I'm in contact with a gentleman that has a 355 Lt1 for sale... here's what I know about it so far:

Block: Original 60,000 mile block Lt1 w/ 2boltmains
Bored .030 over 8,000miles ago
New bearings (checking on brand, p/n etc)

Crankshaft is p/n#14088526 and it was balanced during rebuild.

Pistons are TRW L2441 forged for an .030 over block. (I believe it's a 9:1 CR)

Only main concern I have left is the rods.... he's taking pics and emailing them to me before I go for a first hand look at the engine...

But I have heard mixed reviews on TRW pistons, and considering the block is for a forced induction application (8-10psi on lt4 head castings) I seem to gather the crank should hold the power, but the rods and pistons are going to be the weaker link... Any other things I should look for? (I'll also get the pics up later tonight when he zips them my way)

 

Sent some pictures of it so far - looks like it's been sitting a little bit by the top of the cylinder and it's piston...






If anyone could host them outside Imagstation, I know a lot of people wont be able to see them...

 

In my own opinion, I would never buy that shortblock. A .030" block is at the end of its rope, especially with a forced induction motor. In other words, if you ever need to bore it again, you'll have to find another block. Besides, for a high-power engine, you'll want maximum block integrity. In my case, I'm using a standard bore (4.000"). I believe Rich Krause is only running .010" overbore (4.010") on his mega HP engine.

 

There's no problem using a .030 over block. Its been done with small blocks for years, and there are several people on this board running 355ci forced induction lt1s. The TRW forged pistons should be fine, unless you're looking to run really high boost.

 

Like I said, only 8-10psi on lt4 heads. I know you can run 8psi intercooled on the stock bottom end with a perfect tune and supporting mods, and it'll be a matter of time till it goes. This shouldnt push it too much... I'm just wondering what people think as a more reliable bottom end.

I've read enough to know I might as well go for a Street-Twin clutch as well, and just get it over with as opposed to swapping clutches all the time.

It's a convertible - if I put more then 600hp out of it I'll bend the body in half, even with the weld-in subframe connectors. Not to mention the convertible weighs more then a coupe. If I wanted a really fast car, I'd buy the 355 and stickon a blower, and drop it in a gutted 78' Datsun or something silly

Honestly, if I blow the motor and it NEEDED to be re-bored, I've got other things to worry about, and i wont put 15k on it by the end of 2006! I've owned it almost two years now, and havent put 10,000 miles on it. I dont drive it in bad weather.

 

I think anyone that says its not safe to run a .030 overbore is a tad bit ****. BTW, what is this guy asking for this thing?

 

Your completely missing the point! What good is a block if you can't ever overbore it? One time use....we're not talking disposable razors here!

As for running .030 overbore with forced induction, no one said you can't do it and do it well. The point is why give up block integrity if you don't have to???

 

I had always understood that with a .030 overbore you could bore another .010 safely at least. Am I mistaken?

 

Whats that odd wear pattern about midway down the cylender on that last picture. Or is that just a reflection?

 

The big picture here is look what he would be getting. A pre-assembled shortblock, probably cheaper than if he were to purchase all the parts and pay to have a new block machined slightly, etc. I know my short block alone probably cost me close to $2500 with the machining and I did all the assembly myself. How many times is someone going to tear into a motor for a rebuild?

 

Did I read it wrong? This .030 engine already has 8000 miles on the rebuild, right? With studs showing, my guess is that it wasn't a transportation car; more likely it has been run a bit hard. Metal remembers every little (or big) stress that was ever put on it...a lot like women.

I'd rather start with a 68000 mile stocker and add my own good parts, especially with boost. Even if it's dirt cheap, the block will be at least .040 over before you can run it.

You pays your money and you takes your chances...


My $.02.

 

Just because it has head studs doesn't mean it was abused.....it's a 355...my guess is that if someone was looking for an all-out "race engine" to "abuse" i doubt highly they would have built it as a 355ci

 

OldSStroker's point was that if someone knew enough to stud the heads, this wasn't a "Sunday" driver rebuild. Odds are the engine was put through its paces. You can take a chance with a .040" LT1 block with a power adder if you want....but I won't.

 

I realize the thoughts, I wouldnt overbore past .040 myself if the motor were really under strain...

I would just as easily take my 150k block out of my z28 now and have it re-bored, but in all honesty as was said, the casting just isnt going to be quite as strong as it could have been, so I'm going to need a new block...

I realize that someone went so far as to take the motor and build it specifically for boost. That is what it was going to be used for, but never got to the final stage. A few thousand miles, and a 383 was installed in it's place to make more power.

Yes, you get what you pay for, but at this point I dont know what signs to look for that would be indicators either way of the motor's condition from a far. Of course I'll pick it up and do the final inspection in person, but for now I'm trying to decide if it'd be a worthwhile shortblock - and what you might think it be worth. I've been trying to gather more details before I start to haggle price so I'm well armed. I have requested a pile of more pictures already, and am looking for the specific information on the build (when, by whom, balance sheets etc) already, but I'm not good enough to recognize fine details about it'd condition...

I can tell the one piston bore has rust on the top from where the piston sat, and it looks like the face of another is darkened, from rust (not possible on these alloy pistons?) or perhaps from detonation? And the motor was run with glycol, and not dexcool... I can see that much easily, but beyond that, I dont know enough.

Thanks for the responses so far, if nothing else it's a good education experience on buying a used engine.

 

If those have been mostly street miles on an unmodified, never rebuilt engine that's not seen any nitrous, that might be an excellent block for rebuilding. Even Nextel Cup teams who replace all the rotating and reciprocating bits after every race reuse blocks, perhaps as much as 5000 miles if nothing goes wrong. New LT1 blocks are rare, and not really stronger than a "seasoned" street block that has the stock bore.

If you've put most of the miles on it, "the devil you know is better than the one you don't." Bret sometimes looks for mid 90's Buick Roadmasters or little old lady Caprices which had 5.7 LT1s. Many of them have never seen full throttle for more than a few moments.

Josh read me correctly.

My $.02