GM Bowtie block "184" max bore?

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Abbottracingheads
Expert
Expert
Posts: 780
Joined: Fri May 18, 2007 6:46 pm
Location: Crane, Texas
Contact:

Re: GM Bowtie block "184" max bore?

Post by Abbottracingheads » Sat Jan 13, 2018 5:50 pm

Call Marvin Shaw. The WOP shop can do it.
Abbott Racing Heads and Engines

Keith Morganstein
Guru
Guru
Posts: 5234
Joined: Sun Feb 19, 2006 10:19 am
Location: MA

Re: GM Bowtie block "184" max bore?

Post by Keith Morganstein » Sat Jan 13, 2018 8:50 pm

Dragsinger wrote:
Fri Jan 12, 2018 12:15 pm
We have no reasonable access to that test. I hope to hear from some builder who has experience with that specific block casting.
Buy your own ultrasonic tester. They are inexpensive these days and they work

https://www.ebay.com/p/Sseyl-Um6500-Han ... 3052318353
Automotive Machining, cylinder head rebuilding, engine building. Old school shop, semi-retired moonlighter. Can't seem to quit #-o

Frankshaft
Expert
Expert
Posts: 651
Joined: Sun Jul 05, 2015 6:01 pm

Re: GM Bowtie block "184" max bore?

Post by Frankshaft » Sun Jan 14, 2018 10:01 am

swampbuggy wrote:
Sat Jan 13, 2018 6:32 am
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. :)
You are correct, but, it works. I had 1 Dart Iron Eagle block at 4.250 for years. It never lost a head gasket. And it wasn't a mild deal. Bill Mitchell did in fact sell a 454 that was 4 inch stroke. And 4.250 bore. Its kind of dumb to take a brand new block to the limit though.

swampbuggy
Expert
Expert
Posts: 562
Joined: Mon Apr 04, 2011 8:54 pm
Location: central Florida

Re: GM Bowtie block "184" max bore?

Post by swampbuggy » Sun Jan 14, 2018 12:11 pm

Thanks Frankshaft for your reply, it makes me feel better about going to 4.185" on my NEW block. It is shy 4.125" as received from Dart Machinery. There are small holes in the deck appx. .250", when you view down into certain ones which line up with the outside of the cylinder bore you can see that the cylinder walls are THICK, and even at 4.185" they are STILL gonna be THICK, i am happy to see (say). BTW what is the purpose of those holes, let air get out ? Mark H.

Post Reply