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#1
01-25-2009, 10:18 PM
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How to choose a cam
Here's the application: 1977 Can AM, TA6.6, turbo 400 w/shift kit, stock rearend (3.23). Heads are from early 70s 400 (72cc), Edlebrock performer RPM intake, stock qjet carb. Anyone want to suggest a good cam for this combo? Slightly rough idle is preferred, but want to get the most out of this engine / combo. Was thinking about the comp xtreme energy 51-224-4 cam. Any suggestions?
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#2
01-25-2009, 11:00 PM
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Early `70`s 400 heads with 72cc`s? Look for the casting number.
Cams need to be chosen by the engine size, compression ratio, rpm limits, head flow, gear, body weight etc. and the intended use of the vehicle. |
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#3
01-26-2009, 09:47 AM
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Early heads from the 70's were all over the place as far as cc size. The only way to be completely sure is to cc them.
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#4
01-26-2009, 11:14 AM
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cam questions
all, I know the heads are 72cc
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#5
01-26-2009, 12:07 PM
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Check the code on the heads, it's the large number over/on the center exhaust ports.
go to the wallace racing site, www.pontiacpower.org you'll find the advertised cc's there. you'll find alot of good info there. i cant help pick a cam; but i hope this helps. |
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#6
01-26-2009, 11:04 PM
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hopefully Cliff or one of the other builders will jump on here.my suggestion is to not use an XE cam.they are good for lower compression motors,but once you get up to 9.5-1 there seems to be problems.they are so good at building pressure that it can cause detonation.
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FREEDOM ISN'T FREE BUT WORTH FIGHTING FOR |
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#7
01-27-2009, 01:19 AM
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Agree with other posters. 72CC heads on a 400 with stock pistons usually results in 9.8-10.1 compression. Not good with a XE cam with 110LSA that builds cylinder pressure. Detonation city with 3.23 gears in a heavy car.
I'd look into a Crower grind with 230 degrees intake duration and 112-114LSA.
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I could explain all this to the girl at the parts store, but she'd probably call the asylum. White '67 LeMans 407/TH350/Ford 3.89... RIP Red '67 LeMans. 407/TH400/Ford 3.25 |
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#8
01-27-2009, 02:45 AM
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If you are looking for someone to spit out part numbers for a good cam that would work good in your application, here you go.
Crower 60916 112 LSA 221/229 @.050 This is a relatively mild cam Summit 2802 114 LSA 224/234 @.050 This is the cam I run with a similar combo. Crower 60243 112 LSA 228/235 @.050 This is a Cliff favorite for the 400. There are plenty of other choices out there, but these are some of the more popular for a combo that is 9.5 to 1 compression ratio, similar to yours.
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79 Trans Am 400 4 spd WS6 68 Firebird 400 Convertible 70 Pontiac GTO 2007 Pontiac Solstice |
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