[prostreet64]

The 400 block out of my son's car has been at the machine shop for a going over and a bore out to 60 over for the new pistons. Got a call from the machinist today with a problem that wasn't discovered until after the bore and final hone. There is a small hole in the #4 cylinder wall about halfway down and it connects to the water jacket. Maybe a void when the block was cast? Anyway, he can sleeve it but from you guys who have done this before what are the potential problems that might arise? I have read that a sleeve will affect the adjacent cylinders. How is that usually dealt with?

[mgarblik]

In a perfect world, I would look for a new block. In the real world, it sounds like the block is fully machined and ready to go and then they found the defect. Unfortunately, this happens sometimes. Not sure what kind of power the engine is going to make and what type of racing you do. In NHRA Stock or Super Stock, the engine would likely not make competitive power with one sleeve stuck into a fully finished block. This is because #2 and #6 cylinder WILL be distorted when the sleeve is installed in #4. That's just the way it is, no way around it. So to make #2 and #6 straight and round, they would have to be honed oversize .002"-.004". Even the best cylinder hone operator probably couldn't get by with less. Now, if the cylinders are just bored and have .004-.005" left for the final plate hone, you will be OK. Another option would be to buy ( 4 ) .065" pistons and install the sleeve and final hone the right side .065". This being the race section, I assume you want the block as perfect as possible.
For a street engine on a budget, I would put 1 sleeve in on a shelf at the bottom and do the best salvage hone job I could get by with on #2 and #6. It would not be optimal, but a street engine would likely never know it. It all depends on your goals and budget.

The good news is it was found before the engine was assembled and on the dyno or in the car. Hope you get it sorted out.

[Half-Inch Stud]

Sleeve it and be happy.

[hurryinhoosier62]

Originally Posted by mgarblik

In a perfect world, I would look for a new block. In the real world, it sounds like the block is fully machined and ready to go and then they found the defect. Unfortunately, this happens sometimes. Not sure what kind of power the engine is going to make and what type of racing you do. In NHRA Stock or Super Stock, the engine would likely not make competitive power with one sleeve stuck into a fully finished block. This is because #2 and #6 cylinder WILL be distorted when the sleeve is installed in #4. That's just the way it is, no way around it. So to make #2 and #6 straight and round, they would have to be honed oversize .002"-.004". Even the best cylinder hone operator probably couldn't get by with less. Now, if the cylinders are just bored and have .004-.005" left for the final plate hone, you will be OK. Another option would be to buy ( 4 ) .065" pistons and install the sleeve and final hone the right side .065". This being the race section, I assume you want the block as perfect as possible.
For a street engine on a budget, I would put 1 sleeve in on a shelf at the bottom and do the best salvage hone job I could get by with on #2 and #6. It would not be optimal, but a street engine would likely never know it. It all depends on your goals and budget.

The good news is it was found before the engine was assembled and on the dyno or in the car. Hope you get it sorted out.

This ^^^^^^^^

[steve25]

Sleeve it .
Fill the block to the bottom of the timing cover holes.

Sell those Pistons.
Get new custom Pistons made in a Bore size needed to compensate for the block distortion.

Contact total seal and have them make you the ring size you might now then need.

Sleep soundly.

[prostreet64]

Thanks guys for the input. This car is mostly street driven with a trip to the track on occasion. Engine makes close to 500 hp at the flywheel. We definitely have some things to consider before deciding how to proceed.

[lakefect]

i have one sleeve in my 70 RA3 block .060 over.done back in 1978 still running strong!!

[prostreet64]

lakefect, that is good to know. Hope we will have a good outcome like yours.

[mgarblik]

Originally Posted by prostreet64

lakefect, that is good to know. Hope we will have a good outcome like yours.

Agree, mechanically, a repair sleeve should work fine and be reliable. Power wise, the more straight and round, they can get the companion cylinders, the more power it will make. IMO, if running quality forged pistons, I would sacrifice a little extra piston to wall clearance for straight and round cylinders with a torque plate installed.

[prostreet64]

mgarblik, I just talked with the machinist and that is exactly what he said. He will use a minimum interference fit to minimize the effect on the adjacent cylinders and he will super cool the sleeve so it will 'drop' in. The needed cleanup on #2 and #6 should be very little and therefore not add much to the piston to wall clearance.

[nas t eh]

I have a stupid question.
Was the block sonic checked for wall thickness? Could this be the result of core shift and the cylinder with the hole was the worst cylinder, but there are others that are thin in spots and really it would be better to source another block?

[Dragncar]

Well, at this point you might want to sonic check the whole thing if that has not already been done.
If it checks out I would be inclined to sell the pistons and get some .065- .070 pistons, whatever you need to make sure all 8 holes are round. Might want to fill it first too.
I know its a lot of work, but we all have had to do some rethinking in the middle of projects before.
Both the original WT 400 block and the 1970 HO 455 block in my GTO had a sleeve in the # 1 hole done by the previous owner.

[misterp266]

. . .

[hurryinhoosier62]

Originally Posted by prostreet64

mgarblik, I just talked with the machinist and that is exactly what he said. He will use a minimum interference fit to minimize the effect on the adjacent cylinders and he will super cool the sleeve so it will 'drop' in. The needed cleanup on #2 and #6 should be very little and therefore not add much to the piston to wall clearance.

See if you can talk him into using sleeve retaining compound as well.