good cam for 250 cc heads
good cam for 250 cc heads i gotta 98 z28 m6 with strange 12 bolt and 4.10 gears. im rebuilding the engine am curious as to what cam to use with my gmpp ls6 heads. the specs on the heads are 62 cc combustion chambers, 85 cc exhaust runners, 250 cc intake runners, and flow about 300 cfm at .600 lift. im gonna run the ls6 intake and 42 lb fast injectors. the shortblock contains of stock crank, manly forged i beam rods, and cp forged pistons with valve reliefs. i have a 228r cam in it now and LOVE it. i was thinking reuse this cam but would also thinking going bigger. this car will have to be my DD for a few more months. thanks for any info
JMO, but 250cc is a huge head for 346ci. There are several choices in the 205 to 220cc range that offer similar peak numbers.
If this is your daily driver, those heads will make for a lazy setup in any part throttle operation. You might consider running your stock heads until you have another DD lined up, then run the GMPP LS6 heads along with a custom cam spec'd by one of the reputable vendors here once you don't have to deal with the daily grind.
If this is your daily driver, those heads will make for a lazy setup in any part throttle operation. You might consider running your stock heads until you have another DD lined up, then run the GMPP LS6 heads along with a custom cam spec'd by one of the reputable vendors here once you don't have to deal with the daily grind.
JMO, but 250cc is a huge head for 346ci. There are several choices in the 205 to 220cc range that offer similar peak numbers.
If this is your daily driver, those heads will make for a lazy setup in any part throttle operation. You might consider running your stock heads until you have another DD lined up, then run the GMPP LS6 heads along with a custom cam spec'd by one of the reputable vendors here once you don't have to deal with the daily grind.
If this is your daily driver, those heads will make for a lazy setup in any part throttle operation. You might consider running your stock heads until you have another DD lined up, then run the GMPP LS6 heads along with a custom cam spec'd by one of the reputable vendors here once you don't have to deal with the daily grind.
I ran a similar setup. 346, Dart 250cc heads,ported FAST 92. I cannot speak for the 250cc ls6 heads but everybody I talked to and everyshop told me that 250cc heads will ruin my car it wont make any power. Hell many told me that the heads would not even work on a 346 with 2.08 valves. Dart told me to call FMS Alan was even iffy about the heads. He still made me a cam though (high 230s)and my car ended up making over 480whp once I finally got it tuned right and the bugs worked out of it. With 10 bolt and t56 of course but regardless it runs really hard.
My point is the big heads despite what everybody will say may end up working well. I lost a little bit of bottom end but after 4500 its a complete animal.
You are on forged rods. I would buy some LS7 lifters and plan to rev up. You also have power on the table if you ever want to go bigger cubes I could see those heads working really really well. I also beleive that the GMPP heads you have are set up for a 3.90"bore. I would run them and see what happens. Just get the right camshaft/intake and you will be fine.
PM me how it goes.
My point is the big heads despite what everybody will say may end up working well. I lost a little bit of bottom end but after 4500 its a complete animal.
You are on forged rods. I would buy some LS7 lifters and plan to rev up. You also have power on the table if you ever want to go bigger cubes I could see those heads working really really well. I also beleive that the GMPP heads you have are set up for a 3.90"bore. I would run them and see what happens. Just get the right camshaft/intake and you will be fine.
PM me how it goes.
You'll need to err on the smaller side of the intake duration to keep the low and mid rpm power decent, but you'll want plenty of overlap to make good power (8-10 degrees at .050). I would recommend something like a 226/230 .597/.600 110LSA +1 advance cam ground with EPS lobes.
As you can see, this is fairly close to your 228 cam, but the valve events are better suited to the flow of your heads. Lobes will make more power too.
As you can see, this is fairly close to your 228 cam, but the valve events are better suited to the flow of your heads. Lobes will make more power too.
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2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
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