. It's something I'm familiar with and I think it will allow me to run higher spark plug gaps to complete the burn in the combustion chamber. As for the head bolt holes, thats nothing a drill bit can't solve(aka professional machine shop).

Removing the balance shafts is good for a couple reasons. First it removes the balance shaft belt that is the culprut of most timing belt breaks. Second, removing rotating mass from the crank is the best place. Typical power increases are in the area of 5-15hp just by removing these. Also, removing these will increase your oil pressure slightly. Not necessarily a reason to do it, but low RPM oil flow is always good.

I understand about the balance shaft belt taking the timing belt out, but I think this is more due to the fact that most people do not replace this belt w/ a timing belt. My truck has over 200k and it has not had a problem with this and I think it's due to the regular replacement of both belts and the fact that it is hardly ever seen anything close to redline. I also wonder if oil maintance has something to do with this also since there have been bearing failures on the balance shafts.

I agree around the crank being the best place to remove weight, for racing applications. But I've also see where removing too much weight made the car "buck and surge" at lower speeds because of the lost recipricating weight that would not allow the engine to smoothly transition from each power stroke. I want to avoid this. Now the vehicle I'm referring to was an EXTREME case (8 ? lb flywheel and clutch assembly on a 2.5 liter BMW E30), but I just wanted to find out if anyone who had done the Removal of the balancer shafts felt something simular.

I really doubt you'll want to nitride the crank as it is pretty stout as is. And in NA form, you won't be pushing it's limits at all unless it a full race motor running extreme compression and alcohol or something. As far as I know, there are no nitrided cams available. There is no need. You will want to upgrade the lifters (hydraulic lash adjusters) in either head you choose and going with upgraded springs and retainers is good, but you won't be pushing the limits of the stock springs unless you have a pretty steep cam profile. ARP head studs are always recomened, mostly cause the stock pieces cost about the same and the ARP units are far superior. Adjustable timing gears are probably good on an NA motor, but not so much on the turbo. Basically this is because most cams are designed well from the manufacturer and need no adjustment. Not to say there isn't any room for additional power.

Nitriding is offered by one of the major cam companies (Comp cams I believe), I read an artical where they recomended this (For about $100-150) to extend the life of the cam when using high spring rates. I would bet that they don't do it in house, and all I would have to do is find out who does it for them(or if there is a local guy that does it) and I should be able to get any cam, crank, etc. nitrided. Granted, I really don't need it, but I want it.

Upgrade the HLA's? Didn't know that there were upgrades out there. Every DSM parts supplier I've looked at that mentions lash adjusters only mentions stock replacements. Can you tell me more about this? Also, Where do I find upgraded followers/rockers??

In short, yes, you are REALLY overbuilding the motor. With all the parts you want to add, you should be good for about 600hp. I seriously doubt you'll make more than 300hp, but not many people try this route. Dare to be different, but realize that for the money, forced induction will almost always reap more power.

I aggree, but this really isn't an engine that I will care about power. This is an engine that HAS to get me to and from work every day, and I like to play. So, I want alittle more "umph." Like said before," I am more than likely gonna keep this motor NA." That doesn't mean the power bug won't bite me on this truck also and having me slapping on a little T3 in the future, it's just not in the plans now.

Robert Venable · Post by **Robert Venable** » Tue Oct 03, 2006 11:34 am

DJpowerHaus wrote:Is E85 readily available in your area? A motor with stock pistons and a 1G head would probably love 11:1 compression running 110oct E85.

No, it is not readly avalible and I WOULD NOT recomend using it unless you swap the fuel system over for a system that is compatible with it. BMW is having problems out the ying yang because of people running this stuff.

I think you'll be fine with stock rods, bearings, etc. If you dont want to use the stock pistons, I'm not sure what your options are for a middle of the road compression ratio. Maybe you could get OEM mitsubishi 1994 Galant DOHC 2.4L pistons and find out how to get the wrist pin size right for 6 bolt rods.

Thanks for the heads up on the Galant pistons, never even thought about that. I'll try to look up some specs on the compression ratio and such for this motor-- got any places for me to start researching??

Or you could just do the mods you want to do, get the redily available 8.7:1 Wiseco pistons and turbo it. You wont regret it!).

Not out of the question

You might gain some info about your head swap from http://www.roadraceengineering.com/1gcasin2g.htm . People from www.mightyd50.com might also be able to help. DSM sites have way more info on the longblock than we do. Check out the big DSM sites for help there.

Thanks for the heads up on Road Race engineering. I made this post originally in MightD50 first and still have not a single response. I currently am tring to set up my cox e-mail account to allow me to sign up at DSMtuners.com. My next try will be signing up at Evolutionm.net and checking out Eclipseforums.org. I was just hoping this place and MightyD50 would be the only places I would have to ask due to the fact that a majority of the posters are mature and open to other's opinions (although there are exceptions). From my readings on DSMtuners.com, I'm not impressed.

Project Zero G mainly focuses on the details of making it RWD (water pipes, IC pipes, etc). Most long block stuff is the same on DSM stuff (other than plugging holes on heads for RWD cooling).

True, but I've noticed a few of the guys on here have built rather nice motors and I've also noticed guys like you and Bill Hincher are extremely well knowledged in multiple areas. Thats why I've gone threw almost every single post on this site.

jeffball610 · Post by **jeffball610** » Tue Oct 03, 2006 1:36 pm

If you're going to stay NA, you will not want a piston that lowers compression beyond 9:1. For more "fun" and "power" you want to go higher than that. 11:1 is not out of the question and shouldn't be too hard to tune considering you want adjustable cams and such. You can also lower this some with a thicker head gasket. Cometic sells a large selection of 87mm DSM head gaskets. The stock DSM coil is very good and adjusting the plug gap shouldn't be necesary. Again, this is a low power engine. I know you "might" change your mind, but building an engine is something you dont' want to do twice. Setting the motor up now for turbo and not running one for a while is fine. Trying to build an NA motor that you "might" upgrade later really isn't what you should do. IMHO. You could build a killer NA street motor, but the parts you are talking about are well beyond what you need. Stock parts will work fine. Like you said, you have over 200k on your motor. What's wrong with that reliability? You will notice a nice bump in power just going with the DOHC from your stock motor. I have removed the balance shafts from my 92 Talon TSi AWD and noticed no ill effects. Not even a rougher idle. The only downside might be that you should change gears a little faster becuase the mass will slow faster just like it speeds up faster. Not much though. The lash adjusters built for the 2000 Eclipse are the upgrade. They typically cost about $8 each. They have larger oulet holes in both the top and side to give more oil flow. Anyone that ownes a DSM knows about lifter tick. As far as I know, there are no upgrades for the rockers. They are well designed from the factory. The best upgrade for those would be new stock replacements.

Basically it sounds like you're going to spend $5 on a daily driver motor. You can if you want. I'm building a nice 2.4L to handle 400+hp and won't be spending more than about $2k. (plans do change though) For more reference material on this, you might also check out DSMTuners.com, Magnus Motorsports, Buschur Racing, Slowboy Racing, and others. DSMTuners has a large section of vendors that you can link to.

Post by **DJpowerHaus** » Tue Oct 03, 2006 1:53 pm

There are rocker upgrades available. They are from the Evos. They are lighter and the weight that remains is closer to center where it matters.

slowboyracing.com wrote:

100% Mitsubishi OEM Stock Rocker Arm

Our local mitsubishi dealer sells these for $25.00 per unit. After picking up our pride, we found the whole sale part number and our currently doing our best to keep them in stock.

These are 100% factory originals.

Fitments -

Mitsubishi Eclipse 4G63 1990-1999
Eagle Talon 4G63 1990-1997
Plymouth Laser 4G63 1990-1994

MD 375091

Our Price:

$21.00 (each)

Post by **DJpowerHaus** » Tue Oct 03, 2006 2:37 pm

Its pretty simple. You can't just toss it in a car tuned for gasoline and expect it to run as well! That'd be like putting diesel fuel in your eclipse. Its just stupid. Anyone who blames the FUEL and not the person using it in the wrong application needs to open their eyes.

You need around 30% more fuel to get the proper performance and air fuel ratio from E85. I can see how maybe E30 owners have trouble with their fuel systems. I'd even think Starion people might have trouble (but I doubt it, i've seen the materials that make up the fuel system and they should be able to handle it). Older cars use older materials in their OEM fuel systems.

Yeah E85 will eat rubber seals. Yet again this would be an example of using it in the wrong application. The auto industry has not used true rubber seals since the early 80s in most cases. Any injectors, fuel pumps, "rubber" hoses, etc. you can now buy will likely be constructed to handle large percentages of Ethanol. Most people that use modern parts performance or oem should not have problems.

Many Subaru people have been using this fuel on OEM fuel supply systems for literally YEARS. They usually use a piggyback MAS modification device to adjust the aforementioned 30% increase in fuel needed. Some even calculate how big 30% bigger injectors would be and just swap them with no piggyback.

Once the A/F ratio is tuned properly for E85 you can take advantage of the 110oct rating of the fuel by either adding timing or adding boost which WILL make more power.

Robert Venable · Post by **Robert Venable** » Tue Oct 03, 2006 3:00 pm

jeffball610 wrote:If you're going to stay NA, you will not want a piston that lowers compression beyond 9:1. For more "fun" and "power" you want to go higher than that. 11:1 is not out of the question and shouldn't be too hard to tune considering you want adjustable cams and such. You can also lower this some with a thicker head gasket. Cometic sells a large selection of 87mm DSM head gaskets.

I understand what you are saying, but I would still preffer the lower compression for multiple reasons.
1. The possibility of a future turbo
2. 93 Octane fuel is as high as it gets here, I will be using this motor for lower rpms and will be reducing overlap (which adds to the dynamic compression ratio vs a wide overlap spread) the temperatures are normally rather high here, and humidity in Louisiana is extremely high (100% at times) all of which add to the chance of detonation.
3. I'd rather be able to run 87 octane to go back and forth to work for gas prices. And I'd rather not have to run it overly rich to preven detonation.
4. As you said bellow, I would rather not have to rebuild my lower end if I did go to a Forced induction setup.
5. I'm sure I could think of others, but I'm going plank right now

The stock DSM coil is very good and adjusting the plug gap shouldn't be necesary. Again, this is a low power engine.

Again, you are correct. But this is simply because I'm more familuar with this setup. And whats wrong with upgrading to something better than "Good"?

I know you "might" change your mind, but building an engine is something you dont' want to do twice. Setting the motor up now for turbo and not running one for a while is fine. Trying to build an NA motor that you "might" upgrade later really isn't what you should do. IMHO. You could build a killer NA street motor, but the parts you are talking about are well beyond what you need. Stock parts will work fine. Like you said, you have over 200k on your motor. What's wrong with that reliability? You will notice a nice bump in power just going with the DOHC from your stock motor.

I know "the parts {I'm} talking about are well beyond what {I} need," And I know that "Stock parts will work fine." Thats the point. I am building an higher output engine that will have no problems lasting just as long as the stock lower output did. Could I save money buy using stock parts, without a dough I could. But lets say 3 years from now I'v just finished figuring out how to get my new 72mm Ball bearing turbo to spool up at 7200 RPM and the 1st time I go out and reach 42 psi of boost my #2 rod spits out the side of the block. I'd be pretty pissed and I'd regret not using those aftermarket rods, wouldn't you?? Will that ever happen, not likely, but I would like to know that 3 years from now I will beable to do anything I want (within reason-- something more like a 70 MM turbo

). Besides, what does it hurt (besides my wallet) by overbuilding the motor??

I have removed the balance shafts from my 92 Talon TSi AWD and noticed no ill effects. Not even a rougher idle. The only downside might be that you should change gears a little faster becuase the mass will slow faster just like it speeds up faster. Not much though.

How does it idle when you are putting around in a parking lot with the clutch engaged??

The lash adjusters built for the 2000 Eclipse are the upgrade. They typically cost about $8 each. They have larger oulet holes in both the top and side to give more oil flow. Anyone that ownes a DSM knows about lifter tick. As far as I know, there are no upgrades for the rockers. They are well designed from the factory. The best upgrade for those would be new stock replacements.

Thanks for the heads up, but wouldn't the higher flow allow more bleed down of the lifters, reducing peak lift/duration and increasing the lifter noise??

Basically it sounds like you're going to spend $5 on a daily driver motor.

I'm ok with that, Why?? Because I'd rather spend 5k on it once than 2 k this time and another 5k later.

Thanks again man.

BTW:Don't worry, most people don't understand me either.

Robert Venable · Post by **Robert Venable** » Tue Oct 03, 2006 3:06 pm

DJpowerHaus,

The problems BMW has been having have been Seized up fuel pumps, engines running erratically, and other different things.

BTW, thanks for the info on the rockers I saw those on SBR, but didn't relize they were upgrades.

Robert Venable · Post by **Robert Venable** » Thu Oct 05, 2006 1:43 am

jeffball610,

I've been thinking, and I started talking with a fellow tech at the shop and he reminded me of something I had completely forgot when I was thinking about building this motor. I Don't normally warm my engine up enough in the mourning to run forged pistons. Maybe this would change after I built my motor, but Maybe you are right and I should rethink this whole thing.

In the mean time, I've found a site on the web that seems to be selling Piston and rod combos for 4G63s (smaller bore) for REALLLLY cheap. Talking about Aries pistons w/ eagle rods for about the cost of just the pistons from SBR..
http://stores.ebay.com/DYNOFLO-PERFORMA ... QpZ2QQtZkm

Robert Venable · Post by **Robert Venable** » Thu Oct 05, 2006 8:43 pm

mattmartindrift wrote:I have one thing to say about low RPM, high torque motor.....LS1!!!!

But I'm already building a V-8 For my S-10 (before the MM). I was originally planning the head swap a couple months ago when I found a $200 S-10. I could not pass it up and I figured since the MMM was in far better condition that It would be stupid to tear it down and have 2 nondriveable vehicles.