Engine doesn’t sound right to me

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VanDuster

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Hi Everyone,

I’m relativley new to the side of muscle cars but have had this duster for a while and was finally able to start it a few months ago. Took a while after the old wiring harness fried itself. It’s a stock block and heads but has a cam installed in it. I followed the instructions on breaking the cam in correctly but something just doesn’t sound right to me. Almost like there’s just no power to the engine? I put the video up on you tube. I don’t know what the engine sounded like before as this was the first time I fired it up after I baught the car(the engine was not installed at that time)

This is the cam I was given with the car.20-224-4 - Xtreme Energy™ Hydraulic Flat Tappet Camshafts


 
No that doenst sound right I hear a god awful tick. Have you checked the oil for metal? Maybe a bad lifter or wiped lobe? Timing can make one tick. Im sure more qualified people will respond.
 
Does it have adjustable rockers,if so adjust them.
Pull valve covers and investigate.
Bend pushrod,broken rocker,collapsed lifter...
What oil did you break it in with?
 
Personally it Sounds like the headers are leaking to me. They can be a pain to seal up. Should be able to take a long handled screwdriver and use it as kind of a stethoscope to help pin point it. I personally use the aluminum gaskets because they’re thick enough to make up for warpage and imperfections and I torque the fasteners to specs.
 
That does sound like an exhaust leak so start there. There may be some low level clattering too, but it's hard to say with the echoing and audio quality.
OP, what engine in this? 318? 360?
Do you have a list of parts that went into it?
Have you set the ignition timing? If not, that is next.
 
I tend to lean towards the exhaust leak too.

Get a 3 or 4 foot length of hose put one end to your ear and start moving the other end around by the exhaust.

If there's a leak it will amplify itself in the hose.
 
Hi,

Ya sorry for the video quality,Thanks for the reply’s. I will definitely look into the header leak. As for the parts that went into the engine I believe it’s mostly stock 360 other than the cam and lifters that went into. It’s got an edlebrock 750 carb and eddlebrock intake.

The rockers are not adjustable but I can look into getting adjustable pushrods and see if that helps.

For timing I can not remember what it was set for but I believe I started are 15 initial and gave it a bit more.
 
Yes a quiet exhaust is needed with a new cam or engine rebuild. I always put mufflers on for initial start up, even on my race car. Then I can hear any mechanical noises that are going on. Silence the mulffer and ex leaks, then post another video of the sound. You shouldn't need adj push rods.
 
VanDuster said:
Almost like there’s just no power to the engine?
Click to expand...
How do you qualify that statement? Have you driven the car or just let it idle?
Also there are quite a few "believe's" in your description of the engine and tune up... when you believe the ignition starts
at 15 initial it might as well be way off?? Just askin'...
 
Exhaust leak, then listen for metal to metal clacking, that be rockers loose from a flat lobe, but you're probably fine and it's just the leak.
 
Sounds like a header leak at the flange to me as well.

I would drop to a 600cfm carb as well, that carb is too big for that motor
 
I think that cam might be too big for a low comp 360 eng that's why it feel slow ,how does it feel when you get it up in the higher rpm's? what rear gear do you have?
 
Leaks of ANY kind ruin a project! A lot of good tips here. What headers are they? (I quit using cheapies many years ago.) What is the flange thickness? It is likely warped or an uneven surface, most are. Did you put a straight edge on header flange before installation? This is rarely done. Yes, proper torque, and tightening sequence after making flange flat, and use a quality copper header flange gasket, (read reviews). I'll put 20 bucks on a header flange leak to make this interesting.....
 
I once had a 451 that had the timing marks off when I bought it.. They had lined up the dot on the cam sprocket with the crankshaft key way. WRONG! Might work for a Chevy, but not a Mopar big block. It had no power, but would idle OK. Cam was about 20 degrees off! Make sure your cam timing marks are lined up perfectly.
 
Yes a lot of good ideas on here. I am definitely going to look at the header leak first, they are Hedman headers. Came new with the car when I got it. As for the timing it was set with a timing light months ago and I can’t remember the exact number but it was close to 15 initial. I can check it once I fire the engine up again but I was just trying to get some ideas on what to check before I start working on it again.
 
I have a similar 230/237/110 cam. It runs gangbusters in an 11/1 engine with a 750DP.
At 8.1 the 63* ICA will bleed a lot of cylinder pressure back into the intake at idle. She won't wake up until mid 3000 rpm, and that would be normal for that size of cam, with that factory Scr. And 15* initial is about right.
In the video I hear two problems
1) a lot of top-end clatter, and
2) one distinct, every second revolution,"clank", for lack of a better word.

As to the first one; you're gonna need to find the source of that before it gets ugly. It could be a lack of oil to the topend,improperly installed rockershafts, too-short pushrods, collapsed lifters,rocker arms reversed, etc.
As to the second, if you cannot find it with the stethoscope or similar tool, disconnect the plug wires one atta time until the noise goes away, or at least changes. Now you know which cylinder is doing it. To me, it sounds more like a clank, so while I hope it's a header leak, I kindof don't think it is. I can tell you what I DON't think it is: Not a rod, not a wristpin, not a piston. So the bottom-end, to me, is ruled out. And not a rocker arm or lifter. So what's left? IDK, I hope it's a header leak.
Put a vacuum gauge on it. If the needle keeps time with the clank, it ain't a header leak. If it doesn't........Maybe it's the fuel-pump.
You know that the rocker shafts have a specific orientation and that rocker arms come in lefts and rights, correct? I guess I would start with verifying that.

She idles with a nice lope,(I like it) far in excess of what my cam does, the Hughes HE3037AL which has advertised numbers of 276/286/110 @.008 which compares to yours at 274/286/[email protected] . I was a tad disappointed with mine,lol,until I drove it. After that I didn't much care.
 
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Fix the exhaust leak,then order .030" longer pushrods to make up for the smaller base circle of that cam.
 
Factory head gaskets were steel shim @ approximately .020 thick. Fel-Pro perma-torque gaskets compress down to .038 thick, I believe. Not to mention, how many times those heads were milled/cleaned up by a machine shop? All these items affect valve lash. A topic all its own. Hopefully, at some point hardened exhaust valve seats were installed by a machinist. There are endless possibilities here. A push rod length checking tool is a very cheap investment. Rocker shaft orientation, we all made that mistake, (once), at some point. Also to save $$, make your own push rods, if needed. Very easy and quick with simple tools.
 
I really appreciate everyone post on here. I will check all of these things when I get a chance and report back.
 
Sound isn't going to tell you anything, aside from you have a header leak. Get the hot idle where it should be (mild cam, stockish engine, should idle 650-800), and take a vacuum reading. If that's lower than you think it should be, take some compression readings. If those are low, maybe there's an issue with the cam installation. But first things first.
 
I like the flatout graphite exhaust manifold gaskets. Never had one leak and can be reused.
 
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