Megablock core shift.

Well, i now know why the number 2 cylinder split. Core shift. I had the block sonic checked and the passenger side bank of cylinders are all too thin, .142 was number 8. Crap. Sooo, sleeve it? All 8 cylinders would run about $1600 and i would go to a smaller than the current 4.504 bore. Would like input on what to do. If i have to reduce bore size to make this thing viable, how much would i have to go? 4.40? More? I may just consider selling it since the aluminum world block i have my name on is almost ready to ship to me. I will post in the what is it worth section for an idea of what to ask for it.

That is a siamese block...therefore it should retain it's column strength if done properly. >>>IF DONE PROPERLY.<<< I'd poke around and find a competent machinist and let him tell you what the dimensional limits are but, The better Darton sleeves can go pretty thin and hold ...IIRC .080 wall.
SO...it's very conceivable that you can put 8 sleeves in it IF IT'S REQUIRED. Do you have the sonic #'s for ALL cylinders?

I just got a phone call from the shop. Haven't got the numbers yet. If i sleeve it, i am thinking i may as well go with a bit thicker sleeve and have a block that will let the rings seal, and live.

4.440 is a good size. Good rings available and 2 overbores at .030 per.

Ford bore size IIRC ? Be a 520ci on a 4.25 stroke ?

Tex

You're scaring me! My 2002 megablock has one at 0.135" and one at 0.137"! And this is on the thrust surfaces. This is my B1 motor that makes 1060 hp.

Discussed it at length with my builder (Tony Bischoff) and he felt sleeves would not offer any benefit and they are thinner. He recommended filling the block and not looking back. That's what I did.

This is mine.............

And this is why high dollar Mopar blocks get such a bad name....I have bought a number of them over the years....They aren't cheap, and nobody stands behind them....Called the manufacturer back and it was just thrown in my face....They don't care, so I stopped buying them.

Personally, a +$6000 engine block should come with a full CMM print out of all dimensions and they're results...If it doesn't, it could be a paper weight and you wouldn't know it..Bought a couple of paper weights in the past. That leaves a pretty lasting impression i can say.

In this day and age, if there isn't a CMM report, its not worth buying...Manufacturer's should start stepping up.

I worked at GM for many years, in block machining as a matter of fact, and I could scan the matrix off any block and pull up all the dimensions from that exact block.......

If all a manufacturer is doing is some machining and then selling it to you, then they are only doing half the job...Hell, these days a Keyence vision system can measure most features in seconds...I program these things all the time. Its not rocket science or expensive.

A friend of mine runs an AMC at .090" been together quite a while. Around 425 cube, been 9.40s in stock chassis American. The cost of Darton sleeves are probably worth more than the block. Does it need 8?
Doug

Doug, haven't seen the paperwork yet. My guess is 4.

Mark do you have any idea where those measurements where taken, top, center or bottom of the bores?
I know one shop in SO CA scans the cylinder walls and list the thinnest place, not good in my opinion. They were the reason I bought my Dakota 1000 sonic tester, I test each bore in 12 places, top, center and bottom on all four sides of each cylinder and write them down on my form as I do each measurement.
I calibrate it to a known thickness, not a frequency, on each block so I can try and get every measurement as accurate as possible

I believe that they took top middle and bottom and recorded the lowest number. I know that the lowest 2 were on the bottom.

I got a quote for four Darton ductile iron sleeves put in 2 4 6 8, $1200.00.
I did a compression check before adding stroke, and #8 was down 15 psi from the rest. A lower than average reading showed up in #8 after going to 550 cubes and running it on the dyno. That also happens to be the thinnest thrust side (#8) at .142. So. I may as well do all 4 if i am going to fix it?

At that Price I would definitely repair. Hell even if all 8 were done where could you get a decent block for $2400. With your world block coming you know have a spare that can be rotated in if you need to freshen up the engine you put in the car.

If you don't mind coming to Buffalo, send me a PM, Farley's is $100/sleeve

My megablock needed #1 sleeve............# 6....it is a common problem,....Muscle motor's did mine, 572 b1 engine = 1050 HP

If it’s already 30 over would you sleeve it’s?

Right now the block is at 4.5043 and oistons were coated to take up the extra .0043. Since the core shift hurt the even# cylinders most, i thought i may as well do all four. Especially since #8 is the thinnest and showed weaker than average cranking compression on two seperate builds.

Damage to my 496 stroked mega lock.

Ours is on a 4.565 bore and this is what we got with our paperwork, runs fine but is only 700hp and we only use 6300rpm+its street driven>

I would think the people casting these NEW blocks would’ve at least made the walls .300 to start with. Hell my 1939 9N ford tractor has sleeves that pop in and out for easy service, I guess they were to smart back then.