[RotorHead]

I built a 350 about two years ago, since then I have had the motor in two different vehicles and have had three different cams in the engine. I have quite a few passes down the track in the early days of the engine with the two big cams. I ended up putting the engine in an s10 and the engine didn't run for 6 or so months, I did turn the engine over from time to time to oil the engine. After I got it running I found the cam that was in it made unpractical for the street so I put in the third cam, a voodoo 262. The truck runs very well and is mean on the street but is nice to drive. I seem to have a little noise on the bottom end, it sounds like a rod knock, but I'm puzzled why. An old diesel mechanic I know believes that with all the cam changing that was done caused a rod bearing to prematurely wear due to the excessive amount of metal in the oil from the break in of three cams and three sets of lifters. Not to mention the zinc additive that was used all three times. It seems to be a plausible hypothesis but before I swing the engine again, I'd like some distance opinions. Also, does anyone have experience with the aftermarket knock sensors that operate a light? I'd like to monitor the problem and eliminate all possible options before I open it up.

[richard stewart 3rd]

Hi
Well every answer you'll get on thiss will be a guess, heck you can guess as well as anyone else. Quit fooling around & open it up & find out for sure what the problem is. JMO
Rich

[DoubleVision]

Check the torque converter bolts first. They are prone to back out and it sounds Identical to rod knock when they do.

[RotorHead]

Originally Posted by DoubleVision

Check the torque converter bolts first. They are prone to back out and it sounds Identical to rod knock when they do.

That would be nice. The other day i thought it might be in the tranny, ended up talking my self out of it, but I'm glad you said it. As soon as I get up I'm going to check it out. I used grade 8 and lock washers, but anything can lose torque.

[ericnova72]

Check for a cracked flexplate also, it can give the same symptoms. Cracking between the lightening holes and/or cracking between the crank flange bolt holes.

[RotorHead]

Absolutely, i'll have a mirror and light to make sure I inspect it good. I hope it's nothing major, the sound is pronounced but seems to come and go. We'll see.

[FmrStrtracer]

Pull your oil filter and cut it open. Best to use a pipe or tubing cutter if you have access to one that big. Check the filter media for particles of bearing. If youve got a rod or main knock, you'll find copper and silver glitter.

[RotorHead]

I'm not sure it's a rod. Converter and flex plate checked good. I'm running roller rockers with studs and guide plates, someone told me that that valve train can be noisy. I'm using a voodoo 60102, which is fairly new. The truck sounds fine when It's idling and at cruise, I hear the noise at about 3500 RPM going down the highway and when I accelerate hard then let off, it ticks in sync with the decelerating engine.

[eloc431962]

Make sure the balancer is not working loose also. It will make a odd knock when loose.


Cole

[RotorHead]

What are the chances that my rod bolts stretched? When I built the motor I did not change the rod bolts. I had the rods worked but I kept the original bolts, I can't tell you how old they are. I'm turning just over 400 at the crank, so I didn't think it would be a problem. I have yet to open the motor up, trying to find a cherry picker. I'm going to pull the valve covers and take a look at my pushrods and guide plates, I also got a set of percy's header gaskets since my other gaskets had chunks missing from blow out.