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#1
05-10-2019, 10:42 AM
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Crack in bottom of bore, Now What?
Just got my block back from the shop after freshening when I noticed this little crack at the bottom of the bore. About 3/4 in long. Its a 1970 YZ .030 over No's Matching stock build up. There doesnt seem to be any problem on the opposite side of the bore, theres plenty of material there and no visible crack, but it is on a seam from the casting. So whats the next step? I am wondering what the shop will reccomend for a fix, could this be welded, does it need a sleeve, or something else? Am I over reacting and it is nothing to worry about? I have seen worse at the bottom of a bore. The shop is supposed to be reputable but they missed this so who knows.
Last edited by tonyk; 05-10-2019 at 10:50 AM. |
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#2
05-10-2019, 11:11 AM
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Bring it back.
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#3
05-10-2019, 11:51 AM
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Yeah, they need to re-mag it. Might need a sleeve.
.
__________________
. 1970 GTO Judge Tribute Pro-Tour Project 535 IA2 http://forums.maxperformanceinc.com/...d.php?t=760624 1971 Trans Am 463, 315cfm E-head Sniper XFlow EFI, TKO600 extreme, 9", GW suspension, Baer brakes, pro tour car https://forums.maxperformanceinc.com...ght=procharger Theme Song: http://www.youtube.com/watch?v=7zKAS...ature=youtu.be |
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#4
05-10-2019, 12:10 PM
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Was the block just bored or honed?
If so that may just be a tool location scratch.
__________________
Wernher Von Braun warned before his retirement from NASA back in 1972, that the next world war would be against the ETs! And he was not talking about 1/8 or 1/4 mile ETs! 1) 1940s 100% silver 4 cup tea server set. Two dry rotted 14 x 10 Micky Thompson slicks. 1) un-mailed in gift coupon from a 1972 box of corn flakes. Two pairs of brown leather flip flops, never seen more then 2 mph. Education is what your left with once you forget things! |
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#5
05-10-2019, 12:45 PM
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They said it only needed a finish hone.
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#6
05-10-2019, 12:48 PM
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Can you see it from the lifter side?
Understand not wanting the crack to grow on a NM engine. If it does go all the way through...You'll still have a crack, that can grow, even with a sleeve. 3/4" would be well below the oil ring. So depending on what direction the crack goes through, if it even does, you'ld have the option of drilling a small hole through and stopping it. I've ran engines with chunks gone in that area. So as long as that doesn't grow it shouldn't hurt a thing. Clay |
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#7
05-10-2019, 07:23 PM
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Remag the block. If it is truly a crack, a sleeve will take care of it.
__________________
“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
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#8
05-14-2019, 12:57 AM
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No matter what you do sleeve, weld or what ever the first course of action would be to stop drill it.
__________________
Tim Corcoran |
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#9
05-14-2019, 08:05 AM
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So it’s a crack, or a bore gauge artifact?
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#10
05-14-2019, 08:49 AM
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From the pic provided, it does look like a little crack. Has a zig-zag kind of look to it. Not sure what the best course of action would be on that one. Stopping the crack, if it a crack is very important. It is in a non-water, non critical area of the block. Kind of a weird place for a crack of that type. More typical for a chunk to be just missing there. Verifying a crack with dye penetrant or Mag is first.
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#11
05-14-2019, 11:27 AM
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I have a .030 over 455 that was bored decades ago and never assembled that has the same crack. Mine seemed to center around core shift. The machinist that bored it, said to grind it out, and it would be fine. It just never made me feel warm and fuzzy, and I never assembled it, plus I got at out of oval track racing about the same time. That engine was to be the next years power plant of a newly constructed 70 Judge clone car, that also never got completed.
My daughter came into the picture at that time, (1982) and I didn't have the extra coin to continue racing so it just sat, and is still sitting.
__________________
Brad Yost 1973 T/A (SOLD) 2005 GTO 1984 Grand Prix 100% Pontiacs in my driveway!!! What's in your driveway? If you don't take some of the RACETRACK home with you, Ya got cheated    
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#12
05-14-2019, 06:55 PM
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I've got a 400 block with the same crack coming from the bottom of the bore where there's a small anomaly in the casting. I'd bet a lot of blocks do if you knew right where to look. I used it as is for awhile. Eventually something else let go first. I agree, it doesn't give that great feeling knowing its there when you're out beating the life out of it or a long way from home.
__________________
Robert 69 Firebird-462/Edel round ports/currently running the Holley Sniper/4sp/3.23posi/Deluxe Int/pwr st/vintage air/4wl disc( a work in progress-always ) http://youtu.be/eaWBd3M9MN4 |
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#13
05-14-2019, 08:26 PM
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Quote:
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#14
05-15-2019, 09:31 AM
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Thrust side BDC, outside of block on even # cylinders and lifter side on odd # cylinders, could/might be a problem for a high winder with loose fitting pistons. With tight side clearance I didn't have any problems at all. Other good cylinders in those blocks didn't have any ware compared to where the damaged cylinders were hurt. Clay |
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#15
05-15-2019, 02:13 PM
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#16
05-16-2019, 10:49 PM
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GT. |
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#17
05-16-2019, 11:40 PM
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#18
05-17-2019, 11:26 AM
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#19
05-17-2019, 04:12 PM
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__________________
************************************* 1968 Lemans. 37,000 original miles. GTO clone. 462ci/KRE 290 heads. UltraDyne 280/288 Solid/850 Qjet by Cliff/Performer RPM/TSP 9.5" in TH400/8.5" 3.42 gears/3950# Race weight/12.58@106 at Bandimere speedway high altitude |
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#20
05-17-2019, 04:21 PM
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