View Poll Results: What do you think on this topic?
Hell yeah! The EVO needs a new powerplant!
60
10.87%
I guess they should change it...
37
6.70%
Don\'t know
34
6.16%
Nah, why should they change it?
105
19.02%
Hell no! This is the best engine to use in the EVO!
316
57.25%
Voters: 552. You may not vote on this poll
4G63... outdated and archaic?
Evolving Member
Joined: May 2003
Posts: 258
Likes: 0
From: [6][5][0]san mateo, California..."rEpN dA YaY aReA!!"
i doubt it. since they been using for diff cars.. such as eclipse, n evo 1-8 .course its the best engine they built.they have been winning rally races.with the 4g63. i thnk its a good engine...they have been usin the same engine for years, n they must be doin sumthing right. if not wrong.
n course the legindary tommi mackinin been winnin races with evo 6
n course the legindary tommi mackinin been winnin races with evo 6
!
Originally posted by Ender2664
Back to the porsche thing real quick. The biggest reason that they went away from the air cooled was convieniance. Air cooled takes alot more monertering than the average "rich man" is willing to due. You have to constantly watch your oil pressure and oil temperature. My next door neighbor has the last year C4S, and we carry an extra quart of oil in the car at all times, and quite often you need to add oil. Not to mention that it holds something like 15+quarts and the oil changes are over 400 bucks. But another huge issue was that it is air cooled, and to get the air to cool the engine you need to be moving. Therefore if you are stuck in traffic for a while, you can sit and watch you oil temp sky rocket...at which point you have 2 choices, pull to the mataince lane and sit and let it cool down, of jet onto a off rap as quick as you can to get the oil temp down. Air cooled sound 1000000 times better, but like i said the reason that they went away from it is it is a bit of a hassle.
Back to the porsche thing real quick. The biggest reason that they went away from the air cooled was convieniance. Air cooled takes alot more monertering than the average "rich man" is willing to due. You have to constantly watch your oil pressure and oil temperature. My next door neighbor has the last year C4S, and we carry an extra quart of oil in the car at all times, and quite often you need to add oil. Not to mention that it holds something like 15+quarts and the oil changes are over 400 bucks. But another huge issue was that it is air cooled, and to get the air to cool the engine you need to be moving. Therefore if you are stuck in traffic for a while, you can sit and watch you oil temp sky rocket...at which point you have 2 choices, pull to the mataince lane and sit and let it cool down, of jet onto a off rap as quick as you can to get the oil temp down. Air cooled sound 1000000 times better, but like i said the reason that they went away from it is it is a bit of a hassle.
Winston
I didnt read all 5 million posts, but I am sure there have been lots of posts about why it is good and bad powerplant. I believe that the 4G63 is great and shows withstanding the test of time. But I also believe that technology is starting to leave it behind a little bit. You might have said this already in this long thread, but what about incorporating the MIVEC system into the 2.0 liter motor? Getting the advancement in the valvetrain might help bring the motor into the 21st century with a bang. Hell they are using variable valve timing in nearly every car these days, why not have MIVEC AND TURBO?? Maybe its been said, maybe not...but whatcha think????
Newbie
Joined: Aug 2002
Posts: 13
Likes: 0
the overlap of cams will kill a turbo motor. Most variable timing engine got variable timing disabled so that they can tune the engine to a "race" spec aka linear power delivery. The cross over of cams makes it hard to turbo charge a motor. It might work with advanced electronics but it will drive the price up. Long run, leave the variable crap out.
Newbie
Joined: Nov 2003
Posts: 54
Likes: 0
From: Kennewick, WA
I'm surprised there really has been very little technical discussion over the 11 pages of this thread.
A good motor will have the following:
For reliability:
Stiff, strong block.
Iron works very well here but is heavy. The typical honda open deck design doesn't work well in high boost situations as the cylinders will walk/move without some kind of extra support. There is a reason the aftermarked Dart Honda block is solid deck. It would be interesting to see Mitsu or one of the other manufacturers make a closed deck, steel lined aluminum block.
Stiff, strong crank.
This means a good forged crank, supported by lots of bearings. This is about a wash across current 4-cylinder designs.
Strong rods that are not too heavy
Pistons that are strong enough to resist some detonation
Now on to the items that make power:
Rod to stroke ratio
Longer rod to stroke ratios seem to make more power/torque and make the engine slightly more resistant to detonation and require less timing lead. These are all good things, but if the ratio gets too high, the rods get heavy and the acceleration curve of the reciprocating parts can get pretty high limiting maximum rpm. The sweet spot here seems to be between 1.7:1 and 2:1
Bore to stroke ratio
Oversquare designs (bore>stroke) breathe slightly better (something mostly fixed by 4-valve pent-roof heads) and will rev faster and higher. Undersquare designs tend to make slightly more torque, but have a lower redline. Square to slightly oversquare is probably best for our intentions.
Head and cam design.
The head must be designed to maximize squish, minimize dead areas and minimize any tendancies for detonation. Port design must maximize flow velocity at lower rpms, but not restrict maximum flow at the upper rpms (see some conflicts here....). Cams also affect where the maximum torqe and horsepower occur. If you can get the bottom end to stay together, most of the power and personality/drivability of the engine is found in the head and cams.
How does the 4G63 stack up?
Stiff, closed deck iron block proven to take large amounts of boost in stock form. ++ but could be lighter
Stiff, well supported stong crank proven to take large amounts of boost in stock form. ++
Fairly strong, relatively light stock rods proven to take more than moderate amounts of boost. +
Pistons seem to be strong enough, but it would be nice to have a true forged piston.
Going from memory here (dont' have the data at work), the rod to stroke ratio is around 1.7:1 and the bore to stroke ratio is just slightly undersquare. Ideally, I think we would like to see a bit longer rod and slightly more bore. This will likely require a new block to make this work as you will need more deck height and more bore spacing.
The head design has come a long way in the EVO 8. I'm not saying there couldn't be some improvements, but it works pretty well out of the box. The way to tell this is how much improvement is found before and after porting. We are getting into some diminishing returns here, or you end up speicializing the engine to a narrow rpm band.
What would I like to see?
An aluminum, closed deck, steel cylinder liner block. Less weight is very good.
A little more rod to stroke ratio, maybe up to 1.9:1 or so.
A slightly more oversquare bore to stroke ratio.
Variable valve timing to boost low end torque but not limit high end power. Although additional cam duration for high rpm performance is not as important in a turbo motor as in a N/A motor.
More displacement wouldn't hurt either.
It would be an interesting exercise to post all of the above info for the popular engines and see how they compare, especially the bore to stroke and rod to stroke ratios.
Mark
A good motor will have the following:
For reliability:
Stiff, strong block.
Iron works very well here but is heavy. The typical honda open deck design doesn't work well in high boost situations as the cylinders will walk/move without some kind of extra support. There is a reason the aftermarked Dart Honda block is solid deck. It would be interesting to see Mitsu or one of the other manufacturers make a closed deck, steel lined aluminum block.
Stiff, strong crank.
This means a good forged crank, supported by lots of bearings. This is about a wash across current 4-cylinder designs.
Strong rods that are not too heavy
Pistons that are strong enough to resist some detonation
Now on to the items that make power:
Rod to stroke ratio
Longer rod to stroke ratios seem to make more power/torque and make the engine slightly more resistant to detonation and require less timing lead. These are all good things, but if the ratio gets too high, the rods get heavy and the acceleration curve of the reciprocating parts can get pretty high limiting maximum rpm. The sweet spot here seems to be between 1.7:1 and 2:1
Bore to stroke ratio
Oversquare designs (bore>stroke) breathe slightly better (something mostly fixed by 4-valve pent-roof heads) and will rev faster and higher. Undersquare designs tend to make slightly more torque, but have a lower redline. Square to slightly oversquare is probably best for our intentions.
Head and cam design.
The head must be designed to maximize squish, minimize dead areas and minimize any tendancies for detonation. Port design must maximize flow velocity at lower rpms, but not restrict maximum flow at the upper rpms (see some conflicts here....). Cams also affect where the maximum torqe and horsepower occur. If you can get the bottom end to stay together, most of the power and personality/drivability of the engine is found in the head and cams.
How does the 4G63 stack up?
Stiff, closed deck iron block proven to take large amounts of boost in stock form. ++ but could be lighter
Stiff, well supported stong crank proven to take large amounts of boost in stock form. ++
Fairly strong, relatively light stock rods proven to take more than moderate amounts of boost. +
Pistons seem to be strong enough, but it would be nice to have a true forged piston.
Going from memory here (dont' have the data at work), the rod to stroke ratio is around 1.7:1 and the bore to stroke ratio is just slightly undersquare. Ideally, I think we would like to see a bit longer rod and slightly more bore. This will likely require a new block to make this work as you will need more deck height and more bore spacing.
The head design has come a long way in the EVO 8. I'm not saying there couldn't be some improvements, but it works pretty well out of the box. The way to tell this is how much improvement is found before and after porting. We are getting into some diminishing returns here, or you end up speicializing the engine to a narrow rpm band.
What would I like to see?
An aluminum, closed deck, steel cylinder liner block. Less weight is very good.
A little more rod to stroke ratio, maybe up to 1.9:1 or so.
A slightly more oversquare bore to stroke ratio.
Variable valve timing to boost low end torque but not limit high end power. Although additional cam duration for high rpm performance is not as important in a turbo motor as in a N/A motor.
More displacement wouldn't hurt either.
It would be an interesting exercise to post all of the above info for the popular engines and see how they compare, especially the bore to stroke and rod to stroke ratios.
Mark
Evolved Member
Joined: Dec 2003
Posts: 1,074
Likes: 0
From: UK
I know this may not seam that related but what the hell. I came across a company called Millington race engines here in the UK the other day. They have been tuning the for Cosworth engine for many years now and offer full race engines. The Cossy unit is a 2.0ltr, 16 valve turboed engine like the Evo. Looking into it a little deeper it turns out that they will build you some very interesting motors. The Cossy block (200) is iron but they will offer you an alloy one that (in N/A spec) can weigh as little as 86Kg for a 2.0ltr!!!!!! They have larger bores so they can be stroked out to about 2.6ltr (with a sorter stroke than a 2.3ltr Evo I think) and will run up to about 11.5 to 1 comp. ratio on a turbo!!!! Now if someone could do this for the Evos 4G63 engine then that would be amazing. 1000bhp Evo anyone?
Originally Posted by BlackLoTuS
Wow, I didn't know they made Magnesium camshafts these days!! Do they spntaneously ignite after 1000 miles or so? Oh, never mind, I think you meant magnesium valve cover which is not a performance enhancement just a weight saver.
I do think the 4G63 is outdated. If
came out with a good turbo GDI motor with Variable Valve timing, they could actually make more power while passing emissions. Now if only could devote the money and resources to develop these tech nologies... Oh wait! I for got they DO have GDI & MIVEC, now all they have to do is get off their lazy @$$es and make a 2000cc perfomance version with a turbo. It used to be that the only engine blocks that could stand up to boost were made of Iron. New manufacturing techniqes like a new high-pressure casting system invented by Yamaha to completely eliminate air pockets in aluminum castings allow for much stonger aluminum blocks. Let's face it, with cars getting as heavy as they are, we could use as many weight savings as possible.
Remember, making power is rarely the issue with most production turbo motors these days, its passing emisisons while making the power that poses the challenge.
I do think the 4G63 is outdated. If
came out with a good turbo GDI motor with Variable Valve timing, they could actually make more power while passing emissions. Now if only could devote the money and resources to develop these tech nologies... Oh wait! I for got they DO have GDI & MIVEC, now all they have to do is get off their lazy @$$es and make a 2000cc perfomance version with a turbo. It used to be that the only engine blocks that could stand up to boost were made of Iron. New manufacturing techniqes like a new high-pressure casting system invented by Yamaha to completely eliminate air pockets in aluminum castings allow for much stonger aluminum blocks. Let's face it, with cars getting as heavy as they are, we could use as many weight savings as possible.Remember, making power is rarely the issue with most production turbo motors these days, its passing emisisons while making the power that poses the challenge.
Originally Posted by evo542
somebody mentioned that the block should be aluminum!, you are plain wrong!!. Aluminum likes to stretch more when excessive heat is present, that's why cast iron works the best for FI engines.
Originally Posted by HoLeeRay
i'm just wondering, how many cars out there have engines with FI and intelligent cams?
Also, if they redesign the block I would like to see an extended bore to bore spacing so we could have 2.3Lish engine with the same stroke. That would make for a killer high revving engine that could also be stroked out to 2.8L
Bring on the GT42R 