Small Block & Big Block Chevy Specific Mouse & Rat Motor Discussion & Conversions

.080 over chevy 350?

Thread Tools
 
Search this Thread
 
Old 12-08-2006, 08:07 PM
  #1  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default .080 over chevy 350?

this is just a question after seeing some shortblocks on ebay that were .080..i thought the max bore on a standard chevy 350 was .060? im not going to buy one, i was just looking around killing time at work today and ran across them. I dont think ive ever saw a .080 piston for a 350 for sale. im sure or obviously you can order them..i guess its for those dirt track people trying to squeeze every last ounce out of that "cubic inch" limit.
Old 12-08-2006, 08:29 PM
  #2  
6 & 8 Second Club
 
mrdragster1970's Avatar
 
Join Date: Aug 2006
Location: Illinois, RT 66 dragway area
Posts: 2,284
Likes: 0
Received 0 Likes on 0 Posts
Default

People have done dumber things. I have never gone or let any of my buddy's go more than .060.

But I'm a big fan of custom pistons. I go up .005 when I rebuild my big blocks to keep everything tight.
Old 12-08-2006, 09:03 PM
  #3  
On The Tree
 
CNC BLOCKS N/E's Avatar
 
Join Date: Oct 2006
Location: NORTHEAST
Posts: 124
Likes: 0
Received 0 Likes on 0 Posts

Default

We sonic test all theblocks that go through our shop abd we only find a few that would be safe at .060 or have any ring seal.
Old 12-08-2006, 10:11 PM
  #4  
7 Second Club
iTrader: (5)
 
Villain281H's Avatar
 
Join Date: Nov 2001
Location: Gainesville, Florida # of drag strips runs: ?!?!?
Posts: 8,834
Likes: 0
Received 1 Like on 1 Post

Default

I've never gone or heard of anyone going above .060 overbore. But as they say, to each his/her own.....
Old 12-09-2006, 08:18 AM
  #5  
10 Second Club
iTrader: (14)
 
WheelsUp84z's Avatar
 
Join Date: Oct 2005
Location: Concord, NC
Posts: 1,384
Likes: 0
Received 4 Likes on 4 Posts

Default

i would think the block would have to be brand new and probably filled to the top with block filler, i personally dont like to go any more than .040 but thats just personal preference
Old 12-09-2006, 05:18 PM
  #6  
11 Second Club
iTrader: (17)
 
Armyman2445's Avatar
 
Join Date: May 2006
Location: Greenville SC
Posts: 574
Likes: 0
Received 0 Likes on 0 Posts

Default

Ive seen a machine shop do that when I was picking up my heads. The cylinder walls were paper thin. I know it wouldnt hold boost or spray with out blowing the walls apart.
Old 12-09-2006, 05:28 PM
  #7  
TECH Veteran
iTrader: (18)
 
SHINER's Avatar
 
Join Date: Sep 2005
Location: SW Houston
Posts: 4,185
Likes: 0
Received 0 Likes on 0 Posts

Default

usually anything that is 60 over is going to have to resleeve the block.
Old 12-09-2006, 05:44 PM
  #8  
Teching In
 
wicked@boost's Avatar
 
Join Date: Oct 2006
Posts: 41
Likes: 0
Received 0 Likes on 0 Posts
Default

i guess u can go 0.0100 with a 454ci or 400ci blocks without sleeving. some one correct me if i am wrong.
Old 12-09-2006, 06:07 PM
  #9  
TECH Veteran
iTrader: (18)
 
SHINER's Avatar
 
Join Date: Sep 2005
Location: SW Houston
Posts: 4,185
Likes: 0
Received 0 Likes on 0 Posts

Default

Originally Posted by wicked@boost
i guess u can go 0.0100 with a 454ci or 400ci blocks without sleeving. some one correct me if i am wrong.
are you meaning 100 over or 10(.1)?

In that case 100 over is Waaaaaayyy to much and the block is now worthless.
Old 12-09-2006, 08:53 PM
  #10  
On The Tree
iTrader: (19)
 
1badnova496's Avatar
 
Join Date: Mar 2006
Location: Hartselle,Alabama
Posts: 113
Likes: 0
Received 0 Likes on 0 Posts
Default

i ran a 505 bbc for a little while in my car which was a .100 over 454 block with a 4.25 stroke. i never had a problem with anything as far as ring seal or overheating but i have seen other blocks(454s) that shouldn't go over .060. i have seen an .080 over 350 before and it was a masterbuilt brand crate motor.
Old 12-09-2006, 10:54 PM
  #11  
6 & 8 Second Club
 
mrdragster1970's Avatar
 
Join Date: Aug 2006
Location: Illinois, RT 66 dragway area
Posts: 2,284
Likes: 0
Received 0 Likes on 0 Posts
Default

BBC is way way different than a SBC. I have friends that have gone 4.375,
I would never do it but they have done it. Never more than 800 HP, and never on spray or boost. I have seen maybe 2 out of 10 crack, but they were low budget guys.

I personally have been .105 over on a stock block, 1000+ HP and many many pass'.
I was probably going to go 1 more rebuild at .110 over, but the crank split and took out that block. 505" is a very popular build with my buddy's. There are not many .060 blocks left anymore. We only used older blocks in those days, 60's-70's. I don't know anything about these new BBC blocks. Besides we all use big bore stuff now anyway.

There has never been a problem going .100 over on older blocks, and if you find a tall deck truck block, you should be all set. We have had great luck with them.
Back to SBC, I still say .060 is the max I would risk, and that's for a drag only motor, that will not see a lot of wear & tear.
Old 12-09-2006, 10:58 PM
  #12  
TECH Veteran
iTrader: (18)
 
SHINER's Avatar
 
Join Date: Sep 2005
Location: SW Houston
Posts: 4,185
Likes: 0
Received 0 Likes on 0 Posts

Default

hmm, learn something new everyday! Good info Mr.Dragster!
Old 12-10-2006, 12:21 PM
  #13  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default

yea, thanks for the info

obtw..this is the auction that sparked my question..
http://cgi.ebay.com/ebaymotors/350-C...spagenameZWDVW
Old 12-10-2006, 12:30 PM
  #14  
TECH Veteran
iTrader: (18)
 
SHINER's Avatar
 
Join Date: Sep 2005
Location: SW Houston
Posts: 4,185
Likes: 0
Received 0 Likes on 0 Posts

Default

what makes it a NASCAR motor?
Old 12-10-2006, 01:08 PM
  #15  
TECH Fanatic
Thread Starter
iTrader: (13)
 
redbandit98's Avatar
 
Join Date: Feb 2004
Location: Ft.Smith AR
Posts: 1,164
Likes: 0
Received 1 Like on 1 Post
Default

650 bucks man...super $$ Nascar build..
Old 12-11-2006, 02:35 PM
  #16  
6 & 8 Second Club
 
mrdragster1970's Avatar
 
Join Date: Aug 2006
Location: Illinois, RT 66 dragway area
Posts: 2,284
Likes: 0
Received 0 Likes on 0 Posts
Default

Finally something I actually know about.

You guys are like rocket scientists with this modern stuff.
Old 12-12-2006, 11:11 AM
  #17  
11 Second Club
iTrader: (3)
 
MARKSZ71's Avatar
 
Join Date: Nov 2001
Location: bama bitch
Posts: 1,582
Likes: 0
Received 0 Likes on 0 Posts

Default

got a friend that went 125 over, but he cemented his big block,went 6 years on this combo and just pulled it out to go with a larger bore block
Old 12-12-2006, 12:27 PM
  #18  
Staging Lane
 
Something's Avatar
 
Join Date: Mar 2006
Posts: 58
Likes: 0
Received 0 Likes on 0 Posts
Default

Like everyone else pretty much said, I've only heard of .80 over on a Big Block. I mean I'm sure someone's done it, but that big of an overbore on a small-block just doesnt sound safe.
Old 12-14-2006, 05:04 PM
  #19  
Staging Lane
 
johnjzjz's Avatar
 
Join Date: Jun 2006
Posts: 60
Likes: 0
Received 0 Likes on 0 Posts
Default

having been in the buzz a while -- sonic testing is the only way to tell if the core has a shift in it -- that will tell you how thick a cylinder is SBC normally 200 thick or their abouts 400 sbc are thin some wont hold up to a stock 030 re build --- 427 454 block in a 4 bolt .100 and even .125 is not un heard of because they are plus .300 thick -- race motors BOE TY type sbc .500 thick and bbc Boes are .850 thick to start with so 4.250 454 bore can end up 4.600 and still have real race life in it i hope this helps == jz
Attached Thumbnails .080 over chevy 350?-cimg0458.jpg  
Old 12-17-2006, 12:42 AM
  #20  
12 Second Club
 
Vintage Iron55's Avatar
 
Join Date: Nov 2006
Posts: 120
Likes: 0
Received 0 Likes on 0 Posts
Default

I have a 283 bored .080 over, but it is a 1959 block and it can go .125. I wouldnt try it on a 350 though. If it were possible to go .080 over where would you get the pistons? Custom jobs no doubt. I discovered .080 283 was limiting on piston selection big time. I think I will just bore it out the rest of the way to a 301. use 302 pistons. easier to get rings too.


Quick Reply: .080 over chevy 350?



All times are GMT -5. The time now is 01:50 PM.