420A what the f is wrong with 420a?

[josh_effin_tyre]

Hey guys I have a question for you. Why is a dsm 420a so unresponsive to bolt ons. Don't jump in and start ranting, because I am totally serious and would like a serious answer. I have never in my life seen a motor like this one, every bolt on you can get for it produces the amount of hp that one bolt on does on any motor. Really wtf, diamond star really dropped the ball here! I have been searching online for 3 days and I still don't have an answer so I thought I would ask here with all the wealth of knowledge I figured I could have a understanding of the flaw.

 

[josh_effin_tyre]

Well bad news. The rod started knocking recently and a bullshit mechanic checked my compression and said I had a bent valve. Instead of waiting for a machinist to fix it I got another head. During the swap I found a bad smell coming from the bolts I removed and when the head was off, I noticed play coming from the #1 piston. Also at top dead center the #4 piston was flush and the #1 was about a 1/4 inch below the top of the block. Oh well, the cheapest motor I found was 1400 for a short block with 10.5:1 compression. I'm curious about the cams I had in the original head though. The intake cam has 532 on one side and 272 on the other with what appears to be LA. The exhaust cam has 532 and 252, is that stock or should I reuse those?

 

[psantiago]

In response to first post: The bottom line is that the amount of $ spent in parts to turn a 12 sec 1/4 or better would easily put a 4G in the 10s or better. I have a fully built 2.2L w/ 9.25:1cr and PortFueler setup and best was 12.60s @ 109mph. (5yrs ago). For what I've spent over the years, one could buy 2 very capable DSMs today.

 

[psantiago]

Weak OEM piston materials- ringlands prone to fracture easily. OEM head gaskets are weak. OEM cylinder head flow dynamics: although a design used by Chrysler from what was once said to used in a capable Lotus platform- the volume and other features were changed for the purpose of US emissions, thus, need to be improved upon in order to make substantial gains. Lastly, PCM. These are the primary issues with the platform. If someone wants to improve upon it- gotta be ready for a love/ hate relationship. Love my car but then again it has been sitting for a long while...

 

[TallestHERETIC]

The 420A engine was built specifically for economy, efficiency, and to also have the look of an eclipse. Its still a DSM but w/o the high performance, insurance and high maintenance costs of the turbo versions. This engine blew away the 4G64 and 4G63 in sales numbers, though. In 1999, only about 7-8% had a turbo engine. Everything else was 420A and a few were the non turbo 4G64. The 420A is no slouch, either. Here's a video of a fully built and racing-spec tuned 420A in a dodge stratus!

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[Francispugz_420a]

The 420A engine was built specifically for economy, efficiency, and to also have the look of an eclipse. Its still a DSM but w/o the high performance, insurance and high maintenance costs of the turbo versions. This engine blew away the 4G64 and 4G63 in sales numbers, though. In 1999, only about 7-8% had a turbo engine. Everything else was 420A and a few were the non turbo 4G64. The 420A is no slouch, either. Here's a video of a fully built and racing-spec tuned 420A in a dodge stratus!

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Then mankind can Forge them to be a little power efficient .

 

[josh_effin_tyre]

Yes we can, in fact all we need is a few thinkers, a couple doers and the 420a could be a beast of an engine. Problem is everyone is ready to jump on the quick horsepower train. Very few people actually want to build an all motor car anymore. Parts manufacturers only make performance parts if there is a market. Problem is if they don't do it there will never be a market.

 

[psantiago]

Yes we can, in fact all we need is a few thinkers, a couple doers and the 420a could be a beast of an engine. Problem is everyone is ready to jump on the quick horsepower train. Very few people actually want to build an all motor car anymore. Parts manufacturers only make performance parts if there is a market. Problem is if they don't do it there will never be a market.

Perhaps you have, but, "MB"- check in with him. Bullett has been through it all and remained dedicated to All motor even after building an 11sec boosted 420a. At one point I remember seeing him testing out individual TBs. etc. Talked with him a few times at the various Shootouts and can say he really knows the motor in it's NA form. A high compression 2.4L cloud, w/ 2.0L head would be a pretty solid starting point. This does look pretty yummy though:

 

[Wrathofwalrus]

420a head actually flows better than the 4g stock vs stock. 420a is a great platform, if you have what it takes, but you're not going to make any power NA, especially on stock ecu. The highest hp NA running megasquirt only made 175 or so whp. Oem pistons can handle up to 280whp before shattering.

 

[Wrathofwalrus]

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[josh_effin_tyre]

Wow, nice vid and exquisite car! It seemed plenty peppy. I know the 420a isn't the best platform for making power, but I have come to love them. I had no plans to build one until my motor locked up. I still don't want to do a full build, however since I need to replace it anyway a little better is always a good place to be. So I'll go 10.5:1 with the bolt-ons and see where I'm at.

 

[Wrathofwalrus]

JE 10.5 pistons and Manley rods from real street would cost about a grand, not bad at all. It'd be a waste to get them and not boost the car. The block will need to be honed to .020 over. You cant run a lot of boost on the stock ecu because there's no way to control timing. Megasquirt standalone would be what you want if you ever wanna up the boost like in the video, Hes running MS3, 24psi. You wont be satisfied NA with this car no matter what bolt-ons you throw at it or how you tune it. 175whp is less than what a newer civic si is putting down.

 

[Wrathofwalrus]

For a simple 8psi build all you need is a 255lph walbro fuel pump and a 12:1 fmu to run safely. (besides obvious turbo bits), which will put you around 220whp.

 

[bmxfelon420]

For a simple 8psi build all you need is a 255lph walbro fuel pump and a 12:1 fmu to run safely. (besides obvious turbo bits), which will put you around 220whp.

How would you control timing then? Or is the advance so low on the stock tune to begin with that it isnt a problem?

 

[Wrathofwalrus]

How would you control timing then? Or is the advance so low on the stock tune to begin with that it isnt a problem?

Yup, its not a problem for low boost(around 12psi and under). Stock ecu bases timing on intake temps, Higher boost= much hotter air. Wiring in Megasquirt is the best way to control the 420a for high boost setups.

 

[josh_effin_tyre]

Well I have been satisfied with it so far. It's not a slouch, except for take off, however it's still my daily driver for now. I'm getting the 10.5 short block because it's fairly cheap. I would get another rs for any heavy modding, and I absolutely refuse to get a turbo car. I have never liked them personally, and I'm not knocking anyone who has one. I am currently looking for a 98-99 rs to drive until my crate engine gets here, then when it does arrive, I can look into the the spare and see what I have to work with.