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Originally Posted by 71 super
Use the timing light and determine the location of the source of the noise with the hose etc. From the cam specs posted there should be no problem with the pushrods unless there is a geometery issue- i.e pushrods are too long, bt with the info you have posted about the builder I am sure he would have checked the length and such when he degreed the cam. You said that the timing was @ 4 degrees when you went to the other shop in NY and that the engine had been run in at the bakersfield shop- correct? Have you spoken to the builder about the change in timing? Is the distributer a stock type or MSD billet etc? My thinking is if the motor was set up on dyno, the curve in the dist. and carb adjustments maybe off somewhat in and actual vehicle vs ideaql conditions and changes in atmosphere etc. All of these are tuning issues and do not answer your first question where is the noise coming from? Check with light to determine location and move from there. As for the components comment no it does not matter what you paid, however if like my self and the last big motor I built- 408 dynoed at 575 hp, things like pistons etc do make a difference- the first incarnation of the motor lasted exactly 6 days in which the end result was pieces of a cheaper piston migrating from #8 to #2 cylinder and a fire ball flashing at least 6 feet beyond the tailgate when this happened. I have been down this same road several times with "hot" motors so the type of components do bear relevance in how things act/react. The reason for the explosion migration was due to a "pro" who milled the tops of the pistons just a little too thin, and combined with a improperly setup distributer all hades broke loose literally and figuratively- turned a $8000 motor into a pile of scrap in 8 seconds or so. Sorry to step on your toes but been there done that. If you locate the source of the noise- valve train or lower end, you will need to run a comression test- tester is about $25 at any parts house follow the intructions on package- If a pushrod has bent, it could have been caused a misalignment at the valve stem as it bent, bending the valve and in turn leaving it in the combustion camber with the piston and the noise you have heard is piston to valve contact- not good. The compression test will indicate if the valve is open as you will not have compression on that cylinder and if that is the case you have bigger problems than initially thought- ie. cracked head in seat area, busted piston, and or busted block. If you are afraid to drive as I would be, the before mentioned tests are something that you can do in your driveway parking garage etc. in a couple of hours by yourself. Hope this helps get you going in right direction. Harold
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Harold,
Thank you for this information. This is really useful and is something that I can do to see what is going on. Ill get a comp tester and timing light this afternoon and see what I can find. The distributor is MSD I think Its not stock and the carby is Edelbrock 1407.
(Sorry correction here its a 1405, I did mention that it is too small for this engine but it has a electric choke and is essential for NY cold starting over performance) I agree that these might not all match perfectly and were items that were on the list to upgrade at some point.
I am under the distinct impression that everything used to build this engine is very high quality and it should be as strong as an ox. I am very much hoping that the valve has not hit a piston, I have been down that road before and its game over as you mentioned. Without doing major things like taking rocker arms off and so forth your suggestions will be really useful to try to diagnose the problem.
I was actually on the phone with the builder when at the mechanics here in NY and he is aware of the timing being at 4deg. It was adjusted back to 14 and it ran like a charm. Then slowly the ticking and so forth happened. I am still waiting to hear back from the builder and will let him make suggestions however I will follow what you have suggested as this will only help.