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Discussion Starter #1
Installment #1

Joined up here a cuppla months back, lurked a bit while I studied some of the particulars of the 4G platform while I was looking for a suitable 4G GS Eclipse. Started a thread about the ‘07 I was buying and then have been conversing privately via email w/Sabertooth^2 about my build plans. BTW, he’s been a great help in all this and deserves a BIG thanks for all his help!

Ok, so a little long winded back story and then we’ll move on to the actual turbo build parameters for the ‘07 Eclipse GS I picked up in 2-21 in the next installment.

Started playin w/cars a bit late since I was already 30 when I began modding. Started back in the late 80s w/a German built ‘74 Ford Capri w/a 2.0l SOHC motor, same engine used in the Formula Ford race series.

Played with it, tweaked it with stock parts until I finally hit the performance wall and started making refinements to the stock stuff and eventually repurposing other cars parts and aftermarket stuff to improve the cars performance.

Ended up with a little 2.0 that screamed like a banshee and revved like a bike motor with handling that made it feel like it was on rails. This car was light, like 2200lbs, so even with less than 200hp it was a blast to drive, until … I got T-boned by a catering truck. Didn get hurt but the car was toast.

Next up was a ‘78 Ford Courier w/a 2.3l SOHC engine. Played with it for a cuppla years but the pressure from my then GF was too much to bear so the modding stopped at a rebuilt short block, cam, header and exhaust, improved ignition, and a bigger carburetor.

Then I went into a performance hiatus for a few years till I bought a ‘92 NA 4g63 DOHC 2.0l Eagle Talon in ‘96. This package had everything I’d dreamed about doing to my Capri and more as stock equipment. DOHC 4 valve head w/roller rockers, computer controlled engine management, fuel injection, oh man, I was in mechanical heaven!

Having had it for about 6 months and during one of our hottest Texas summers on record the thermostat stuck closed and with the outside temp at 110 in a matter of minutes the show was over and I was now the owner of a dead Talon. It got so hot that when I popped the hood it was pulsing oil and coolant out from between the head and the block, which was quite a sight.

At the time I was just beginning to surf the ol www. so I decided to see what I could find as a long block engine assy to just drop it in and get the Talon back going again. Lo and behold, when I did a search for Eagle Talon I found there was a wealth of information, clubs all over the world and a thriving aftermarket for these cars.

Anyway, found a used engine, had it shipped in, dropped it in and did my 1st timing belt swap. Doing that swap and realizing the precision with which the engine was built and timed, I was hooked and fell happily back into the modding game again.

Joined a local DFWDSM group and surfed and studied about these awesome lil 2 liters. Began conceptualizing what I wanted to do with the Talon but was always stonewalled by all the local DSMers whose mantra was always “Sell it and buy a turbo car, modding an NA is a waste of time!”

Being a bonified hard head I just went my own way and eventually wound up with an NA 4g63 that could even top end a stock AWD AT Talon TSI (turbo) a buddy of mine had. And, while many of my buddies cars were constantly sittin on jackstands while they repaired this or that or were waiting for parts mine was out terrorizing the roads around DFW on a daily basis, havin fun, rackin up tickets, you know, the usual.

During all this fun myself and 4 other DSMers opened up a small performance shop and called it Bar None Motorsports. We all had full time “real” jobs and did our shop stuff late into the night in a one bay storage building, then eventually into my 2 car garage with an attached 4 car car port.

Our focus was on building dependable hot street cars and always turned down anyone who wanted to build a drag car project. We had loads of fun and built some really fun toys but eventually split up over the concept of opening a full time shop.

The vote was 3 to 2 for opening a real shop while I felt we needed another year or 2 under our belts to make it a viable operation with a big enough following to enable us to make a go of it. BTW, the other 3 never did open a shop, so that was the end of Bar None Motorsports.

Between then and now I did a few other projects for customers and have owned DSMs ever since along with a cuppla Mirages and my trusty Dodge Ram pickup.

These days I’m single, in semi-retirement, still working, though far afield of my realm of industrial equipment mechanicing and have finally started drawing social security. My bills are cheap, everything’s paid off, have no debt so most of my $$ can go towards my toys, wooohoo!

All the above leads me back to my ‘07 4G GS turbo Eclipse project. This is very likely to be at least one of my last hot rods so it’s gonna be one tricked out MoFo for sure!

As a tribute to my old ‘74 Capri the ‘07 Eclipse project will be dubbed The Rolling Toy Box which is what I called the ‘74.

This build will take a while but I plan to throw every trick I’ve learned along the way into this build with no stone left unturned! Along with the turbo engine build every wearable joint in the suspension will be replaced and the overall suspension system upgraded w/coil overs and sway bars and it will all be as well documented as I can make it, so get ready to have some fun!
 

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Discussion Starter #2
Installment 2 – Basic Engine Build Parts and Parameters



Since the idea here is to build a fun to drive and own hot street car, the focus is gonna be to keep it dependable, at least as much as is possible.

While big HP goals and dependability don’t really go hand in hand there can be a lot of things done within a build to minimize potential pitfalls and future problems. Being a big fan of overbuilding things this is one way to do so.

If you build an engine with the intention of runnin it right at the edge of what it’s capable of outputting you more often than not will have performance and durability issues pop up, sometimes in very catastrophic and ex$pensive ways. This can really take the wind right outta your sails!

What I’m after here is a 350-500hp daily driver. One that’s rev happy and capable of much more hp and revs than it’s intended to be run at.

Basic Engine Parameters:

4g64 7-bolt 2.4 block from a 3G Eclipse

Kia DOHC g4js 2.4 head

4g63 7-bolt 2.0 (88mm stroke) crank

162mm Manley Turbo Tuff 7-bolt rods

Wiseco 10:1cr pistons

This combination, with the appropriate ancillary hardware, will yield what’s called a long rod destroker 2.1 engine capable of dependably hittin out to a max of 12,000rpm.

While this possible rpm threshold is an interesting number my plans are to keep it more in the 8-9,000 range as the max it will see for the sake of durability.

Two main reasons for choosing this combination is that it yields a better rod length to crank stroke ratio that again gains in the durability factor while also increasing the amount of time (dwell) the piston spends at TDC (top dead center) and BTDC (bottom top dead center).

The improved rod angles this combination winds up with makes for a lessening of the violent action the pistons make as they rock over at the top and bottom ends of their rotations. Then the increase in the time the pistons dwell at TDC and BTDC allow for a better/more efficient burn of the intake charge at TDC while similarly offering more dwell at BTDC which allows for better cylinder filling of the incoming intake charge.

Here’s a link to an interesting article on this concept Stroke to Rod Length Ratios and Building a Long Rod Stroker EJ205 - MotoIQ While this deals with adding this concept into a Subaru build the technical properties of the overall package remain similar.

Now this combination also has a cuppla trade offs in that power at lower rpms is decreased and the propensity for detonation is increased at the top end of the rev range. However, for the purposes of this build I’ll gladly make such a trade off as I personally don’t care about the performance at low to mid range Rs and detonation prevention issues will be addressed in a few unique ways we’ll get to later. Secondly this build isn’t intended to run more than a max of about 30psi of boost so detonation won’t be as difficult a part of the overall equation anyway.

4 bangers by nature always make their best power in the upper Rs which this set of build parameters accentuate while also offering a more durable engine overall by minimizing some of the engine stresses normally associated with running at high revs.

Having read the late, great Smokey Yunicks thoughts on this concept many years ago in his book called “Power Secrets” it’s been a personal dream of mine to build such an engine, which I’ll finally be doing!

Lots more to come as we explore other parameters for this build in both the basic parts and all the sub assys as well in future installments.
 

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Interesting about wanting a smaller destroker engine to be able to rev higher, I can see some advantages to that

I do have a WRX with EJ205, it is commonly known that the 2.0 is actually preferred to the 2.5’s (EJ255 06+ WRX and EJ257 STi engines) for the thicker cylinder walls
Although the STi engines do have more of a closed deck

however the best of them all is the JDM STi EJ207, 2.0 with thick cylinder walls, more closed deck, best flowing heads, high revving, and AVCS valve timing
 

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Discussion Starter #4
It's all aimed at high revving durability with the inherent increased dwell to aid in cylinder filling and evacuation. This is really old school stuff as will be several other facets of the build then mated to all the new technology I can cram in too.

At this point I'm in parts acquisition mode. Already have a lot of parts but no block yet though I hope to be gettin that this coming week.

I snagged a 2004 Hyundai 2.4 DOHC head last week but want to find a Kia head locally and then compare the 2 before I settle on which one I'll ultimately use.

The Hyundai head uses a roller rocker design which adds in more moving parts (potential points of failure) over the direct acting Evo style Kia heads where the cam acts directly on the valves. This design kinda reminds me of the old Ducati Desmodromic motorcycle heads except those used a cam to both open and close the valves.

The Kia head also has a larger chamber area which might seem counterintuitive on the surface but actually helps to deshoud the valves and hence offers a flow increase which is a definite plus.
 

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Discussion Starter #5 (Edited)
Hmmm, more research has revealed an interesting point. Seems from 99-05 the Hyundai and Kias share a common 2.0 and 2.4 head, but, there are 2 different chamber shapes, one more rounded, while the other is a square shape with rounded corners. Can't seem to find what delineates where one or the other specifically is used.

Here's a pic of the unusual square chamber design
102140


I walked past several 2.0 Kias last week at the junkyard as I was focused on finding a 2.4 head, then picked up their only 2.4, which was the Hyundai version, mostly for research purposes. Will be going back there in a cuppla days and will take another look at the Kia 2.0 heads if there are any left.

The 04 Hyundai Sonata g4js head I picked up was the last year they used that design head before going in 05 to a timing chain engine like the Evo X uses. The 06 and up Theta version engine is also the version that replaces the roller rockers and hyd lifters with the bucket style direct cam operated valve set up so that style head is off the list. Stuck with the roller rockers I guess, which should still do fine with the right springs etc.

The g4js I yanked the head from was also a closed deck design block which leaves that open as a possibility for a boosted application as well. I was tempted to go ahead and get that block for research purposes as well but it was gettin late and my stomach was growlin thinkin about a local Gyro joint I had planned to hit on the way home :>P

'Sides, I really wanna use a Mitsu bottom end any way. Don't mind doin a lil bit of cross breeding but the purist side of me still has me wanting to stop at the head assy.
 

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Discussion Starter #7
Haven't truly decided yet which one I'll be using. That decision will come after lookin at a Kia head for comparison, though supposedly they're the same. Not sure yet which chamber design I like better but hopefully I will have both of 'em in front of me so I can do a more thorough comparison before I settle on the one I want to use.

Pics are great and all but I'm a more tactile oriented kinda guy and would rather get my big ol monkey paws on 'em and get up close and personal with both chamber designs.
 

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So why aren't you using a Mitsu head though? I realize Kia/Hyundai bought Mitsu's 4G6* series engine dies and cloned their own versions of them but idk why you'd use those instead over a legit Mitsu head, why not our own 4G69 head? It's one of the few with MIVEC and has good flow, Evo 9 with MIVEC would be next up

If you use a Kia/Hyundai head you might have to swap the cam angle sensor reluctor wheel
 

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pcfreak4, I respect your queries but please read on to better understand the whys of my parts choices:

The main reason for usin a Kia/Hyundai head is 'cause an Evo head is high as giraffe pussy comparatively and that's the only DOHC head Mitsu ever made for that platform, at least in the right rotation for our 4Gs.

Secondly I feel the DOHC is a better way to go over a 4g69 head for the availability of aftermarket support for it. The 4g69 has almost no support while there's plenty to choose from in the way of intakes, throttle bodies, larger valves, adjustable cam sprockets, bronze valve guides, cams and valve springs/retainers for the Evo/Kia/Mitsu DOHC head design.

While some of the things I mentioned above can be done with a 4g69 head in the end you're still left lacking as far as adjustable cam sprockets, cam selection, valve spings/retainers.

I'm not saying my build choices are for everyone but thankfully I get to build it the way "I" want to and that's all that matters to me.

This build is gonna cost a buttload of cash and that's cool, I expected such when I set my sights on the build parameters and honestly I refuse to limit my goals for the build by trying to use a stock SOHC head because to be completely blunt ... it won't get me where I wanna go with this build.

I respect anyones choices for how they wanna build their wheeled toys, most especially those who do it themselves as opposed to just havin the cheddar to drag boxes full of parts to a shop and then "have" it built.

This build is gonna be a ballz out one built w/my own 2 hands, the few brain cells I still have kickin around upstairs and RUM, can't forget the rum :>)

If you think the head and block choices I've lined out are a bit off the well beaten path, just wait, you ain't seen nothin yet, so buckle up and stay tuned :>P
 
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Took a slight detour today on the build program and picked up another toy.

With our surge of spring weather here in NE Texas, the bluebonnets in full bloom and all, I've been jonesin for a bike, so ... I just brought one home.

It's an '81 Suzuki GS1000L. All bike, so fairings, windshield or even a sissy bar, just 1000ccs of raging testosterone bliss on 2 wheels!

The one that dies with the most toys wins and ... I'm IN the game for sure ;>)
 
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