2G Is this platform dead? 4G64 upgrades

[Potmus63t]

Looks like 4G63 and even 420a have builds, guides, and a decent amount of support. I understand the 4G64 is similar and has a lot of interchangeable parts between it and the 4G63, and the more popular upgrade for the 64 is to use a 63 head to convert it to DOHC. For a modest say 250-275 whp goal, it looks like a DOHC swap and forced induction will be required.

Now, in 2024, is it even something that can be done? I’ve been reading 15/20 yea told posts that detail quite a bit, but not all of what it would take to pull this off. Of course the vast majority of part suppliers are either out of business, or they no longer offer the part I’d need.

Attempting this with a GST model would no doubt be easier, however I was handed a 98 Spyder GS for free, and it’s rust free and in good shape. Nothing I’ve seen out there for full vehicles is as clean as the car I have, and most of course have been modified extensively.

So I ask, is this platform dead? A lost cause?

Extra stuff:

I haven’t been in any car scene in 15 years. Rebuilt the top end of a 79 trans am 20 years ago, and was my first experience messing with anything. After that I had a 2000 Ford Contour SVT that I dropped in a 3L bottom end and used the rest of the stock 2.5 SVT parts (from lower plenum up) to go 210whp n/a. This isn’t a daily driver, more of a ‘fun’ car as I missed driving a manual trans car, and this one has a standard transmission. Definately feel like I’m driving on ground level compared to my 2017 F350 diesel.

 

[jinscho]

Its very doable. Another potential route is to do what i did and source a 4G63 and swap the block out entirely. 64 and 63 blocks are super easy to swap between and you'll probably be happier with the 63 swap as it simplifies everything.

 

[Potmus63t]

Its very doable. Another potential route is to do what i did and source a 4G63 and swap the block out entirely. 64 and 63 blocks are super easy to swap between and you'll probably be happier with the 63 swap as it simplifies everything.

I just don’t see where guys are finding parts. I can find a 63 head with no cams. People recommend 94 Galant cams and say where you can purchase them, yet they are no longer sold from that source and finding them on the 2nd hand market has been impossible. Some folks retain the 63 cams, yet I haven’t come across a head with cans in it yet. That's not even bringing up sourcing what I need on the ECU side. The ‘boost’ controllers and all that stuff is new territory for me. A straight engine build I’m pretty confident in though.

I had considered a full swap, but read that there are other complications that come from it. One of which was moving motor mount locations. That was as far as I’ve read into it.

In a position to spend some money, but I hesitate to piece meal parts for fear that I won’t be able to find things I’d need to complete the build.

For reference it’s a 98 Spyder. Do think I mentioned it in my original post.

 

[DSMPT]

So I ask, is this platform dead? A lost cause?

From the beginning, there was no specific market for 4g64 since DOHC 4g64 didn't come with many cars, this is a similar case for 4g67 too. The differences between those and 4g63 were very little. So while the parts for 4g63 are still available then 4g64 platform is still alive. It would be dead in the same moment when 4g63 would be dead though.

 

[Potmus63t]

From the beginning, there was no specific market for 4g64 since dohc 4g64 didn't come with many cars, this is a similar case for 4g67 too. The differences between those and 4g63 were very little. So while the parts for 4g63 are still available then 4g64 platform is still alive. It would be dead in the same moment when 4g63 would be dead though.

From everything I’ve been sifting through on here, it appears that there is support ONCE you convert to a 63 DOHC. Correct me if I’m wrong here.

Trying to do my due diligence in researching here, with this forum being a guide. I’ve come across maybe a dozen posts with good information for what I’m trying to accomplish, with links to another 50-75 posts that share pieces of information. Some links to websites that I need to use the time traveler option to view as they are no longer available to view. Countless numbers of posts saying ‘use the search’ function. Mix all that up with contradictory posts on what you need or routes you need to take.

I’m willing to learn, and even pay to do things right. I’m glad to see there are still members on here that are active. It’s just the sourcing of parts I don’t see how guys are finding things for a 25 year old car when the aftermarket world has seemed to move on.

 

[jinscho]

The 4G63 is a direct swap in terms of mounting points for the 4G64 in the 2g Spyder - I know from experience. The motor mounts are in the same exact position - the only things you'll have to worry about are on the electrical front, but those are also easy enough to work around. As for the "where" - second hand market is your go-to. Performance Partout and DSM Partout are my personal go-to providers for parts, though I've purchased from Miller Import Parts (now "Kannapolis Auto Parts") in the past as well. I've never purchased parts from Rix Racing, but have worked with them on tuning services - all in all, there are SEVERAL good "used parts" vendors that are still very involved in the platform - you just have to look.

Feel free to peruse through my build thread.. after all, my Spyder started life with a 4G64 under the hood. That long-block is now sitting in a corner of my garage collecting dust and I wouldn't have it any other way - the 4G63 swap was definitely the right choice.

 

[99eclipsegs-2t]

I've been sourcing parts for almost five years, good things take time and effort. I'm enjoying the experience of my stock 4g64 SOHC while I build out several 4g63 motors for this car. the Spyder allows you to almost plug and play the 4g63 without moving motor mounts as you described earlier, that applies to non turbo hardtops, not the Spyder. there's a write up on adding a turbo ECU to the Spyder, at that point its almost ready for boost and a fuel pump rewire.

 

[DSMPT]

I can find a 63 head with no cams.

The DOHC 4g63 head and DOHC 4g64 head is the same.

People recommend 94 Galant cams

People are mixing up between the cams and the cam gears. The DOHC 4g64 cams are almost the same as the DOHC 4g63, it's just intake cam is a bit different that is designed for N/A 2.4, but not a big difference from the 4g63's. The cam gears are the ones obviously different that they have different timing marks from 4g63 since the 4g64 has a 6mm taller deck height. But you can still make it without the DOHC 4g64 cams/cam gears by using 4g63 aftermarket adjustable cam gears or modifying the stock 4g63 cam gears.

it appears that there is support ONCE you convert to a 63 DOHC.

Yes, you have more helps if the engine is DOHC.

It’s just the sourcing of parts I don’t see how guys are finding things for a 25 year old car

That's the recent biggest issue that we started facing with since some years back.

 

[spyderdrifter]

There are a few members that I've seen over the years turbo the 4g64 with the SOHC head. Anything is doable if you want it to be, however, swapping to the 63 head will just be the better solution long term due to the aftermarket support that is offered. This isn't to say you need to do the head swap, just saying your options will open greatly if you did do it, or as suggested, swap to a full 4g63.

 

[Potmus63t]

The 4G63 is a direct swap in terms of mounting points for the 4G64 in the 2g Spyder - I know from experience. The motor mounts are in the same exact position - the only things you'll have to worry about are on the electrical front, but those are also easy enough to work around. As for the "where" - second hand market is your go-to. Performance Partout and DSM Partout are my personal go-to providers for parts, though I've purchased from Miller Import Parts (now "Kannapolis Auto Parts") in the past as well. I've never purchased parts from Rix Racing, but have worked with them on tuning services - all in all, there are SEVERAL good "used parts" vendors that are still very involved in the platform - you just have to look.

Feel free to peruse through my build thread.. after all, my Spyder started life with a 4G64 under the hood. That long-block is now sitting in a corner of my garage collecting dust and I wouldn't have it any other way - the 4G63 swap was definitely the right choice.

I appreciate the sources. As I said, issues I have been encountering were dead links on 15 year old posts. Modern day Craigslist, marketplace, eBay, and Google haven’t shown much that’s promising. A few hits on some items, but not enough to give confidence.

I like to do as much research as possible and get all the parts I need to finish the task, minus any little hardware stuff that can be sourced easily.

I have looked into your build page. You’re in a spot that I’m trying to get to. Appreciate the help. I do see a lot of folks mention going to a g1 63 motor and mentioned the 6 bolt I’ve and over. Haven’t found out if it really matters if it’s a 6/7 bolt. I don’t see why it would. But worth bringing up in case I find a complete motor.

There are a few members that I've seen over the years turbo the 4g64 with the SOHC head. Anything is doable if you want it to be, however, swapping to the 63 head will just be the better solution long term due to the aftermarket support that is offered. This isn't to say you need to do the head swap, just saying your options will open greatly if you did do it, or as suggested, swap to a full 4g63.

That’s what I’ve been seeing myself. The support is much greater when you swap over to the 63 head.

Seems to be a great deal of arguments between…
- keep sohc and turbo it. Hear mixed reviews, limited power, reduced redline, keep boost low, gains slightly above that over a stock 63t.

- change head to dohc, turbo it, keep boost low or change pistons to lower compression and then you can get more boost out of it safely.

- straight up motor swap to a 63t. Have a stock platform to build off of and treat it like a gst from this point on.

Seems everyone has a different opinion on which is best. I’m not so concerned with cost, but if there is a 10 step process vs a 20 step process, then I’d definitely want the more straight forward route. I’m not looking for a monster build, not looking to make a name for myself. I’m 40 and my ‘street days’ are really behind me. Just want something that I can have fun with that isn’t as much of a snail as this car is in stock form. Beautiful car, much better look than my old 08 civic si. But even with the zero torque of the k20 in the civic, it was more fun driving around.

 

[DSMPT]

If you go with sohc or dohc would be up to you. All depends how or what you want with your car. Why you find many info for the dohc swap is because there is a complicated process that you have to understand when you swap the head.
As for the cam(s), if you would like to go with aftermarket cam(s), then should go with dohc. It wouldn't give you options if sohc.
Either sohc or dohc would be just fine if you are looking for a fun to drive car. You wouldn't have a hard time for sourcing engine parts yet. You would when you need to upgrade the drivetrain components. That's the serious issue we have recently.