GM Bowtie block "184" max bore?

[Dragsinger]

We have a "184" GM block that is now 4.155 bore. It has a damaged cylinder and will require increasing the bore to 4.180 to clear the damage. Is that block OK at 4.180 bore?

[pdq67]

Why not sonic check it and know for sure?

pdq67

[Dragsinger]

We have no reasonable access to that test. I hope to hear from some builder who has experience with that specific block casting.

[Frankshaft]

4.185. Probably could go 4.200.

[swampbuggy]

The maximum recommended bore size is in General Motors paperwork or online if you have all the numbers correct numbers

[swampbuggy]

, hey Larry where do you live at

[user-17438]

I have gone 4.185 on those without problem. I can see going 4.200 not an issue also.

[Dragsinger]

Swap,

I live in Kilgore, East Texas

[pdq67]

Does Bill Mitchell still sell a SBC block that can at the extreme overbore go to 4.250"??

pdq67

[Belgian1979]

I have this block. 4.180 is the specified limit on those.

[swampbuggy]

PDQ67------ a 4.250" bore in a 4.400" bore center block would only leave .150" between the bores, are you not thinking of the fairly new 4.500" bore center block??? Dart machinery offers this block in iron (and) aluminum. The MAX. recommended bore diameter for this block is 4.250", and that would leave .250" between bores. A 4.400" bore center block (original S.B.C. design) at 4.185" leaves one with only .215" between bores. Mark H.

[Krooser]

Time for a sleeve?

[racinnut15xm]

We have no reasonable access to that test. I hope to hear from some builder who has experience with that specific block casting.

You are in Kilgore per your other post. Take it and get it sonic tested, you aren't in the sticks I'm sure a local machine shop can do it. I think it should also be asked how much HP you plan to push through it.

[pdq67]

PDQ67------ a 4.250" bore in a 4.400" bore center block would only leave .150" between the bores, are you not thinking of the fairly new 4.500" bore center block??? Dart machinery offers this block in iron (and) aluminum. The MAX. recommended bore diameter for this block is 4.250", and that would leave .250" between bores. A 4.400" bore center block (original S.B.C. design) at 4.185" leaves one with only .215" between bores. Mark H.

Not the RO7 4.5" bore space NASCAR block.

I seem to remember that Bill Mitchell DID/DOES sell a SBC block that would bore to 4.25" and that there is a head gasket just for it because of the thinness between the cylinders.

pdq67

[Dragsinger]

about 680 horse, 12:1 compression, no power adders, conservative tune, race gas, about 7600 upper RPM, lightweight car, powerglide, 1/8 drag race.