diesel
02-26-2006, 04:22 PM
#1
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diesel i just finished a cam and spring swap and my motor sounds like a diesel motor.
really loud valve noise at idle, and louder as you increase rpm. any suggestions on how to fix this???????
really loud valve noise at idle, and louder as you increase rpm. any suggestions on how to fix this???????
02-28-2006, 10:13 AM
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the rocker arm does not have n e play in it when the valve is shut.idk know the center line. and i am running stock rockers so i dont believe valve clearance is an issue. its only a 542 572 lift cam.
02-28-2006, 02:38 PM
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Valve lift has very little to do with valve clearance. You should check valve clearance with the checker spring method before you run the car. The valves will come in contact with the piston in the overlap cycle between 20 degrees before tdc and 20 degrees after tdc. At full lift the piston will not be near the valve.
Kurt
Kurt
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03-01-2006, 09:24 PM
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Your sure that the noise isn't just the regular "cammed" sound? Cammed cars have more valvetrain noise period. Depending on ramp rates, and other valvetrain components some are louder than others. That cam has 11* of overlap, so it'll have a decent lope at idle. Assuming the cam was degreed correctly, I don't see why it would be making any abnormal noises unless something was damaged in the process.
03-01-2006, 09:38 PM
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so is 11* of overlap alot? is it possible to have ptv clearance problems? it sounds like a grear wine and rods knocking. also the water pump does not seem to be cooling cause within about 3-5 minutes it reaches over 220. also i did a code reader scan on it and it said high output cam sensor??
so what does all of this mean??
so what does all of this mean??
03-04-2006, 06:32 PM
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Originally Posted by 98slowt/a
well i tore the motor apart and i found out that the timing gears were off 3 tooths on the crank gear. how bad is this?
I would do a leak down test to make sure that all of the valves are seating properly. If it was indeed 3 teeth off I can almost guarentee that the intake valve was kissing the piston providing it is a stock short block. I have seen this happen before and if your lucky, I mean real lucky you might be ok.
Hope this helps.
Tim
03-04-2006, 07:33 PM
#15
Sounds like you've got ptv contact especially since the cam was off timing.
I had the problem with a big block chevy, ptv was fine with a big lift short duration cam, then I swapped it out to a smaller lift with longer duration. This cam gave it exactly zero ptv clearance for about two degrees somewhere before TDC right when the intake valve opened. (cold)
It may seem like it's off topic comparing an LS1 to a BBC but here is a picture after the valve head broke off at 5000 rpm, it ran great for 250 miles, it was a newly built engine that ran in the 11's.
I ended up needing several new pistons, a new rod, a cylinder sleeved, new heads, etc, this was with 500 miles on the new engine.
So what I'm trying to say is get it right before your engine grenades like mine did.
I had the problem with a big block chevy, ptv was fine with a big lift short duration cam, then I swapped it out to a smaller lift with longer duration. This cam gave it exactly zero ptv clearance for about two degrees somewhere before TDC right when the intake valve opened. (cold)
It may seem like it's off topic comparing an LS1 to a BBC but here is a picture after the valve head broke off at 5000 rpm, it ran great for 250 miles, it was a newly built engine that ran in the 11's.
I ended up needing several new pistons, a new rod, a cylinder sleeved, new heads, etc, this was with 500 miles on the new engine.
So what I'm trying to say is get it right before your engine grenades like mine did.
Last edited by 8a8mfh; 01-10-2008 at 07:38 PM.
03-04-2006, 11:06 PM
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so i got the motor all put back together and started it and everything sounds good. no noises and it revs smooth. havent had a chance to drive it though