400 Block at .060 OS ??

[Garys1969RR]

I picked up a 400 motor, 230 block. Got it apart, and the bore is measuring 4 13/32". That's 4.403! Looks like it is is .060 over size. ARRRGGG! This has the big main supports, and I was planning to use it on my 512 build. Cleaned the piston top off, and it has 60 stamped on it! Does that mean .060 OS? Dang. Any way to salvage this block? Sleeve it, fill the water jackets with block fill? Help! Here's a pic of the piston top.

 

[Garys1969RR]

Website giving probs. Won't let me edit, so here's a pic of the piston.

........I think it's a Silvolite 1274-060 cast piston.

 

[Jerry Hall]

What size bore do you need for the 512 build? I would have the block cleaned and checked at the machine shop. If any cracks or defects find another one. My 30 over 400 block with the 440 crank and rods comes up to 451 cu. inches. You are probably not going with the stock bore on a stroker engine. If this block is clean at .060 I would use it.

 

[Garys1969RR]

Are there .060 OS pistons (4.40) with a 1.32 C Height? That's what I need. Flat top, forged, valve reliefs.

 

[m79ded]

Are there .060 OS pistons (4.40) with a 1.32 C Height? That's what I need. Flat top, forged, valve reliefs.

Gary those pistons are for a stock 400 build, unfortunately they will not work for your big inch build. There is a piston from Diamond that is 1.305 CH specifically designed for the 512 it's part # 52015. It's very light. you can ask about custom bore size

 

[Garys1969RR]

Well, I have a couple other 400 motors in the spare engines pile. Plus I want to keep the cyl walls as thick as possible, and had decided to use the ICON 823.033 flat top piston for the 512 build. That's a flat top with 1.322 C Height. So I guess I'll be looking through my spare motors for a stock bore size block, as I need to go .035 over for the 512. Anyone int in a 230 block, .060 over?

 

[cryplydog]

Gary, 440 Source has a great web page for reference and sizes. If you haven't looked I would highly recommend it.

 

[Garys1969RR]

Gary, 440 Source has a great web page for reference and sizes. If you haven't looked I would highly recommend it.

Ok, I will look there again. Guess I was under the impression that 400 blocks only had pistons available going up to 4.375, for the stroker motors. 451, 512.......Looks like they have a 4.380 piston for a 512. This block is already at 4.400

 

[Garys1969RR]

Did find a 4.400 bore size ICON piston with 1.322 C Height. That's a .060 oversize. Just thought that might be a little too much for a 400 block, building it into a 512.

 

[andyf]

You need to take the block to a machine shop to see if it is usable. They can look at the bores and see if it needs to be honed or bored. They should also have a sonic checker to tell you if the walls are thick enough. Odds are that the 060 over block is used up but it is possible you can use it if it hasn't been run much. Nobody on the internet can tell you anything about that block, you need to have a good machine shop look at it.

 

[BSB67]

If this block is clean at .060 I would use it.

Figure out what the block cleans up at, call Diamond and tell them you want the 52007 or 52407 piston but to fit you finish bore diameter. If you don't like the price, use a different block

 

[dvw]

Sonic it. Koffel used to build Comp Eliminator motors at 4.400". Just depends on the core shift.
Doug

 

[Garys1969RR]

Ok, taking it to the Block Shop today. I don't think I'm going to be able to use this on a 512 stroker race only motor. May be able to use it for a 451 street motor at .060 over.

 

[747mopar]

My 400 based stroker is bored .60" over, the machine shop checked it out and said it would be no problem. If it had cast pistons and isn't all rusty it will likely clean up for a forged piston just fine but the machine shop is the first step.

 

[Garys1969RR]

Well it is showing a bore of 4.406. That's .066 Over std. So if I run .008 piston to wall clearance, then I'll have about .002" to hone. That might work. 4.068 final bore size. I guess I need to look for a sonic tester now, see how much iron I have left in the bores. I wonder if filling in the bottom half with block fill would help? Some kind of cement they put in the water jackets to help support the outside of the cyl walls. Anybody ever used this? Drag race only motor.

 

[6PKRTSE]

I would have no issues at all going +.060" on any block as long as it sonic checks out good. Done many builds over the years using JE and Wiseco pistons back then.

 

[dvw]

[QUOTE="Garys1969RR, post: 911183377, So if I run .008 piston to wall clearance, then I'll have about .002" to hone. That might work. 4.068 final bore size. [/QUOTE]
A .060" over piston fits a .060" over bore block, not a .066" over bore block. If it sonic checks ok. It'll need a custom piston.
Doug

 

[Garys1969RR]

Found a place that will sonic test it for $60. Not bad. Plus will look in my spare motors pile for a stock bore 400 block.

 

[Garys1969RR]

[QUOTE="Garys1969RR, post: 911183377, So if I run .008 piston to wall clearance, then I'll have about .002" to hone. That might work. 4.068 final bore size.

A .060" over piston fits a .060" over bore block, not a .066" over bore block. If it sonic checks ok. It'll need a custom piston.
Doug[/QUOTE]

It has been bored .060. Then had 40 K miles put on it. The machine shop says the largest point on the bore is .066. I' guessing say .002 original clearance, and .004" wear takes it to .066. Anyway, leaning towards a .035" over piston starting with a stock bore block, and getting it bored to .035. Prob the best way since I have 1 on hand, although it's a 630 casting.

 

[BSB67]

A .060" over piston fits a .060" over bore block, not a .066" over bore block. If it sonic checks ok. It'll need a custom piston.
Doug

It has been bored .060. Then had 40 K miles put on it. The machine shop says the largest point on the bore is .066. I' guessing say .002 original clearance, and .004" wear takes it to .066. Anyway, leaning towards a .035" over piston starting with a stock bore block, and getting it bored to .035. Prob the best way since I have 1 on hand, although it's a 630 casting.

I think what Doug is saying is generally the clearance is ground into the piston on typical shelving piston. A 0.060" over shelving piston for your motor will probably measure between 4.395 to 4.398, depending on the type of aluminum.