so i know we all have heard about this thread a thousand times before.. but i want some first person insight..

if somebody could give me a list on what exactly needs to be rebuilt in the 420a engine.. to run a turbo safely and effectively ..i would greatly appreciate it.

thanks. scotty*

 

First off Scott. What are your goals with the car? You can run up to 12psi on a GOOD, and I stress GOOD, motor on stock internals. That power gain will be a significant one for you. Later, you can upgrade pistons, rods, headgasket, head studs, valves/springs, cams, etc.

Your question, like everyone else who makes threads like this, is very vague. You need to specify your expectations.

...and welcome to the site.

 

I really would never suggest running more than 10psi on the stock pistons of a 420a. Not to mention you are guarenteed to blow a headgasket from running boost on a 420a.The list is as far as the turbo system goes, you can easily find that information

 

I wouldn't either TE, but someone always throws in the "you can run 12psi on stock internals" line. I recommend 10 psi too, just in case it spikes to creeps. Hell, 8psi is "safe" in my eyes. At least until the head gasket and studs are replaced. And with the 420a, you might as well upgrade the top end to prevent valve float.

 

yea .. sorry about being so vague...
... im not that much of a noob to cars but, i still need alot of help.

ok.. i have a 1997 420a mitsubishi gs.. it has about 116000 miles on it... i have no internal work done to it yet.. (only external... ex. aftermarket sparks. aem intake. Full venom exhaust) .. and i know other then the aspiration with the exhaust.. those things are useless.

ok. so. im looking to turbo my exlipse as i said.. i want to run about 15 psi safely. i AM looking to rebuild the engine.. for power and reliability. also for the turbo.i AM going to bore it .20 and have the machenist install JE pistons as well as h beam eagle rods while there in there.

ive heard from many people.. many different ideas.. some say that boring it out .20 and installing the je pistons + h beam e rods is all i need for the reliabilty with a turbo.

and some also say that once i do that.. other things will get all the stress.. and this is the part where i become lost.. i do not know where to go from here

should i rebuild the top and bottom end.. yes?no? if so. can you give me a list of effective parts to do so....

thanks,
scotty*

 

Yes you will need to rebuild the top end as well as what you listed on the bottom end. Make sure with the bottom end you go with the lower compression pistons whatever they come in (either 8.5:1 or 9.0:1 CR). And obviously all new bearings, ect.) You might even think about replacing the main studs with ARP. But for the top end your probably gonna want to replace the valve springs, and cams. And also the head studs and i would go with a cometic MLS head gasket. With all that you should be able to run what you are looking for.

Of course remember you need all the fuel and electronic components to get it to work

 

thanks.. is 8.8:1 good?.. and

where could i find all the electronics at?.. as well as the fuel systems.

 

there are plenty of places online that sell that stuff. But i believe the two best sites for the 420a are http://www.turbosystem.com/auto/eclipse/eclipse.htm <<<Hahn Racecraft

and www.cimotorsports.net

 

ok now heres the thing.. ive heard that the 420a no matter built or stock.. will let you down. blow up etc...

would you say give it a go.. or is there any engines i can use as a crate that i can swap into my 1997 eclipse?

 

there really is nothing you can swap that would be feasible to do so.

But as far as the 420a goes. It can be a very good motor, it jsut takes time and money to do it. Which is the reason alot of people shy away from it. Those engines will always have that headgasket issue. But a well built motor will have no problems if done right and if tuned right. Just look at hahn and their 420a. Last i heard they were trying to get into the 10's