deja Posted May 15, 2006 Share Posted May 15, 2006 This can't be good, rust and cam are rarely a good thing. I guess this is what happens when you buy an engine that's been sitting for too long. I would have thought the oil would have prevented this. Anyway I'm looking for a replacement when I rebuild this. I have no plans to run this car on the strip. I want to keep it close to stock, making a daily driver and want to get some decent gas mileage. The engine is out of a 1995 Z28 LT1. The car will most likely have a 4L60E auto, but that isn't written in stone yet, still considering the T56 6 speed. Any opinions on a cam for this scenario would be appreciated, I assume there are better, cheaper options than going stock GM. Quote Link to comment Share on other sites More sharing options...
jbc3 Posted May 15, 2006 Share Posted May 15, 2006 I'll send you a stock cam for the cost of shipping... Quote Link to comment Share on other sites More sharing options...
deja Posted May 15, 2006 Author Share Posted May 15, 2006 I'll send you a stock cam for the cost of shipping... That would be great. You've got Email. Quote Link to comment Share on other sites More sharing options...
Z-8 Posted May 15, 2006 Share Posted May 15, 2006 Yeah, your going to have a few things that need to be taken care of when you go over your engine. I got a LT1 from a '95 caprice cop car, and when I pulled the cam out, one of the lopes had been ground down about an 1/8". I rifled through the lifters and found one that had a portion of the roller look like it had melted a little. So there are going to be some problems. But when I dropped it off at the machine shop, they said it was one of the better looking used engines that they have ever seen, so that was cool. I went with the small cc304 cam, I also switched from 4l60e to t-56. Good luck with your build man. Quote Link to comment Share on other sites More sharing options...
deja Posted May 15, 2006 Author Share Posted May 15, 2006 I have pertty much decided to replace almost everything including pistons, but thought the cam was going to be something I could keep. Hopefully there won't be more surprises when I take to the machine shop. Quote Link to comment Share on other sites More sharing options...
fastzcars Posted May 15, 2006 Share Posted May 15, 2006 That cam looks like it's made from billet steel? I thought GM only install cast cams in there cars. Just a thought, if all the lobes are not ground down too far, you could have the cam reground. Just a thought:mrgreen: . Quote Link to comment Share on other sites More sharing options...
5foot2 Posted May 15, 2006 Share Posted May 15, 2006 The lt1 motors run roller cams. That cam looks like it's made from billet steel? I thought GM only install cast cams in there cars. Just a thought, if all the lobes are not ground down too far, you could have the cam reground. Just a thought:mrgreen: . Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 15, 2006 Share Posted May 15, 2006 My stock cam looked similar to yours minus the rust and pitted lobe surface. My LT1 is also from a Caprice so I planned to replace the cam anyway. I put in an LT4 HotCam and high rev springs, all the lifters were good. Now it has a bit of a lope and pulls hard to 6000 rpm. The donor car had the 4L60E but I replaced it with a T5. Thought about the T56 but didn't want the expense or the additional weight, plus the T5 had a mechanical speedo output which made driving the Datsun speedometer much easier. Sounds like your engine may have had an oiling problem at some point. Good thing you decided to go through it completely instead of just replacing the cam. Wheelman Quote Link to comment Share on other sites More sharing options...
deja Posted May 16, 2006 Author Share Posted May 16, 2006 I came close to just installing the engine but my SBC buddy told me to at least pull the mains. Then I decided to pull the heads, then oh what the hell, lets tear her down. You're right good thing I might have wasted a lot of time. Kind of disappointing on an engine that's supposed to have on 79,000 miles. Looks like it got water in it some how. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 16, 2006 Share Posted May 16, 2006 The odometer of the donor I got mine from showed 102,000. It was a retired Montana state highway patrol car so probably had decent maintenance and sat around idling a lot. I pulled the mains and rod bearings before installing the cam, they were in very good shape so I left everything in place. It compression tested at 190 PSI in every cylinder. Sounds to me like yours may have seen some boost or nitrous and blew a head gasket. Did it have oil in it when you received it? What did it look like if it did? What about the coolent? Wheelman Quote Link to comment Share on other sites More sharing options...
Paz8 Posted May 16, 2006 Share Posted May 16, 2006 How are the exhaust valves in the heads? Bet that a few are alittle rusty. That cam looks like it sat and got pitted then someone started the engine and it ran dry a few seconds, check the cylinder bores for scoring. I hate dishonest people that KNOWINGLY sell damaged stuff. Quote Link to comment Share on other sites More sharing options...
deja Posted May 16, 2006 Author Share Posted May 16, 2006 Did it have oil in it when you received it? What did it look like if it did? What about the coolent? Wheelman It had oil, very dirty oil. There was a little sludge in the pan, but not much. The coolent was that orange stuff and didn't look all the good. Quote Link to comment Share on other sites More sharing options...
deja Posted May 16, 2006 Author Share Posted May 16, 2006 How are the exhaust valves in the heads? Bet that a few are alittle rusty. That cam looks like it sat and got pitted then someone started the engine and it ran dry a few seconds, check the cylinder bores for scoring. I hate dishonest people that KNOWINGLY sell damaged stuff. I haven't taken the head apart yet. I planned on having them gone over anyway. Quote Link to comment Share on other sites More sharing options...
mark Posted May 16, 2006 Share Posted May 16, 2006 I have pertty much decided to replace almost everything including pistons, but thought the cam was going to be something I could keep. Hopefully there won't be more surprises when I take to the machine shop. Make sure you discuss balance with the machinest. Lt1's are a little different. If you have the rotating assembly neutrally balanced, you will need to use a flywheel that is the same or have your flywheel balanced. Mark Quote Link to comment Share on other sites More sharing options...
deja Posted May 16, 2006 Author Share Posted May 16, 2006 Make sure you discuss balance with the machinest. Lt1's are a little different. If you have the rotating assembly neutrally balanced' date=' you will need to use a flywheel that is the same or have your flywheel balanced. Mark[/quote'] Good tip. Pretty sure I'll be running a 4L60E. Thats what the engine was running before so its running a flexplate. But if I go T56 I will make sure I get the Flywheel balanced. Quote Link to comment Share on other sites More sharing options...
mark Posted May 16, 2006 Share Posted May 16, 2006 Good tip. Pretty sure I'll be running a 4L60E. Thats what the engine was running before so its running a flexplate. But if I go T56 I will make sure I get the Flywheel balanced. Same deal with an auto. The flex plate will not be neutrally balanced. Quote Link to comment Share on other sites More sharing options...
deja Posted May 16, 2006 Author Share Posted May 16, 2006 OH! Thanks, I will remmebr to bring that up at the machine shop. Quote Link to comment Share on other sites More sharing options...
wheelman Posted May 17, 2006 Share Posted May 17, 2006 What Mark is talking about is that the LT1 is externally balanced just like the SBC 400 was and most of the post 85 SBCs. This means you have to use a flex-plate or flywheel with a counter weight on it unless you have the rotating assembly balanced by the machine shop. If I were you I'd have the assembly balanced but make sure to get a neutrally balanced flex-plate or flywheel and a harmonic balancer with a keyway in it. The LT1 harmonic balancer is not indexed to the crank so it has no slot for a key. Get a good aftermarket harmonic balancer that is made for a neutrally balanced engine. Most for older small blocks will work fine. Another thing you need to keep in mind with the flex-plate/flywheel is that the newer cranks (LT1 included) are set up for a 1 piece rear main seal and have a different bolt pattern so an older flex-plate/flywheel will not work. Wheelman Quote Link to comment Share on other sites More sharing options...
deja Posted May 17, 2006 Author Share Posted May 17, 2006 What Mark is talking about is that the LT1 is externally balanced just like the SBC 400 was and most of the post 85 SBCs. This means you have to use a flex-plate or flywheel with a counter weight on it unless you have the rotating assembly balanced by the machine shop.If I were you I'd have the assembly balanced but make sure to get a neutrally balanced flex-plate or flywheel and a harmonic balancer with a keyway in it. The LT1 harmonic balancer is not indexed to the crank so it has no slot for a key. Get a good aftermarket harmonic balancer that is made for a neutrally balanced engine. Most for older small blocks will work fine. So what you are saying is GM balances the whole egnine after it is built by counterweighting/drilling the flywheel/flexplate and harmonic balancer? So if I have the machine shop balance my crank/pinstons I need a different neutrally balanced flywheel/flexplate and harmonic balancer? If I simply get the crank polished and add my new pistons I can't simply use the stock flexplate and harmonic balancer? It would be easier/cheaper/better to get neutrally balanced flex-plate and balancer? Its all so confusing, LOL. Quote Link to comment Share on other sites More sharing options...
jbc3 Posted May 17, 2006 Share Posted May 17, 2006 It is not "balanced" as far as spinning each assembly and drilling/weighting each crank and putting weight on the flywheel for EACH motor.... Every crank is balanced the same (or within a small range) and every flywheel/flexplate has the same sized weight on it. That brings the motor close. For your average street car, it's fine. If you are planning on leaving the stock tune and 5800 rev limit, the stock balance is probably fine. The problem comes when you start mixing and matching parts. By neutral balancing you no longer have to figure out if something will work. If you want When you take the motor to the machine shop, make sure you have the flexplate and balancer along with the rods/pistons so they can neutral balance the whole assembly. The stock balancer hub is not keyed. You could have it notched or replace it with an aftermarket hub. This may be overkill if you are planning on a stock rebuild and stock tranny. Jody Quote Link to comment Share on other sites More sharing options...
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