engine noise

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slim 67

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I'll start with the build, 360 LA block, 308 heads, comp xe268 cam,273 adjustable rockers, kb pistons,rpm intake, 650 eddy carb. I have what sounds like a lifter noise that is much more audible under acceleration. I have adjusted the valves .030 past zero and rechecked them several times. I then put on new lifters, all new exhaust gaskets, pulled spark plug wires off one at a time and test drove it, nothing I have done seems to make any difference. This build has about 200 miles on it and has made this noise since the first time it was driven. I also checked the timing and retarded it just to make sure it wasn't detenation. I have 170 to 180 psi of compression and run 91 octane gas. Any suggestions will be greatly appreciated, i'm about ready to give up on this thing since i've been chasing this noise for over a year now! Thanks in advance.
 
A couple more things, it has a 904 tranny w/mp 2500 stall, tti headers and 2.5" exhaust w x pipe.
 
check flexplate to torque coneverter bolts and gravel shield. Might even be a cracked flex plate (lets hope not).
 
Are the lifters from Comp Cams?

There has been a few fellows on here that has had problems with the Comp Cam lifters.
 
exhaust leak at header? I have had to use thicker gaskets than what came with TTI headers on only 2 vehicles. Take a piece of rubber hose and put it to your ear with the car running and run it around all surfaces of both headers around the mating surface to the head.
 
They are indeed comp lifters but there was no change in the noise at all when I put in another complete set. Both times I broke them in as suggested,I do realize it's not a good idea to change lifters but I'm at the end of my rope here.
 
an exhaust leak can sound EXACTLY like a lifter tick....eliminate the variables...
 
slim 67 said:
They are indeed comp lifters but there was no change in the noise at all when I put in another complete set. Both times I broke them in as suggested,I do realize it's not a good idea to change lifters but I'm at the end of my rope here.
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OK did you install another set thinking that would solve the problem? To me if you have changed to another set and it is still making the noise it would be most likely something else. Like a exhaust leak. I had to tighten down more on TTI headers some more to get rid of a exhaust leak when I first broke my motor in and started driving it.
 
I think I will try a set of these remflex gaskets and see if they take care of the problem. These heads do have the small ports under the exhaust ports but I tapped them 5/16-18 and installed set screw w/loctite when I built this thing. I appreciate the responses from everyone and if there are any more suggestions lets hear them, thanks again!
 
could the rockers be hitting on the valve covers.
all it takes is for one to be touching just a little. it will make a rucoues.
 
you might try the Cometic header gaskets - I have had good sealing with them - NOT the TTi.
 
It sounds like pinging. 180 is high for 91 with iron open chamber heads. You will want to be very careful tuning. Also, that Edelbrock is always lean from the factory. I'll put money you need to buy the strip kit for the carb and go up in jet and metering rod, and more than likely swap the springs under the power pistons. It's lean under full throttle. slow the timing curve down so it doesnt come in full until 3K, and drop the centrifical amount to 14-15° with initial at 18-20°. I think the 750 Edelbrock would be a better fit.
 
I had the same issue with a small block!!! My so called machinest left the lifter galley plug out of the rear near the distributor drive gear. I bought new lifters, pushrods, adjustable rockers and after all that it did the same thing. Do check for this!!! easy to do!! Pull the distributor out and get a mechanics mirror faced toward the frt of the engine. If its not there you will have to pull trans to put it in.
 
Check closely the contact point of the rocker to valve tip.Sometimes the rocker shafts need to be shimmed to keep the contact patch correct. If they are riding on the edge of the valves they will be noisy.
 
moper said:
It sounds like pinging. 180 is high for 91 with iron open chamber heads. You will want to be very careful tuning. Also, that Edelbrock is always lean from the factory. I'll put money you need to buy the strip kit for the carb and go up in jet and metering rod, and more than likely swap the springs under the power pistons. It's lean under full throttle. slow the timing curve down so it doesnt come in full until 3K, and drop the centrifical amount to 14-15° with initial at 18-20°. I think the 750 Edelbrock would be a better fit.
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I'm betting this is it. As soon as I read you saying it made the noise worse when you accellerated I thought spark knock. Several yrs. ago I ruined a 360 in 150 miles by not properly setting the timing and letting it spark knock. It's an easy check by just backing off the timing a few degrees and see if it makes a difference. I've also noticed the 650 Edelbrock carbs being jetted lean which will make spark knock worse.
 
i have this noise with my 360la... i used the same series cam (not sure if its the exact number). I was told you get the "SEWING MACHINE" effect due to the ramp on the cam. When it closes it makes this noise. Do a search on here and you will find posts talking about it.

I was like you and spent a great deal of time checking things over. Well I have around 1k miles on my engine that my brother and I put together last year. It is in my 88' Wrangler and has seen heavy abuse...5k rpm sand hill climbs :)

It could also be the lifters like mentioned as there was talk about comp cams having a batch of bad ones and they had a big call back on them.

I just deal with the noise....turn the radio up or open up the exhaust ..problem solved!!
 
When I say it's much more noticable under acceleration I mean 0 - 30 mph over a long distance, I don't have to be hammered down. The rythem of the noise is as if it is one cylinder or one lifter. I did advance the timing to 18-20 initial and that pinging was a completly different sound. With all that being said I very humbley give my thanks to all the suggestions and will go through and check every one of them for the possible solution. I ordered a set of remflex header gaskets from vic's today and I will give them a shot as soon as they get here and let you know what I find out. My next focus will be on the dist., it is a mp unit that came with the electronic ignition conversion that I put on the original motor about 15 years ago and maybe the springs are getting weak. My timing is all in by 2K ( probably a little early?).Thanks again!
 
One more thing, I did go as rich as possible on the chart with just metering rod changes with out changing jets. The next step would be jets and rods, I will take a look at this also.
 
slim 67 said:
When I say it's much more noticable under acceleration I mean 0 - 30 mph over a long distance, I don't have to be hammered down. The rythem of the noise is as if it is one cylinder or one lifter. I did advance the timing to 18-20 initial and that pinging was a completly different sound. With all that being said I very humbley give my thanks to all the suggestions and will go through and check every one of them for the possible solution. I ordered a set of remflex header gaskets from vic's today and I will give them a shot as soon as they get here and let you know what I find out. My next focus will be on the dist., it is a mp unit that came with the electronic ignition conversion that I put on the original motor about 15 years ago and maybe the springs are getting weak. My timing is all in by 2K ( probably a little early?).Thanks again!
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Ok. I misinterpreted your description. You just said it got worse under accelleration so I assumed you meant under full throttle. I doubt your dist. springs are getting weak as I think that's about where the mopar performance dist's were set. You want the timing all in by 2000-2500 with a perf. cam. Another thing to check is that your header pipes aren't touching any other piece of metal. I had that happen when I first put my car together. One of the pipes on the pass side was just barely toucing the bracket that goes from the engine to the trans. and would rattle at 30-45 mph and sounded like something serious. I had to take the motor to trans. bracket off and grind about 1/8" off for clearance then it was ok. Also any other piece of metal most anywhere near any dirvetrain component that is loose or real close to another can reverbarate and cause a rattle.
 
I havent had a loud XE268.. larger ones yes, but not smaller (I've run a few and an XE262) How do you adjust the rockers? How many turns on the screw from snug? It should be between 1/2 ad 3/4 of a turn past snug.
 
I have an XE268 cam inmy 318 with Comp lifters. Runs great, but sounds like a sewing machine above idle. Not too loud, but audible. I had one Comp lifter collapse after 6K and replaced it with a Mopar unit. It could be a combo of noisy Comp lifters and the ramp rate of the cam.
 
I've read some of the thread, not all of it.
Just a quick question, are you running a mechanical or electric fuel pump?
Mechanical pumps, once worn, do sound like a lifter noise then gradually sounds like a rod bearing as it wears.
Possibly another thing for you to look at.

Hope this helps,
All the best,
Giles
 
Mad Dart said:
Does it makes the same noise at idle?? just not as loud??
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I can't hear the noise at idle at all, It has to be in gear accelerating. I have even put it in neutral rolling down the road and reved it up several times but still don't hear it then either. To answer a couple more questions, I adjusted the rockers to zero lash then went .030" or 3/4 of a turn. Yes it's a mechanical fuel pump but I just changed it out and that made no difference either. Could the #7 slip tube on the headers be leaking since it is a slip fit? It seemed like this was a nice fit since it had to be perfectly lined up to go togther but this is the first set of headers I have ever run.
 
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