How high you can rev has alot to do with your bottom end, too. Piston dwell time @ TDC will have alot to do with the engines VE at higher rpm. Flame travel Across the piston is a big part of the process. Rod angularity (stroke/rod ratio) is primarily for bearing stress, and it can also play a role in how you tune your ign timing. Thats why I like the 2.1. Taller deck, longer rod with out the issue of packing the ring lands too close b/c of the wrist pin. Added displacement is from cyl bore.

 

that is what im looking into doing. A 2.1 with a 40r. Dont you have to use a 4g64 block or something. I dont know much about the 2.1 de-strokers

 

4g64 block, 4g63 crank.

 

aww gotcha....

 

here's another stroker kit one could consider:

http://www.norrisdesigns.com/proddet...d=evo%2D034012

 

currency conversion is about $4k USD

 

here's another stroker option:

http://www.rcdevelopments.com/portal...mart&Itemid=76

 

You're right, BUT you're just not done adding thats all. Add the time it takes to locate, purchase, strip down and clean the donor motor. Now add machining time. Then add balancing and blueprinting time. Now add a small % for R&D time.

All though there is no argument that $8000 is a lot of money, $8000 is a very good price for a lot of motor.

There are alternate/cheaper packages out there but they are inferior to this combonation. Take any other engine package out there, dress it with the same head, turbo, intake etc and see which will not only win on the dyno, but most importantly, on the track.

Limiting factors of max rpm is piston speed which is all dependant on the stroke and rod length, rod angle ratio. If you really want to understand all of this just do a simple google search on rod angle ratio, long rod vs short rod etc. Really, im really trying not to write a novel here.

 

I've been building engines for 10 years, I know exactly what it takes to put together this short block. I'm not claiming to be better than anybody else, I'm just saying I have the experience to know what it takes to do this.
You don't have to preach rod to stroke ratio, and piston speed to me, I've done the math, just like most other engine builders have. It goes much deeper than just those two things. You have to consider side load, piston dwell, the forces acting on the main and rod bearings, where to locate the ring pack, etc, etc, etc. I'm not going to "write a novel".

Like I said AMS isn't the first shop to build this engine., it's been done in the Dsm community for years. You can call up any of the major pistons manufacturers, and they will have a piston for this application, or something very very close. Building the same engine with equally strong parts for half the price, doesn't make it inferior. If you buy this engine you're paying $5000 for the shortblock and $3000 for the AMS name.

Instead of getting defensive and jumping on the bandwagon, grab a calculator, write down the parts needed to make this work. Add the cost of machine work and labor, and you'll see exactly what I'm talking about.

 

With all due respect to AMS, like ackerson is saying...Unless something revolutionary has been invented, these tricks were being used by hotrodders.

 

I have nothing but respect for the guys at AMS, and what I said won't affect their sales at all. They are bringing great new products to the market, pretty much on a monthly basis. If you buy the 2.3RR, you are going to be buying a very badass engine, from a company with a flawless reputation, and they will provide whatever support they can to their customers, and even to people that aren't customers. All I'm saying is, a resourceful person with a good engine builder, can duplicate this engine(or close to it), for substantially less money. BUT, they won't be getting the product support, or the customer service that AMS is famous for.

 

a 4g63 can be stroked to just under 2.4L...
a 4g64 does allow for a longer rod ratio at the same stroke and compression height in comparison to the 4G63...
the AMS 2.3RR can be made for less than they sell if for, of course, how do you think they would make money otherwise.
I should know, I'm gathering the parts for a similar but bigger build right now in a 4g63, 102mm stroke instead of 94mm. 1.470:1 RR instead of 1.638:1 RR simply because its a street engine. If running a 4g64 than the ratios could roughly be 1.53:1 @102 or 1.70:1 @94

These numbers still leave a little more room in compression height too.

 

you obviously don't know what there 2.1L drag motor nor their 2.3RR motor are then...

 

A quick, breif and loosely worded explanation:

Well rod ratio effects your dwell at TDC and BDC as well as accelerations between both points. Flame propogation becomes a big issue with a short rod high revving motor as VE's drop and time at TDC becomes far from "ideal". This means igniting sooner creating more pressure against the piston btdc making a loss of power (or less than possible) while still hoping to have peak pressure at an idealized rod/crank angle ATDC. Longer RR has the opposite effect but doesn't spool a turbo as fast because at lower rpm's the pumping events (VE's) are more ideal for the short RR. Regarless though, a longer RR will have less mechanical losses and take advantage or constant volume combustion but can they do have higher pumping losses at low rpm's. The long rod will also inherently have a heavier rod and depending on design a lighter piston. You need to work out the max accelerations and then forces exerted on the bearings to see what loading issues and/or limitations will occur there.

Hence the perk of the 2.3rr (for a road racer or shortly geared auto-x) sitting at a nice in-between position of the 2.0/2.1 and the 2.3/2.4. Lose a little stroke for RR and a little bigger bore to make up some displacement and allow more room for deshrouding in the head.

 

I know and agree 100%, but I just didnt want to starting writing a huge post, novel. Wasnt trying to preach.

Not sure if I understand the hating or why some are trying to discredit this awesome engine. If you can do it yourself and can actually get the same internals, more power to you. You being an engine builder should understand how much time goes into a race engine, what is your time worth? What about overhead? Most evo owners dont know a real engine builder or even have any idea where to find a machine shop. Nor do they want to.

AMS is a company that is entitled to make $ on thier products. The value of thier customer support, proven combonations, experience and durability is worth every penny. Thier long list of customers and builds speaks for itself.