Matching cam to heads.
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TECH Senior Member
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From: NW Houston, TX
Matching cam to heads. Ive done my homework on this one. Ive picked out my heads, and im pretty much set on thoes. Now its just time to match the cam up to the heads. Im looking at the MTI R1 and thats a 232/236 .575/.578, not sure what LSA or if I want any advance ground into it yet. So heres the information I have so far if I was to ground the cam on a 112 straight up.
ICL-112
IVO-4
IVC-48
EVO-50
EVC-6
ECL-112
Overlap-10
Using an .042 gasket
SCR-11.54
DCR-8.42
Using the cam specs at .006 I found out that with me spinning the engine to 6900 that I would need a 31.9 primary length and 1.70 diameter (fairly close to the hooker/jethot design)
The heads flow peak at .550 (296) and drop at .600 (294). I will be using a 59cc combustion chamber
Ive tried playing around with different LSA's (110, 112, 114) and different advance (0, +2, +4) and I cant get the numbers to make any sence to me. Can someone help point me in the right direction on where to go next. FWIW the off the shelf R1 is on a 114+4.
ICL-112
IVO-4
IVC-48
EVO-50
EVC-6
ECL-112
Overlap-10
Using an .042 gasket
SCR-11.54
DCR-8.42
Using the cam specs at .006 I found out that with me spinning the engine to 6900 that I would need a 31.9 primary length and 1.70 diameter (fairly close to the hooker/jethot design)
The heads flow peak at .550 (296) and drop at .600 (294). I will be using a 59cc combustion chamber
Ive tried playing around with different LSA's (110, 112, 114) and different advance (0, +2, +4) and I cant get the numbers to make any sence to me. Can someone help point me in the right direction on where to go next. FWIW the off the shelf R1 is on a 114+4.
Most of the time, MTI has their cams ground +4. This would put your IVC at 44 degrees ABDC which is right about where you want it. Keep in mind, your DCR will go up quite a bit with a 108 ICL, but your torque curve will be a little meatier.
Unless you plan on spinning the motor to the moon, I'm not a big fan of closing the intake valve past 46 degrees ABDC on a 346. 44-46 seems ideal. 48 degrees (with cam straight up at 112 ICL) is a pretty late closing point IMO.
Do you already own this cam? If not, there are more modern cams with similar specs at .050, but faster ramps and more area under the curve. A TRak cam or an F-14 would be better choices IMO.
Unless you plan on spinning the motor to the moon, I'm not a big fan of closing the intake valve past 46 degrees ABDC on a 346. 44-46 seems ideal. 48 degrees (with cam straight up at 112 ICL) is a pretty late closing point IMO.
Do you already own this cam? If not, there are more modern cams with similar specs at .050, but faster ramps and more area under the curve. A TRak cam or an F-14 would be better choices IMO.
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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.
