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Discussion Starter #1
...with stock rods and crank, which block has the most torque???? 2.2?, 2.5 tall block?, 2.5 common block???..... just curious any info would be appreciated, thanks in advance!!!
 

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I loved my 2.4 turbo setup on E85.. I let several people drive it and they raved about the torque for years afterwards. Had it on the dyno and it blew their minds how flat the torque curve was, and the fact that they just couldn't start a test at a low enough RPM to figure out where the torque started. ;)

Not the biggest numbers ever, but that was literally at 3psi of boost. ;) Never got a chance to dyno it with the boost turned up.
 

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2.5T is like a tractor. I have pulled from a stop in 2nd numerous times and have noticed until I go to shift and im already in 2nd. 2.2 is more topend (stock). No idea on the 2.5 long block, it rated the same as the NA 2.5 common block, but who knows what it could do being turbo-d
 

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Yeah the VNT also had 210 ft. lbs.

With an MP computer, my 2.2 t1 gets that same instant full boost that the high torque t1s are supposed to get, possibly better, at a full time 11psi. If it was worth it I would have taken it to a dyno to see what numbers its putting down.
 

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and the 2.5 T1 high-torque where they gave you full boost ASAP was 210ft-lbs. Course I think the VNT was up there in torque too????


My 2.5 dyno'd 200hp, 280ft-lbs at 12psi. It was "mostly" stock. I'm hoping for 300hp at 12psi on my new 2.5 :)
280ftlbs, impressive at the wheels, garrett t3 and intercooled? excites me to try a 14psi 2.5TII pull on the dyno next weekend!:brows:
 

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If we are talking carb... I forget the technical benifits of the unique 2.5 long block (can't find the dodge garage discussion about it), but I believe it would be a choice worth looking at, because the issue with turbo-ing it was that the rods were not strong enough and you needed to get expensive custom rods for it.
 

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You could carb a 2.4.. Little bit of fabrication.. I'd go with some side draft carbs.. But then again, building for torque, you wouldn't want side drafts.
 

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I'd spring for HD rods to get the better rod ratio in a built tall block. I think it would be a better motor than a CB if it's strong enough. Put a 16 valve head on it and it would really be nice!
 

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I'd spring for HD rods to get the better rod ratio in a built tall block. I think it would be a better motor than a CB if it's strong enough. Put a 16 valve head on it and it would really be nice!
The tall deck block used a longer rod. About .236 longer. The TD block is an excellent choice for a engine build, but needs a stronger rod for a high horse turbo motor. This would mean either $550 custom alloy rods or crazy expensive custom made 4340 forged rods. Around $1200 last time I looked into it. For a NA or low horse turbo motor, adding good rod bolts to the TD rods would help durability.

There are many pros and cons to rod length.
Shorter rods will help low speed airflow increasing torque. This is because it is accelerating and decelerating around TDC faster than a longer rod motor. This will come at the expense of more rod angularity, increased ignition timing required, more cylinder wall wear & piston rock, higher piston speed around TDC, etc.

A longer rod motor should in theory make more high RPM horsepower but less low speed torque. The gain is very small, but it is a gain. A horrible $ per horsepower investment, unless budget is not much of a factor.
 

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I had a GLH turbo with a 2.5 turbo, two-piece intake, GLHS intercooler, +20 injectors, 3 inch exhaust, and a Garret turbo. This was next to an automatic trans. It dynoed at 227hp and 375lbs/tq with 16 psi. The car ran 12.6s @ 105. I could 60ft with Syclones. I had M&H slicks. It would change lanes when the boost came on. It was fun to drive to say the least.
 

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Discussion Starter #16
And yes this is an N/A build, 11:1 pistons, dual weber 32/36's (downdrafts) or single holley 500, polished/ported and big valved head, port matched intake, header/exhaust, .528" 288/288 mechanical flat tappet cam, turbo-auto/2600 stall converter...
 

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So better to gain stroke from the crank, rather than the rod?

Definitely, the increase in stroke length will up the engine's low/midrange rpm grunt considerably. I've never looked into this...but with what you have in mind..
is there enough clearance at the bottom of the cylinders to accommodate a 1/4" stroker crank, clearance for the rods angle using the regular T1 rods?
 

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So better to gain stroke from the crank, rather than the rod?
You don't gain stroke with a longer rod. Crank determines stroke. Displacement remains the same but rod ratio changes. Rod ratio is rods length to stroke ratio. The 2.5 CB has a terrible rod ratio of 1.45:1. This is due to the huge stroke of the 2.5 crankshaft. A TD 2.5 has same displacement but because of the longer rods, the rod ratio changes to 1.51:1. FYI-The 2.2 comes out to 1.64:1.
For drag racing the ideal rod ratio is thought to be 1.80:1! High RPM motors are even higher. There are factory rod ratios over 2.0:1! These are motors that like to rev but are down some torque as a result. Like most things, there are compromises with rod ratio. Like I said before, for drag racing that happy medium is thought to be 1.80:1.
 

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you should be looking at light weight rods and pistons, like forged pistons and 2.4 Eagle rods to drop a ton of weight. Then you should look at running a steel crank, to remove flex at high RPM, 2.2 only stock. This type of thing is more important than a little more bottom end, where the engine isn't going to spend anytime anyway..

sad rod ratio works well at wipping the air and getting a little more flow out of a poor flowing head. So the 2.5 and the 782 are a good match lol
 
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