Ls1 block advice
 

Hi all I'm new to the forums and am seeking some advice from the community. I purchased a 2001 Trans Am about a year and a half ago and early this spring ended up having a loud taping noise coming from the motor. I decided to try and get it taken care of right away so I could enjoy it for the summer (live up north). Anyways it turned out that my cam had a chunk taken out of the top of a lobe and after removing the cam found out that the front cam bearing had spun and was gouged up (bearing actually spun so far back the oil gallery was completely exposed...explains my 15-20 psi hot oil pressure i suppose.) I ended up finally getting the block out and bringing to my engine builder to handle it. He later called and told me the block was a reman and the machine shop told him it had been bored out 20 over already. (Im aware that ls1's cant really be bored much at all) So basically my question is will the block hold up to just bolt-ons and a gm hot cam for very long because I already have some money in machine work (cam bearings and a hone so far) or should i scrap it and go with something else. Also i put approximately 7000 miles on the car when i bought it before the tapping started and was told my pistons are also shot the last I talked to him. My budget is pretty tight and I just want something that runs so I planned on just a stock bottom end rebuild until I had the money to have something else built. He's giving me a good deal on the rebuild because hes getting his business started up. He worked at a dyno shop in Omaha until he left to work for himself so I trust him to do the work.

Thanks everyone for any replies

If the block is 20 over then I would find another one. Not worth the risk

You might be better off finding a low mileage shortblock. They can be had for $500-$1000 depending on mileage.

I just sold a complete 2001 ls1 for $1,300 for reference

Ya that is what I have been thinking is going to be the better option. Unfortunately there is not a whole lot to chose from for LS1 blocks around here unless they need a rebuild also

You could get one shipped directly to you.. What is your budget?

Most shipping places like I use charge $150-$200 to ship something like a shortblock. Just food for thought

Right now my budget is only like 1500 for a shortblock. I'm not really too concerned about mileage since I plan on doing something else later down the road anyways so I would just drive it til it blew up more than likely. Also Its not my only vehicle so I can always wait til I have a little more cash if I need to. I planned on waiting a couple more weeks anyways before I did anything.

I have read in a SA design book that you should only bore a stock aluminium block to a max of 0.005". So your already 0.015" over that. I'm new to LS too, but could you sleve the holes? There are several engines that we do this to commonly at our diesel shop. I realize this is not a diesel. And if it could be done then you have to look at cost because it's probably more expensive than getting a replacement unless you own a machine shop. But if it could be done it would be cool to press in some 4.1" or 4.25" sleves... You would have a monster.

Ya you can resleeve the block but the cost to do it is really high from my understanding especially on my tight budget. After thinking for a few days what I might do is try and find a cheap bare LS1 block or one that needs a rebuild because my crank is good from my old block and so are my rods so that can all be reused. All I'll need then is pistons and a set of heads.

Like said in an earlier post I can also try and find a low mileage running LS1 and skip all the other headache.

If it helps with the cost, any other gen 3 will swap in its place. 4.8/5.3/5.7/6.0.

Sleeves are 2k for parts and labor, and he will need a new rotating assembly as well. As well as new heads for the 4.125"+ bore, new intake, new fuel system. List goes on lol

But yeah, a 427 would be a good replacement.

Thompson motorsports has iron shortblocks brand new right in your budget area I believe they are in the $1,900-$2,000 area.. Check them out

Ok I will take a look. I'm wondering if I should just go with a 6.0 so it leaves me room to grow in the future instead of spending anymore on the LS1

I like the 6.0, however 5.7-6.0 they are really close in power.

The reason the 6.0 is more popular is because it has a 4" bore and ls3 heads can be used with them, don't use this as the sole reason to go 6.0 though.

It just comes down to what you want with the car.

My ls1 is bored to 3.920. I make about 440 rwhp through a 4k stalled auto. Got around 3k miles on it so far with 0 issues. Probably 15 or 20 track passes. Sees at least 1 wot pull every time I drive it.

It is balanced as well

Nice, however I wouldn't recommend it. Most shops won't either.

Sweet. I put about 7000 miles on mine after i bought it but I was making way less power than you.

Im gonna talk to my engine builder and get his opinion on the issue aswell. He might have a good LS1 block laying around that can be used. Im not really in a position to gamble money on a rebuilt engine only to have the block possibly be ruined and have to do it again.

Also I looked at the thompson blocks and the cheapest iron one i saw was still 2400. Maybe I was looking in the wrong place?

Give them a call, they're engines come with aftermarket Pistons and rods on some of them. I'm sure you can get them in a stock piston/rod combo and save some cash

Check out our 4th of July sale thread. We have 10% off of our motors until the 8th. Its a great time to buy, Even when you are in a pinch. Let us know if we can help you with your selection.
Thank you,
Kyle
972-853-2450
Thompson Motorsports

Ok cool. Well I'll probably be giving you a call soon to price some things out. Thanks everyone for all the replies

You could always look at LKQ for a cut out from 500-1500 complete. Drop it in and ride

Ok ill make sure to keep that in mind also