420A To build myself or send to a shop?

[Muddy_Lotus]

Hey everyone! I apologize if this isn't in the right category this is my first time posting here.

I just picked up a 97 eclipse rs with a 402a in it. I want to do a rebuild on it since the engine in it is knocking. However I've never done a full rebuild before. I had an 03 mini cooper that I did part of a rebuild on head gaskets new cylinder head etc. I've replaced a lot of stuff and I'm pretty good with electrical wiring but I've never fully rebuilt anything. I'm just not sure if this is something I can tackle myself or if I would be better off having it done at a shop. I'm trying to avoid dumping an obnoxious amount into the car if that's at all possible.

My goal is some built internals with a small turbo. That's what I had in mind nothing too big or crazy. This is just a car I plan on having some fun driving around and possibly taking to the local meets.

I really appreciate any advice anyone might have for me as I'm trying to determine which direction to go. Thanks so much!

 

[97egl]

420A is an easy motor to work on. If you have a cherry picker or some type of hoist to get the engine out you can do it yourself. I pull mine from my circle track car and rebuild/freshen it up every year. The hardest part is probably timing the engine to be honest. And if you've done a headgasket you've done a timing belt.

If you've got knocking it could be piston slap due to out of tolerance piston to wall(cylinder) clearance, it could be a rod bearing going out, or it could be the wrist pin hole in the piston is worn out. Depending on what it ends up being you may end up needing some machine work done.

I can't tell you much about boost on these motors as my racing class is N/A. If you plan on running more that 5-7 psi of boost you will need built internals like you said you want. I would say you need to expect to spend at least 2000 dollars to rebuild your motor with forged internals for higher boost levels as well as engine management and tuning. And thats probably a low estimate if your buy a lot of stuff used.

 

[JGL122]

My advice would be to buy an engine from a junk yard and swap it. This of course is dependent on if you have a good junk yard around and a work area to do it in. If you have a daily to drive and a place to keep your car while you work on it, then doing an engine build can be done. You'll be able to take your time and save up for parts. It'll be cheaper than a shop doing an engine rebuild for you.

 

[Muddy_Lotus]

420A is an easy motor to work on. If you have a cherry picker or some type of hoist to get the engine out you can do it yourself. I pull mine from my circle track car and rebuild/freshen it up every year. The hardest part is probably timing the engine to be honest. And if you've done a headgasket you've done a timing belt.

If you've got knocking it could be piston slap due to out of tolerance piston to wall(cylinder) clearance, it could be a rod bearing going out, or it could be the wrist pin hole in the piston is worn out. Depending on what it ends up being you may end up needing some machine work done.

We do have a cherry picker and all the tools needed to pull it. My husband and I actually flip cars in our free time but usually the most involved we get is swapping out an engine.

I was thinking probably like 5lbs of boost but still with the built internals. I really want reliable power I don’t want to be blowing out internals with this car. Thanks so much for all the information it kind of confirms what I was thinking myself. I think I will probably do it myself and then take it to be tuned. There’s some good tuning shops local to me I can take it too.

 

[Muddy_Lotus]

My advice would be to buy an engine from a junk yard and swap it. This of course is dependent on if you have a good junk yard around and a work area to do it in. If you have a daily to drive and a place to keep your car while you work on it, then doing an engine build can be done. You'll be able to take your time and save up for parts. It'll be cheaper than a shop doing an engine rebuild for you.

I do have another car I daily so it isn’t an issue if this thing sits in my garage for a while. We have some yards around here that actually have some spare engines but I’m not sure what shape mine is in. I think I’m going to pull it this weekend and see what condition it’s in before pulling one from a yard. Luckily I’ve never pulled a bad engine from a yard but it’s always a gamble and if I’ve got a good block I’d like to keep it and cut my costs.

Do you have any advice for buying parts? I’ve never bought engine components minus that one time I bought a cylinder head off eBay and that felt really sketchy

 

[DirtMcGirt]

Since you have another vehicle, I would attempt to rebuild yourself. With all the info out there, as long as you have the proper tools, or the ability to get them, and some patience, you should be good to go. If you decide to tackle the rebuild, I have some Eagle rods, JE low compression pistons, and ARP head studs available in the classifieds. I installed them with the intention of adding a turbo, but that never happened, so the parts, while used, were never abused. Good luck whichever path you decide to take.

 

[609DSM]

I second on rebuilding yourself since this isn't your only car. The 420a motor is very forgiving, obviously dont so sloppy work. Although I have made stupid mistakes with my 420a eclipse but because of what the 420a motor is, didn't really hurt it. Not a great performance engine, you CAN run boost at good levels but not like a 4g63t can handle. Good luck and have fun!

 

[BLACK'98DSM]

Just realize that you will need an aftermarket ecu to tune the car. The stock ecu cannot be tuned.

 

[Muddy_Lotus]

Just realize that you will need an aftermarket ecu to tune the car. The stock ecu cannot be tuned.

Good to know. I didn’t know about that. Thank you!