defrag010
15+ Year Contributor
- 420
- 7
- Sep 24, 2004
-
n/a,
Alabama
I've pitched the idea to a few friends, but they mostly nay-say just because it gives them something to do, not because they know any better.
Anyways, I was looking at the big piston size book at work a while back, and I started to look at the 2JZ-GE naturally aspirated supra pistons. I was aware by trolling around on supraforums that these n/a 2jZ-GE motors are easily able to put down ~800whp safely in stock form with good tuning, and it just dawned on me that these could possibly be used as an extreme budget high-compression alternative turbo piston in wake of the n/a 4g63 pistons, which are pretty weak in stock form.
Digging a little deeper, I found out that these supra pistons are Pressure cast, which is why they are obviously putting down insane horsepower figures in stock form. I figured that if 6 pistons can safely manage 800 whp, that's 133 horsepower per piston, which one would assume that using that number, you could safely manage 533 horsepower out of four of them. This is all assuming that the rod is strong enough to withstand the power.
So I found a guy on supraforums to sell me a set of 6 pistons for 50 shipped, and I started to measure once I got them. The supra piston has a stock bore of 86mm (1mm bigger than a stock 4g63), and is short on compression height by .5mm. The ringlands are in the exact same spot as the 4g63 piston, and the wristpin is 1mm bigger on the supra piston (which would be the equivalent in size to a 2G piston).
The construction of these pistons are quite different, using compact skirts and a narrow body. The supra piston looks to be more structurally sound (I can assume this also by the amount of power they can withstand), while being lighter than the 4g63. I don't have a scale, but I can definately tell a difference.
As you can see in the first pic, the dish size is similar in size to the n/a 4g63 pistin pictured next to it. You can also see the similarity in the ring location/size, and the overall size and compression height of the piston.
The top profile of the pistons are different, and the supra piston gives adequate relief for the intake valves (which could come useful in a 4g63 for running a HUGE intake cam!).
I don't have dish measurements, because of the way the supra pistons's valve reliefs are. After alot of research, I found out that the 2jZ-ge cylinder head has approximately 47cc volume, which is close to a 4g63's 45cc. Since the 2jz-ge is a 10.2:1 compression ratio, the .5mm in added quench height (.5mm shorter compression height) from being installed in a 4g63 should equate to around 9.5:1 compression.
I don't really know where I'm going to go with this, but I'm just making this post as a long-term update to any progress and results I make with using these pistons in a 4g63.
I've been researching these pistons for about 4 months so far, and now it's time to start the phase of toying around with it.
So far, my plan is going to consist of using Cryotreated 1G bigrods with ARP hardware, pressfit to the 2jz-ge pistons as a turbo buildup alternative. The goal is not to succeed the stock 4g63 pistons in power output, yet present a higher compression OEM-form alternative to buying forged pistons. I have seen alot of people "overbuild" their engines, and use 9.0-9.5:1 forged pistons just so they can get more compression and not even come close to exceeding stock piston power level. Hopefully, this will allow people to get the compression they want and not have to spend tons of money when they aren't going to make mind-blowing power.
I realize that alot of people will say this is a dumb idea, but if there weren't people who thought outside the box and tried new things, we wouldn't have as big of a swap-database as we do today. This could turn out to be a good project, or it could turnout to fail miserably. Either way, I'm open to suggestions (not flames) that can possibly help me out along the way.
Anyways, I was looking at the big piston size book at work a while back, and I started to look at the 2JZ-GE naturally aspirated supra pistons. I was aware by trolling around on supraforums that these n/a 2jZ-GE motors are easily able to put down ~800whp safely in stock form with good tuning, and it just dawned on me that these could possibly be used as an extreme budget high-compression alternative turbo piston in wake of the n/a 4g63 pistons, which are pretty weak in stock form.
Digging a little deeper, I found out that these supra pistons are Pressure cast, which is why they are obviously putting down insane horsepower figures in stock form. I figured that if 6 pistons can safely manage 800 whp, that's 133 horsepower per piston, which one would assume that using that number, you could safely manage 533 horsepower out of four of them. This is all assuming that the rod is strong enough to withstand the power.
So I found a guy on supraforums to sell me a set of 6 pistons for 50 shipped, and I started to measure once I got them. The supra piston has a stock bore of 86mm (1mm bigger than a stock 4g63), and is short on compression height by .5mm. The ringlands are in the exact same spot as the 4g63 piston, and the wristpin is 1mm bigger on the supra piston (which would be the equivalent in size to a 2G piston).
The construction of these pistons are quite different, using compact skirts and a narrow body. The supra piston looks to be more structurally sound (I can assume this also by the amount of power they can withstand), while being lighter than the 4g63. I don't have a scale, but I can definately tell a difference.
As you can see in the first pic, the dish size is similar in size to the n/a 4g63 pistin pictured next to it. You can also see the similarity in the ring location/size, and the overall size and compression height of the piston.
The top profile of the pistons are different, and the supra piston gives adequate relief for the intake valves (which could come useful in a 4g63 for running a HUGE intake cam!).
I don't have dish measurements, because of the way the supra pistons's valve reliefs are. After alot of research, I found out that the 2jZ-ge cylinder head has approximately 47cc volume, which is close to a 4g63's 45cc. Since the 2jz-ge is a 10.2:1 compression ratio, the .5mm in added quench height (.5mm shorter compression height) from being installed in a 4g63 should equate to around 9.5:1 compression.
I don't really know where I'm going to go with this, but I'm just making this post as a long-term update to any progress and results I make with using these pistons in a 4g63.
I've been researching these pistons for about 4 months so far, and now it's time to start the phase of toying around with it.
So far, my plan is going to consist of using Cryotreated 1G bigrods with ARP hardware, pressfit to the 2jz-ge pistons as a turbo buildup alternative. The goal is not to succeed the stock 4g63 pistons in power output, yet present a higher compression OEM-form alternative to buying forged pistons. I have seen alot of people "overbuild" their engines, and use 9.0-9.5:1 forged pistons just so they can get more compression and not even come close to exceeding stock piston power level. Hopefully, this will allow people to get the compression they want and not have to spend tons of money when they aren't going to make mind-blowing power.
I realize that alot of people will say this is a dumb idea, but if there weren't people who thought outside the box and tried new things, we wouldn't have as big of a swap-database as we do today. This could turn out to be a good project, or it could turnout to fail miserably. Either way, I'm open to suggestions (not flames) that can possibly help me out along the way.