346 -> 383 conversion
10-22-2006 | 07:18 PM
#1
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TECH Junkie
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From: Casselberry FL
346 -> 383 conversion What internals can/should I re-use for this conversion?
I bought a used 346ci LS1 shortblock a couple of years ago. It contains a balanced stock crank, Eagle rods, ARP bolts, 228/228 575/575 114LSA cam and Wiseco pistons. The original owner stated he built it for a 300 shot of nitrous and then decided to go with big displacement.
I know I'll need a 4" crank (the Eagle will be sufficient for my goals), but is it safe to re-use the rods, bolts & pistons?
The block is noisey, and I assume it is the forged pistons. I don't have any details on the piston style/alloy other than remembering it has valve reliefs when we installed it. I remember my friend who assembled/installed it telling me my compression should be ~11.2 with my '98 heads milled .030 and stock head gaskets. The chamber is 63cc. Is it worth my while to switch pistons - will they be quieter or better for a N/A application (and why)?
Even though I'd be leaving power on the table, I'm tempted to stick with my current heads. If I'm not satisfied with the performance, I'll cross that bridge later. Burning through a set of $1800 slicks is not my goal
How will this cam behave in the 383? I hate changing springs as well as paying for someone to do it. I'd rather let the displacement make the power and go tame on the cam lobes. I might even commit a sin and put the LS1 intake back on if traction is too much of a problem.
Thanks!
I bought a used 346ci LS1 shortblock a couple of years ago. It contains a balanced stock crank, Eagle rods, ARP bolts, 228/228 575/575 114LSA cam and Wiseco pistons. The original owner stated he built it for a 300 shot of nitrous and then decided to go with big displacement.
I know I'll need a 4" crank (the Eagle will be sufficient for my goals), but is it safe to re-use the rods, bolts & pistons?
The block is noisey, and I assume it is the forged pistons. I don't have any details on the piston style/alloy other than remembering it has valve reliefs when we installed it. I remember my friend who assembled/installed it telling me my compression should be ~11.2 with my '98 heads milled .030 and stock head gaskets. The chamber is 63cc. Is it worth my while to switch pistons - will they be quieter or better for a N/A application (and why)?
Even though I'd be leaving power on the table, I'm tempted to stick with my current heads. If I'm not satisfied with the performance, I'll cross that bridge later. Burning through a set of $1800 slicks is not my goal
How will this cam behave in the 383? I hate changing springs as well as paying for someone to do it. I'd rather let the displacement make the power and go tame on the cam lobes. I might even commit a sin and put the LS1 intake back on if traction is too much of a problem.
Thanks!
Yep you need at least different pistons designed for the 4" stroke and you may be able to keep the rod depending on the length you have... 
10-23-2006 | 07:00 PM
#5
If you don't want to much power and are worried about traction, why are you building a stroker? Not trying to be an ***, just trying to save you some money if you don't really want that much power. Of course if you just don't want the money you can wire it to me 
Have fun with your build and keep us posted
AJ
Have fun with your build and keep us posted
AJ
10-23-2006 | 07:22 PM
#6
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TECH Junkie
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From: Casselberry FL
1) I want faster acceleration coming out of slow corners in 2nd/3rd/4th gears.
2) I don't want to burn up tires needlessly
3) I want more top speed out of each of my gears
4) I don't want to use radical cam lobes due to valvespring life
5) I want a broader and higher torque band than what I have now
My thoughts were:
- increase the displacement just enough to get more torque down low without worrying about gearing or valvespring life.
- Switch from 3.73's back to 3.42's to get more speed in each gear
I'm back to debating this vs. a L92-block after a rules clarification. I have to decide if there's more value for my application in building a L92 shortblock with the inexpensive L92 heads & L76 intake, vs a 383 LS1.
It seems like the latter is more cost effective for my goal so long as I don't need to buy new heads and intake. I highly doubt I'd consider switching heads/intake until I had some seat time with the new engine to determine if I had more room to play with. I don't want to spend more money to make the car harder to drive and slower around the track due to wheelspin.
2) I don't want to burn up tires needlessly
3) I want more top speed out of each of my gears
4) I don't want to use radical cam lobes due to valvespring life
5) I want a broader and higher torque band than what I have now
My thoughts were:
- increase the displacement just enough to get more torque down low without worrying about gearing or valvespring life.
- Switch from 3.73's back to 3.42's to get more speed in each gear
I'm back to debating this vs. a L92-block after a rules clarification. I have to decide if there's more value for my application in building a L92 shortblock with the inexpensive L92 heads & L76 intake, vs a 383 LS1.
It seems like the latter is more cost effective for my goal so long as I don't need to buy new heads and intake. I highly doubt I'd consider switching heads/intake until I had some seat time with the new engine to determine if I had more room to play with. I don't want to spend more money to make the car harder to drive and slower around the track due to wheelspin.