[IntenseImages]

hi all,

not sure if ya all remember my probs i was having with my engine and cam install a while back, but anyway, engine ran great above 2500 rpm just had no low end power.

i was told to advance cam and thatshould help.

anyway, i got a cam degree kit to double check the numbers

cam card specs are as follows
cam lift .286 int .296 exh actual numbers match these perfect

valve lift 429 int 444 exh did not check actual numbers here yet

lobe centers 112 int 116 exhaust actual reading came out to 108 on the intake, have not checked exahust, but if it off as much as intake it should read 120 when i check

sae duration 279 int 289 exh
duration at .050 209 int 220 exh i am coming up with 217 int havent checked exhaust yet

now correct me if i am wrong, but if i am showing a 108 intake centerline, this would show that cam is installed advanced 4 degrees, right?
would i still want to advance it more to get more low end?

any advice you all want to give a novice at this would be appreciated

eric

 

[chrysler300le]

I know you asked for my opinion and help on this. I'm not very experienced with degreeing in the vehicle like that and with heads on. I do know that valve springs can push on the lifters and make the valves open a few degrees later then what they really do when the lifters are pumped up. Does the cam card say at what degree the valves should open and close? If so thats what you need to check. If not do it by the Mopar Performance way of checking the degrees at about .050" on both sides of max lift. Add the two numbers together then divide by 2 and the number you get is the installed centerline. Confused yet? I'll try to clarify better.

So basically turn the engine clockwise till you get max lift on dial indicator. 0 your indicator or just remember to stop at a number more then .020" past max lift. .050" is a good round number. Stop there and record your degrees. Turn engine around again till you get to .050" lift before max lift. Record degrees. Add the two numbers up and divide by 2 and thats your installed centerline.

 

[IntenseImages]

I know you asked for my opinion and help on this. I'm not very experienced with degreeing in the vehicle like that and with heads on. I do know that valve springs can push on the lifters and make the valves open a few degrees later then what they really do when the lifters are pumped up. Does the cam card say at what degree the valves should open and close? If so thats what you need to check. If not do it by the Mopar Performance way of checking the degrees at about .050" on both sides of max lift. Add the two numbers together then divide by 2 and the number you get is the installed centerline. Confused yet? I'll try to clarify better.

So basically turn the engine clockwise till you get max lift on dial indicator. 0 your indicator or just remember to stop at a number more then .020" past max lift. .050" is a good round number. Stop there and record your degrees. Turn engine around again till you get to .050" lift before max lift. Record degrees. Add the two numbers up and divide by 2 and thats your installed centerline.

ok a little clarifycation, rocker arms are removed (this is why i havent checked valve lift yet) i am using a dummy lifter. i did set dial indicator at 0 on max lift and did the checking at .050 before and .050 after max lift, and that is how i got the 108 centerline

eric

 

[chrysler300le]

Its possible the point on the lobe was wiped out during break in and moved where max lift is. You could still try advancing cam 4 degrees and see what happens. Did the cam card tell you where the open and closing points are at on the cam?

 

[IntenseImages]

Its possible the point on the lobe was wiped out during break in and moved where max lift is. You could still try advancing cam 4 degrees and see what happens. Did the cam card tell you where the open and closing points are at on the cam?

ok if lobe was wiped during break in then wouldnt the lift be different than what cam card says?

as far as opening and closing, the only numbers that it shows on here are sae timing, i beleive this is what you are referring to so i will post them

sae timing
btc28 abc72 bbc80 atc28

.050 timing
btc-8 abc36 bbc46 atc-6

thanks

eric

 

[IntenseImages]

ok 2 other questions real quick, if i do go ahead and advance it more, how much should i do, and if i do this will i need to worry about piston to valve clearance.

also, i will be advancing it at the cam using mopar performance offset cam keys

thanks

eric

 

[chrysler300le]

sae timing
btc28 abc72 bbc80 atc28

.050 timing
btc-8 abc36 bbc46 atc-6

Yes use those numbers. The intake valve should start to open 28 degrees btc and close 72 degrees abc. I would go with the .050" specs though. So see if it opens 8 btc and closes 36 abc. Tell me what it does and get back to me.

 

[IntenseImages]

sae timing
btc28 abc72 bbc80 atc28

.050 timing
btc-8 abc36 bbc46 atc-6

Yes use those numbers. The intake valve should start to open 28 degrees btc and close 72 degrees abc. I would go with the .050" specs though. So see if it opens 8 btc and closes 36 abc. Tell me what it does and get back to me.

ok will do, thanks

eric

 

[Evildriver-3]

Then post all the cam's numbers as to it's specs and then everything you got

 

[Bummo]

That dummy lifter is a solid lifter, right?

 

[Evildriver-3]

yes he is using a solid lifter and not under the vavle spring either

 

[Guest]

Seems like a lot of trouble to gain a marginally better off-idle response. Now, let me first say that I do not have a degree-kit, nor have I degreed a cam in. I have read about it, and understand about advancing a cam or retarding it, as the case may be, to move the power band a bit. I say this so as to not honk anyone off in some misunderstanding where said other person might think I was insulting them. Still, the timing marks are there for a reason. I mean, how many people actually degree a cam in? Naturally, for that last bit of power in an area, do it, but there's nothing wrong with installing it straight up. Okay, advance it 4 degrees, but go back and do it even more? How far around are you gonna go with it? At some point, you have to leave it and look to other ways to wake up the bottom-end power.
Have you done anything as far as advancing the ignition? Initial and perhaps a quicker curve? Carb accel. pump shot quicker squirt and/or enlargement...or is this a TBI?
Stock exhaust or opened up a bit?

 

[sheriff]

Seems like a lot of trouble to gain a marginally better off-idle response. Now, let me first say that I do not have a degree-kit, nor have I degreed a cam in. I have read about it, and understand about advancing a cam or retarding it, as the case may be, to move the power band a bit. I say this so as to not honk anyone off in some misunderstanding where said other person might think I was insulting them. Still, the timing marks are there for a reason. I mean, how many people actually degree a cam in? Naturally, for that last bit of power in an area, do it, but there's nothing wrong with installing it straight up. Okay, advance it 4 degrees, but go back and do it even more? How far around are you gonna go with it? At some point, you have to leave it and look to other ways to wake up the bottom-end power.
Have you done anything as far as advancing the ignition? Initial and perhaps a quicker curve? Carb accel. pump shot quicker squirt and/or enlargement...or is this a TBI?
Stock exhaust or opened up a bit?

fi agree w/gendak -- what may be gained by adv/retard cam is very little. installing straight up will be the way to go. dinking with adv or retard will give yu very little and what yu gain on one end will be lost on the other. look for other mods to gain what yu need. timing,fuel -- ect.degreeing a cam is ok to make sure the centerlines are what they are supposed to be. good luck -- sheriff --

 

[chrysler300le]

Ok Sheriff and Gen1Dak, the decision was made months ago for eric advance his cam. What you two dont' understand is lining up the dots isn't perfect. There is a such thing as production tolerences. Don't think that cranks are perfect. With time the journals become out of index. For a V-8, the journals need to be 90 degrees from each other. The indexing can change slightly between the journals and the key way for the timing chain. Then add in chain stretch and its production tolerences, Block core shift, tolerences in cam machining and the timing of the cam can become several degrees off. Four degrees may not seem like much but it moves the power band about 1500 (+/- 500) rpm. I degree all my cams and let me tell you it makes a world of difference. I recently put together a magnum engine all stock but checked the timing to what the MP magnum engine book has and found out i was about 3 degrees retarded. Because the keys were $50 for a set and i was in a hurry to put the engine together i ran like that for 3 months. A few weeks ago i advanced the cam 4 degrees. I gained 2 mpg and it now rarely kicks out of overdrive where as before any small hill it kicked out of overdrive. Eric isn't advancing his cam hopeing to pick up extra power that he thinks he should have. He is doing this to put the cam where it was designed to be.

 

[Evildriver-3]

Cam degreeing can make a motor run good, or just run, or barely run, lets say you put it in straight up, but the cam card say's install at 108 for best results and the cam is ground on a 110 and the dot method is way off like explained and now it's at 114, it ain't gonna run very well, especially in low comp motor

 

[sheriff]

Ok Sheriff and Gen1Dak, the decision was made months ago for eric advance his cam. What you two dont' understand is lining up the dots isn't perfect. There is a such thing as production tolerences. Don't think that cranks are perfect. With time the journals become out of index. For a V-8, the journals need to be 90 degrees from each other. The indexing can change slightly between the journals and the key way for the timing chain. Then add in chain stretch and its production tolerences, Block core shift, tolerences in cam machining and the timing of the cam can become several degrees off. Four degrees may not seem like much but it moves the power band about 1500 (+/- 500) rpm. I degree all my cams and let me tell you it makes a world of difference. I recently put together a magnum engine all stock but checked the timing to what the MP magnum engine book has and found out i was about 3 degrees retarded. Because the keys were $50 for a set and i was in a hurry to put the engine together i ran like that for 3 months. A few weeks ago i advanced the cam 4 degrees. I gained 2 mpg and it now rarely kicks out of overdrive where as before any small hill it kicked out of overdrive. Eric isn't advancing his cam hopeing to pick up extra power that he thinks he should have. He is doing this to put the cam where it was designed to be.

i believe the last sentence of my post said just that. if it is off change it.

 

[Guest]

What? WE don't understand?!!!!! I believe I clearly stated that I understood the procedure in the first sentences of my post. So it'll run poorly at straight up? Flip it over and look at it the other way. Advancing the cam will improve low rpm power, so a retarded cam improves upper rpm power. This is not a disputed fact. Maybe, when you advanced your cited cam, "300," you moved the power band to where you do most of your driving? Maybe this is why you managed better mileage? If you advance the cam, but fly along at 80mph on the hwy, will it still get better mileage? Probably not. You all cite production tolerances. So, you still have those production tolerances, but your cam is NASA-perfect. Chain stretch? Fact of life unless you swap for gears. That makes tons of sense. What about an aftermarket engine with all hi-perf. parts? The whole package is much tighter in tolerances. Some still degree the cam (these tend to be for competition, or max effort in a given rpm range). To degree when the loose tolerances aren't there seems silly according to you, 300. I mean, you degree for loose tolerances, right? Did it ever occur to you that maybe by degreeing the cam for more advance, you take advantage of what is probably a fatter low rpm fuel curve? Maybe a sharper tune-up (particularly on carb applications) would accomplish the same thing? Like I said, advancing once is fine, but there was talk of going back and advancing it even more. Hell, put in 90-out. If a little is good, why not? You cannot out-guess fate, and you can only do so much to adjust for "production tolerances." Kicking in and out of overdrive is not controlled by some sort of PCM power meter. Granted, your engine was probably making more low rpm power (more torque, thus more vacuum). The MAP sensor reads the vacuum and it goes from there. Could be fooling yourself too. Maybe the kickdown is off from the last time you worked on the cam. And please don't pop off with the 5000 lb truck comment. I know torque is the goal here. I guess it's my own fault. The cams I buy are already cut with a 4 degree advance in them to account for those production tolerances, so I don't have to degree them, it's already been factored in. Again, I didn't say don't degree it, I said there's a limit to how much you can advance it, and expect from it. Chysler300, didn't you post this statement? "I'm not very experienced with degreeing in the vehicle like that and with heads on. I do know that valve springs can push on the lifters and make the valves open a few degrees later then what they really do when the lifters are pumped up." WHAT? That's what you have to offer? (But WE don't understand?) And you degree ALL your cams? Something's not right with that.
I know, I know. I come off ranting as if I know it all. I don't. At least I can admit it. Actually, I was offering an alternative route to what has already been done, or at least compliment what's been done. Okay, I'm wrong. I don't "understand." You're all right. So right, in fact, any other possible solution appears to be a threat to you somehow.
"300" You say Eric is not doing this to pick up low rpm power, but to put it where it's designed to be. Didn't Eric say it ran great above 2500 rpm, but was a essentially a dog below 2500 rpm? So, it sounds like he ran it, didn't like the results, and now is "putting it where it is designed to be." Sooooo, he's looking for more low rpm power....or did I miss something? Hey Sheriff, glad you're out there. Hang tough.

 

[chrysler300le]

Yea you did miss something. You missed that Eric talked about his vehicle months ago and that it wouldn't run good below 3000 rpm. He just put in a new cam and didn't degree it. The cam is a 340 replacement cam and by todays standards is a tame cam. He decided to advance his cam or at least check it to see if its right. Thats what he is doing now. Even though you get cams advanced 4 degrees don't mean other things are perfect such as crank, block, and chain.

Even though I said i don't have much experience in the vehicle i have plenty of experience on the engine stand. I also have plenty of experience with engines that are 4 degrees off and they are total dogs. I said my cam was 3 degrees too retarded from factory specs so i advanced it 4( you can only do even numbers). I just figured up on paper tonight and it moved my power band 2500 rpm( I don't have a tach in my truck, had to use speedo). So now my truck is 1 degree advanced from factory specs. My better fuel mileage is because the engine is set up the way its suppose to be. It now gets the same fuel mileage as the original engine which was to factory specs.

 

[IntenseImages]

ok from what i see you both are saying essentially the same thing, just in a different manner.

yes gen1dak i agree with what you are saying about degreeing isnt going to solve everything. however, i should have been more clear, i have not advanced cam at all as of right now, i put it in, lined up dots, and while i had a ton of power above 2500 rpm, it did run like crap lower than that, not bad, just no power, i got the degree kit so when i went to either advance or retard cam i wasnt just tossing a key in hopes it was the right one, i want to do this once and once only. therfore i am checking with the kit to see where it is at right now.

as of now with just tossing it in, lining up dots and breaking in cam, it is showing that it is 4 degrees advanced, i did not advance it, this is the way it was installed, dot to dot.

i already have the power i am looking for, i am not doing this in hopes to gain more power, i am doing it in hopes to put power band at a more usable level on the rpm band.

i do also agree that some timing adjustments and carb tuning are in order, i ahve a rebuilt carb waiting to go on it, it is also a bit larger than original carb but still usable for this engine, i have a rebuilt distributor with a higfher performance curve on the springs waiting as well, if this doesnt work then i have a few other distributors lying around i can try.

i already have most of these ideas and plans in place, just i am taking my time, this time and making sure that it is done right, instead of just slapping it together and hoping that it works.

and as far as rockers and lifters changing the readings, i am not using them, i am measuring directly off of the lifter.

once again thank you all for all of the time and information you ahve given me on this

eric

 

[sheriff]

Ok Sheriff and Gen1Dak, the decision was made months ago for eric advance his cam. What you two dont' understand is lining up the dots isn't perfect. There is a such thing as production tolerences. Don't think that cranks are perfect. With time the journals become out of index. For a V-8, the journals need to be 90 degrees from each other. The indexing can change slightly between the journals and the key way for the timing chain. Then add in chain stretch and its production tolerences, Block core shift, tolerences in cam machining and the timing of the cam can become several degrees off. Four degrees may not seem like much but it moves the power band about 1500 (+/- 500) rpm. I degree all my cams and let me tell you it makes a world of difference. I recently put together a magnum engine all stock but checked the timing to what the MP magnum engine book has and found out i was about 3 degrees retarded. Because the keys were $50 for a set and i was in a hurry to put the engine together i ran like that for 3 months. A few weeks ago i advanced the cam 4 degrees. I gained 2 mpg and it now rarely kicks out of overdrive where as before any small hill it kicked out of overdrive. Eric isn't advancing his cam hopeing to pick up extra power that he thinks he should have. He is doing this to put the cam where it was designed to be.

OK!!,chrysler300le, i also degree all my cam installs and rebuilds. mainly to assure the cam is to specification and to point out some to the other problems you pointed out. some of your theories on variations in cam timing i agree with and some i don't. if you have a crank that is not indexed properly or a variation in journals, degreeing the cam to 1 cyl will not set it properly for the other cyls. if this is the case you need to fix the root cause for cam being timed wrong. same for timing gear/chain. i have seen the term (core shift) batted about as being root cause of all sorts of problems.(not so) as far as core shift, this happens during the casting process. casting may look like an unshelled georgia peanut, but after milling to spec, this won't change during the blocks life other than normal wear. the only thing you could see is thicker/thinner places in the casting walls. my point is don't try to compensate for other problem with cam timing. have a good day. --sheriff--