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420a swap

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Ryan Richards

Probationary Member
8
0
Feb 8, 2018
48006, Michigan
So some back story I had a 2003 eclipse gs I was working towards making a beauty but unfortunately she got T-boned and now sits in my driveway unfortunately without doing much research I bought a 99 eclipse gs thinking I could drop a 4g63 after doing some research around here I have found that is not quite as simple as I thought. But I have found that a 4g63 from a Evo 8 is also a left Bayside engine which leads me to the question of will my engine from my 03 gs with the Evo 8 head swap will bolt into the 99 gs?
 
So some back story I had a 2003 eclipse gs I was working towards making a beauty but unfortunately she got T-boned and now sits in my driveway unfortunately without doing much research I bought a 99 eclipse gs thinking I could drop a 4g63 after doing some research around here I have found that is not quite as simple as I thought. But I have found that a 4g63 from a Evo 8 is also a left Bayside engine which leads me to the question of will my engine from my 03 gs with the Evo 8 head swap will bolt into the 99 gs?


It will require extensive modifications and custom engine mounts. It will not "just bolt in"
 
It will require extensive modifications and custom engine mounts. It will not "just bolt in"
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Its almost as easy a bolt in. 3/4 engine mounts line up using an evo 8 engine and trans.

The 4th (the top trans mount) just needs to be hogged out some.

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This swap is only gonna get more popular as clean unmolested GST and GSXs get harder to find and cheap unwanted 420a cars get more desperate for homes. Also prices are dropping on Sirius II 4g63 engines currently. Hard to say when prices on S2 4g63s will bottom out as they do make good swaps for 3rd gens, probably 4th gens. Lancers, and Mirages. Probably some galants too. Along with the people using them in RWD setups.

The hard part is gonna be electrical, but thats not hard compared to fabricating a bunch of shit no one makes. You only need about 40$ worth of tools and an electrical manual to get that tracking.

You can use a 3g trans. Might need to do some google searching on cv axles people have used. But you can also make it AWD with a 2g rear subframe, evo 8 t-case and trans, and a 2g AUTOMATIC awd rear diff. Only the AUTO was also available as a gear ratio for the evo.

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Trans mount does not need to be hogged out... it needs to be cut off and moved forward.

OP this swap is not for newbs and you won’t find all the information you need on the web. The guys that have done this swap have shared pics, but have kept everything close to their hip.
 
Trans mount does not need to be hogged out... it needs to be cut off and moved forward.

OP this swap is not for newbs and you won’t find all the information you need on the web. The guys that have done this swap have shared pics, but have kept everything close to their hip.

Yeah I found one guy that moved it, but I swear another guy just widened the bolt hole when I first heard of this swap being feasible 7/8 years ago. Lots more guys have done it now. Reach out to them to see what they did.

No I wouldn't recommend this swap to someone with no tools, and just starting out. I'd recommend a good job and house first. But is feasible, its not a hard swap if you're willing to search and find solutions to problems.
 
Yeah I found one guy that moved it, but I swear another guy just widened the bolt hole when I first heard of this swap being feasible 7/8 years ago. Lots more guys have done it now. Reach out to them to see what they did.

No I wouldn't recommend this swap to someone with no tools, and just starting out. I'd recommend a good job and house first. But is feasible, its not a hard swap if you're willing to search and find solutions to problems.

So step 1 is post on a forum to have some one else tell you how to do anything. The OP Is well on his way thanks to your guidance . ROFL

It would be easier to swap a 3rd gen base model with a manual trans. It's almost plug and play, compared to an LS swap :sneaky:
 
If you want go with a cheaper option you can also get a Sirius II 4g64 block and get a 4g64 DOHC head from a Kia optima/Hyundai sonata. You can use forged internals for the block. As for the head you can use evo 8 internals. The evo intake and exhaust can bolt on to the head. Use a 3g fwd transmission. Check out 3g forums and evo forums. They have loads of information on 4g64 swaps. Check out @99 OZ Edition dsm build thread.
 
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When I sold my turbo'd 420A back in 05 guys on the forum I belonged to at the time were getting all excited about the Neon Srt4 motor being swapped into these cars. I got out so I don't know ... did that ever become a viable option?
 
When I sold my turbo'd 420A back in 05 guys on the forum I belonged to at the time were getting all excited about the Neon Srt4 motor being swapped into these cars. I got out so I don't know ... did that ever become a viable option?

Different block. Can swap the srt4 internals into the 420a or go the full on fab route. Def still easier to either move the mount, or widen it.
 
http://repo.jackmoves.com/v/shawn/Eclipse/evo_swap/parts/

This guy moved the mount.

The red car from taiwan that was the first car widely talked about on the net apparently used a 420a trans with a swapped bellhousing. That one just used the stock trans mount.

Edit: To be clear, I don't the validity of swapping the bellhousing on the 420a trans.
Probably be easier to use a 3rd gen trans.
 
Different block. Can swap the srt4 internals into the 420a or go the full on fab route. Def still easier to either move the mount, or widen it.

Please stop spreading wrong information. SRT4 internals do not fit in the 420a block. This has been known for a long time. The rods are too long and do not bolt onto the 420a crank. There are several other reasons they do not fit. The SRT4 internals do work in the 2.4L found in the cloud cars.
 
Tanro
Yes I was looking into a Evo 8 swap but I don't have the rest of the engine block just the head which is neatly placed on my 4g64 which is why I was wondering if the 4g64 would work, but are you saying I would have to pick up a Evo trans and t-case because a eagles wouldn't bolt on to the 64?
 
My Evo head is already on a 4g64 inside a 3g that is in my driveway T-boned hence why I was wondering about the compatibility
 
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