Howdy everyone,

Long time lurker, finally decided to become a member. Did some searching for an hour or so, but didn't come up with much. I have a line on what has the potential to be a very sweet deal. It is a 454 block that is said to now be a 468, callies crank, h-beam rods of unknown brand, je 13:1 pistons, and LS6 heads that are supposed to be ported to the hilt, stainless valves with titanium goodies.

My question is, how do I distinguish LS6 heads from the rest?

Now for the bad news. The current owner stored the car over the winter, failed to drain the block, and it cracked a sleeve. Supposedly it was noticed before it scored the piston at all.

What are my options on taking care of this? Would I do better buying a block for 200$, and starting all over? Or would it be cheaper to have that one cylinder sleeved? I was told that if I were to sleeve a cylinder, the cylinders next to it could be forced out-of-round, and to correct it id have to bore those (and thus all 8 cylinders) to get things back into shape. Is this the truth?

 

LS6 heads are probably 291 castings. Cast iron (heavy) rectangular port closed chamber heads. They have pretty good flow characteristics but with aftermarket choices, they're not all that good by today's standards plus aluminum heads are now inexpensive compared to engines 40 years ago. The closed chamber will shroud the valves if larger valves are installed. There really isn't any bad Mark IV BBC head castings. They all perform well. Some just do better than others.

Depending how bad the crack is, the cylinder can be resleeved. A machine shop will have to make the final decision. Although it's costly, it's cheaper than buying a new block and having it bored out for the old pistons or buying a used block and having even more machine work down to it although a new aftermarket block is far superior to a production block.

 

I absolutely hear you on the aluminum heads (and aluminum block for that matter), but to be honest money isn't very abundant right now, I'd like to do a fairly budget build, and work with what I have for now. Then once it's in the car, if I decide I need more oomph, I can upgrade from there.

Do you know if installing a sleeve will typically warp the surrounding cylinders? Any idea what a ballpark price would be on such a job? I'm just trying to get a feel of what I'll be looking at before shopping around.

By the way, thats an awfully sharp setup you have. I've played around with alcohol bikes, and shifter carts, so I certainly have respect for anyone with a monster like yours!

 

Both rear cylinders in my Dart block have been sleeved after I threw a rod. It was a lot cheaper than spending $3000 for a new block then hundreds more prepping it for use. A new block needs to be bored out, cam bearings installed plus other prep work such as frost plugs, gallery plugs etc.

Putting a sleeve into a block needs to be done by a machine shop. They need to bore the cylinder out so that the sleeve can be pressed in. They leave a lip at the bottom of the cylinder for the sleeve to butt up against. They then mill the top of the sleeve down to the deck height and bore it out for the piston. Chances are there will be distortion in adjacent cylinders which just requires honing to the proper size again.

For a run of the mill production block, it may be cheaper to just buy another block. If you have a rare casting or expensive aftermarket block like mine, it's cheaper to have it repaired. If you want to spend the money, you can have 8 sleeves put into a block that's been bored out to the maximum and bring it back to stock specifications. Production blocks all have weak castings. They're not really designed for such extensive repairs. My Dart Big M block can be bored out .120" over and will still have .250" thick cylinder walls so sleeves didn't weaken the casting at all.

I have no idea on pricing. Call around to machine shops and ask. If I dig around through all my invoices, I might be able to find the repair bill but that was years ago plus I had the machine shop put the short block together.

It's taken me 10 years to get the car to where it is now. The performance curve has leveled off with only tiny increases each year. I'm still looking for that 8 second timeslip but it's hard to get when you race at altitude. The last track day this year I finally beat my best time from last year by a very small amount. Next year, who knows. The fiberglass doors going on over the winter will shave some more weight off. After using alcohol for quite a few years and switching from carbs to injection a couple of years ago, I'll never go back to gas or carbs in a race car.

 

Well, I decided to pick up the engine, so heres a little update:

The block isnt cracked on one of the cylinders. It's actually cracked on the headgasket surface. About 4" long. Nothing can be done about this, right? It's a 70s era 4 bolt block too....what a shame.

The heads are real deal ls6 heads. 2.30 intake, 1.90 exhaust if I measured correctly. Looks like they barely fit. dual spring valve springs and titianium keeps on stainless valves as advertised. A little rust has evolved where the intake ports have been worked over, but I dont think its anything that cant be addressed. The previous owner swears up and down that this engine revved to 8500 RPM every weekend, but that just sounds scary to me. I'm used to 4 cylinders that rev to 13,500 from the factory, but a big block to 8500 just sounds like too much to me.

Appears to be eagle rods, hanging onto a set of JE pistons that I was told are 13:1. The dome on them makes me to believe this is true. The pistons hardly have any markings on them at all. However, I believe they are on .010" over, not the .030" over that I was told. I've only got a composite micrometer, so I dont want to bet the farm. However, it's always been spot on before. 4.260 would be .010" over stock, correct?

The pistons will be slung around by a Callies crank that, by the looks of things, has been drilled and balanced.

The cam has me in a bit of confusion. It has a bunch of numbers hand-engraved on the end of it, but no brand markings anywhere that I see. Anyway that I can figure out what I've got?

Oilpan with a trapdoor, baffle, and kick out.

Everything seems to be in real good shape, other than the block. I spent the day scraping old gaskets, and spraying everything down with wd-40, and putting it in baggies.

So now my questions are, what are my options? I'd like to turn this pile of parts back into the monster it once was. One thing I noticed is that front-most main bearing seemed to have elevated wear on it compared to the others. However, the crank itself is spotless. What would cause this?

Someone talk blocks with me for a second. What are the differences in the 454 blocks, other than 2 bolt/4bolt? I know theres several versions, but do not know the differences. Should I be looking for any particular version in particular? Would it be financially stupid to buy a 2 bolt, and have it mated to my 4 bolt caps?

Thanks everyone for the help. This is my first experience building a domestic vehicle. I'm looking forward to learning about this dinosaur!

 

A block with a cracked deck is scrap metal. Everything else should be checked out by a machine shop. Have the crank and rods magnafluxed. No sense trying to reuse them if they have a crack. Without cam grind numbers, it's hard to tell exactly what it is. I doubt you would want to use it on the street.

8500 is high for a BBC but not uncommon. I spin my 540 to 7500. Lightweight rotating assembly keeps the reciprocating weight down.

Like the BBC heads, there aren't really any bad block castings. Just find a 1970-1990 454 block. A 2 bolt main can be studded and be just as strong as a 4 bolt.

 

These are the markings on the cam:

NC 0301
x1605
4254/5247 2002A
R110 ER

Once again, much appreciated for your time and knowledge.

Edit, also its a solid roller cam if thats of any help. Also running 1.7 roller rockers. Naturally, it'll be a race gas only engine since of the compression. I realize its hard to ballpark hp/tq but do you have even a rough estimate of what I would be looking at for output at the crank?

 

After talking to the machine shop, I've decided to just look for a 4 bolt. To convert a 2 bolt to a 4 would nearly double my block-preparation expenses.

Why are the Post-1990 blocks out of the question?

 

1991 was the start of the Gen V block. It shares little in common with the older Mark IV blocks other than it's a direct replacement. The newer Gen VI blocks are based on the Vortex design which changed even more but at least for the better.

Using an older Mark IV block allows the multitude of aftermarket parts available for the BBC.

 

If you want a factory 4-bolt block, look at a HD Truck/RV wrecker... lots of those vehicles used 454s and they were usually the 'HD Service' engines, so the good stuff, like 4-bolt caps, steel crank, etc. Might be hard to find a pre-1990 block now though, as thats getting pretty old.

 

Alright, Mark IV is the only way to go.

So what about the 427 block. Thats the same bore right? So with my crank is should be just the same?

Now heres where I'm going to show how green I really am to these engines. But then again, those are engines that rev to 14,500rpm on 87 octane, a .6 liter engine can make 120hp, and do it for thousands of miles. In my experiences building bike engines, tolerances are ridiculously tight. Boring a cylinder without having the piston in hand is simply something you do not do.

On these engines, how tight are piston-to-cylinder clearances? I found a block that has already been bored, and finish honed. But, if I were to buy pistons, would I just be shooting myself in the foot for buying a block that was bored without the pistons in hand?