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PostPosted: 23 Dec 2009 15:07 
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Cameron wrote:
Yes but the 4G63 have stroker kits designed for performance from HKS/JUN etc

The 4G94 isnt a performance motor, its not even close, just because its 2.0 doesnt mean your going to get figures similar to an evo, mitsi make a 4G64 so why dont people with evos use the 4G64 to make a EVO 2.4? Because its not a good base to work with, revs to 6-6500k so whats the point :?:



ummm, dude?
http://forums.evolutionm.net/evo-engine ... sions.html


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PostPosted: 23 Dec 2009 17:31 
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Yes agreed that there are some people using the 4g64. With those guys running 27 or 29 pounds of boost they are a pretty long way from the factory base motor though. If you are prepared to do rods pistons arp head studs and fasteners and a whopping big turbo what lump isnt going to make power. Reliability is another issue in itself though. The link you posted was for a car that had already lunched one block in a big way given he said a piece of the block put a hole in the radiator. So the big 2.4 crank can be used and healthy numbers returned but durability of things like the block being used outside its intended paramters could be a problem. I think the low value for the rod length to stroke ratio puts a lot of lateral force into the cylinder wall from the piston. Add to that high boost pressures and higher than stock rpm and it over stresses the block.
On from that there's probalby some aftermarket bracket to bolt around them to strengthen and support the blocks so they dont crack and all that. But if you consider you have to replace, alter or strengthen everything including the block does it really make it a good base motor?
Its a bit like grandmas old axe, had 7 new handles and 3 new heads but its still a dam good axe... :oops:

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PostPosted: 23 Dec 2009 19:38 
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Chook wrote:
The link you posted was for a car that had already lunched one block in a big way given he said a piece of the block put a hole in the radiator.


if you read it correctly it says he lunched a 2.0 litre engine

Quote:
When the 2.0 block blew up, a piece of block ended up in the radiator, it punched a small hole in the core. I managed to repair it to get the car running, but I don't trust it!


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PostPosted: 23 Dec 2009 21:59 
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I think some of you are missing my points. I understand the concepts of long vs short stroke, bore stroke ratio's etc. You can talk about bike engines of f1, with huge hp outputs. Even our trusty 4g92 mivec with short stroke and high hp rating. The point im making is there are long stroke turbo motors out there, im talking 100mm+ that are doing "very" well, thats a fact. They dont rev to the moon, they dont have to.
Done a quick search and come across some guys in america selling turbo kits for the 4g94 sohc engine. I do know the american dynos inflate hp figures, but with a standard evo8 turbo they make 340hp at the wheels. Sorry no rpm or tq numbers, but I thought that was pretty good considering the sohc head still!
I hope someone does this conversion. I would love to see the results. I wont make any predictions. The numbers will speak for themselves (good or bad).


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PostPosted: 23 Dec 2009 22:18 
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scux101 wrote:
Chook wrote:
The link you posted was for a car that had already lunched one block in a big way given he said a piece of the block put a hole in the radiator.


if you read it correctly it says he lunched a 2.0 litre engine

Quote:
When the 2.0 block blew up, a piece of block ended up in the radiator, it punched a small hole in the core. I managed to repair it to get the car running, but I don't trust it!

To scux101: Thanks mate I did read it correctly. It was a 2 litre block. My point was that he blew a block already and then the 2.4 stroke crank would have an even greater stress on the new block due to the altered stroke to rod length ratio. So you would have to wonder how long the next block would last.

bbbrad wrote:
I think some of you are missing my points. I understand the concepts of long vs short stroke, bore stroke ratio's etc. You can talk about bike engines of f1, with huge hp outputs. Even our trusty 4g92 mivec with short stroke and high hp rating. The point im making is there are long stroke turbo motors out there, im talking 100mm+ that are doing "very" well, thats a fact. They dont rev to the moon, they dont have to.
Done a quick search and come across some guys in america selling turbo kits for the 4g94 sohc engine. I do know the american dynos inflate hp figures, but with a standard evo8 turbo they make 340hp at the wheels. Sorry no rpm or tq numbers, but I thought that was pretty good considering the sohc head still!
I hope someone does this conversion. I would love to see the results. I wont make any predictions. The numbers will speak for themselves (good or bad).

I dont disagree with the long stroke turbo idea, in principle it makes good sense to get the turbo spooled early via the extra displacement and then not have to rev to the moon. Sounds like the basics behind a supercharger setup to work best from low in the rev range and not rev too high doesnt it?
I was thinking more about how much work has to be done specifically to either of the 4G64 or 4G94 motors for it to be a durable build and dealing with what the manufacturer designed into things like the block due to their intended use. If the amount of work and money is massive then is it really the best starting point? Or could less money form a different starting point end up getting a better result? Of course if money is no concern and you want to be different then thats cool, you can pretty much pick anything and make it work with enough time and effort. Just dont want anyone painting themselves into a corner by starting from a pont that isnt suitable in the long run.
It actually then begs the question about bothering to run the mivec head at all? Apart form this is a mivec forum and thats kind of why we're all here lol.
If you can get a good turbo cam grind on the soch 94 cam and enough flow in the head, and dont want to go too crazy. You'd bprobably only get a small additional bonus from the 4g92 mivec head. Things like the cams are all wrong with the high duration and large overlap for the turbo so you'd still have to get those reground.

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PostPosted: 23 Dec 2009 22:32 
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bbbrad wrote:
I think some of you are missing my points. I understand the concepts of long vs short stroke, bore stroke ratio's etc. You can talk about bike engines of f1, with huge hp outputs. Even our trusty 4g92 mivec with short stroke and high hp rating. The point im making is there are long stroke turbo motors out there, im talking 100mm+ that are doing "very" well, thats a fact. They dont rev to the moon, they dont have to.
Done a quick search and come across some guys in america selling turbo kits for the 4g94 sohc engine. I do know the american dynos inflate hp figures, but with a standard evo8 turbo they make 340hp at the wheels. Sorry no rpm or tq numbers, but I thought that was pretty good considering the sohc head still!
I hope someone does this conversion. I would love to see the results. I wont make any predictions. The numbers will speak for themselves (good or bad).


Fine if someone has a spare 20k lying around, or you could just buy a gsr motor for $1500 and bolt it in

To get 340hp@ wheels with a evo turbo on a SOHC 94 nothing will be standard motor wise to achieve that.

Why are we on this anyways this has nothing to do with mivec, are we not on a MIVEC forum?

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PostPosted: 23 Dec 2009 22:54 
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Title, 4g92 mivec head into 4g94
We are discussing the bennifits of using a long stroke 94 block with a mivec head. All posts relevant I think. Thanks everyone. Cheers.


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PostPosted: 23 Dec 2009 23:23 
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Chook wrote:
I dont disagree with the long stroke turbo idea, in principle it makes good sense to get the turbo spooled early via the extra displacement and then not have to rev to the moon. Sounds like the basics behind a supercharger setup to work best from low in the rev range and not rev too high doesnt it?
I was thinking more about how much work has to be done specifically to either of the 4G64 or 4G94 motors for it to be a durable build and dealing with what the manufacturer designed into things like the block due to their intended use. If the amount of work and money is massive then is it really the best starting point? Or could less money form a different starting point end up getting a better result? Of course if money is no concern and you want to be different then thats cool, you can pretty much pick anything and make it work with enough time and effort. Just dont want anyone painting themselves into a corner by starting from a pont that isnt suitable in the long run.
It actually then begs the question about bothering to run the mivec head at all? Apart form this is a mivec forum and thats kind of why we're all here lol.
If you can get a good turbo cam grind on the soch 94 cam and enough flow in the head, and dont want to go too crazy. You'd bprobably only get a small additional bonus from the 4g92 mivec head. Things like the cams are all wrong with the high duration and large overlap for the turbo so you'd still have to get those reground.


Yeah, good point about the cam timing/duration thing, but then again, the honda vtec turbos always seem to make unbelievible power on standard cams.
Cheers.


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PostPosted: 24 Dec 2009 04:25 
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Im doing this swap too

I got some custom pistons to suit 92 mivec head on a 4g94 block

Image

My mate sent the whole 4g92 head to piston manufacturer :lol:

Ill update you when i finish manufacturing the 4G94 H-Beam forge connecting rods


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PostPosted: 24 Dec 2009 07:18 
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Thats cool. Keep us posted.


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PostPosted: 24 Dec 2009 08:28 
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Those pistons look great. Your looking at an N/A application though right?

bbbrad, yeah the honda boys do all sorts of things its true. Fundamentally turbo cams and N/A come at things from a different angle. Yes they both want as much air to get in and out as possible but the N/A cams rely greatly on the cam overlap to do that, and turbo grinds dont have this area of inclusion. That would be why the big power cam grinds for the good old 4g63 from hks or someone are around 272 and our factory mivec inlet is 300. I guess on a turbo application it doesnt matter if you are blowing a ton of unburnt fuel and air directly out the exhaust valve thats open at the same time as the inlet if the turbo is large enough to pump the extra wasted air. Might make for some sort or unexpected antilag system or just whopping big pops and bang and flames on overrun. :D

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PostPosted: 25 Dec 2009 06:20 
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that link i posted is just one build, they are builds on that site where ppl have been reving to 9k on built 2.3 and 2.4 engines with long strokes, most are street driven with high hp and others are autocrossed and dragged. take some time to read a few builds and see how sucessful and reliable these cars are performing with high rod stroke raitos. i think e ven buschur has a 2.4 engine build reving to almost 10k reliably


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PostPosted: 25 Dec 2009 08:08 
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http://forums.evolutionm.net/evo-engine ... build.html


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PostPosted: 08 Jan 2010 19:45 
wow. very interesting posts while im gone. =)

so Chook, having a 4g94 Mivec (or DOHC by itself) is not worth it right???


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PostPosted: 08 Jan 2010 20:32 
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ClixT wrote:
wow. very interesting posts while im gone. =)

so Chook, having a 4g94 Mivec (or DOHC by itself) is not worth it right???

Like what Loch said it does not mean it has a high stroke it cannot work. I guess we just have to wait and see.


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