Carbureted LSX forum - Good news and bad news......

I've been working on getting my carbed LS1 running and going in my 68 C10. I fired her up last night. It was late and I wasn't able to get a video. Sorry. Man, does she have a rowdy idle, too!! With the open headers, she sounds MEAN!!!!

I have an issue, though. It sounds like something is rubbing or hitting somwhere. There's a grinding noise, mostly noticeable when I shut it off or rev it up a little. The trans is bolted up, but the torque converter is not. At first, I thought the converter had vibrated against the flexplate and that was causing the noise, but the converter is still sitting snug against the trans. I looked for anything that may be rubbing or hitting anywhere, but there's nothing visible. I'm thinking maybe the starter could be the culprit. It may not be fully disengaging. I also don't have any accessories hooked up yet.

Anybody have any ideas?

Bolt the converter up FOR SURE

Did you install a double row timing chain?

Easy your flex plate is spinning and rubbing converter. I'd put those converter bolts in asap

Get some earplugs and a VERY trusted friend.... climb under and have him start the motor while you take a look...and yes I'd bolt the converter up first before starting.

BE CAREFUL and DO NOT TOUCH ANYTHING SPINNING :D

I would not worry about any noises till the project is fully together and there is not a doubt in your mind that pending pieces that are not yet completed are making noise.

Id agree with the rest of the crowd. Im assuming it had good oil pressure, so we can eliminate that variable? Probably the converter. Eric L

I talked to the guy that built the transmission. He said the engine spinning creates a vacuum type vortex that will cause the converter to spin also. He said the center hub on the converter is likely to be rubbing, causing the noise.

So it looks like you guys were right, so it won't be started again until I get trans cooler lines, fluid and a dipstick installed so I can bolt up the converter.