New build thread; 48 Plymouth

[falconvan]

Oh yeah, I don't regret adding a third pedal. I'm getting ready to put new siding and gutters on our house; I guess once that's done I'll pull the engine and see what the issue. I talked to a local shop that builds a lot of LS motors and they think it's the cam.

[40FordDeluxe]

Oh yeah, I don't regret adding a third pedal. I'm getting ready to put new siding and gutters on our house; I guess once that's done I'll pull the engine and see what the issue. I talked to a local shop that builds a lot of LS motors and they think it's the cam.

That very well could be. When I yanked the cam out of my 5.3 I was surprised how bad the cam bearings were. Main and rods looked normal but the cam bearings were toast. They weren't worn through layers like you'd expect. It was like oil film built up on the top side of the bearings and over time went around the bearing making it rough etc. I might have them some where. If I can find them I'll take a pic. The machine shop I had replace them said it's pretty common due to how warm these engines run. He said they had to do quite a few of them.

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[falconvan]

Once I started looking into it from the cam possibly being the issue I found several videos on youtube of similar problems. The majority of them seem to be chewed up cam journals and lifter rollers at the back half of the motor. So I guess I'm going to pull it back out and see what happened.

[53 Chevy5]

Once I started looking into it from the cam possibly being the issue I found several videos on youtube of similar problems. The majority of them seem to be chewed up cam journals and lifter rollers at the back half of the motor. So I guess I'm going to pull it back out and see what happened.

You've got me pretty nervous about the 5.3 I have in mine. What year is your motor?I've heard the ones that shut off cylinders down the road gave problems.

[falconvan]

It’s a 2001. Overall I think the LS is a great platform as everyone is building them . But it does look like they have some cam issues

[v8nutz]

That's interesting, I had to replace my cam bearing too. The rods, mains and cylinders looked pretty good. I had some worn rockers and push rods also.

[40FordDeluxe]

That's interesting, I had to replace my cam bearing too. The rods, mains and cylinders looked pretty good. I had some worn rockers and push rods also.

The rockers are another issue that should be looked at. The needles drop out of the end cap and make all kinds of bad things happen. Several different places offer upgraded trunion kits to fix this. I just did the rockers for my 5.3 last week. I went with the bearings again but wish I would have went with the bushings now. At least these bearings have a normal housing and won't come out like the factory ones can. I got my trunion kit from Michigan Motorsports.

https://www.google.com/search?q=trun...hrome&ie=UTF-8

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[53 Chevy5]

Seriously, is there some preventive maintenance I should look at on mine? I have about 165K on it. Like the others said the rods and mains were fine, but now I'm worried about the top end.

[falconvan]

I can’t really think of anything preventative you can do other than regular oil changes and maybe some kind of additive. You might ask your local GM dealer mechanic; they probably deal with a lot of them.

[Dave Severson]

Seriously, is there some preventive maintenance I should look at on mine? I have about 165K on it. Like the others said the rods and mains were fine, but now I'm worried about the top end.

Just wondering if the zinc additive for oil when using a non roller cam in an engine with today's oil might help it? It's supposed to prevent wiping out cam lobes on hydraulic or solid lifter cams? Maybe a call to a cam tech at Comp Cams might be in order? If it's a continuing problem with LS engines I'm sure they've dealt with it by now.

[falconvan]

Just wondering if the zinc additive for oil when using a non roller cam in an engine with today's oil might help it? It's supposed to prevent wiping out cam lobes on hydraulic or solid lifter cams? Maybe a call to a cam tech at Comp Cams might be in order? If it's a continuing problem with LS engines I'm sure they've dealt with it by now.

That's a good point, Dave. Once I get mine out I think I'll call them before reassembling.

[falconvan]

As suspected, the 5.3 ate the cam and spun one of the cam bearings. I really didn’t want to go through a full teardown; this build has been so frustrating. I also didn’t want to stick another couple of thousand dollars in it. So I did the opposite of what most people are doing. I sold all the LS stuff and made just enough to order GM Goodwrench 350. It’s just a basic bone stock 260hp but it’s new and has a 3 year warranty. I just want the thing to run and drive at this point, could care less if it’s fast and this was the most financially and labor friendly way to get there.

[53 Chevy5]

That is the opposite of what most people do but that doesn't make it bad. I have the 5.3 in mine and I love it so far but if I were to do it again, there's a pretty good chance there would be a 1990 ish 350 in there with throttle body injection. Like you said, power is great, but when I come to think of it I don't even know if I floored Rita yet.

[stovens]

I did the same for my 460, cheaper to buy a rebuilt longblock with a warrenty than rebuild with the same parts!

[40FordDeluxe]

That is the opposite of what most people do but that doesn't make it bad. I have the 5.3 in mine and I love it so far but if I were to do it again, there's a pretty good chance there would be a 1990 ish 350 in there with throttle body injection. Like you said, power is great, but when I come to think of it I don't even know if I floored Rita yet.

IMO the throttle body was the worst. Crap mileage and always issues with the ecm and distributor. Just go tuned port.

Sorry to hear about the 5.3 but like you said they do have their issues. They sure like to eat green backs. That 350 will be just fine IMO.

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