4g64 / 4g61

[caliboy23]

Ok, lets say someone is totally bored and has a lot of money they don't mind wasting. Would they be able to put the 4G61 crank into a 4G64 block with out trouble? I know custom rods, custom pistons and all that. But would the 1.6 crank fit into the 2.4 block? I'm guessing the main journals are the same size.

I just finished watching a video of how they make an F1 engine, and those radicly destroked 2.4 liter V8's just sound so nice at 18,000 RPM's. I just got to thinking about that kinda stuff. I know the uses for it would be very minimal, and we don't even have a cam profile to take advantage of really high RPM's. But ......... what if ?

 

[90laserRSfwd]

what if that person tried it and let us know (with pictures included too)

 

[caliboy23]

Yeah exactly. We've done everything else with the 4G63 / 4G64 motors. Why not try it? If I had a 4G61 crank and a 4G64 block I might actually get around to that some day. Hell, maybe even one of the 1.5 liter cranks outta the single cams might fit also. I'm gunna look around for the clearance numbers just to educate myself. If the small crank fits, we may have a new project for somebody.

 

[Freerevving]

That is actually a very good idea... I love high revving engines... especially ones that can rev to 10,000 (not too fond of rotary engines, though)

The big concern, I would think, would be the length of the crank and the journal spacing... When the displacement gets small enough, the spacing is almost always too different.
If you could make a 1.8 or 1.85 (1.9) with the 1.6L crank, you would have something serious... You might even be able to achieve this with the 2L block, although you would have to do some stroke x bore (+ head volume) calculations to be sure. If you do start on this, just remember to keep the rods long and the pistons short

 

[biglady112]

1.6l, 1.8L, 2.0L and 2.4L 4G engines all use the same rods and same width bearings. I would assume the bearings are all the same size too. But they may differ.

To put it in short, there is not a valve spring on the market that can handle more than about 12,000-13,000rpm safely. As far as I know, the Kiggly springs are at their limits at these levels.

Steven

 

[BoostFrenzy]

To put it in short, there is not a valve spring on the market that can handle more than about 12,000-13,000rpm safely. As far as I know, the Kiggly springs are at their limits at these levels.

I was just thinking that. But if you wanted to go that high, you would have to have some sort of hydraulics to operate the valves. Same thing F1 has. And I'm pretty sure that those are some expensive parts because F1 is cutting edge technology where teams break the bank for the best.

 

[caliboy23]

Yeah the valve springs could only take so much before they float. But like I mentioned, we don't even have a cam available that could maximize an engine that revs that high. I hear the evo's have a 288 available but even that wouldn't do enough at 12,000 RPM. I would say a 295 to keep it pulling to the limit. Not to mention our tranny's don't like shifting above 8500. I imagine the tranny wouldn't like 12,000 much either.

I went looking around for a 4G61 crank online. So far all I can find is the entire engine from the guys who do the 4G63 swaps on 4G61T.com

If anyone hears of something that comes up, let us know.

 

[Freerevving]

You'd want some 300's or 305's to rev to 10k+... and I think 13k is out of the question

When you're revving that high you want to get rid of hydraulics... they help cause valve float... Maybe f1 cars have an advanced system, but we're not going to get away with it without some corporate sponsors... Solid lifters are commonly used for high revving engines like this

The most important thing for your head is to have a lightweight valvetrain and some stiff springs. I'm pretty sure that everything you need, to do this right, is available except you'll have to research getting cams and the right length connecting rods ...

I'm thinking custom (longer) rods on oversized stroker pistons, and a 1.6L crank... a 4g64 block... etc etc... You probably can get back to 2.0L or more... maybe you should check out the 1.5L crank first..... just remember that less stroke, and less rod ratio, is safer and longer lasting at any rpm

 

[tkelly27]

I don't think it was hydraulic lifters, but rather hydraulic systems to close the valves. 16-17k is where the limit of springs (not the springs we have available, but springs in general) can no longer function. That's the figure I was told anyway.

 

[Freerevving]

apparently there is more than one journal size

eBay Motors: 1.5L 1500 Chry Mitsubishi Dodge Ply Crankshaft Kit (item 280197069824 end time Aug-28-08 07:03:01 PDT)

eBay Motors: 1.5L 1500 Chry Dodge Ply Mitsubishi Crankshaft Kit (item 270208264636 end time Aug-28-08 07:07:03 PDT)

you could probably get a clean bock from these guys, although I'd shoot for a 6 bolt block:
eBay Motors: MITSUBISHI EXPO GALANT 4G64 2.4 LITER SHORT BLOCK 92-95 (item 370021146824 end time Sep-04-08 17:08:06 PDT)

Here's just one good place for custom rods:
Aluminum Connecting Rods
or it might be cheaper/easier for custom pistons, but I don't know I haven't priced the difference... I know JE will do a custom piston set for about 500

so far I know BC has 288's

Just an example of parts that we should be looking for... anyone else?

 

[delta448]

Mitsubishi Sirius engine - Wikipedia, the free encyclopedia
Seems the 4G61 crank is the only OEM option, if in fact the journals are correct. Specs on the 4G61 are 82.3mm bore and 75mm stroke.

So, with a 75mm stroke and a 86.5mm stock 4G64 bore, you could theoretically have a 1.76L engine. With a 0.060 (the max I'd ever consider) overbore to get up to an 88mm bore size, you'd end up with a 1.82L. I'm not trying to discourage anyone, I'd love to see it done, but I'd imagine that a 2.1L (using the 88mm crank from the 63) would be able to rev as high or higher than any valvetrain/transmission currently available could withstand.

 

[Freerevving]

So, with a 75mm stroke and a 86.5mm stock 4G64 bore, you could theoretically have a 1.76L engine. With a 0.060 (the max I'd ever consider) overbore to get up to an 88mm bore size, you'd end up with a 1.82L. I'm not trying to discourage anyone, I'd love to see it done...

If you could make a 1.8 or 1.85 (1.9) with the 1.6L crank, you would have something serious...

Mitsubishi Sirius engine - Wikipedia, the free encyclopedia
Seems the 4G61 crank is the only OEM option, if in fact the journals are correct...

Do you know if any of these are compatible? They're cousins and have a lot of choices in small cranks:

Mitsubishi Orion engine - Wikipedia, the free encyclopedia

 

[Freerevving]

I can't find 300's but Comp Cams will do a custom grind..


Is anyone still following this?

 

[Defiant]

I just wonder where they get these ideas. I'm guessing a tainted well.

 

[Freerevving]

If you think of an engine as an "air pump", there are two ways to get it to move more air:

1)more displacement

2)small displacement but High RPM's


Defiant maybe you're right, maybe the OP had an idea with no real motivation behind it

 

[Freerevving]

If you think of an engine as an "air pump", there are two ways to get it to move more air:

1)more displacement

2)small displacement but High RPM's


Defiant maybe you're right, maybe the OP had an idea with no real motivation behind it

here's some motivation

<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/iDqDW41J4BY&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/iDqDW41J4BY&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>
<object width="425" height="344"><param name="movie" value="http://www.youtube.com/v/nO4IpFBaXZ8&hl=en&fs=1"></param><param name="allowFullScreen" value="true"></param><embed src="http://www.youtube.com/v/nO4IpFBaXZ8&hl=en&fs=1" type="application/x-shockwave-flash" allowfullscreen="true" width="425" height="344"></embed></object>

I just noticed that this was moved to the hangout... and I re-read the OP... oops oh well, maybe I'll be the one

 

[Defiant]

Ah. It's another one of those dreams, kind of like those ones I keep having with Vanna White, but without the mess.
Or do you intend to convert your quick street car into a million-dollar race machine to compete in hillclimb competitions?
Start at the foundry. Cast a new block, and get to work at the hammer-forge on making a new crank and rods.
It's a different world. A motor that spins to 10K+ isn't anything you'd want to live with, let alone pay for.

 

[dragonov_elite]

Well there could be a simpler solution to the valve train if you would be willing to spend the money.

Welcome to Coates International Ltd.

Welcome to Coates International Ltd.

http://www.coatesengine.com
/technology-document.html

Just thought i would throw the idea out there.

 

[Colt4G63 also]

^^^^^^^^^^^^^^^^^ Exactly what I was going to suggest. Those valves have no rev limit that I know of. And I have A 4g61 layng around that I'm not using. I'll let the crank go for less than the cost of a Coates cylinder head.

 

[dragonov_elite]

My mom has a colt vista with a 1.8 so maybe once that thing dies ill snag that up and look for a 2.4 . +1 that someone needs to try this with the Spherical Rotary Valve Assembly and see where it ends up .

 

[Freerevving]

Ah. It's another one of those dreams, kind of like those ones I keep having with Vanna White, but without the mess.
Or do you intend to convert your quick street car into a million-dollar race machine to compete in hillclimb competitions?
Start at the foundry. Cast a new block, and get to work at the hammer-forge on making a new crank and rods.
It's a different world. A motor that spins to 10K+ isn't anything you'd want to live with, let alone pay for.

Wow Defiant... your view on these things really shows your extreme lack of exposure to the performance world. Do you look down your nose at everything just because you don't feel compelled to do it? Or maybe you just don't see the point? Either way, your mis-informed comments have never helped me much.

Maybe you were referring to the BMW?

but the Polo is a budget engine... I know all about what went into building that thing, the guys name is PoloV8 on the vortex I've also seen many like it... it's pretty simple... The ITB's and the Standalone were the biggest expense, and neither one of them is completely necessary. I will admit it's a lot easier to find 300 degree cams for a VW.

And the cost of coates would be out fo the question

High-revving engines are not that hard to make... in the end, they do the same thing as an engine with more displacement... it's just something that hasn't been explored much in the DSM world

 

[bastarddsm]

Wow Defiant... your view on these things really shows your extreme lack of exposure to the performance world. Do you look down your nose at everything just because you don't feel compelled to do it? Or maybe you just don't see the point? Either way, your mis-informed comments have never helped me much.

Maybe you were referring to the BMW?

but the Polo is a budget engine... I know all about what went into building that thing, the guys name is PoloV8 on the vortex I've also seen many like it... it's pretty simple... The ITB's and the Standalone were the biggest expense, and neither one of them is completely necessary. I will admit it's a lot easier to find 300 degree cams for a VW.

And the cost of coates would be out fo the question

High-revving engines are not that hard to make... in the end, they do the same thing as an engine with more displacement... it's just something that hasn't been explored much in the DSM world

There is a good reason that you will never see very many high(10k+) rpm dsms. Our valve train will not allow it. We cannot use a cam large enough to make any useable power up there. With much more than .400" the rockers tend to come off the end of the valve stem, an with our small base ciricle on our cams much more than 288* duration causes clearance issues with the heel of the cam and the rocker, Not to mention the sky high ramp rate required to accomplish this.

Granted a 4g63 that revved like a sportbike would be great...its probably not going to happen. Especially with our trannys that are more tempermental than a feminazi on her rag.


Edit: that coates head would work, but you'd need a billet crank and good rods to withstand sustained high rpm abuse. However at this point the engine really isn't a 4g63 anymore.

 

[Freerevving]

I'm really not trying to start a huge debate

There is a good reason that you will never see very many high(10k+) rpm dsms.

because rpm's that high are not necessary with turbos... Plus the rod ratio is about at its limit for 8500 with a 4g63

We cannot use a cam large enough to make any useable power up there. With much more than .400" the rockers tend to come off the end of the valve stem

they tend to come off the valve stem... and you know this how? I would like to see some shred of proof to show this... Even so, it's a problem that solid lifters can solve, if it's true.

an with our small base ciricle on our cams much more than 288* duration causes clearance issues with the heel of the cam and the rocker

what? that makes no sense to me... sorry if I'm being rude. The only thing to be concerned about is the ramp rate.

Not to mention the sky high ramp rate required to accomplish this.
.

Thanks to Mitsubishi, our stock springs are adequate to handle 288*... and we have many aftermarket springs available with higher rates... The largest concern here is spring bind.

Granted a 4g63 that revved like a sportbike would be great...its probably not going to happen. Especially with our trannys that are more tempermental than a feminazi on her rag.

Our trannies are far from tempermental when compared to German transmission... and mostly german cars are being made to rev that high.. I'm suprised more people don't know about GL4. It solves high-revving problems and others. Something else to keep in mind... a burst of torque is more likely to kill your drivetrain than some high revolution pulls.

Edit: that coates head would work, but you'd need a billet crank and good rods to withstand sustained high rpm abuse. However at this point the engine really isn't a 4g63 anymore.

Has anybody ever priced a Coate's head? Even though I really like the design/concept, I'm willing to bet the price is more than most of our cars.

The engine would be in no way a 4g63... Maybe the key, here, is to start with a 4g61.. they came with 16 valves, even turbocharged, and might have compatible manifolds or other parts.

what a lot of people don't understand is that there is a lot of formulation needed to the bottom half... sure, a lightweight and responsive valvetrain is needed in a high revving engine, but eventually what's going to decide weather your block will grenade is going to be your rod ratio and balance. Anything can handle 10k+ rpm if the stresses are distributed properly... I don't see it happening safely with a 4g63.... I know it's more than possible and safe with a balanced 1.6L crank... You might want to lighten, but you don't need a billet crank... and valve clearance is a big issue

What a lot of people fail to realize it that this really is unexplored territory with DSM's... reason being, N/A engines have really no other alternative than to rev higher to make more power, while turbo charged engines can simply turn up the boost

It would be nice to see someone do this successfully, to explore uncharted territory, to actually be different... instead of trying to be different just like everybody else.

I think I might be more interested in doing this if I had a FWD vehicle, as they seem to be allergic to torque

 

[TunaTalon]

Moving valves up and down real fast is neat technology and fun to talk about.
Flaming Defiant is a source of pleasure but not productive.
But the limits of the 4G63 is related to air flow, not the inertia of the valve train.

Freerevving has a good summary of the physics of the valve train, but after 23 comments no one has mentioned sonic flow through the valves.

To make more power more air has to flow through the valves and the speed of sound (mach one, or sonic flow) is a hard limit for air flow. At sonic velocity no more air will flow through the valves even if they stay open and the pressure differential across the valve increases. Once mach one flow rate is reached putting more energy into forcing air through the valve just results in more energetic shock waves and bad things happen.

As a practical matter chocked flow starts to occur at about 0.6 mach and VE falls off quickly as RPM increases. The following quote is from page six of http://www.kidzuku.com/StrokeOrNot.pdf.

Aside from the history lesson, the message I get from this is that no matter how strong the main caps, or how well designed the pistons, there is a hard performance wall where the intake velocity approaches sonic flow through the valves. The 2.0L 4g63 with stock valves reaches 0.6 mach index at 9600 RPM. The 2.3L stroker reaches 0.6 mach index at 8400 RPM. Trying to spin the 2.3L stroker much past 8400 RPM will just hit the wall quicker as volumetric efficiency drops off.

When you set out to design a really high revving engine start with a head that has more valve area per cylinder displacement than the 4G63. But then it wouldn't be a DSM any more.

 

[Defiant]

Wow Defiant... your view on these things really shows your extreme lack of exposure to the performance world.

Now, which "performance" world are you referring to? The engineering and development labs that the Formula 1 constructors use, or the kind of crafting and endless failure and repair that a team like John Force's does? Or by "performance world", do you mean the 17-year-olds that are common on internaweb car forums and who somehow after seeing a segment by Matchett think they can convert their street car to carbon disc brakes. Or, who suggest Coates Spherical Valves on anything other than the handful of small blocks they've been built for?

Do you look down your nose at everything just because you don't feel compelled to do it?

I've out-lived the compulsions. I've been through enough disappointments of my own, and observed those of others in person and on the web sufficient to have more of a grasp on reality. If I can save just one person from riding into a box canyon while leaving a trail of unrecoverable paper money, I've accomplished my goal.

Or maybe you just don't see the point?

The "point" is often quite visible: Things like twin turbos, AWD everything, switchable transfer cases, targa tops, Cyclone heads, camshafts being spun backward. What is hard to see is these grand projects getting finished.

Either way, your mis-informed comments have never helped me much.

You'll usually find my level of being informed is correct, but it is far from infallible. However, there is a simple setting on web forums to block posters. You're more than welcome to do so with mine.

Maybe you were referring to the BMW?

I was referring to the folly of ever hoping to attain anything like that car's performance with a DSM. It wouldn't be hard. It simply can't be done. Realizing and admitting this as fact greatly simplifies things.

but the Polo is a budget engine... I know all about what went into building that thing, the guys name is PoloV8 on the vortex I've also seen many like it... it's pretty simple... The ITB's and the Standalone were the biggest expense, and neither one of them is completely necessary. I will admit it's a lot easier to find 300 degree cams for a VW.

What's the lifespan of the motors he's breathed fire into? What's the teardown and rebuild schedule? It's pure racing. It's a motor whose design is a decade newer that the DSM's. It won't be happening in the DSM world, and in cases like Shepherd's where it has been, the cars turn into cruisers whose trip odometers never see double-digits.

And the cost of coates would be out fo the question

Are you looking down your nose at someone's compulsion to experiment?

High-revving engines are not that hard to make...

when they're in Honda, or motorcycles. If you're starting with a DSM engine, they're not hard to make. They're just impossible to make.

in the end, they do the same thing as an engine with more displacement...

Suffer explosive failure?

it's just something that hasn't been explored much in the DSM world

Because for those wanting to venture into those jungles, there are paths that have already been macheted out and trails that are passable. Just as there are huge-power producing DSMs- but not through absurdly high crank revolutions.