383 rotating assembly in 346?
08-10-2013, 10:35 PM
#1
383 rotating assembly in 346? OK a little confused still trying to see what I'm going to do with my short block.. I was looking on tsp at the 383 rotating assembly will this work in my ls1? And exactly what are the benefits from this? It doesn't make it a 383 right? it still needs to be bored but this biggest you can go is abouT .5 right.. any suggestions what I should do with the car ? I need to rebuild my bottom end but thinking about just getting one from thompsons thinking about milling the heads just for clean up and running thinner head gaskets i plan on running n2o small 100-150 shot, I want about 450 rwhp n/a with the current mods is it achievable I plan on running a racetronic fuel pump as well what else would I have to do to get where I would like to be.. mods in sig
08-10-2013, 10:55 PM
#2
Yes, it will make the displacement 383. It's a longer stroke crank than stock. You probably would not see large gains in rwhp over a 346, however you should net some good gains in usable torque. If you are going to be rebuilding the bottom end anyway I say go ahead and put in a forged stroker kit.
08-10-2013, 10:56 PM
#3
450rwhp from a 346 is pretty easily done these days, but a 383 would/could make more power. I would look at it like this. If you are going to buy a rotating assembly it seems pointless to me to buy a 346 rotating assembly vs the 383 knowing the costs isn't much different and I can make more power. Your block needs to be taken .003-.005 over but even if you go 346 it needs to be cleaned up and you may have to go that far anyway. .003-.005 wont hurt you either way. The 4.00 stroke crank is what really gets you to the 383 and yes that will work just fine in your motor, with aftermarket rods and pistons. If you reuse your stock crank then the 346 would save you more money over the 383.
If your motor doesn't need to be built, technically you could just throw on some heads and be in the area you are looking to be at. Some ported 243's or as cast 225's would work great for either combo.
If your motor doesn't need to be built, technically you could just throw on some heads and be in the area you are looking to be at. Some ported 243's or as cast 225's would work great for either combo.
08-10-2013, 11:02 PM
#4
383 with a nice cam will def get you 450rwhp will some ported/aftermarket heads...the 383 is made by having bigger stroke...the bore is only opened up to 3.905 from 3.898 which could vary delending on what machine shop says...someone else will have to chime in about block clearancing I'm not sure bout that
08-10-2013, 11:33 PM
#5
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OP, I went with Thompson Motorsports when I did my 370 LQ9. Some of the best customer service hands down! The new shortblock is awesome! It even has a 1 year warranty
08-10-2013, 11:44 PM
#6
Very fast response thanks everyone @ HCI2000SS yea he is a really nice guy I spoke with him a few times on what I should do.. I'm trying to stay away from the iron though
@WildCAMARO i have the torquer v2 with slightly ported 243s i could send them in for some cnc porting though
@TEXAS-SPEED OK I didn't have to change out my 346 crank but I always wanted a 383 that should also tame that torquer a little better the the 346 right?
@Decadence Yea I think im just going to have my short block rebuild with the 383 rotating assembly
@WildCAMARO i have the torquer v2 with slightly ported 243s i could send them in for some cnc porting though
@TEXAS-SPEED OK I didn't have to change out my 346 crank but I always wanted a 383 that should also tame that torquer a little better the the 346 right?
@Decadence Yea I think im just going to have my short block rebuild with the 383 rotating assembly
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08-11-2013, 12:05 PM
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The M4 cam would be a much better choice for that motor IMO! Case in point: I had the Torquer V2 in my old HCI LS1 setup, and I now have a TMS cam in my 370 LQ9 (very similar to a M3 cam) and it drives even a tad better than the old setup.
08-11-2013, 01:07 PM
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383 Yeah 383 would be way better. I'm about to post some 6.200 rods and a set of JE pistons 3.905 bore for a 383 setup. You would need a 4.000 stroke crank to accommodate the other parts
