Hi guys, I have aproblem and need help please, iam useing arrington camshaft cc607 but there is aproblem there is no vacume in intake manifold some guys told me that I have to change the timing chain to advance it 4 degrees, is that would help or something wrong? Working with phase 4 heads and ported intake and stoke block 6.1 I checked all gasgates there is no leak, any idea?
What do you call "no vacuum"? These cars can idle with less than 10 inches. I'm not familiar with that cam, could you post the specs. You may have a MAP sensor problem, not a cam problem. (as long as you're sure you don't have any leaks) Give me a rundown of your car...i'm sure we can help.
my cam spec. Dur. 227/233 @0.050 Left. 607/607 lope. 116 the map sensor is working good before fixing this cam and i changed it to make sure. and yes there is no vacuum presure inside the intake !!! there is something on cam paper spec. written advance crank ang. 4 degrees dose that mean i should change the stock timing chain with adjustable one to advance it 4 degrees ?? or thats wont work ? i need aserious help guys becouse i dont know what to do we checked everything even the PCM .... the last thing is the cam becouse before fixin the cam the car was perfect ... even i sent an email to ARRINGTON but they didnt answer me !!! what should i do guys ???
It is !!!! we reset the timing chain before installing the camshaft and we checked there is no teeth missing.
Is the car throwing any codes? Does the car run at all? Sounds like you're timing is off...BAD. If it was 180 out, i would think you would have PTV contact. I've contacted Arrington's cam designer for you, lets see what he says.
Kyle, I noticed that the OP did not share this info here. Here are a couple quotes from srt8oc forum from the OP...
If the car is running then it has vacuum, I would say your vacuum gauge is wrong. Things to check. 1. Check that all vacuum hoses are connected 2. Make sure that the throttle body is not stuck in the open position 3. Verify gauge by sucking on the end of it All of your codes are normal except the camshaft sensor code which would not cause 0" of vacuum. PM me your number and I will call you tomorrow. Dont advance the cam, you have other issues.
Um ya. You're a tooth off OP. And if the thrust was incorrect which I haven't seen happen yet on a stock timing gear. Are you running the Manley adjustable unit??. Those are the only units I've seen create that problem. Pull it a part and double check it bud.
Guys ! we double checked the timing chain there is no tooth missing up !! and yes we also checked all hoses and gauges they are working perfectly ... Its a camshaft bad grind !! do you know why ? becuase its shorter than other cams for 0.050 inches and its alarge space. fftopic:
Okay, well pull it out, and stick another one in there. (that's what she said) I'de change lifters as well. Are you installing the cam straight up? How are your timing marks set up when intalled? Are you degreeing it in with a wheel? Cam...would 1 tooth off make THAT much of a difference? i mean 0 vacuum...wow?
I think you're measuring the cam incorrectly. First off you must measure the base circle which would be across 90 degree's of the lobe. Then you measure the lobe height and deduct the base circle measurement and that will give you your lobe lift. So lets say your lobe lift is .331, multiply that by 1.65 (your rocker ratio) and that will give you .546 lift. Now the only way you could not be making vacuum if you have no MAJOR leaks would be being off on the install. Dookie, worst case senario. The cam is so far advanced the intake valve is not opening on the downward stroke. With out knowing the cam spec (duration and event timing) it's hard to say that one tooth off would do it. OP, just for reference. Cylinder number one, drivers side, closest to the front of the car is at top dead center. The cam alignment pin is at 12:00 and the crank key way is at 2:00, pointed right at the Mopar casting on the oil pump.
Cam, I believe Arrington uses 1.72 RR, which is where they get their advertised lift at .050. Also, if he was THAT far advanced, wouldn't he have PtV contact?
Well the rocker ratio is actually variable depending on lobe lift. Arrington plays it safe and uses 1.72 because their cams are HUGE. With a low lift cam (lets say mid .550), you'll find that the ratio works out to be around 1.62-1.63. And the more lift, the higher the ratio. And yes, he would have a issue with PTV.
ten foe...higher the lift the farther the rocker travels perpendicular on the fulcrum circle creating a larger ratio. By that...my current cam LL is .35881/.35198 x 1.72 = .617/.605 GL. Installed 3 degrees advanced and had 0.080" on the intake valve, and 0.120" on the exhaust valve...Close, but permissible. (thanks to pistons having reliefs)
Chit, that ain't close. I've seen and meaured cam(s) that were into the piston with a pumped lifter and the guy who spec'd it was betting on preload being around .040 and that netted a VTP clearance of .030 or less. Now that takes some balls.
