I know you 383 guys like to up your compression, run a hotter cam, and rev your motors up to 5500 rpms (or higher), but I'm wondering if anyone has tried to get more power by increasing flow, rather than compression and rpms.
A vortec 5.7 is rated for 292 HP in a marine application:
http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/2010_5700_Marine.pdf
I know from the automotive side, that aftermarket heads flow much better than factory heads, even the vortec ones:
http://cgi.ebay.com/ebaymotors/350-383-Sbc-Small-Block-Chevy-Procomp-Aluminum-Heads_W0QQitemZ370209722848QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item56323811e0&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|72%3A1171|240%3A1308
As well as flowing better, the aftermarket heads have better combustion characteristics, which allows you to run a higher compression ratio without having to run 89 octane (or higher)
To me, it seams like the logical way to get some more power out of a 5.7. I'm just wondering if anyone has tried it? Obviously you would want a closed cooling system to avoid salt water and two different types of metals.
Modern Gen 4 small blocks (4.8, 5.3, 6.0) all have aluminum heads, and idmar uses them in marine applications all the time.
My plan would be to start with a 4 bolt main vortec truck block, rebuild the bottom end, and run a hotter (marine) cam and aftermarket heads (With slightly higher compression ratio). This would allow me to continue to use mercruiser manifolds (which you cant do on a gen 2,3 or 4 small block).
If the GM marine 5.7 is rated at 292, than this setup should easily yield 360 or so.....
Anyone ever tried something like that? I bet you 383 guys are all already running aftermarket heads.....
A vortec 5.7 is rated for 292 HP in a marine application:
http://www.gm.com/experience/technology/gmpowertrain/engines/specialized/marine/2010_5700_Marine.pdf
I know from the automotive side, that aftermarket heads flow much better than factory heads, even the vortec ones:
http://cgi.ebay.com/ebaymotors/350-383-Sbc-Small-Block-Chevy-Procomp-Aluminum-Heads_W0QQitemZ370209722848QQcmdZViewItemQQptZMotors_Car_Truck_Parts_Accessories?hash=item56323811e0&_trksid=p4506.c0.m245&_trkparms=65%3A12|39%3A1|72%3A1171|240%3A1308
As well as flowing better, the aftermarket heads have better combustion characteristics, which allows you to run a higher compression ratio without having to run 89 octane (or higher)
To me, it seams like the logical way to get some more power out of a 5.7. I'm just wondering if anyone has tried it? Obviously you would want a closed cooling system to avoid salt water and two different types of metals.
Modern Gen 4 small blocks (4.8, 5.3, 6.0) all have aluminum heads, and idmar uses them in marine applications all the time.
My plan would be to start with a 4 bolt main vortec truck block, rebuild the bottom end, and run a hotter (marine) cam and aftermarket heads (With slightly higher compression ratio). This would allow me to continue to use mercruiser manifolds (which you cant do on a gen 2,3 or 4 small block).
If the GM marine 5.7 is rated at 292, than this setup should easily yield 360 or so.....
Anyone ever tried something like that? I bet you 383 guys are all already running aftermarket heads.....