Auto GSX 2.3L with Genesis Coupe 2.0T Pistons

[DSMPT]

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1998 Auto GSX 2.3L with Genesis Coupe 2.0T Pistons


Read more about this vehicle here...

 

[import solutions]

What did you modify for these pistons

 

[DSMPT]

Machined down the compression height for 100mm stroke.

 

[import solutions]

All Over is bolt on?

Eres Hiroshi?

 

[DSMPT]

All Over is bolt on?

Not only the compression height. Also need to machine the small end of rods for the pistons, like 2G pistons on 6 bolt rods. And use a thicker head gasket to lower the compression ratio and to have a sufficient piston to valve clearance. The compression ratio goes around 11.6 if use the standard .051" cometic head gasket. I set to 10.5:1.

This project was just from my curiosity and not to use forged parts was like a brake for myself not to raise the boost. Of course, to use ready-made forged parts is much easier but was not my purpose.

Eres Hiroshi?

Yes, I am. Excuse me, have we met before?

 

[import solutions]

How much did those pistons cost?. They see good to a 2.4 piston alternative. With some Oversize, which size are these 86 or 86.5?

También soy de México por eso te preguntaba

"I'm also from Mexico—that's why I was asking you."

 

[DSMPT]

How much That pistons cost?, they see Good to a 2.4 piston alternative With some Over size, wich size are these 86 or 86.5?

I used a DNJ Engine Components piston kit, costs around $220 with OEM piston rings. So quality is good. You can find cheaper one on eBay about a half price. But I did not use them because I was not sure about the quality. Some Honda pistons also can be used but they are not designed for turbo engine, so I chose Genesis 2.0T pistons. Since the pistons and the rings are designed for turbo engine. The piston size is 86.00mm. And this piston can not be used for 2.4L because this piston's compression height is lower than 2.4L (4G64) piston's compression height.

También soy de México por eso te preguntaba

Ahhh OK so probably we know each other in local or facebook. PM me please!

 

[Murdertalon]

I was told by a Honda guy that all Honda engines use forged internals factory, is there any truth to this or is it specific engines or something? I actually have no idea as I don't mess with Hondas.

 

[DSMPT]

I was told by a honda guy that all honda engines use forged internals factory, is there any truth to this or is it specific engines or something? I actually have no idea as I don't mess with hondas.

For this project, the piston's specs needed to be 85.00-86.00mm and 22mm wrist pin and the compression height 1.13" or a little bit higher than 1.13" to machine down. Honda's F22 pistons have the numbers very close. So I checked F22 pistons but they were cast. I am not sure about all Honda's pistons though.

 

[arrowhead]

Good find.
So what is the comp height 1.13? with 22mm pin diameter, do you know the stock dome height.
This looks like a good option for an n/a motor.


Mandy

 

[DSMPT]

Good find.
So what is the comp height 1.13? with 22mm pin diameter, do you know the stock dome height.

The comp height of 2.3L (4g63 block + 150mm rod +100mm crank) is 1.13". The Genesis coupe 2.0T pistons have approximately 1.17" height (I used a cheap digital vernier caliper, so not super exactly). So the pistons need to be machined down about 1mm / .040".
The genesis pistons are almost flat top, have approx -2cc~-2.5cc dish (the depth of dish is 0.65mm). After machine down 1mm, the pistons would have 7.9mm thickness (the stock thickness 8.25mm minus 0.35mm) in the center of piston.
About the rods, I used 7 bolt rods since it is easier to find a 7 bolt 100mm crank than 6 bolt one. Just machine the small end width. I shaved 2mm each side, so the total would be 4mm.

 

[DSMPT]

This looks like a good option for an n/a motor.

Yeah, actually I was planning this for a non turbo 2.3 stroker but since this car is my daily drive, I couldn't wait to prepare all necessary parts. So I decided to go for turbo setup with lowering the compression ratio.
If you have a way to machine the pistons and rods, would be cheaper than buying a high compression forged piston kit.

 

[DSMPT]

Replacing the insurance for balance shaft.

 

[AWD-Tony]

So this car is running? How do you like the set up and how in the world did you figure this out?

 

[DSMPT]

So this car is running?

Yes of course Tony, it has been running for 6+ years since I built this engine. This 2g and a 1.7L Civic is my daily car. In this year mainly I am using the civic since gasoline got expensive. But I recently am motivated to drive the 2g more, so just for in case I am replacing the timing belts and pulleys as regular maintenance before restart to drive this 2g more often.

How do you like the set up and how in the world did you figure this out?

Fun to drive, the 16g spool like a 14b in a 2.3L. It was just out of curiosity. I wanted to see myself how it would work this setup, so I built it.

 

[AWD-Tony]

I didn’t see the dates of the post

 

[1990TSIAWDTALON]

It sure looks nice Hiroshi!

 

[DSMPT]

It sure looks nice Hiroshi!

Thank you Marty!

 

[DSMPT]

I didn’t see the dates of the post

I posted this here in 2017 but this was done in 2016.
When I bought this 2g it had a 6 bolt 2.0 but I destroyed it 3 times by playing with nitrous hahah. Then decided to make it as a fun-to-drive daily car. That's why I used the stock rods as to curb my desires. Otherwise I would keep modifying the car
I was also curious about building a 2.3 without aftermarket forged parts and how 10.5 compression ratio on 91 pump gas would actually work.

 

[DSMPT]

Switched with FD rims and did a compression test, 215 psi to 230 psi on all cylinders. And the alternator just died I knew it was gonna stop working soon since the voltage was dropping little by little when it gets hot. Finally it stopped charging today.

 

[Mech Addict]

Cool idea and slick execution. Are you running a stock piston to wall clearance, and how would that compare to a forged piston?
I use my car for dd, and not planning to increase power much above stock. I would sooner try to improve the low rpm torque and throttle response over more top end. Hadn’t considered it seriously because it seemed like forged pistons were the only option for stroker. My impression is that forged have to be set looser in the bores, and consequently not great longevity. I live in a pretty cold climate, and have concerns that would only exaggerate the drawbacks of forged slugs.

 

[DSMPT]

Are you running a stock piston to wall clearance

A little bit looser than the stock PTW clearance. Where I live is pretty hot, one of the hottest city in the world, so I always prefer loose side but it's still much tighter than common 2618 forged piston's clearance.

I would sooner try to improve the low rpm torque and throttle response over more top end. Hadn’t considered it seriously because it seemed like forged pistons were the only option for stroker. My impression is that forged have to be set looser in the bores, and consequently not great longevity.

You also have an option to go with 4032 forged pistons that would allow you to have much tighter clearance than 2618 pistons.

I use my car for dd, and not planning to increase power much above stock

That's my plan on this 2g. I care more about low/mid torque than top end power. I even barely do WOT on this 2g.

 

[DSMPT]

Finally I got off my backside to solve the factory oil pressure gauge issue. I had been lazy to do that for many years since the day I bought this GSX. The symptom was with a good working sender, the gauge needle "sometimes" moves, but only a few millimeters max. Even apply a direct 12V, the needle doesn't go above 1/4 position. The sender, harness and gauge coil ohm seemed to be good. I didn't see any issue actually but the gauge was not working as it should.
I disassembled the gauge and found that the needle base which is a white tiny plastic that is supposed to be hooked between the needle and the coil pole piece was popped off from the pole piece. I returned it in its position carefully. Now it's reading as it should. Was good not to spend money to buy another factory gauge.

 

[DSMPT]

For a change of pace, planning to put the 2g back as it was before. With the JDM taillights, early EVO intake manifold, stock 2g exhaust manifold w/ ARC heat shield.

 

[DSMPT]

My MAP sensor is a Mitsu style Omni sensor. I had to do something for its mounting location if I use the early EVO intake manifold. I really didn't feel like extending/modifying the MDP sensor wirings to mount it in somewhere else or switching with a spare AEM MAP sensor. Also didn't want to modify the manifold. So I tried to mount it in almost the same location as the MDP sensor by using a vacuum block that has been laying around.
The factory MDP sensor plug can reach and won't contact with the hood since the early EVO intake manifold gives us much more room under hood than the stock 2G manifold.