engine noise

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slim 67 said:
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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A slip fit can definetly leak. That's the type of headers that was on my car when i got it and #7 always leaked. It was easy to tell because burned gasses (black soot) built up on the pipes next to the slip fit.
 
Did you take a piece of rubber hose and listen around the headers where they meet the head???? Its the cheapest diagnosis......Why start buying stuff and replacing stuff if not necessary???

Just trying to help...
 
On the slip fits, yes, they can leak... A S/E racer friend of mine uses a thin skin of gold (hi temp) silicone inside the slip joints.
 
slim 67 said:
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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The "in gear" part of this post is good evidence of trust bearing movement resulting in flex plate / torque coverter noise. Seen it several times on Ford 302s, Crown Vics etc..
 
If it's only under power, I'm inclined to lean towards teh exh noise or driveline... but you'd know a flexplate sound...lol
 
redfastback said:
Did you take a piece of rubber hose and listen around the headers where they meet the head???? Its the cheapest diagnosis......Why start buying stuff and replacing stuff if not necessary???

Just trying to help...
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No I didn't, if the new remflex gaskets don't fix this I will tie a hose by the slip fit joint and run it through the window and head down the road and see if I can hear anything and I do appreciate your help very much. Right now I'm waiting for these gasket and as soon as I get them on I will let you know what I find thanks again everyone.
 
RedFish said:
The "in gear" part of this post is good evidence of trust bearing movement resulting in flex plate / torque coverter noise. Seen it several times on Ford 302s, Crown Vics etc..
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I have the sfi external balance flex plate and neutral balance convertor. I did check the thrust on the crank when I built this motor and it was within spec,( .010 - to .014 is what comes to mind but don't quote me on that). I wish I had used a better quality convertor than I did, I haven't read anything good about these MP units since I bought this one. This tranny was dial in to this block just to make sure I didn't need offset dowel pins. I made a fixture here at work that I could zero to the cone on the front pump then check it to the counter bore on the back of the crank and it was within .005". But I will pull the gravel shield and look and make sure I don't see something funky going on anyway. Thanks for the input!
 
do a search on valvetrain noise and look at all the other possibilities maybe your answer lies within.
 
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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Always lean from the factory? Really? When I worked at a parts store in the early 90s, they were always rich out of the box. We were at 3200 feet, so that had an effect on it.

Piston slap.
 
I just wanted to update this thread since I completely dissasembled this thing yesterday. Number 5 main bearing was badley gaulded but it wasn't spun. This was the very last thing that I thought the problem was as I have heard bad bearings in the past and the were always noisy at start up and at idle which this was not. They are federal bearings and I had my mains and rods set up at .002 clearence. I used bearing gaurd assembly lube and primed my pump before start up so this was a little suprising to say the least.
 
Depending on the type of valve springs you are using - 273 rockers can sometimes touch the side of the spring retainer on the underside of the rocker arm. I have a set I use on my car and I found that I needed to re-leave about half of them on that part of the arm. The old DC mopar hot rod books talk about doing this. You need at least .040" clearance if my memory serves me correctly. This could be another source of your noise -
 
Here at sea level, they are lean out of the box, and the floats are ALWAYS off.
 
slim 67 said:
Yes
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Odd... That's the closest one in the oil supply chain to the pump. Look on the back of the bearing and see if it was the correct size. It's possible it was packaged wrong and only it was an incorrect size and the others were correct. I can only think that if it was the only one that was gaulded the clearance must have been too tight.
 
fishy68 said:
Odd... That's the closest one in the oil supply chain to the pump. Look on the back of the bearing and see if it was the correct size. It's possible it was packaged wrong and only it was an incorrect size and the others were correct. I can only think that if it was the only one that was gaulded the clearance must have been too tight.
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Wonder if he put the bearing half's in back words on # 5, top on bottom bottom on top?
 
Only #5? That is odd... What about the rod on 8? Was it a full groove, 3/4 groove, stock type? What does the crank journal look like? Sounds to me like an issue with the crank journal if it's only that one... The shells in with the lower shell on top would have siezed the rod it feeds.. I think that's #8 in very short order. If the rod is ok, the surface of the journal, or the main bore should be carefully checked.
 
3404spdvaliant said:
Wonder if he put the bearing half's in back words on # 5, top on bottom bottom on top?
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Ok, give me a little bit of a break here. I'm not a rocket scientist by any means but come on! I work in a machine shop where we perform maint. on 250K$ injection molds that have .0002" tolerences. All of my clearences on my rods and mains were dead nuts .002". I got my new clevite bearings today and they are full groove instead of half groove like the other ones, that should help, but I do agree something was wrong. Imho since they back bearing is 1.25 wide instead of .875 there is that much more area that needs lube with no oil groove, apparently that was alittle too much. Thanks for the help and suggestions!
 
Hey you never know the dumb sh*t that people can do, even trained people.
Nobody is perfect, right?

BTW what did the oil gear/housing look like when disassembled?
 
Slim, Did you run a brush thru the #5 main oil galley? Did you measure the crank's main journal for taper? It should have less than .0003... with none being the best. This will not be shown on plastigage, and it's enough to hurt the oil wedge. Also, if you have a full groove set, you are very possibly making it worse. More oil goes to the rods with a full or 3/4 groove set, thus starving the main surface itself more.
 
One other question.. the cam is not grooved on #2 and #4 cam bearing jounals, correct?
 
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