Yesterday after work I thought I would take the Mustang around the block again....I did then I reset the timing from 10 back to 6-7 well upon changing the timing I heard a knock, never heard it before on this engine and I put my hand on the A/C compressor bracket and can feel it.... got a broom handle and stuck it to the engine valve covers.... I can hear it but it does not sound like it's in the valves... but you can hear it more so on the passenger side. I then put it on the oil pan...again I can hear it but it did not sound like it's from there.... if I can feel the knock through the bracket where might it be coming from? I also listened to the timing cover and water pump..... does seem louder up front on the passenger side......... any ideas? It's a new rebuilt 302 .40 over less than 200 miles on the rebuild.... had the RPM's up to 3000 once or twice but mainly at 2500 rpm when driving ( I need an overdrive) oil pressure is always good never dropped and the temps are stable. what's the main cause of a knock on such a new engine? I had the shop build the short block along with line boring and balancing the engine. would like to pull the caps off but the shop is not open yet so I need to know if it's going to void the warrantee.. Thanks Jeff.

Did you have the broomstick calibrated?

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Outlawed tunes from outlawed pipes

nope not yet..... bet I looked pretty silly doing that... but if it is a bearing it will be with a few whacks over the shop owners head... that should get it up to speck. Jeff.

Sod, Check your balancer bolt to make sure it's tight. I have heard Fords sound like they have a rod knock and it turns out to be a loose balancer.

Royce

I built an engine for a guy who was a little hard of hearing.... He took the engine and installed it himself and ran it for about 200 miles and spun a bearing!

Well I warrenteed it and myself and a few other pros looked that thing over and could not find out why. Gave it back to him and 500 miles latter he was knocking again! I was not happy. So we dug deeper and found out that he was deaf to certain tones, one of them being the ping of a detonating engine! He drives like Jehu and he also had done his carb himself and had that thing running so rich it was thinning the oil down with gas! The combo of too much timing and the detonation as well as his heavy foot and gas filled crankcase would never work.

Dont know if any of these things are your problem but check the weird things too.

Check your oil level. If you have too much oil your lifters could be making noise from aireation.

Just a thought, but it did happen to me after some idiot changed my oil and put in 6 and a half quarts. When I took it back it back he goes, "oh, it's a big block, it takes more oil".

Take all the belts off and start it up to rule out accessories.It could be a loose timing sprocket too.Hood luck.

'Might be worth pulling the timing cover off to check for timing chain slop, since you say it was line-bored.

Just a little late on this thread but I found out the prev. owner of this car had the WRONG h-balancer on it......bought one off of ebay and the knock was gone.... Thanks for all of your help at that time. Jeff.