Camshaft centerline question
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 2,019
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From: Na
Camshaft centerline question
Here's a question for you guys. I have a 74219 roller camshaft (.525/.525, 219/219) and also a complete superram upper and lower intake system. I will be using these components on a GM ZZ4 350ci shortblock with 200cc Dart Pro1 heads, and 1-5/8 longtube headers. My question was should I install this cam straight up or advance/retard for best performance? This will be a street/strip car with an auto and 3.07. I also have a 9 way adjustable timing set. I really appreciate your help. Thanks. 
Team Owner
Joined: Oct 2004
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From: altered state
St. Jude Donor '05
Most guys just install it straight up and call it a day. Might want to check the cam card of MFR. to see what they recommend. Personally I'd get a degree wheel and use it. May not seem necessary because a 219 isn't considered big, but pulling a timing cover once the motor is in the car doesn't sound fun to me. This way you know for sure your cam timing is optimized. Theyr'e worth it
Race Director
Joined: Sep 2000
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From: The Top of Utah
I would install that cam advanced 4*. However, most cams have the dowel pin located such that a dot to dot installation IS 4* advanced. There is a similar thread going on somewhere. The C4 Performance/Mods forum maybe? If you can supply more specs, like the lobe separation angle, and the intake centerline, I can probably tell you if the advance is "ground in" or not.
RACE ON!!!
RACE ON!!!
Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by NUckINg FuTS
Lobe seperation and intake centerline is 112.
I found the thread I was referring to: http://forums.corvetteforum.com/show...1&page=1&pp=20
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Le Mans Master
Joined: Mar 2002
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From: Castro Valley Calif.
St. Jude Donor '03 thru '26
Like Ralph, I installed mine @112*, but we both have big inch motors. I'd recommend 108* to you so you could help make up for the lack of velocity of your heads.
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Safety Car
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From: Pettis Performance 565 with two stages of Nitrous Supply nitrous 1.082, 4.61 at 155, 7.17 at 192
Most cams are ground with 4* advanced. If that cam is ground straight up I would install it 4* advanced. For a street motor like yours I think that would be your best bet.
Le Mans Master
Joined: Mar 2002
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From: Castro Valley Calif.
St. Jude Donor '03 thru '26
We're both saying the same thing.......108 is 4* advanced from 112. Think of it this way: 108 comes before 112 as the motor turns, therefore it's advanced
Edit: Mike, this is kind of ironic........the cam I referred to in that other post is an Erson 219 which came with 4* ground in. I installed it at 112 (4* retarded) but I still have too much lower end. I think I'm going to end up going 4* more to 116 when I get some miles on the car
Make sure you degree it so you know where you're at, and it wouldn't hurt to check PV clearance at 108 and 112* in case you want to play with it later
Edit: Mike, this is kind of ironic........the cam I referred to in that other post is an Erson 219 which came with 4* ground in. I installed it at 112 (4* retarded) but I still have too much lower end. I think I'm going to end up going 4* more to 116 when I get some miles on the car
Make sure you degree it so you know where you're at, and it wouldn't hurt to check PV clearance at 108 and 112* in case you want to play with it later
Last edited by Caboboy; Mar 13, 2005 at 05:45 PM.
Le Mans Master
Joined: Oct 2002
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From: Las Vegas - Just stop perpetuating myths please.
I recall advance cam for low-end and retard cam for hi-end.
This last time i just installed my Crane cam straight up as when i degreed it as it came in dead n_ts on - i was tired of playing with it that day (and didn't have a 2* crank key that day either ). The Ponitac racing crowd recommends at least a 2* advance crank key to compensate for timing chain stretch and i used that on my GTO with nothing to complain about though i never raced it.
All i know is that advancing the cam produces more low end pwr while retarding makes more top end pwr. But they say all chains stretch somewhat - thats why some use gear drives.
Just my 2 cents but with those big azz runners (200cc) on top'a only 350 cubes u may want to retard a bit and race at higher rpm - if u can (hi-stall converter/gearing). IMHO big runners do nothing for u at low rpm. But those 3.08 gears gotta go my friend. BTW nice induction and i wish i had one of those Lingenfielter ram manifolds on my GEN II LT1.
cardo0
). The Ponitac racing crowd recommends at least a 2* advance crank key to compensate for timing chain stretch and i used that on my GTO with nothing to complain about though i never raced it.All i know is that advancing the cam produces more low end pwr while retarding makes more top end pwr. But they say all chains stretch somewhat - thats why some use gear drives.
Just my 2 cents but with those big azz runners (200cc) on top'a only 350 cubes u may want to retard a bit and race at higher rpm - if u can (hi-stall converter/gearing). IMHO big runners do nothing for u at low rpm. But those 3.08 gears gotta go my friend. BTW nice induction and i wish i had one of those Lingenfielter ram manifolds on my GEN II LT1.
cardo0
Burning Brakes
Joined: Feb 2003
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From: SouthBend IN
don't throw the 308's out just yet.
i have 195cc heads on a 9.8-1 355 and have plenty of bottom end. I do have a RPM dual plane and 750 VS though, not sure how different that is than the ram ? But with my 218-230 @ .050 cam i made 421 RWTQ on the dyno @ 2200.
Et's are in the sig.
i have 195cc heads on a 9.8-1 355 and have plenty of bottom end. I do have a RPM dual plane and 750 VS though, not sure how different that is than the ram ? But with my 218-230 @ .050 cam i made 421 RWTQ on the dyno @ 2200.
Et's are in the sig.
