Ya I know, your not supposed to do this, D**m it. I already have the Ducticle assembly and the block bored, honed and decked and hopes for a bunce of HP. But -- in the process of gringing for Rod clearance I managed to uncover some day light in the coolant area.

I have about a 1/4" dimple with some very fine daylight showing through. It measures an 1" from the Pan rail and 1/2" or less from the Bore.

My question is the fix, if any. I've heard some uncomfortable vibes about trying to weld cast iron (especially near the finished bore).

What do you think, should WE try welding or using something such as Devcon?

Complexity now Perplexity!

Bruce

 

Changa,

Welcome aboard! Man, you saved a good one to start with.

I hate it when that happens - except when I do it intentionally. Sometimes it is necessary to machine right through an intended casting passage to make things the way you want them. I've done it on iron heads more than once, and I've had really good success welding the casting with a nickel alloy filler. It incorporates the iron molecules very well and has a simial machinability when you're finished. Best of all, it's at least as strong as gray or nodular castings. If you know a trusty welder with a large TIG and can round up some nickel filler, you're on your way.

The epoxy idea is a little scary to me, but I'm somewhat of a chicken-sh*t anyway.

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Later,
Vader
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"I'm'a do Things My Way - It's My way or the Highway."
Adobe Acrobat Reader

 

Man, I hate to see your first post being on such a bad note.

I don't know of anything that'll hold well enough. Welding would be the only thing that woud possibly work, but I don't think I'd try it. For one, it will distort your cylinder bores, and possibly the entire block (Mains, etc...) Besides, you would need to get someone with lots of experience to weld it for you, because cast iron IS really difficult. The main problem is, that a pin-hole will let coolant into the oil and destroy your bearings, and likely the block you're trying to save anyway, and most definately the rotating assembly that you forked out some $$$$ on.

I hate to be the bearer of the bad news, but you really need to find a new block. I know I would in your shoes. Keep in mind that I do realize you have lots of money in the machine work, I have almost $700 in mine with just a .030 overbore.

Good luck.

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Working on:
'84 Z28 LG4 305 with 200,000 original miles!
Added dual elec fans.
145 MPH IROC Speedo
Building 430 HP 350 (ZZ430)
using primarily GMPP parts.
Short block sitting on a stand.

Starting to look like the Kicker poster child!

ASE Certified Master Tech

 

You could try brazing it. There are welding techniques that may work, I'm no welding expert, maybe ede or somebody else like him around here with that kind of knowledge will point you in the right direction.

That's just one of the risks you take... I hope you can get it squared away somehow.

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"So many Mustangs, so little time..."
ICON Motorsports

 

I've never tried welding cast iron yet myself but I watched my boss weld a crack in an exhaust manifold once. Stick welder with cast iron welding rods. The key to getting a good weld is to heat up the area to almost cherry red first then weld it while it's still hot. Now when you think about that to an engine block I'm sure some distortion will occur.

You could always put a temp patch over the hole and fill the cooling passages with block filler but then it doesn't become a very good street engine.

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Follow my racing progress on Stephen's racing page
and check out the race car

87 IROC-Z Pro ET Bracket Race Car
383 stroker (carbed) with double hump cast iron heads and pump gas
461 Big Block installed and ready for the 2001 racing season

Best results before the 383 blew up
Best ET on a time slip: 11.857 altitude corrected to 11.163
Best MPH on a time slip: 117.87 altitude corrected to 126.10
Altitude corrected rear wheel HP based on power to weight ratio: 476.5
Best 60 foot: 1.662

Racing at 3500 feet elevation but most race days it's over 5000 feet density altitude!
Member of the Calgary Drag Racing Association

87 IROC bracket car, 91 454SS daily driver, 95 Homebuilt Harley

 

First, I want to say thanks to the responses that you guys took the time to post.

I'm not the kind a guy that takes NO for an answer very easily (my wife doesen't either...hmmm) and I don't like the brutal truth. One of the Posts said 'Scrap it!--Start over!'. That was all to familiar as that's just what was laying in my gut. In the forefront of my mind though, was that there just had to be better way.

So, with my dobber down and my tail between my legs I went back to the shop where I spent all that money. Man I found out that I was not the only As****** that's made this mistake.

A little more seriously and FYI, they did have a solution that was a little more to my liking and that was to use a pipe plug. They happened to have a block there that looked very good. I had to assume that it sealed as well as it looked.

Anyway I was happy, took my block over to a friend of mine that has a first class machine shop and he set it up on a horizontal boring machine with all the digital settings. We started with a small size and ended with a 1/2 inch pipe plug. The plug will set in very solidly but wind up with a very irregular shape. There are a couple of differnt angles that meet at that point plus the area that I ground. Areas with a lot of thread and one spot with very little thread (sealing problem again or at least questionable).

With nothing to lose I feel that it's a viable solution (with a little luck) and would try it again.

Back to the brutal truth again, I now have a fresh block on the stand. I must confess the cost of the block and machining is a small percentage of the final engine cost, not to mention the peace of mind.

Thanks again - Tell it like it is!

Bruce

 

You were real lucky that it happened in a place that a pipe plug could be used. I didn't even think of that, because from your description I thought it would have been in a place that was curved.

That is actually a fairly common repair method for all sorts of things: extremely trashed bolt holes, cracks in block decks, etc. They're pretty useful little things.

Glad to hear you got it revived!

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"So many Mustangs, so little time..."
ICON Motorsports