420A Build Questions

[mulletman365]

Looking to build my 420 a at a decent budget. I know reliable comes at a price and the stock block can’t handle a crazy amount. But I want to make about 300-350 if I can push more. Any recommendations on what to purchase. I know stage 2 valves h beams and different pistons but do they make a full stage 2 kit or anything like that

 

[pauleyman]

Have you considered all that you will need to do this? It's a lot more than just engine internals. What does "decent budget" mean. You won't make that power naturally aspirated. You're going to need some sort of forced induction, a manifold, more fuel which means fuel management, Clutch. What is "stage 2" valves?

 

[BLACK'98DSM]

There really aren't any staged "kits". You can get pistons + rods as a kit and gasket/seal kits, but that's about all.

First you need to tear down the engine, take measurements and write a list of what you'll need. Pistons, rings and bearings are sizeable based on your current wear level and needed machine work.

Valves aren't necessary at all unless yours are worn beyond use. You can go +1mm for additional flow on a naturally aspirated build but with forced induction, you can just raise to boost level to increase air flow.

There's plenty of threads here about 420A modifications, and plenty more on 2gnt.com
I suggest reading through and studying the information available, then determining the health and condition of your engine before continuing. Some of the parts information is outdated but the concept is still the same and there's still plenty of parts available to achieve your goal.

 

[mulletman365]

Have you considered all that you will need to do this? It's a lot more than just engine internals. What does "decent budget" mean. You won't make that power naturally aspirated. You're going to need some sort of forced induction, a manifold, more fuel which means fuel management, Clutch. What is "stage 2" valves?

Well I picked up some twin turbos from my buddy that he bought for his from summit racing really cheap. I don’t really know much about building gas engines I’m more of a diesel guy so stage 2 is something ig that isn’t in the dsm.

 

[mulletman365]

There really aren't any staged "kits". You can get pistons + rods as a kit and gasket/seal kits, but that's about all.

First you need to tear down the engine, take measurements and write a list of what you'll need. Pistons, rings and bearings are sizeable based on your current wear level and needed machine work.

Valves aren't necessary at all unless yours are worn beyond use. You can go +1mm for additional flow on a naturally aspirated build but with forced induction, you can just raise to boost level to increase air flow.

There's plenty of threads here about 420A modifications, and plenty more on 2gnt.com
I suggest reading through and studying the information available, then determining the health and condition of your engine before continuing. Some of the parts information is outdated but the concept is still the same and there's still plenty of parts available to achieve your goal.

I do plan on going with forced induction I got a twin turbo kit for the car for a great price obviously that’s overkill so I just want to run a single turbo

 

[mulletman365]

I do plan on going with forced induction I got a twin turbo kit for the car for a great price obviously that’s overkill so I just want to run a single turbo

I just don’t know where to start really I just want a solid build when I say budget I mean like 10k or less

 

[CKOPOCT]

Second the reply to mine the forums and read up on what's been posted. You will not only need the intake parts (turbo, intercooler, manifold, waste gate, bov), but you will need all of the other pieces that will be a part of managing the added air and power. You'll have to see if the stock MAF can handle what you are tryung to do. You may decide to use a different MAF or go with a different setup like speed density. That decision may lead to changing other things.

You'll need more fuel so you don't run lean and can make use of the added air. That means a fuel pump, injectors, and a fuel pressure regulator.

The srock ECU wasn't designed to process the amount of air, so you'll need an ECU and a way to tune your setup.

You'll need a larger exhaust system. You may need cams depending on where you want your power band and what the 420a stock cams can do.

You should also invest in good gauges so you can actively monitor things like oil pressure,, boost, and exhaust/O2.

You should also research how much power/torque the transmission can handle given its age and history, and assess if you need to have it refreshed, beefed, or modified. If it's a stick, add the cost of a new clutch that can handle the power.

Lots to think about. The more power you want to make, the more there is to consider. I think quality 300 is doable for $10k if you do the research and buy used where prudent. The amount of info and choices all have a lot to do with what you are willing to spend and do. So sending you on a reading/forum mining quest isn't a matter of not wanting to address your question; it's a matter of just how deep the rabbit hole can go, and researching it will be more expedient and better for you than starting with us throwing parts suggestions at you right now.

Once you have researched it and know how deep you want to go, then we can give you targeted recommendations that lead you to action and answers instead of frustration and false starts.

 

[DrewmHolland]

honestly what you'll need is forged rods and low compression forged pistons, ~$1000, valve springs, ARP head studs, the strongest sprung clutch you can find, and like 15psi of boost. with an eBay turbo kit it'll be like $700. you'll also need poly mounts (I'm making 250hp at the crank and destroying my rubber mounts) and you might need a different radiator (idk if the stock one still fits or not but its gonna explode anyway because they're plastic) then you gotta get an FMU, larger injectors ~450cc, a 3 bar map sensor and some sort of standalone ECU and Wideband AFR gauge. I still use the stock ECU with 10psi and make 250HP but if you really want to make 300-350hp safely then you'll need a standalone. Also put the flywheel bolts in with as much red Loctite as possible.

 

[BLACK'98DSM]

idk if the stock one still fits or not but its gonna explode anyway because they're plastic

What? It isn't going to explode. Plastic radiators may not have as long of a lifetime as all aluminum rads, but they aren't just exploding. Installing a turbocharger does not raise the pressure of the cooling system at all, unless the headgasket is not sealing properly.

 

[DrewmHolland]

What? It isn't going to explode. Plastic radiators may not have as long of a lifetime as all aluminum rads, but they aren't just exploding. Installing a turbocharger does not raise the pressure of the cooling system at all, unless the headgasket is not sealing properly.

I agree but the heat from the turbo being inches away will make it very brittle in the middle which I why I don’t recommend it, that and the fact that the cast log turbo headers available on eBay trap so much heat that coolant will boil in the head when you shut your car off.