Trying to find out what cam I need for a 73 400 4bbl

[WH23G3G]

Ok my 73 Charger has been at a shop since July being worked on. They've tried to get the engine tuned right. They got the alignment done and straightened out but still can't get it running and idling right. They wanted to know what camshaft I had put in when I built the 400. It was only a Sealed Power CS-661. They looked at the specs and told me that's why it won't idle or create any vacuum. It's .040 over, has flat top pistons I reused, Hastings plain cast rings, 73 cast crankshaft, 73 rebuilt cylinder heads, elgin HD springs, mp pushrods, melling rockers, mp windage tray, melling hp oil pump, 73 intake, 73 hp exhaust manifolds. Here is a link to the specs from Federal Mogul http://fme-cat.com/overlays/part-detail.aspx?brand=SP&PartNumber=CS-661&pt=Camshaft#.UmXVpd_D_IU. They want to know what the engine came out of and said they could find out. They said this camshaft is too wild for this engine. The only numbers I have on the engine is 6T400 and a partial VIN 6D181929. I was told it was a 400 from a passenger car built at the Belvedere, IL plant. But the shop told me they could tell me if it came out of a 76 Charger, Fury, or whatever. But I told them I don't think they would be able to. Can anyone look at the link and tell me if the cam is indeed to wild for a stock 400. They tried 2 different rebuilt TQs I had and couldn't get it running and idling right. Then was told to buy a $350 Edelbrock 650 and it doesn't do a whole lot better. Should I get a camshaft for a 76 400 if you can even get one? I know Sealed Power shows the same cam for many years. Any suggesstions?

[flyinlow]

The cam lift, overlap  and duration look like a oem Mopar Magnum cam replacement.  Not that wild.

[Mebsuta]

Yah I agree, CS-661 is the 383 Road Runner cam.  I used the MP version in 383 RR.  Idles with 16 inches of manifold vacuum when warmed up.

CS-327 is the 400 lo-po cam, 206/209 @ .050, 0434/.431 valve lift. 

[WH23G3G]

If they can't get this engine to idle right and produce any vacuum what else do they need to check? He's already taken care of any vacuum leaks. He says the exhaust manifold is leaking at the head and is going to replace the gaskets. I'm sure he won't take any suggestions but is there anything else they should check? The mechanics working on it both told me no wonder they couldn't get the engine to idle right with the cam specs I showed them.

[Mebsuta]

Right now, the ignition timing on mine is set at 15 degrees BTDC at idle.  On the timing chain, at the crank sprocket, it's set at the 4 degrees advanced position, which is 2 degrees advanced at the cam.  When it's warmed up it has a good, happy idle.  Nothing wild about it.  

It sounds to me like something is not in phase, either ignition or cam, because the cam like CS-661 was used in 73-74 400 hp cars, like the Road Runner.  It should run alright unless there is just no compression at all.  Late ignition or valve timing will cause low manifold vacuum.  Maybe the distributor is 180 degrees off.  I think that is a pretty common mistake.  

[flyinlow]

It's been a while since I worked on stock exhaust manifolds but I  don't think they use gaskets from the factory.  Just clean and flat surface.

Have you done a compression check?

EGR valve sticking open? This will mess up your idle. Most people lookng for performance, disconnect it or block it off.

[firefighter3931]

If the cam wasn't installed properly the idle and performance characteristics will suffer. The cam needs to be degree'd in on the proper intake centerline.

Ignition timing also comes into play. If the timing is retarded or the timing curve is lazy it will affect performance.


Ron

[flyinlow]

This mechanic that's been working on you idle for four months and does not listen to suggestions.  He doesn't drive a chevy does he? 

The reason I ask is some GM cars run their vacuum advance off of manifold vacuum instead of ported vacuum. Doing this on Mopars sometimes causes idle problems.

[WH23G3G]

He says he use to have a bunch of Chargers back in the day. Mostly the older cars from the 60s and 70s that come into their shop are all GM. I know I couldn't get the timing to do anything. He's played with it but I don't know what all he's done. He works on it at his leisure. I had the machine shop that did the cylinder honing and cleaning install the new cam bearings and camshaft. I just put the new timing set on when I did the reassembling and matched the marks on the cam and crank gears when installing. This one here has a ported vacuum switch but no EGR, it uses ports in the manifold. They are not clogged. He's one of those mechanics that won't listen to any suggestions because he already knows everything. So I can ask him if he's done certain tests. What should I ask? I did all I could to get in running right but I couldn't and I've known the shop for almost 10 years so I brought it to them because they said they would have it running right in no time. But it's almost 4 months later and no progress except alignment.

[Mebsuta]

If it was my car and sitting in my garage, first thing I would do is remove all eight spark plugs, block the throttle wide open, and with a fully charged battery, do a compression test on all eight cylinders. 

Mine cranks about 150 psi like that when it's warm.  Some people think that is low, but that's what the books says it's supposed to be for 383 RR, 68-69.  If yours was like 120 or even 100 psi, I think it would still be okay.  In the past, with different heads and cam, mine has cranked over 160 psi, but it did not run any better that way.  It was just more picky about timing and what grade of gasoline you could use. 

[flyinlow]

You said you had a '73 400 intake ,I think they had EGR valves. The Exhaust Gas Recirculation valve opens during part throttle acceleration. If it sticks open due to dirt or rust it will allow exhaust gas into the intake ports during idle causing a poor / erratic idle or stalling. It would also be be open at WOT when it should not be reducing power. Unpluging the vacuum line to the valve will prevent it from working, but if it is stuck open it will still pass exhaust gas when it should not. A block off or test plate will close it off positively.  A piece of sheet metal will work too.

Not sure this is your problem , just a possible cause.

Picture of similar intake:

[flyinlow]

Normal Tuning order is:  
1. engine mechanical, compression good, valve adjustment (you have hydraulic lifters so N/A)
2. ignition timing, and proper sparkplugs/gap
3. carburation tuning

When you assembled the engine did you verify that the vibration damper timing mark was at true TDC ? If the outer ring on the damper has slipped the timing is not where you think it is. Not a common issue but 40 years old.

Do a compression check. A stock compression ratio of 8:1 and a stock magnum cam should be 120 PSI or higher and all within 20PSI of each other.

Degreeing the cam would be nice to eliminate issues, but with the engine installed its a chore.

Describe  "engine won't make any vacuum."  What is your Vacuum at idle, is it steady ? Vacuum at 2000 rpm, is it steady?

[WH23G3G]

Mine has floor jets, not egr valve. I'm not sure if the mechanic has done a compression test. I will have to ask. I've never been at the shop when he's been working on it. All I know is that he thinks the cam is too wild and both the owner and mechanic think so. I was asked to swap out the original numbers 6321S TQ which I had restored by Carb XChange to a 650 Edelbrock and I'm thinking I wasted that money because now the mechanic is asking about the cam. Meaning the Edelbrock probably hasn't helped at all. I compared the cam specs out of the 73 Chrysler Chassis Service manual and it's pretty close except duration. I didn't degree the cam, I just lined up the dots. If the distributor is 180 out would still even run? He says it starts up a lot easier than when I brought it in.

[flyinlow]

Umm,..  The floor jets in the intake are where the exhaust gas enters the intake manifold to dilute the intake mix and lower combustion temps. The EGR valve taps exhaust from the heat riser crossover port ,the hole on the right in the picture and lets it enter the hole on the left going to the two jets on the floor of the intake manifold. The EGR valve itself is not present in that picture.

If the distributor was 180* out the engine would not run, unless you move the plug wires 180* to match.

The TQ was a good carb in its day. Came on a '73 400. Hard to find quality parts for today and the expertise on them is getting rare also.

A 650 Eddy. should work well on a mild 400. How did they install that carb on the factory intake which is a spredbore intake. The adaptors frequently caused vacuum leaks.

'73 400 H.P. cam In. 268*/ Ex.284* duration 46* overlap,   lift .450 In./ .464 Ex.  Factory specs. on duration are longer because they measure from zero lift. Aftermarket cams specs. measure from .050 lift. so they are less .

[cudaken]

Mine has floor jets, not egr valve. I'm not sure if the mechanic has done a compression test. I will have to ask. I've never been at the shop when he's been working on it. All I know is that he thinks the cam is too wild and both the owner and mechanic think so. I was asked to swap out the original numbers 6321S TQ which I had restored by Carb XChange to a 650 Edelbrock and I'm thinking I wasted that money because now the mechanic is asking about the cam. Meaning the Edelbrock probably hasn't helped at all. I compared the cam specs out of the 73 Chrysler Chassis Service manual and it's pretty close except duration. I didn't degree the cam, I just lined up the dots. If the distributor is 180 out would still even run? He says it starts up a lot easier than when I brought it in.

W H, what kind of vacuum is the motor pulling? I have a MP 509 cam and a lower than I like compression 383 than I would like and it idles just fine. Well the Road Runner does have the nick name Miss Lumpy but no problem idling.  

I am with Flying Low about checking to see if the outer timing ring has slipped!
Dang, I thought I saved a video from U Tube how to check but I didn't.   Just do a search on U Tube you will find one to your liking.

When you say it Will not idle, what do you mean? Does the engine idle to fast, dies when you put it in gear or just plain not stay running in park? If you can drive it, how does it run? Good, OK or just plain like crap?  

When you where trying to time the car, did you have the vacuum adv unhooked? Which cylinder where you using as number one?   Not meaning to be insulating, but easy to get confused on, ask me how I know!  

Here is a video on the firing order, makes it easy to remember.  
http://www.youtube.com/watch?v=yRRKxlEQQpo&feature=player_detailpage

Far as your Mechanic   give him the boot! Any Mechanic that thinks 46 degrees is to much overlap is a Fucking Idiot! My 509 cam has 64 degrees and it will idle!

By the way, where do you live? Maybe we can find you some local Mopar Help.

Cuda Ken  

[cudaken]

Here is the Video I watched.

http://www.youtube.com/watch?v=bhIP5YKCgRE

Cuda Ken

[cudaken]

W H, I was visiting my friends shop and we talked some about your problem. Besides being a general repair shop he all so races. Bow Tie guy but he knows is stuff.

First step would be to disconnect all vacuum lines from the intake and plug the hole and see how it runs. I know you said there are no vacuum leaks, but something was missed. If you have power brakes, it could be a bad booster.

Second step, time the engine using a vacuum gauge. Advances the timing until you have maximum vacuum and see how she idles.

Third step if she idles well after step 2 is shoot the timing and see what the timing looks likes. If it is something stupid then it is time to check where TDC is on the damper, outer ring has slipped.

Far as the cam timing, you would have to have missed alining the dots pretty badly for it to effect the idle.

Cuda Ken   

[WH23G3G]

I'm here in North Georgia Gwinnett County. Most guys around here are Chevy or Ford enthusiasts. Occasionally you'll see a random Mopar around. I know when I had it at home and was trying to do the timing with a timing light putting it at 7.5 degrees BTC I couldn't ever get the engine to idle steadily it would vary hundreds of RPMs just sitting in park but it was relatively smooth. But driving it around it was horrible, it had no power. I told that to the mechanic when I took it there and he said all that did no good because the brake booster hose was leaking vacuum because it was one size too big. So I sent it to him to get it running correctly and check to make sure everything I did underneath was safe. I'm going to stop by tomorrow and check on the progress and ask him what it is exactly doing. The mechanic said since the block is a 76 that cam may not be correct for a 76 and whatever car it came out of. I tried to tell him the block doesn't matter, it's whatever cam the factory put in for whatever level of 400 it was. He tried to tell me that he is going to find out exactly what car the engine came out of. I know that's not possible anymore since it only has a partial vin. It was a 76 400 out of a passenger car that was built in the Belvedere Assembly plant. I guess if you knew what models they built there in 1976 you could narrow it down. Plus I told him if you look up a 73 Charger 400-4 and a 76 Charger 400-4 HP anywhere that sells Sealed Power cams it will come up with a CS-661. So I told him I'd like to see how he narrows it down to exactly which model the engine came out of.