STM's 4g63girl Evo build.
Sep 14, 2010, 06:04 PM
#16
907 I see you're new too...he didn't have a question, he made a statement, which was incorrect. Ask the right question and you'll find an answer, make a stupid statement and get a snub *** comment back, that's how it works.
Pricing, steel rod engine is the same price as the 2 liter build. Adding aluminum rods adds $250 to the cost of the engine because of the extra machine work required.
Pricing, steel rod engine is the same price as the 2 liter build. Adding aluminum rods adds $250 to the cost of the engine because of the extra machine work required.
Sep 14, 2010, 06:28 PM
#20
. Inregards to the stupid statement stems from his ignorance in a LR motor... coming from a well known business man like you I guess is true what the say about you. Anyways I guess I(myself) didn't expect a response like that from you.
I'm not going to ruin this thread anymore.. David we can gladly take to this pm's if need be.
Sep 14, 2010, 08:41 PM
#21
But a standard r/s 2.0 can and has taken 10.5k with no issues related to piston speeds. The limit at high RPM's sure isn't the R/S ratio.
As far as a lighter piston.. is it really worth it? It's not THAT much lighter then a standard 2.0 piston, yet you have shorter skirts which COULD mean premature wear (even though the r/s is better)
And yes because you need a longer rod, the rod is going to weigh more. Now I know the piston weight plays a huge role on bearing life, but so does the weight of the rest of the assembly (the rod).
The ONLY possible reason I could think of to go through the trouble for this setup, would be to make a broader powerband higher up; A slightly more rev happy engine. I'm thinking that's where you're going with this.. I'd like to see how it all plays out in the future.
And David I don't take offense to your reply, I didn't expect anything different. Afterall, my name is David also LOL
Sep 14, 2010, 09:29 PM
#22
I love watching this car progress. Its a very clean car and the changes it has made keep producing great results. Keep up the good work.
However I do think the long rod craze is silly. I would be willing to bet money that there is actually no measurable difference in performance by increasing the rod length by 6mm without increasing block height the same 6mm. The piston pin and rod are steel and piston aluminum. You are going backwards in weight and reliability department by raising the pin up into the piston.
There was a graph posted somewhere by I believe a BMW engine that tested rods 100mm and 150mm. The difference in the graph was very small. what do think the difference would be from going from 150 to 156? I will take the lighter weight by keeping steel parts at lower rotating mass.
Then there is dwell time. Turbo engines like fast burn chambers. the faster the fuel burns the less likely the fire will have time to detonate. increasing the dwell time of turbo engine increases its detonation threshhold. More likely to detonate around peak torque.
JE just announce a new shelf stock piston with a very cool skirt design. The piston is strutted skirt design. Which is very strong and very light. It allows the pin to be made very short which is lighter and less likely to flex. The real cool thing was the skirt design. Under power the piston is loaded harder to one side traveling down the bore. On the unloaded side the skirt was reduced in size substantially. this allows the some weight savings and less friction on every stroke. It would be my guess that Dave is using this new piston design since JE is pretty much all he sells and uses. Good stuff..
However I do think the long rod craze is silly. I would be willing to bet money that there is actually no measurable difference in performance by increasing the rod length by 6mm without increasing block height the same 6mm. The piston pin and rod are steel and piston aluminum. You are going backwards in weight and reliability department by raising the pin up into the piston.
There was a graph posted somewhere by I believe a BMW engine that tested rods 100mm and 150mm. The difference in the graph was very small. what do think the difference would be from going from 150 to 156? I will take the lighter weight by keeping steel parts at lower rotating mass.
Then there is dwell time. Turbo engines like fast burn chambers. the faster the fuel burns the less likely the fire will have time to detonate. increasing the dwell time of turbo engine increases its detonation threshhold. More likely to detonate around peak torque.
JE just announce a new shelf stock piston with a very cool skirt design. The piston is strutted skirt design. Which is very strong and very light. It allows the pin to be made very short which is lighter and less likely to flex. The real cool thing was the skirt design. Under power the piston is loaded harder to one side traveling down the bore. On the unloaded side the skirt was reduced in size substantially. this allows the some weight savings and less friction on every stroke. It would be my guess that Dave is using this new piston design since JE is pretty much all he sells and uses. Good stuff..
Sep 15, 2010, 06:33 AM
#25
There is a much larger reason for the long rod than any of you chiming in have considered...........the 4g63 block will absolutely split the cylinder walls. Moving the pin and using a longer rod changes the side loading of the piston and changes where this side loading eventually happens in the cylinder. THAT is the main reason I did it. I've done the same thing as the rest of you, read all the crap on the internet about why to use or why not to use a long rod. The benefits and the down falls of it. In my case and in the case of the 4g63 I don't care what I read, I wanted to be able to push the block further without hard blocking it and I believe this will be a key component in doing so. How's that?
The 2.1 that is currently in my car has a power band that is so superior to most other cars at my power level that it's hard to believe. Granted my car has more dyno runs on it than probably any other, it has more time in development of each part than probably any other and I've spent more time tuning it than probably any other, it still has a ridiculous power band. So I have to sit back and ask, why is it other than the amount of time and development. To compare my power band to others it looks like the car is running a large engine, 2.3 or something, but it is not. The 2.1 uses a 2 liter crank, long rod and a bore that is 1.5 mm larger or .053 inches.
A standard bore 2 liter is 121 cubic inches
A standard bore 2.1 liter engine is 125 cubic inches
A .050 over bore 2 liter is 125 cubic inches
The particular engine is .010 over bore on a 2 liter block, that's 122.36 cu in.
So now I have an engine that is 3 cubic inches smaller than the 2.1, same crank and same rod ratio.
This gives us a chance to get back to back data on the two engines and all the standard rod ratio 2 liter data. Data and dyno testing in my book is better than any of the random bull**** that is written and read on the internet.
Doing the engine this way, if it works out the way I have planned, also means not messing with cam gears for the taller block, no missing bolts in the front cover, no grinding and making things fit to use the 4G64 block.
It will be very interesting to see the difference in this engine design and a 2.1 and what happens to the power curve.
As far as some of the other statements. Moving the pin up in a piston makes the piston more stable, for reference. JE's had this new piston design that was mentioned coming out since the beginning of the year when they were here at our shop, that is not the design we are using as it is still not available for what we are doing.
The theories thrown out on weight are nice.............if all you have is theories. I have a scale and can tell you this combination ends up lighter. I'd also rather throw weight around closer to the crank and not hung out on the end of the rod.
Getting a 2 liter to stay together at 10,500 rpm, big f'ing deal. That wasn't enough RPM 10 years ago.
I have ask myself some days why I bother with posting anything, this isn't my first engine build.
The 2.1 that is currently in my car has a power band that is so superior to most other cars at my power level that it's hard to believe. Granted my car has more dyno runs on it than probably any other, it has more time in development of each part than probably any other and I've spent more time tuning it than probably any other, it still has a ridiculous power band. So I have to sit back and ask, why is it other than the amount of time and development. To compare my power band to others it looks like the car is running a large engine, 2.3 or something, but it is not. The 2.1 uses a 2 liter crank, long rod and a bore that is 1.5 mm larger or .053 inches.
A standard bore 2 liter is 121 cubic inches
A standard bore 2.1 liter engine is 125 cubic inches
A .050 over bore 2 liter is 125 cubic inches
The particular engine is .010 over bore on a 2 liter block, that's 122.36 cu in.
So now I have an engine that is 3 cubic inches smaller than the 2.1, same crank and same rod ratio.
This gives us a chance to get back to back data on the two engines and all the standard rod ratio 2 liter data. Data and dyno testing in my book is better than any of the random bull**** that is written and read on the internet.
Doing the engine this way, if it works out the way I have planned, also means not messing with cam gears for the taller block, no missing bolts in the front cover, no grinding and making things fit to use the 4G64 block.
It will be very interesting to see the difference in this engine design and a 2.1 and what happens to the power curve.
As far as some of the other statements. Moving the pin up in a piston makes the piston more stable, for reference. JE's had this new piston design that was mentioned coming out since the beginning of the year when they were here at our shop, that is not the design we are using as it is still not available for what we are doing.
The theories thrown out on weight are nice.............if all you have is theories. I have a scale and can tell you this combination ends up lighter. I'd also rather throw weight around closer to the crank and not hung out on the end of the rod.
Getting a 2 liter to stay together at 10,500 rpm, big f'ing deal. That wasn't enough RPM 10 years ago.
I have ask myself some days why I bother with posting anything, this isn't my first engine build.
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familyMAN (Jan 27, 2017)
Sep 15, 2010, 06:37 AM
#26
BTW, 94awd, you are right about the dwell time and detonation. The 2.1's will not take the timing the 2 liter does, I can tell you for fact though...........big deal, they make outstanding power with less timing, look at my car for example. Best power band I've ever had and the least amount of timing. I don't care what the numbers are in the timing table, I am more concerned with the dyno sheet shape and right now the shape of the curve make me grin.
Sep 15, 2010, 09:52 AM
#29
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The search engine would do some of these people wonders as well.. lol.
Thanks Dave for the info!
Are you guys using a higher compression piston in this setup as well? Judging by the #s I'd say yes.
I've red that the "reliability" zone for the LR 2.0 is usually in the 9,000-9,500rpm range. 10,000-10,500 is about average and 11,000-11,500 is the maxxed zone.
Personally, I've never taken my car past 8,000rpms since I'm still on stock valvesprings but among the other reasons listed above as benefits for switching to a longer rod, you also reduce how far the piston has to move, reducing friction, which basically means your motor runs a little cooler. Of course, like Dave said, this is all great in theory. Never actually seen someone test a block back to back to see if there are temperature differences, just what I've read.
IMO Evos are one of the most "versatile" cars I've ever seen. There are just SOO many different setups out there for them. Kinda fun to see the pros and cons of each one.
Thanks Dave for the info!
Are you guys using a higher compression piston in this setup as well? Judging by the #s I'd say yes.
I've red that the "reliability" zone for the LR 2.0 is usually in the 9,000-9,500rpm range. 10,000-10,500 is about average and 11,000-11,500 is the maxxed zone.
Personally, I've never taken my car past 8,000rpms since I'm still on stock valvesprings but among the other reasons listed above as benefits for switching to a longer rod, you also reduce how far the piston has to move, reducing friction, which basically means your motor runs a little cooler. Of course, like Dave said, this is all great in theory. Never actually seen someone test a block back to back to see if there are temperature differences, just what I've read.
IMO Evos are one of the most "versatile" cars I've ever seen. There are just SOO many different setups out there for them. Kinda fun to see the pros and cons of each one.
Sep 15, 2010, 10:20 AM
#30
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Sounds like a great option for an easily swapped LR engine. Would definetly like to see it stacked up next to a 4G64 LR2.1. In thinking about the 2, I'm guessing the 2.0LR pistons are lighter then the 2.1LR pistons simply because of the bore size. I would think this would be an advantage too, I am a newb and just a theory so feel free to tear me up haha. Was meant to be a question but came out as a statement.
Anyways, congrat 4G63girl for having the nicest high milage evo I know of.
Anyways, congrat 4G63girl for having the nicest high milage evo I know of.