Lumpy idle hurt motor mounts? Other concerns!

[cougs]

So after having to do the install twice, my charger is driving very well but the lumpy idle of the cam is raising some concerns.  I ended up going with a comp cams 21-223-4 (see the specs below)

1. Can a thumpy/lumpy idle hurt the motor mounts or the engine bearings?  Can we change engine mounts to take out the shake?  It has quite a bit of shake at 650 RPM. 
2. Can a more aggressive cam increase the noise from the valvetrain?  It is not really "loud" (can only be heard with the hood up) but it kinda sounds like we have a solid cam in the thing.  The car has stock rockers.  Will adjustable rockers help this?  FYI, the heads are STEALTH HEADS and the cam specs are 224/230 at .050, 268/280 adv, .477/.480 lift, 110 lobe separation.  Should have some lope, especially being a 383. 

The thing drive and accelerates awesome but the idle quality/sound has me concerned.

Thanks for the help.

[XH29N0G]

See what other's say.   Yes a change in cams can affect valvetrain noise, but it also can bring worn parts to one's attention.  Depends what the sounds are, and whether they are localized to a specific part. My experience was that a swap from a stock magnum cam to a lunati cam with similar specs to yours was that I found that my old stamped rockers were worn.  I am sure there are other discussions of this, but you can see my trials and tribulations at:  http://www.dodgecharger.com/forum/index.php/topic,91797.msg1041714.html#msg1041714  Basically, I ended up hearing tapping noises that I had not heard before.   

Don't know about engine mounts, suspect this is not an issue.  The idle might be better higher than 650 RPM

[cougs]

See what other's say.   Yes a change in cams can affect valvetrain noise, but it also can bring worn parts to one's attention.  Depends what the sounds are, and whether they are localized to a specific part. My experience was that a swap from a stock magnum cam to a lunati cam with similar specs to yours was that I found that my old stamped rockers were worn.  I am sure there are other discussions of this, but you can see my trials and tribulations at:  http://www.dodgecharger.com/forum/index.php/topic,91797.msg1041714.html#msg1041714  Basically, I ended up hearing tapping noises that I had not heard before.   

Don't know about engine mounts, suspect this is not an issue.  The idle might be better higher than 650 RPM

I read the old post...good info.  So you didn't have any noise before the cam swap but afterwards you had valvetrain noise?  Which was fixed after you replaced the rockers?  Did you replace the pushrods when you originally did the swap?  I can't isolate the sound to a particular spot on the engine and while it doesn't seem loud it seems to be happening continuously.   Seems like I may need a new set of rockers. 

[Back N Black]

 The Schumacher strap with help with motor mounts.

http://www.engine-swaps.com/Pages/InstructionPages/TorqueStrap.html

[XH29N0G]

In my case, I could localize the sound and definitely had a ticking on one side and in one part of the head.  My stamped rockers had about 100 thousand miles and were worn. I did replace the lifters and the push rods.  (Ron recommended 5/16 chrome moly pushrod from Mancini and I did that). 

As far as localizing the sound, you can hear things (localize them) by placing a metal rod (1/2 inch) against your skull in front of your ear and then placing the other end on each header tube, or on other parts of the engine.   (I do this at work to localize high pitched sounds from turbo pumps that spin at 20 to 30 thousand RPM.)  A mechanics stethoscope will do the same thing, but I do not know if it will be too loud when put on a header pipe. 

I would make sure you have valvetrain noise related to worn rockers and not something else before breaking into it.  It also may be something else.  I am not the one to give a verdict on noises, but if you post a link to a video, I have found that others on here will help.

The engine mount/strap is something to pay attention to.  I do not know if you have broken the driver's side mount yet, but it can happen (I had it happen more than once with the 383) and it can cause problems.  I have a solid mount on the driver's side, but if I can manage Ron's suggested fix http://www.dodgecharger.com/forum/index.php/topic,13216.0.html will switch to that.

[ottawamerc]

650 RPM at idle?? isn't that way too low I thought they were 900 for a manual and 950 for automatic min. Low RPM's could possibly cause your valve train noise too due to lack of oil pressure and volume?

Scott

[cudaken]

650 RPM at idle?? isn't that way too low I thought they were 900 for a manual and 950 for automatic min. Low RPM's could possibly cause your valve train noise too due to lack of oil pressure and volume?

Scott

Idle speed sound a little low to me as well? 

Cougs are you adding ZPPD to your oil? 

Cuda Ken

[cougs]

650 RPM at idle?? isn't that way too low I thought they were 900 for a manual and 950 for automatic min. Low RPM's could possibly cause your valve train noise too due to lack of oil pressure and volume?

Scott

Idle speed sound a little low to me as well? 

Cougs are you adding ZPPD to your oil? 

Cuda Ken

Yes, I used the Comp Cams break in oil and Brad Penn stuff for regular operation

[firefighter3931]

The idle is too low....get it up to 800 in gear.  The cam & lifters are splash lubed off the rotating assembly and too low of an idle can effect low speed lubrication. 

The Comp XE cams are noisy.....it's the agressive lobe profile that increases valvetrain noise. Just curious....why the deviation from the original plan (Lunati cam) ??

It's possible that the rocker arms have lots of wear....and that will also contribute to a noisy valvetrain. Make sure that the rocker shafts are installed correctly.....the lubrication/oil holes must face down and towards the outside of the engine.


Ron

[cougs]

The idle is too low....get it up to 800 in gear.  The cam & lifters are splash lubed off the rotating assembly and too low of an idle can effect low speed lubrication. 

The Comp XE cams are noisy.....it's the agressive lobe profile that increases valvetrain noise. Just curious....why the deviation from the original plan (Lunati cam) ??

It's possible that the rocker arms have lots of wear....and that will also contribute to a noisy valvetrain. Make sure that the rocker shafts are installed correctly.....the lubrication/oil holes must face down and towards the outside of the engine.


Ron

Ron,
I had to redo the cam install because I botched the timing gear installation the first time around and didn't have a sufficient break-in session.  This is actually the third time I've been down to the cam!   I had the Lunati in the car the first time around and was happy with it but wanted a little more cam (Or so I thought at the time).  I had access to this cam for free so I thought I'd try it.  I also changed out the rear to 3.73 and went to a 2500 stall so I figured the car was set up for it.  The cam is more aggressive than I thought it would be.  I should have my head examined for going with more cam when having idling trouble. 

Heck, I may tear into it again later this summer and put the Lunati back in as the cam and lifters look fine (I kept them in order).  It didn't have the top end or sound of this cam but the valvetrain noise wasn't there. 

[firefighter3931]

The idle is too low....get it up to 800 in gear.  The cam & lifters are splash lubed off the rotating assembly and too low of an idle can effect low speed lubrication. 

The Comp XE cams are noisy.....it's the agressive lobe profile that increases valvetrain noise. Just curious....why the deviation from the original plan (Lunati cam) ??

It's possible that the rocker arms have lots of wear....and that will also contribute to a noisy valvetrain. Make sure that the rocker shafts are installed correctly.....the lubrication/oil holes must face down and towards the outside of the engine.


Ron

Ron,
I had to redo the cam install because I botched the timing gear installation the first time around and didn't have a sufficient break-in session.  This is actually the third time I've been down to the cam!   I had the Lunati in the car the first time around and was happy with it but wanted a little more cam (Or so I thought at the time).  I had access to this cam for free so I thought I'd try it.  I also changed out the rear to 3.73 and went to a 2500 stall so I figured the car was set up for it.  The cam is more aggressive than I thought it would be.  I should have my head examined for going with more cam when having idling trouble. 

Heck, I may tear into it again later this summer and put the Lunati back in as the cam and lifters look fine (I kept them in order).  It didn't have the top end or sound of this cam but the valvetrain noise wasn't there. 

Cougs,

The Lunati is every bit as good as the XE268 and it will idle better and have stronger throttle response. The idle is a little mellower due to the wider lobe seperation (112 vs 110) and the valvetrain will definately be quieter....all things being equal. 

The XE can certainly be made to work in your application....it'll just take a little tuning finesse 


Ron

[cougs]

[/quote]


Cougs,

The Lunati is every bit as good as the XE268 and it will idle better and have stronger throttle response. The idle is a little mellower due to the wider lobe seperation (112 vs 110) and the valvetrain will definately be quieter....all things being equal. 

The XE can certainly be made to work in your application....it'll just take a little tuning finesse 


Ron
[/quote]

Hi Ron,
It definitely takes some finesse!  I'll try to get this to work but will likely put the Lunati back in if increasing the idle doesn't help and the valvetrain noise doesn't cease.  Could using the new Mancini rods with the 100K mile rockers also create some noise until they get broken in with each other?

I think I've found the happy point with the timing, advance and mixture.  Changing the carb helped the most with the idle quality.  I was told that the 600 CFM Carter AVSs don't have the idle circuit to support a performance cam and heads.  Have you heard this before?  I thought about going with a Holley but I wanted to retain the stock look.

Also, this car still has points ignition but I have a MP electronic conversion kit that I've been meaning to install.  Will this help with tuning?

I appreciate you allowing us to tap your knowledge!

Brock

[firefighter3931]

Brock,

(1) the eddy 600 is suited to a stock or very mild build. You have a bigger cam and much better than stock heads so the fuel requirement will be increased. Basicly, the fuel curve on that carb is not compatible with the upgraded engine combination. With regards to idle performance ; you need to get as much idle vacuum as possible to make tuning easy....this allows the idle circuit to function properly.

(2) Ignition is where it all starts. You're wasting time adjusting the carb until the timing curve is dialed in. A cam like that is going to want at least 15* of advance at idle. Best way to check is using a vacuum guage ; simply install the guage and advance the timing until the guage reads it's maximum and stop right there. That is what your engine wants for initial. Once you figure that out it's just a matter of adjusting the mechanical advance to achieve the desired total timing. With closed chamber heads i've found best power being made at 35* so that's what you want to shoot for.


Ron