Whats that clatter at low RPM? Keep in mind, that my timing is really roughly set, my jetting not dialed in, and with no filters on the carbs and a muffler needing replacing, there is a lot going on here.

Piston slap? Exhaust Leak? Valves?

http://www.youtube.com/watch?v=L2S31l-p680

More details on the motor build/innards please, going just on sound it sounds like a collapsed hydraulic lifter...

2056, AA96 mm p and c. 494 webcam with new mechanical lifters. Dual 40 idf, SS heat exchangers.

Seems to be RPM related, are valves adjusted correctly ?????

May be wrist pin ? You obviously have something slaping around in there!

How old is the engine ,how long since the rebuild? Something in the fan floping

around hitting the shroud ? Check every thing 2.3.4. times. but i would't run it

to much . Just enought to diagnose the problem. Keep us informed, bet it's

something simple. Dave

Mine is close to that sound but not quite that loud. Mechanic said valves set too loose. Will found out this weekend.

Total rebuild, with zero hours, other than cam break in. Fan looks good, but hell, it is really hard to see anything up there in the car. Having a hard time even seeing the timing marks on the flywheel!

I know that sound.

You used elephant feet, right?

Tell me you did, and I can put your mind at ease.
They are a hair too long and hitting the valve covers. Pull a valve cover and you will see the impact zone. Pull the feet off, grind them down, and cut a new slot in the end. Easy. Only bad news is if they put a hole in the valve cover.

Come on, tell me you used elephant feet!

Zach

f5 f5 f5
I keep reloading. I can see you are in the thread. Give me my validation.
f5 f5 f5!



Zach

LOL! Settle down, pardner. I am running straight 2 liter adjusters. No swivel feet. And now?

BOOOO!

Zach

could still be some part of the rocker assy hitting the valve cover. it's worth a look.

What is your deck height and compression ratio.

I think I remember a conversation about the AA pistons sometimes slapping the valves slightly when everything is cold and you have tight deck height. But i can not remember the specifics, and could have the facts totally wrong.

That said, why didn't you upgrade your valve train when you put in the 494 cam? Are you using stock pushrods, or the steel cut to fit ones? If stock, you are going to have very poor valve geometry.

Zach

Now I am starting to wonder, but at the time, i think my logic was, if i get 20000 miles out of the motor, that will be about 7 years of driving. Plus, I did not think it was all that far off when I assembled everything. I am getting within 5% of the cams specified lift, and the stem to adjuster angle was not that far out of whack.

..Could it be .....water contaminated gas, (which is also in the carb float bowls)...lowering the octane rating ..COMBINED with ...ignition timing is too advanced.....causing detonation..(which you can hear clearly at idle or lower RPM,s).......the clatter is piston slap,from too advanced ignition timing and detonation from low octane fuel....Fix immediately.

Had a buddy over two nights ago to hold the RPMs while i checked the timing. The old battery died at that point, and it would not start. Got another yesterday and its running again. Then starter would hardly turn, had to add a heavy ground wire from it to battery. Back in biz, gotta get someone over to hold the RPMS. Damn I forgot how hard it is to see the timing marks while its in the car. I think i was skinnier last time i did this.

And now my floor jack has decided to not lift. Jesus, its always something.

while your in a holding mode,Until your help arrives, recheck the timing mark(s) on the fan/impeller...remark them clearly so they are easy too see....AND hang in there, seems like whenever you want to do something immediately...all manner of crap happens to slow you down. It happens to everyone.

Can floor jacks be serviced? This is not some crappy FLAPS jack, its an old school heavy duty (dont recall the make) with all heavy steel construction. I now feel like I am in "gotta fix the truck, so I can go into town and buy some nails to repair the roof" mode.

...........Floor jacks are wierd turkeys....if it was american made the answer is probably.....(I had a monster jack myself, and rebuilt it). probably best to do a web search for the "make" or "brand" to find a rebuild kit., but beware that the cylinder can be distorted, or bent, and the cylinder must be replaced also...It could be a situation that a new one is actually cheaper...and not as much trouble.

Can floor jacks be serviced? This is not some crappy FLAPS jack, its an old school heavy duty (dont recall the make) with all heavy steel construction. I now feel like I am in "gotta fix the truck, so I can go into town and buy some nails to repair the roof" mode.
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...........Floor jacks are wierd turkeys....if it was american made the answer is probably.....(I had a monster jack myself, and rebuilt it). probably best to do a web search for the "make" or "brand" to find a rebuild kit., but beware that the cylinder can be distorted, or bent, and the cylinder must be replaced also...It could be a situation that a new one is actually cheaper...and not as much trouble.
[/quote]

I just swung by FLAPS and got an aluminum jack which seems "ok". Did not want to drive to HF to look at theirs. Oh well. At the least, this one is light enough to carry in the car if I ever am on a road trip and get the sudden urge to adjust the valves.