Lifters? Rockers? Timeing?
#1
Lifters? Rockers? Timeing?
Ok guys and girls im not sure what the hell is making this noise, to start off i will tell you about my engine, 355 ci scat 9000 seires crank, arp bolts top and bottom, ohio pistons, 76cc heads , 10:1 compresion, 292 cam, harland sharp roller rockers (1.5) rpm intake, perfromer 600 carb. (1973 camaro) now here is the problem, after 20 or so min. of driving im hereing a sound like aluminum bouncing around in my engine, it only does it when im giving it gas, up hill or down hill . it ticks at idle, maybe rockers need adjusting. The sound reminds me of a timing issue, but i have done the timing numerous times. The sound is not made when it is cold outside, and also i have a serious bog problem at WOT some help anyone?
[IMG]local://upfiles/1078/E46C98A5F0E549B49BDF9BB91C261F86.jpg[/IMG]
[IMG]local://upfiles/1078/E46C98A5F0E549B49BDF9BB91C261F86.jpg[/IMG]
#2
RE: Lifters? Rockers? Timeing?
i would check the rockers and make sure they are adjusted right, or it might be a ping. try running a higher octane gas or retarding the timing a few degrees. thats what i would try but see what other advice you get.
#3
RE: Lifters? Rockers? Timeing?
69rat makes a good point, engines ping more in hot weather, and 10:1 compression is pushing it for street use. As for the bog, check your accelerator pump, change the stroke and see if the bog changes. You will have to figure out which way to go, depending on the results. Also, your secondaries my be coming in to soon, or you carb needs rejetting.
#5
RE: Lifters? Rockers? Timeing?
i have almost the same problem. 350ci street dominator high rise intake with a holley 650 double pump carb. set of AFR 180cc street heads on the way car idles fine but once you give it gas sounds like something slapping inside the motor also once you let off the gas it backfires and shoots flames out exhaust. have pulled dist. several times and reset tdc, advanced the time retarded the time, new plugs,new wires, new cap, new button,no matter what cant get rid of the backfire. could the cam be causing problems,lifters,valve. also when you jump on it, very sluggish to take off and sounds just like a miss.
#6
RE: Lifters? Rockers? Timeing?
Try adjusting you valve clearance. There may be too much preload ( if u using hydraulic lifters) or not enough clearance (if u using solid lifters). The backfire is a good indication of valves nit closing all the way. Remember, as the engine gets hot the valve clearance is reduced, so it is more accurate to do the adjusting with the engine hot.
Try this site for instructions on valve adjustment
http://shbox.com/1/4th_gen_tech2.html#adjust_valves
Try this site for instructions on valve adjustment
http://shbox.com/1/4th_gen_tech2.html#adjust_valves
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libertyforall1776
Wheels, Tires and other Exterior
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10-08-2007 12:05 PM