Disecting a 2.1 destroker

[skyrone]

Ok so i wan't to do a destroker engine in my 2g. The kit from sbr is not really unreasonable i just have some hookups with a shop that might be able to get me the individual parts cheaper and give me more money for getting the head done. So far from talking with some people i've figured out that you need a 4g64 block, a 4g63 crank, 162mm long rods, and a "custom piston". I was wondering if anybody had exact specs on what a stock 4g64 rod is and stuff so that i could figure this out. To me it seems like if I just got forged 4g64 pistons id be fine but idk any input? I think i might just need 4g64 stroker pistons. Does anyone make such a thing?

 

[SBR Joe]

Ok so i wan't to do a destroker engine in my 2g. The kit from sbr is not really unreasonable i just have some hookups with a shop that might be able to get me the individual parts cheaper and give me more money for getting the head done. So far from talking with some people i've figured out that you need a 4g64 block, a 4g63 crank, 162mm long rods, and a "custom piston". I was wondering if anybody had exact specs on what a stock 4g64 rod is and stuff so that i could figure this out. To me it seems like if I just got forged 4g64 pistons id be fine but idk any input? I think i might just need 4g64 stroker pistons. Does anyone make such a thing?

PM sent.


Joe

 

[pnishr]

Ok so i wan't to do a destroker engine in my 2g. The kit from sbr is not really unreasonable i just have some hookups with a shop that might be able to get me the individual parts cheaper and give me more money for getting the head done. So far from talking with some people i've figured out that you need a 4g64 block, a 4g63 crank, 162mm long rods, and a "custom piston". I was wondering if anybody had exact specs on what a stock 4g64 rod is and stuff so that i could figure this out. To me it seems like if I just got forged 4g64 pistons id be fine but idk any input? I think i might just need 4g64 stroker pistons. Does anyone make such a thing?

Correct on the rods/crank/block. Stock rods on 4g64 (most) are also 150mm, just like 4g63. Deck is 6mm taller, and the radius of the 100mm crank is 6mm longer, making everything even.

Pistons with pin moved up 6mm to complete the set. Wiseco makes them, and anybody that already makes a 4g64 piston can make them with not a whole lot more than a phone-call to them. Many of them have already done it for other customers. And it won't cost too much.

 

[tstkl]

I'm somewhat confused as to why a 162mm rod was used over a 156mm rod. Was it purely to get even less rod angle than the standard 2.0? I have a feeling someone just thought the 6mm's didn't make a huge difference, so they used pistons already in production for the 2.3 and made the rod 162mm.

Sorry for reviving a dead thread, but I thought it would be nice to see if anyone is making 156mm rods, to open up some piston options for us 2.1 guys. Realistically, the rod angle's aren't whats going to limit how high you can rev on these motors. People have taken 2.0's past 10k, so I would think that a 2.1 wouldn't be much of help to anyone.

I'm just looking to make sure there weren't any clearence issuses being adressed by using the 2.3's pistons rather than normal 2.0's in the destroker.

for anyone confused, I'm asking why you can't just cancel the 6mm increased radius with a 6mm longer rod, and not touch the pistons since the 4g64's deck height is 6mm taller.

 

[SpeedAddict62]

I'm somewhat confused as to why a 162mm rod was used over a 156mm rod. Was it purely to get even less rod angle than the standard 2.0? I have a feeling someone just thought the 6mm's didn't make a huge difference, so they used pistons already in production for the 2.3 and made the rod 162mm.

Sorry for reviving a dead thread, but I thought it would be nice to see if anyone is making 156mm rods, to open up some piston options for us 2.1 guys. Realistically, the rod angle's aren't whats going to limit how high you can rev on these motors. People have taken 2.0's past 10k, so I would think that a 2.1 wouldn't be much of help to anyone.

I'm just looking to make sure there weren't any clearence issuses being adressed by using the 2.3's pistons rather than normal 2.0's in the destroker.

for anyone confused, I'm asking why you can't just cancel the 6mm increased radius with a 6mm longer rod, and not touch the pistons since the 4g64's deck height is 6mm taller.

I would assume its just to get an even higher rod ratio - 1.84 instead of 1.77. Stock 2.0 is 1.7.

Manley makes 156 mm rods: Manley Rods. Scroll down to the last page, and you'll see what I'm talking about. They make both 156 and 162 mm, unfortunately both 7 bolt only.

I have been searching A LOT lately on doing a 2.1 destroker, I really like the idea - a better rod ratio with an increase in displacement. I think the real limit on high rpm capability will be head flow, not the bottom end. If I do build a 2.1, I'd like to go with a 156 mm rod and keep some pistons with a little more meat to them.

 

[dsm-onster]

The longer rod allows you to use a lighter piston: a stroker piston. A stroker piston is 15% lighter than an non-stroker piston of the same manufacturer. This lighter piston makes a huge difference in a stroker motor vs. a non-stroked 2.0L motor. Since the tensil force acting on the rod bolts is far less with the lighter mass, at 9K rpms on a 2.0L, the stroker motor can come within 8.6K of that and have the same tensil force exerted on the rods. Thus the revlimit of a stroker is alot higher than the rev limit of an initially 2.4L motor.

A 2.1L can have the same tensil force at a proportional amount higher than the difference in the weight of the stock writst pin piston vs. a stroker piston, or 15%. Therefore whatever a 2.0L can get away with, it's 2.1L destroker counterpart (same manufacturer of pistons, rods and rod bolts), can rev 15% higher or more. Typically over 10K for a 2.1L.

Interestingly, the 2.1L doesn't have much less piston velocity than a 2.0L. So you don't loose the air velocity going from your 2.0L to a 2.1L and you gain 5% more volume flow and 15% more rev range. A 2.1L destroker is alot like a honda h22.

 

[SpeedAddict62]

For high hp applications, does it make more sense to use a shorter rod and heavier piston? Or is the lighter stroker piston still strong enough to take daily driven high hp abuse?