G4CS block Destroked! What pistons?!

[sonicnofadz]

I am currently working on a G4CS block removed from a 1991 Hyundai Sonata. To destroke this motor and run with 2.1 liters (and get a better rod to stroke ratio while I'm at it) I wish to run a regular 2.0L 4G63 crank, regular length 4G63 rods, and OEM NON turbo 6-bolt pistons. The non turbo pistons are of a much higher compression and will make up for the crank's shorter stroke and the taller block. Does anyone know what type of compression this will make? 8.5:1?

 

[fourreGsixty3]

I beleiev it would be 8.5:1 if not a little higher like 8.8, the stock 1G turboed pistons are 7.8:1, and the 2Gs are 8.5:1, also do you know for sure if this combo will work? I believe with destroked motors its a 4g64(or equivilent) with a 2.0 crank, super-long rods(162mm), and special 2.1L destroked pistons.

Dustin

 

[i1nk83]

I seriously hope you are not going to run n/t pistons in a turbo car.Simply stated they will not take the abuse of forced induction. The stock n/t pistons are 9:1, so if you want 9:1 ratio pistons buy aftermarket forged pistons. I'd say that you do not have the knowledge to even start this project much less finish it, either leave it a professional or buy one someone else has put together. Personally the 2.3/4's are a much better choice.

 

[sonicnofadz]

Of course it would work! By definition, a de-stroked 4G64 (G4CS) is when you use the 2.0L 4G63 crankshaft in a taller block (4G64 or G4CS, which are exactly the same to my knowledge) and use the regular length 2.0L 4G63 rods. If I were to use the stock 1G turbo pistons or 2G turbo pistons with a destroked G4CS (normally 7.8:1 & 8.5:1 respectively ) the resulting compression would be somewhere around 6.9:1 or 7.6:1, which is too low. It is correct to assume that if I chose to use 1G NON TURBO pistons (normally 9:1 compression) that the resulting compression would be 8.1:1? Has anyone ever attempted to do this? How well would the OEM mitsubishi 1G non turbo pistons hold up to boost?

 

[JayRolla]

Well the non turbo piston is a 9.1:1 isnt it? I would guess over 8.5:1 for sure. You will have fun tuning the high compression, I know I am.

 

[sonicnofadz]

I seriously hope you are not going to run n/t pistons in a turbo car.Simply stated they will not take the abuse of forced induction. The stock n/t pistons are 9:1, so if you want 9:1 ratio pistons buy aftermarket forged pistons. I'd say that you do not have the knowledge to even start this project much less finish it, either leave it a professional or buy one someone else has put together. Personally the 2.3/4's are a much better choice.

Yeah I don't have the knowledge haha thats funny! There are reports of people putting down well over 300HP using the 4G63 non turbo block + 9:1 pistons This is why I was asking if I could use non turbo pistons, because it seemed like they could take alot of boost even under very high compression. Is there anything structurally different about the non turbo piston versus the turbo piston besides the compression rating (i.e. ring lands, side skirts). I'm pretty sure they are both cast iron and are structurally identical.

 

[92awddsm]

There are going to be many problems with this setup.

1) If the bore is perfect on the 4g64/g4cs, you will have to find a set of .060" oversize n/t pistons. If the block has to be bored .020", you will have to get .080" oversized n/t pistons. Good luck with either.

2) With the 2.0 internals in a 2.4 block, the piston will sit in the hole .236" below the deck surface at tdc. You do realize that is almost 1/4", right? You will be below 7:1 c/r and you will lose your quench area in the combustion chamber. Might sound good on paper but Im sure you will be pissed when you find out a stock 1g 4g63t will make more power than your custom engine.

3) The ring lands on the n/t pistons are thin and very weak. The dome of the piston is also thinner. Eventually, the piston will fail in boosted applications.

If you are going to spend the money, get the right parts to make it work well and last long.

 

[92awddsm]

Yeah I don't have the knowledge haha thats funny! There are reports of people putting down well over 300HP using the 4G63 non turbo block + 9:1 pistons This is why I was asking if I could use non turbo pistons, because it seemed like they could take alot of boost even under very high compression. Is there anything structurally different about the non turbo piston versus the turbo piston besides the compression rating (i.e. ring lands, side skirts). I'm pretty sure they are both cast iron and are structurally identical.

To the best of my knowledge, no one has made a cast iron piston in decades. The 4g63t and n/t has cast aluminum pistons along with most other manufacturers.

 

[sonicnofadz]

There are going to be many problems with this setup.

1) If the bore is perfect on the 4g64/g4cs, you will have to find a set of .060" oversize n/t pistons. If the block has to be bored .020", you will have to get .080" oversized n/t pistons. Good luck with either.

2) With the 2.0 internals in a 2.4 block, the piston will sit in the hole .236" below the deck surface at tdc. You do realize that is almost 1/4", right? You will be below 7:1 c/r and you will lose your quench area in the combustion chamber. Might sound good on paper but Im sure you will be pissed when you find out a stock 1g 4g63t will make more power than your custom engine.

3) The ring lands on the n/t pistons are thin and very weak. The dome of the piston is also thinner. Eventually, the piston will fail in boosted applications.

If you are going to spend the money, get the right parts to make it work well and last long.

Holy crap thanks for the info!@ I was not aware that the 4G64 block had a larger bore. This project is for a spare 1G fwd car we had lying around. We have so many spare parts in our garage that we could have slapped together a destroked block for very cheap, (we could care less if it blew up or not, since it is 1 of 4 of our project DSM's). What kind of piston do I want to run with this setup (if I am using 4G63 crank + rods)? I can get .060 pistons no problem, but I just need to know what compression ratio pistons (9:1 4G63 compression, 10:1???) and what the resulting compression ratio will be once it is assembled into the 4G64 block. If anyone has some specs or part numbers for forged units, I'd would appreciate it greatly!

 

[sonicnofadz]

Wait a second, according to this thread:

http://www.dsmtuners.com/forums/showthread.php?t=100677

The G4CS bore is exactly the same as the 4G63? Why would you say that I would need .060 overbore pistons??

 

[Tsi2nr]

Sine you say that you want something closer to a 2.0, then buy a 4g63 6 bolt with 1g big rods and 2g pistons.

 

[sonicnofadz]

Ehhh...a destroked engine can rev alot higher than a regular 2.0L 4G63 (due to the better rod/stroke ratio). This is why we would like to build it, even though it's displacement will only be 2.1 Liters.

 

[92awddsm]

Wait a second, according to this thread:

http://www.dsmtuners.com/forums/showthread.php?t=100677

The G4CS bore is exactly the same as the 4G63? Why would you say that I would need .060 overbore pistons??

The g4cs has the same bore size as a 4g64. Stock bore size is 86.5 on the g4cs/4g64 and stroke is 100mm. Stock bore on the 4g63 is 85mm and stroke is 88mm. The g4cs/4g64 has a bore size that is 1.5mm larger which would equate to .0590".

 

[92awddsm]

Ehhh...a destroked engine can rev alot higher than a regular 2.0L 4G63 (due to the better rod/stroke ratio). This is why we would like to build it, even though it's displacement will only be 2.1 Liters.

I think you totally misunderstand the workings of a destroked engine. The 2.0 can rev as high as a stock rod 2.1, because it has the same internals, just a larger bore. All you would be doing is changing the block and pistons, not stroke or rod ratio.

The increased rpm's come from the longer 162mm rods that are typically found in the 2.1. With the longer rod, the piston speed is decreased and dwell time is increased. This in turn gives you a better rod ratio and more useable rpms. 4g63 rods with a 4g63 crank gives you the same rod ratio and rpm as a 4g63.

 

[sonicnofadz]

Yeah I don't know what I was thinking...there would be no point in using the stock length 4G63 rods! Thank you again!

 

[fourreGsixty3]

Yes, Kieth(92awddsm) has it right on the head, for destrockers you need the "super long" rods(162mm) shown on magnus' site, stock 4g63 bore is 85mm, the 4gcs, and 4g64 is 86.5mm stock bore thus resulting in the need for .060 over-bore pist5ons, which you wont find. Also 2.0s can rev just as high as 2.1L otherwise the big guys like Shep, and Rau would move from the 2.0 to the 2.1, and the 2.1 would have the exact same rod ratio as a 2.0 since you would be using 1G n/t pistons, and 1G rods. The n/t pistons will be weakend (sp?) from being used on a boosted application.

Dustin

 

[xaixiong]

You wouldn't want to run a 2.0 crank the g4cs uses 100mm crank as the 2.0 use 88mm

 

[mitsubishikid]

You wouldn't want to run a 2.0 crank the g4cs uses 100mm crank as the 2.0 use 88mm

Firstly FYI this post is almost a decade old.

Secondly, you would have to run a 2.0 crank in the 2.4 block in order to make a de-stroker 2.1 liter motor, if the op ran the stock 2.4 block and crank he would have a 2.4 hybrid dohc motor... which is okay and all for low end torque, or for spooling a large turbo, but it is not a de-stroker, which IIRC is what this post was originally about.

By using the 88mm 2.0 crank to de-stroke the 2.4 block, he would effectively have made what we all know, in the dsm world, as the 2.1 de-stroker motor, it would have less low end torque then the 2.4, or 2.3 stroker setups, but among other benefits, it's known to rev more freely then the, 2.4 hybrid dohc setup, and the stroker 2.3 setup.

The non turbo pistons in a de-stroker are a bad idea, and they won't work with most de-stroker kits, using longer custom rods, and forged custom de-stroker pistons is the common consensus here, if you're going to spend big bucks on custom long rods for a de-stroker, why [if you could] put weak cheep non turbo cast pistons on expensive custom de-stroker rods.

 

[xaixiong]

I still have a question though if you guys don't mind helping me on my build. Sorry I can't post anything yet due to me being new to this site. I'm building my g4cs with a 6 bolt head . I have everything internal built already. What I want to know is the pulley and timing belt and cams that I can run to make this work.[DOUBLEPOST=1417808967][/DOUBLEPOST]

Firstly FYI this post is almost a decade old.

Secondly, you would have to run a 2.0 crank in the 2.4 block in order to make a de-stroker 2.1 liter motor, if the op ran the stock 2.4 block and crank he would have a 2.4 hybrid dohc motor... which is okay and all for low end torque, or for spooling a large turbo, but it is not a de-stroker, which IIRC is what this post was originally about.

By using the 88mm 2.0 crank to de-stroke the 2.4 block, he would effectively have made what we all know, in the dsm world, as the 2.1 de-stroker motor, it would have less low end torque then the 2.4, or 2.3 stroker setups, but among other benefits, it's known to rev more freely then the, 2.4 hybrid dohc setup, and the stroker 2.3 setup.

The non turbo pistons in a de-stroker are a bad idea, and they won't work with most de-stroker kits, using longer custom rods, and forged custom de-stroker pistons is the common consensus here, if you're going to spend big bucks on custom long rods for a de-stroker, why [if you could] put weak cheep non turbo cast pistons on expensive custom de-stroker rods.

If you don't mind me asking do you have any info on what needs to be done to run the g4cs block on a 6 bolt 4g63t head?

 

[lasthope05]

OEM 4g64 timing belt and 4g64 DOHC cam gears or adjustables. Everything else is the same. Or you could run the stock 2.0 timing belt with another tensioner pulley in place of the idler.

 

[xaixiong]

OEM 4g64 timing belt and 4g64 DOHC cam gears or adjustables. Everything else is the same. Or you could run the stock 2.0 timing belt with another tensioner pulley in place of the idler.

Ohh Okay I'll be using the 4g64 timing belt and cam gears. I was wondering. I'll be doing a balance shaft delete would it be the same as a regular 6 bolt 4g63t?

 

[C89ZX7R]

My bottom end build is still up in the air. Building the head 1st as either way I go with the bottom end the head is still the same 63 dohc. I have a wideblock G64B with a damaged 6 bolt 64 crank. Still up in the air if Im doing a 63 eagle 100mm or a stock 6 bolt 88mm 2.1 destroker.

 

[mitsubishikid]

Ohh Okay I'll be using the 4g64 timing belt and cam gears. I was wondering. I'll be doing a balance shaft delete would it be the same as a regular 6 bolt 4g63t?

Yes you would eliminate the balance shafts in the same manor as the 6 bolt motors, but make sure you use the oem stub shaft and not the knock off ones sold on ebay, most of them lack the oil groove seen on the oem ones.

on the topic of the timing belt there is a nice posts on using the stock size 2.0 kevlar t belt on the 2.4 here http://www.dsmtuners.com/threads/how-to-use-your-4g63-kevlar-belt-on-your-2-4-stroker.331293/

 

[xaixiong]

Yes you would eliminate the balance shafts in the same manor as the 6 bolt motors, but make sure you use the oem stub shaft and not the knock off ones sold on ebay, most of them lack the oil groove seen on the oem ones.

on the topic of the timing belt there is a nice posts on using the stock size 2.0 kevlar t belt on the 2.4 here http://www.dsmtuners.com/threads/how-to-use-your-4g63-kevlar-belt-on-your-2-4-stroker.331293/

Thanks for the info on the timing belt. Seems like it fits fine. Cam gears would be nice to have to. Than again thanks

 

[modicaUSMC]

I have a G4CS also, you will want a 88mm crank, 156mm rods and the wiseco or similar pistons that are made specificaly for the 4G64/G4CS and 4g63 head build to reach the beloved 2.1L "De Stroker". BE CAREFUL no one makes 156mm 6-bolt rods with a 21mm wrist pin, you will have to have custom rods made and i was quoted just over $900!! make sure you get the 22mm wrist pin, but keep in mind the only 156mm rods/6 bolt/ 22mm pin are the manley I-Beams ($700) this is why im selling my G4CS and looking for a 4G64 so I can have more buying options. you will also have clearance problems possibly with the exhaust and oil pan. make sure to buy the 4g64 head gasket with proper bore size and 4g64 timing belt... worth all the BS in the end with a stroker engine revving like a honda s2k