All You Need to Know: The DOHC 4G9X Headswap
Jul 18, 2013, 11:31 AM
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All You Need to Know: The DOHC 4G9X Headswap
This is pretty much a knowledge dump of the details in reference to the DOHC swap: where to get parts, costs, benefits, etc. Feel free to add to this/correct any info I post.
Preface : As everyone knows, the Single-Cam 4G94 motor is what powered the Lancer ES, LS, and OZ Rally from 2000-2007 (02-06 in the US). You can read up all you want about the 4G94 on Ambystom01's detailed write up of the motor. But you're not here to read up on the single-cam motor, you're here because you've heard legends of the elusive DOHC swap, want to learn more, and/or possibly perform the swap yourself.
------------------------------------------------------------------------
Introduction : The 4G9X series motor is a 16-valve, four-cylinder engine produced by Mitsubishi. They came in Single cam or Dual cam, some with MIVEC. The swappable heads commonly used are the 4G92, the 4G92 w/ MIVEC, and the 4G93. Engine Manual
4G92 DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 108 kW (147 PS; 145 bhp) at 7,000 rpm
Maximum Torque - 149 N·m (110 ft·lbf) at 4,500 rpm
4G92-MIVEC DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 128 kW (174 PS; 172 bhp) at 7,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) at 7,000 rpm
4G93 DOHC 16 Valve
Total Displacement - 1834cc
Bore - 81.0mm
Stroke - 89.0mm
Compression Ratio - 10.5:1
Maximum Output - 103 kW (140 PS; 138 bhp) @ 6,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) @ 5500 rpm
------------------------------------------------------------------------
Sales Pitch So why do it??? The 4G94 isn't exactly a power house and there's very little gain to be had from bolt on parts; let's face it... Lancers (The Non-EVO type)are econo-boxes. I'm not going to BS you, the head swap will not suddenly make your car gain 50 WHP and be some hi-revving monster. What the DOHC swap will do for you is 'awaken 'your mods. I won't go into DOHC theory, you can wiki that, but for the most part DOHC>SOHC. One thing to keep in mind is it's not cheap. If quick, cheap power is what you want, turbo your car or sell it. However, if your Lancer is your project car, your baby, something that you know for sure you'll keep around a long while, and money is no object, then Do it!
------------------------------------------------------------------------
Requirements : So at the Bare minimum, here's what you need to swap out the heads:
The DOHC Head itself (About $1000)
Head gasket (About $135)
Rocker Cover Gasket (About $50)
70mm Idler Pulley (About $75)
Timing Belt (About $80)
Coil Packs (About $160)
Leads (About $70)
Spark Plugs (About $20)
Head Studs (About $140)
So just the conversion itself, with no extra go-fast bits, you're looking at around $1730. Shipping will be another $150 or so dollars. ***Keep in mind the value of the US Dollar fluctuates. The $1400 AUD came out to $1200 USD when I purchased the head in 2010. But a year later, when I purchased the gaskets, pulleys, etc I paid $700 USD for a $500 AUD order.***
------------------------------------------------------------------------
Resources So where do you buy the head? For some reason, Australia holds the world's reserve of DOHC 4G9X heads. I'm sure you can luck out and find a salvaged one on Ebay or in a junk yard, but I'm not doing the research to see what US models came with one.
LLT-Racing: 4G92/92 MIVEC/93E DOHC Heads, Headers, Gaskets, Accessories, Etc
RPW: 4G92 MIVEC Heads, Headers, Gaskets, Internals, etc.
------------------------------------------------------------------------
Difficulty: I for one am mechanically challenged and had a shop put my motor together. But if you have the know how to change your head gasket, then you can do the Headswap yourself. The Head, belts, etc bolts right into place, with the exception of having to shave off a bit of metal to prevent the timing belt from rubbing.
------------------------------------------------------------------------
Interchangeable Parts Just about everything for the 4G94 bolts right up to the 4G92/3 head (Except ignition wires). So if you bought headers or an intake manifold for your 4G94, you're in luck. Again, check out Ambystrom01's write up on the 4G94, linked in the preface for parts.
------------------------------------------------------------------------
N/A vs Turbo Before you put the motor together, you should as yourself "Do I wanna Boost this puppy or do I want to go All Motor?". Determining the answer to this important question will help you save the headache of having to crack open the motor again in the future.
All Motor Because the DOHC motors were originally built with a compression ratio of 11:1, I'd suggest upping your compression to at least 11:1 from the stock 9.5:1. You can probably take the compression even further, but the higher the compression, the greater the risk of knocking. Also, if you plan on buying oversized pistons, keep in mind the Cylinder walls on the 4G94 block are pretty thin (81.0 mm Bore and 89.0 mm stroke)
Turbo I can't give advice since I've always been all-motor, but if you're gonna go Turbo, definitely take advantage of MIVEC on the 4G92 Heads.
------------------------------------------------------------------------
Tuning The Head will run just fine with the stock ECU from the 4G94, albeit a tad bit rich (My AFR was around 11.2:1 before my tune). You can reference the ROM from an AUDM 2000 Mirage as a baseline:AUDM ROM and XML File (Zipped)
------------------------------------------------------------------------
***MORE TO COME***
Preface : As everyone knows, the Single-Cam 4G94 motor is what powered the Lancer ES, LS, and OZ Rally from 2000-2007 (02-06 in the US). You can read up all you want about the 4G94 on Ambystom01's detailed write up of the motor. But you're not here to read up on the single-cam motor, you're here because you've heard legends of the elusive DOHC swap, want to learn more, and/or possibly perform the swap yourself.
------------------------------------------------------------------------
Introduction : The 4G9X series motor is a 16-valve, four-cylinder engine produced by Mitsubishi. They came in Single cam or Dual cam, some with MIVEC. The swappable heads commonly used are the 4G92, the 4G92 w/ MIVEC, and the 4G93. Engine Manual
4G92 DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 108 kW (147 PS; 145 bhp) at 7,000 rpm
Maximum Torque - 149 N·m (110 ft·lbf) at 4,500 rpm
4G92-MIVEC DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 128 kW (174 PS; 172 bhp) at 7,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) at 7,000 rpm
4G93 DOHC 16 Valve
Total Displacement - 1834cc
Bore - 81.0mm
Stroke - 89.0mm
Compression Ratio - 10.5:1
Maximum Output - 103 kW (140 PS; 138 bhp) @ 6,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) @ 5500 rpm
------------------------------------------------------------------------
Sales Pitch So why do it??? The 4G94 isn't exactly a power house and there's very little gain to be had from bolt on parts; let's face it... Lancers (The Non-EVO type)are econo-boxes. I'm not going to BS you, the head swap will not suddenly make your car gain 50 WHP and be some hi-revving monster. What the DOHC swap will do for you is 'awaken 'your mods. I won't go into DOHC theory, you can wiki that, but for the most part DOHC>SOHC. One thing to keep in mind is it's not cheap. If quick, cheap power is what you want, turbo your car or sell it. However, if your Lancer is your project car, your baby, something that you know for sure you'll keep around a long while, and money is no object, then Do it!
------------------------------------------------------------------------
Requirements : So at the Bare minimum, here's what you need to swap out the heads:
The DOHC Head itself (About $1000)
Head gasket (About $135)
Rocker Cover Gasket (About $50)
70mm Idler Pulley (About $75)
Timing Belt (About $80)
Coil Packs (About $160)
Leads (About $70)
Spark Plugs (About $20)
Head Studs (About $140)
So just the conversion itself, with no extra go-fast bits, you're looking at around $1730. Shipping will be another $150 or so dollars. ***Keep in mind the value of the US Dollar fluctuates. The $1400 AUD came out to $1200 USD when I purchased the head in 2010. But a year later, when I purchased the gaskets, pulleys, etc I paid $700 USD for a $500 AUD order.***
------------------------------------------------------------------------
Resources So where do you buy the head? For some reason, Australia holds the world's reserve of DOHC 4G9X heads. I'm sure you can luck out and find a salvaged one on Ebay or in a junk yard, but I'm not doing the research to see what US models came with one.
LLT-Racing: 4G92/92 MIVEC/93E DOHC Heads, Headers, Gaskets, Accessories, Etc
RPW: 4G92 MIVEC Heads, Headers, Gaskets, Internals, etc.
------------------------------------------------------------------------
Difficulty: I for one am mechanically challenged and had a shop put my motor together. But if you have the know how to change your head gasket, then you can do the Headswap yourself. The Head, belts, etc bolts right into place, with the exception of having to shave off a bit of metal to prevent the timing belt from rubbing.
------------------------------------------------------------------------
Interchangeable Parts Just about everything for the 4G94 bolts right up to the 4G92/3 head (Except ignition wires). So if you bought headers or an intake manifold for your 4G94, you're in luck. Again, check out Ambystrom01's write up on the 4G94, linked in the preface for parts.
------------------------------------------------------------------------
N/A vs Turbo Before you put the motor together, you should as yourself "Do I wanna Boost this puppy or do I want to go All Motor?". Determining the answer to this important question will help you save the headache of having to crack open the motor again in the future.
All Motor Because the DOHC motors were originally built with a compression ratio of 11:1, I'd suggest upping your compression to at least 11:1 from the stock 9.5:1. You can probably take the compression even further, but the higher the compression, the greater the risk of knocking. Also, if you plan on buying oversized pistons, keep in mind the Cylinder walls on the 4G94 block are pretty thin (81.0 mm Bore and 89.0 mm stroke)
Turbo I can't give advice since I've always been all-motor, but if you're gonna go Turbo, definitely take advantage of MIVEC on the 4G92 Heads.
------------------------------------------------------------------------
Tuning The Head will run just fine with the stock ECU from the 4G94, albeit a tad bit rich (My AFR was around 11.2:1 before my tune). You can reference the ROM from an AUDM 2000 Mirage as a baseline:AUDM ROM and XML File (Zipped)
------------------------------------------------------------------------
***MORE TO COME***
Last edited by Midnightkid; Jul 18, 2013 at 04:56 PM.
Jul 18, 2013, 11:55 AM
#2
Resources also include Malaysia. You can check out the mivec forum for stuff as well but then you'll be dealing with individual sellers. So that's on you.
Thanks midnightkid I'm sure this will help a lot. It sucks it costs this much for minimal gains. But damn the potential! If I ever just came up on some money just to **** away this would be it. But in the meanwhile $1700 is a nice down payment on an evo.
This is definitely an "I paid her off, she's in good condition, too late to turn back now" mod.
Thanks midnightkid I'm sure this will help a lot. It sucks it costs this much for minimal gains. But damn the potential! If I ever just came up on some money just to **** away this would be it. But in the meanwhile $1700 is a nice down payment on an evo.
This is definitely an "I paid her off, she's in good condition, too late to turn back now" mod.
Jul 28, 2013, 01:12 PM
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I have an 02 oz rally, so If I did the head swap would my car still pass inspection? I live in north carolina and requires yearly inspections. Is it as simple as plug and play? And no cel?
Jul 28, 2013, 03:45 PM
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Ireland does have a bunch of 4G92s, it's just getting them over here is the issue lol
I can't tell you for sure, I have a CEL eliminator. But I wanna say that it will pass regardless. Also, the install seemed pretty straight forward. Everything bolted into place with very little modification. It'll run using the stock ECU and OEM map. Granted before I got tuned, I was running rich (11.3:1). lol
I can't tell you for sure, I have a CEL eliminator. But I wanna say that it will pass regardless. Also, the install seemed pretty straight forward. Everything bolted into place with very little modification. It'll run using the stock ECU and OEM map. Granted before I got tuned, I was running rich (11.3:1). lol
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Oct 12, 2013, 01:44 PM
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Hi i have a 03 lancer oz and wanna do a 4g64 dohc swap. I have been looking but was wondering if i wanted to go all motor n/a. what would be the best dohc head to use to have the most performance and reliability.
Oct 16, 2013, 02:40 PM
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From My understanding, the 4G93E is the best bang for your buck. You can get that from Luis over at LLT in Auzzy-land. They also offer a DOHC head w/ MIVEC
Dec 6, 2013, 07:34 PM
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is the mivec more for turbo or no. my engine and tranny are out and may even install a new front clip from fire wall foward but trying to figure out the best engine and get a list of things needed. i want to figure the head would be for my lancer all engine.
Apr 21, 2014, 01:30 AM
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hi, have been reading a few threads about the 4g94 dohc swap but still left with a few questions.
1. is there a particular reason why everyone is using the 159 teeth belt?
reason for this question is upon more research the 4g94 and 4g93 timing belts in australia are the same. so that made me wonder, why cant we use the standard 4g93 dohc belt which is 156 teeth?
2. what is the reason for grabbing a 70mm idler pulley instead of the stock 4g93 dohc 60mm?
is it all because the 4g94 block doesn't have the auto tensioner? if yes, why not just get an auto tensioner for a 4g93 dohc.
thanks in advance
1. is there a particular reason why everyone is using the 159 teeth belt?
reason for this question is upon more research the 4g94 and 4g93 timing belts in australia are the same. so that made me wonder, why cant we use the standard 4g93 dohc belt which is 156 teeth?
2. what is the reason for grabbing a 70mm idler pulley instead of the stock 4g93 dohc 60mm?
is it all because the 4g94 block doesn't have the auto tensioner? if yes, why not just get an auto tensioner for a 4g93 dohc.
thanks in advance
Dec 13, 2019, 03:12 PM
#14
This is pretty much a knowledge dump of the details in reference to the DOHC swap: where to get parts, costs, benefits, etc. Feel free to add to this/correct any info I post.
Preface : As everyone knows, the Single-Cam 4G94 motor is what powered the Lancer ES, LS, and OZ Rally from 2000-2007 (02-06 in the US). You can read up all you want about the 4G94 on Ambystom01's detailed write up of the motor. But you're not here to read up on the single-cam motor, you're here because you've heard legends of the elusive DOHC swap, want to learn more, and/or possibly perform the swap yourself.
------------------------------------------------------------------------
Introduction : The 4G9X series motor is a 16-valve, four-cylinder engine produced by Mitsubishi. They came in Single cam or Dual cam, some with MIVEC. The swappable heads commonly used are the 4G92, the 4G92 w/ MIVEC, and the 4G93. Engine Manual
4G92 DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 108 kW (147 PS; 145 bhp) at 7,000 rpm
Maximum Torque - 149 N·m (110 ft·lbf) at 4,500 rpm
4G92-MIVEC DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 128 kW (174 PS; 172 bhp) at 7,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) at 7,000 rpm
4G93 DOHC 16 Valve
Total Displacement - 1834cc
Bore - 81.0mm
Stroke - 89.0mm
Compression Ratio - 10.5:1
Maximum Output - 103 kW (140 PS; 138 bhp) @ 6,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) @ 5500 rpm
Attachment 277450
------------------------------------------------------------------------
Sales Pitch So why do it??? The 4G94 isn't exactly a power house and there's very little gain to be had from bolt on parts; let's face it... Lancers (The Non-EVO type)are econo-boxes. I'm not going to BS you, the head swap will not suddenly make your car gain 50 WHP and be some hi-revving monster. What the DOHC swap will do for you is 'awaken 'your mods. I won't go into DOHC theory, you can wiki that, but for the most part DOHC>SOHC. One thing to keep in mind is it's not cheap. If quick, cheap power is what you want, turbo your car or sell it. However, if your Lancer is your project car, your baby, something that you know for sure you'll keep around a long while, and money is no object, then Do it!
------------------------------------------------------------------------
Requirements : So at the Bare minimum, here's what you need to swap out the heads:
The DOHC Head itself (About $1000)
Head gasket (About $135)
Rocker Cover Gasket (About $50)
70mm Idler Pulley (About $75)
Timing Belt (About $80)
Coil Packs (About $160)
Leads (About $70)
Spark Plugs (About $20)
Head Studs (About $140)
So just the conversion itself, with no extra go-fast bits, you're looking at around $1730. Shipping will be another $150 or so dollars. ***Keep in mind the value of the US Dollar fluctuates. The $1400 AUD came out to $1200 USD when I purchased the head in 2010. But a year later, when I purchased the gaskets, pulleys, etc I paid $700 USD for a $500 AUD order.***
------------------------------------------------------------------------
Resources So where do you buy the head? For some reason, Australia holds the world's reserve of DOHC 4G9X heads. I'm sure you can luck out and find a salvaged one on Ebay or in a junk yard, but I'm not doing the research to see what US models came with one.
LLT-Racing: 4G92/92 MIVEC/93E DOHC Heads, Headers, Gaskets, Accessories, Etc
RPW: 4G92 MIVEC Heads, Headers, Gaskets, Internals, etc.
------------------------------------------------------------------------
Difficulty: I for one am mechanically challenged and had a shop put my motor together. But if you have the know how to change your head gasket, then you can do the Headswap yourself. The Head, belts, etc bolts right into place, with the exception of having to shave off a bit of metal to prevent the timing belt from rubbing.
------------------------------------------------------------------------
Interchangeable Parts Just about everything for the 4G94 bolts right up to the 4G92/3 head (Except ignition wires). So if you bought headers or an intake manifold for your 4G94, you're in luck. Again, check out Ambystrom01's write up on the 4G94, linked in the preface for parts.
------------------------------------------------------------------------
N/A vs Turbo Before you put the motor together, you should as yourself "Do I wanna Boost this puppy or do I want to go All Motor?". Determining the answer to this important question will help you save the headache of having to crack open the motor again in the future.
All Motor Because the DOHC motors were originally built with a compression ratio of 11:1, I'd suggest upping your compression to at least 11:1 from the stock 9.5:1. You can probably take the compression even further, but the higher the compression, the greater the risk of knocking. Also, if you plan on buying oversized pistons, keep in mind the Cylinder walls on the 4G94 block are pretty thin (81.0 mm Bore and 89.0 mm stroke)
Turbo I can't give advice since I've always been all-motor, but if you're gonna go Turbo, definitely take advantage of MIVEC on the 4G92 Heads.
------------------------------------------------------------------------
Tuning The Head will run just fine with the stock ECU from the 4G94, albeit a tad bit rich (My AFR was around 11.2:1 before my tune). You can reference the ROM from an AUDM 2000 Mirage as a baseline:AUDM ROM and XML File (Zipped)
------------------------------------------------------------------------
***MORE TO COME***
Preface : As everyone knows, the Single-Cam 4G94 motor is what powered the Lancer ES, LS, and OZ Rally from 2000-2007 (02-06 in the US). You can read up all you want about the 4G94 on Ambystom01's detailed write up of the motor. But you're not here to read up on the single-cam motor, you're here because you've heard legends of the elusive DOHC swap, want to learn more, and/or possibly perform the swap yourself.
------------------------------------------------------------------------
Introduction : The 4G9X series motor is a 16-valve, four-cylinder engine produced by Mitsubishi. They came in Single cam or Dual cam, some with MIVEC. The swappable heads commonly used are the 4G92, the 4G92 w/ MIVEC, and the 4G93. Engine Manual
4G92 DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 108 kW (147 PS; 145 bhp) at 7,000 rpm
Maximum Torque - 149 N·m (110 ft·lbf) at 4,500 rpm
4G92-MIVEC DOHC 16 Valve
Total Displacement - 1,597 cc
Bore - 81.0 mm
Stroke - 77.5 mm
Compression Ratio - 11:1
Maximum Output - 128 kW (174 PS; 172 bhp) at 7,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) at 7,000 rpm
4G93 DOHC 16 Valve
Total Displacement - 1834cc
Bore - 81.0mm
Stroke - 89.0mm
Compression Ratio - 10.5:1
Maximum Output - 103 kW (140 PS; 138 bhp) @ 6,500 rpm
Maximum Torque - 167 N·m (123 ft·lbf) @ 5500 rpm
Attachment 277450
------------------------------------------------------------------------
Sales Pitch So why do it??? The 4G94 isn't exactly a power house and there's very little gain to be had from bolt on parts; let's face it... Lancers (The Non-EVO type)are econo-boxes. I'm not going to BS you, the head swap will not suddenly make your car gain 50 WHP and be some hi-revving monster. What the DOHC swap will do for you is 'awaken 'your mods. I won't go into DOHC theory, you can wiki that, but for the most part DOHC>SOHC. One thing to keep in mind is it's not cheap. If quick, cheap power is what you want, turbo your car or sell it. However, if your Lancer is your project car, your baby, something that you know for sure you'll keep around a long while, and money is no object, then Do it!
------------------------------------------------------------------------
Requirements : So at the Bare minimum, here's what you need to swap out the heads:
The DOHC Head itself (About $1000)
Head gasket (About $135)
Rocker Cover Gasket (About $50)
70mm Idler Pulley (About $75)
Timing Belt (About $80)
Coil Packs (About $160)
Leads (About $70)
Spark Plugs (About $20)
Head Studs (About $140)
So just the conversion itself, with no extra go-fast bits, you're looking at around $1730. Shipping will be another $150 or so dollars. ***Keep in mind the value of the US Dollar fluctuates. The $1400 AUD came out to $1200 USD when I purchased the head in 2010. But a year later, when I purchased the gaskets, pulleys, etc I paid $700 USD for a $500 AUD order.***
------------------------------------------------------------------------
Resources So where do you buy the head? For some reason, Australia holds the world's reserve of DOHC 4G9X heads. I'm sure you can luck out and find a salvaged one on Ebay or in a junk yard, but I'm not doing the research to see what US models came with one.
LLT-Racing: 4G92/92 MIVEC/93E DOHC Heads, Headers, Gaskets, Accessories, Etc
RPW: 4G92 MIVEC Heads, Headers, Gaskets, Internals, etc.
------------------------------------------------------------------------
Difficulty: I for one am mechanically challenged and had a shop put my motor together. But if you have the know how to change your head gasket, then you can do the Headswap yourself. The Head, belts, etc bolts right into place, with the exception of having to shave off a bit of metal to prevent the timing belt from rubbing.
------------------------------------------------------------------------
Interchangeable Parts Just about everything for the 4G94 bolts right up to the 4G92/3 head (Except ignition wires). So if you bought headers or an intake manifold for your 4G94, you're in luck. Again, check out Ambystrom01's write up on the 4G94, linked in the preface for parts.
------------------------------------------------------------------------
N/A vs Turbo Before you put the motor together, you should as yourself "Do I wanna Boost this puppy or do I want to go All Motor?". Determining the answer to this important question will help you save the headache of having to crack open the motor again in the future.
All Motor Because the DOHC motors were originally built with a compression ratio of 11:1, I'd suggest upping your compression to at least 11:1 from the stock 9.5:1. You can probably take the compression even further, but the higher the compression, the greater the risk of knocking. Also, if you plan on buying oversized pistons, keep in mind the Cylinder walls on the 4G94 block are pretty thin (81.0 mm Bore and 89.0 mm stroke)
Turbo I can't give advice since I've always been all-motor, but if you're gonna go Turbo, definitely take advantage of MIVEC on the 4G92 Heads.
------------------------------------------------------------------------
Tuning The Head will run just fine with the stock ECU from the 4G94, albeit a tad bit rich (My AFR was around 11.2:1 before my tune). You can reference the ROM from an AUDM 2000 Mirage as a baseline:AUDM ROM and XML File (Zipped)
------------------------------------------------------------------------
***MORE TO COME***
Where can I get this 70mm pulley, or is it something I'm sent to do??
