LS1 block - 346 vs 383
LS1 block - 346 vs 383 What kind of RWHP and RWTQ gains could I expect if I go with a 383 stroker instead of just doing pistons/rods on my LS1? I think the gains would have to be at least 30RWHP 30RWTQ for me to justify the cost difference.
Last edited by FCar2000TA; Mar 19, 2020 at 12:31 PM.
With the increase in cubes, higher compression will be easier to achieve and you can utilize bigger heads and a bigger cam to increase horsepower.
Yep. With all else being equal, power remains the same... but down probably 300-500 RPM.
Torque goes up the number of cubes... or around 30rwtq across the range.
However, you can add about 8 degrees of overlap and retain essentially the same drivability. And that should add 20-25HP or so.
But you can't really get "better" heads as the 3.9" bore limits things for the most part.
HOWEVER, the MAST 240 LS3 heads flow really well. More than a stock LS3 heads, but they are an aftermarket LS3 head with a rolled valve angle (improves mid-lift flow) with a smaller valve and port (so more efficient) and designed for the 3.9" bore. Even though 240cc intake runner volume is higher than most of the cathedral port stuff, remember the LS3 has more volume and a similar CSA so it's not "too big." Plus, being an 11-degree head, it's closer to an LS7 than an LS3.. and aftermarket LS3s make a TON of power.
If I were building a 383, it would definitely be with the MAST 240s and at least a Medium Runner FAST intake. I'd then cam it with something like a 240/246 114+4 with good lift @ .670" or above and some lightweight roller rockers. It would scream uptop despite the long stroke. And be efficient everywhere. Plus a 15 degree cam wouldn't be horrible in a 383. Really stock-like streetable would be something around 8-10 degrees. So you could tame it down a bit at the expensive of some power. But a LLSR setup as a 240/246 would drive really nice as it warmed up and act more like a 235/241 or so. Plus the lobes are more aggressive so you get more vacuum than a 235/240 hydraulic would give you.
Torque goes up the number of cubes... or around 30rwtq across the range.
However, you can add about 8 degrees of overlap and retain essentially the same drivability. And that should add 20-25HP or so.
But you can't really get "better" heads as the 3.9" bore limits things for the most part.
HOWEVER, the MAST 240 LS3 heads flow really well. More than a stock LS3 heads, but they are an aftermarket LS3 head with a rolled valve angle (improves mid-lift flow) with a smaller valve and port (so more efficient) and designed for the 3.9" bore. Even though 240cc intake runner volume is higher than most of the cathedral port stuff, remember the LS3 has more volume and a similar CSA so it's not "too big." Plus, being an 11-degree head, it's closer to an LS7 than an LS3.. and aftermarket LS3s make a TON of power.
If I were building a 383, it would definitely be with the MAST 240s and at least a Medium Runner FAST intake. I'd then cam it with something like a 240/246 114+4 with good lift @ .670" or above and some lightweight roller rockers. It would scream uptop despite the long stroke. And be efficient everywhere. Plus a 15 degree cam wouldn't be horrible in a 383. Really stock-like streetable would be something around 8-10 degrees. So you could tame it down a bit at the expensive of some power. But a LLSR setup as a 240/246 would drive really nice as it warmed up and act more like a 235/241 or so. Plus the lobes are more aggressive so you get more vacuum than a 235/240 hydraulic would give you.
Already have MMS 220 heads and Mamo FAST 102 intake. Will be getting a Mamo cam to go along with everything. I can get pistons with valve reliefs to allow for a larger cam. I am going to keep the compression under 10.5 so I can add a Magnuson 2300 down the road one day.
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I was reading a thread about making a 383 stroker out of an LS1 and then I saw the price tag on a stroker crank. I think I'm good with the torque from my LS1 lol and besides I think I'll take some weight out to improve acceleration. If you stroke your LS be sure to update this thread.
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Verdad Gallardo Mamo will say a 234/238 114+2 cam or so. And it'll drive nice. He went from a 224/228 in his 346 with AFR 205s to 234/238 with AFR 225s on his 383 back in the day. Drivability was the same. Power was up about 40/40 IIRC. He had bigger heads with more flow and more cam. The 220s are better than the 225s were.
Summit has nice 383 kits for under $2k. I'd start there.
Summit has nice 383 kits for under $2k. I'd start there.
I was reading a thread about making a 383 stroker out of an LS1 and then I saw the price tag on a stroker crank. I think I'm good with the torque from my LS1 lol and besides I think I'll take some weight out to improve acceleration. If you stroke your LS be sure to update this thread.
Mamo will say a 234/238 114+2 cam or so. And it'll drive nice. He went from a 224/228 in his 346 with AFR 205s to 234/238 with AFR 225s on his 383 back in the day. Drivability was the same. Power was up about 40/40 IIRC. He had bigger heads with more flow and more cam. The 220s are better than the 225s were.
Summit has nice 383 kits for under $2k. I'd start there.
Summit has nice 383 kits for under $2k. I'd start there.
Originally Posted by FCar2000TA
What will that do to daily drivability? Most of my driving is stop light to stop light.
Already have MMS 220 heads and Mamo FAST 102 intake. Will be getting a Mamo cam to go along with everything. I can get pistons with valve reliefs to allow for a larger cam. I am going to keep the compression under 10.5 so I can add a Magnuson 2300 down the road one day.
Already have MMS 220 heads and Mamo FAST 102 intake. Will be getting a Mamo cam to go along with everything. I can get pistons with valve reliefs to allow for a larger cam. I am going to keep the compression under 10.5 so I can add a Magnuson 2300 down the road one day.
I just need to figure out what rods and crank I want. I like K1 Technologies. I am almost 100% getting Wiseco -15 pistons. I don't want to bore the stock block past 3.903".
Last edited by FCar2000TA; Mar 19, 2020 at 02:06 PM.
Possibly on national back order. I ordered lots recently on national back order. (Scat, Manley, etc). If you end up stcuk waiting and are in a hurry, check out Molnar. Crank and rods on the shelf
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They've been getting excellent reviews and we put a ton of design time into the Pro LS Rotating Assembly components. American made and the best bang for the buck out there. Very full featured.
American forged, or American made from forged aluminium from China? Granted, it is probably American aluminium either way.