401 Buick cracked block: What to do??

You always get a project that fights you all the way. Well after my waterpump, balancing and transmission issues we hit the granddaddy stumbling block. I got a call from the guy who's rebuilding my 401 and he says they left water in it. The result: a 6" crack at the back of the motor. BTW, its a complete, clean, original low mile motor...F*&k...

He says it's going to cost $500-600 minimum to fix it at a machine shop. He's recommending getting another block.

I'm just wondering what your experiences have been with fixing cracked blocks since 401's are not easy and cheap to find anymore. (Unless someone in Ontario, Michigan or NY has one for sale....)

 

Sounds to me like it shouldn't cost you shit. They're the ones with the $600.00 problem.

 

Agreed.

 

I agree with 1/2done it was not your fault that it happend. They is the key word if they messed it up its on them. I paid for a belt for my lawn mower they gave me the wrong one then wanted to charge me again for the right one. I said if you would have given me the right one in the first place i would not be here so give me what i had originally paid for.... and i got it.

 

Sorry guys, I'm so pissed I can't type. I meant to say that they said someone (not me) left water in the block. I just brought him the motor on the weekend, so he didn't crack it.

 

I'd hunt another block. File that one under shit happens and go on. You might spend a couple of hundred on another block but you would have the peace of mind of having a block that wasn't patched.

 

Bummer deal,, not knowing just exactly where it is cracked, it can be repaired with the tapered threaded plug route or welded. I would use the tapered plug fix myself. I don't think it should cost much more than a couple hundred,, but I'm so out of touch I could be all wrong. If you decide to weld it, that could end up a never ending crack.

 

Take it to a real welder and let him look at it. Listen to how he thinks it could be welded, and pay attention to what he says about pre and post heat, etc.

If he doesn't talk about heating the block before welding, ask him why and go from there.

My dad welded a hole in a Stovebolt and it ran for many more miles. It can be done, but the welder has to know what he's doing.

If it's in a low-stress area I'd go for the welding, but I haven't seen the block and am no way an expert.

Good luck!

 

Start looking for another block
and
sleep
good
all
night.

 

Lock-N-Stitch works extremely well, but it's very labor intensive. I'd bet the bulk of the $600 is labor. It's not a repair for the inexperienced. If your not careful, you can destroy an otherwise repairable block.

 

my freind has one in boston its a 61 401 nailhead and tranny pm me if your interested i think he wants $700 for the hole thing . I will take it apart and ship or ship the whole thing .

 

If it's a crack in the outer water jacket I would think about brazing it togeather. I'm going to try it on my Dodge Bros four. I.ve brazed cast iron before and it seems to work OK.

 

Our 364 was cracked on the ouside water jacked between freeze plugs. We opted to find another nailhead and came across a running, somewhat rebuilt, 425 for $500.

I also recently saw this http://dallas.craigslist.org/pts/715858979.html

 

Even with the current cost of 401s, that's a replace rather than repair. This is coming from a foundryman. Block sees a lot of stress, moves around a lot more than you probably think, and will knock the bottom out of your wallet if it fails after rebuild.

Ahotrod's comment is right on. It probably can be fixed and might even go the distance. But should ya......

 

I`ll second that!!!

 

Oh yeah, here's the other thing. When it cracks one place it moves in other places if there's any gap in the crack. Now in addition to the risk of a hidden crack elsewhere, you have the issue of dimensional movement of machined surfaces.

If I had a dollar for every casting my employers have sold at a loss because of snowballing weld repair, I might actually have enough money to buy some of their assets at the liquidation auction.

 

I just picked up a good 401 core for $400. Got it from my favorite junkyard, French Lake Auto Parts in Annandale, MN.

http://www.frenchlakeautoparts.com/

Unfortunately, shipping one to Toronto from here would probably cost another $400. Call around, you should be able to find a good block for less money than it would cost to repair yours.

Good Luck!

 

Find a machine/welding shop that works with large diesel blocks/industrial equipment. The large Cat/Cummins/Detroit blocks are hugely expensive to replace, so these shops are very good at repairing almost ANY kind of damage. I have seen them fix windowed blocks with a hole the size of a softball in the side of the block.

They will be able to weld it up so nice you'll really have to look to see where the crack was. If done properly, it will be just as strong as the original iron.


Nick

 

i read once on a tube od J B weld that a farmer in minnesota once used it to repair a cracked engine block on his tractor

 

Try asking here
http://www.buickstreet.com/forum/

or..probably $$ though

http://remanufactured.com/Bare_Engine_Blocks_and_Cylinder_Head_Cores.htm

 

I good lock stich repair is as good as new... but not cheap. It depends on were the crack is... is it easy to get at? A 6 inch repair is going to cost $300.
I wouldnt throw it away but I would first look for a cheaper used block. As the supply of 401's shrink the repair cost will make more sense.

 

If its an external waterjacket, I would irontite it (lockstitch) and not worry about it. Seen many done. If its internal, the end of the crack can't be found, or ends at the deck or mains, just get another block.

Also, a lot of shops will price a repair really high if they don't want to do it. I would call around to other shops also. Try Wright Engines in thornhill (905-881-4939) Bill Wright is an old guy who has been doing this forever and practically lives in his shop. His shop alone is worth the trip. Stuff piled to the rafters - neat shit everywher you look.

He also has at least one nailhead sitting on the shelf (although I think its a 264).

I have seen him fix stuff that I thought was ready for the scrap bin. He's also semi retired so he sets his own hours - about 5pm until 2 or 3 in the morning.

 

Thanks for the input and suggestions. I'm going to try and find another 401 block first and explore the repair at another shop.

I generally like trying to save stuff if possible, but I don't want to spend a lot of $$ fixing something that won't be as good as new.

 

Just wanted to let you know how it turned out. I took the block to United Welding in Mississauga, ON. These guys repair mostly large truck and industrial engines. This is all they do.

Not cheap, but they do good work. Mine was an external crack and it ended up being the only problem in the block (thank God).

They boiled and magnafluxed it, made the repair, put in all new frost plugs and pressure tested it for $380 plus tax. You can hardly tell where the crack was now and they had it back to me in less than a week. They also guarantee their work.

So I guess it turned out OK.

 

Also, Muggy Weld makes some rods to weld cast iron. Drill/terminate the ends of the crack, prep and weld. I've got a 401 which the old guy told me was good, pulled from a '64 Wildcat in his field. Looked it over but wasn't till I power washed and degreased it I found the famous crack by the starter. Looks to be the waterjacket, going to give the Muggy Weld a shot, nothing to loose at this point.

Anyone else use their rods?

 

Guess it was just a coincident you posted at 4:01 today Lol
Glad you got your block fixed . 401's are a hard and rare engine to find here in Ontario .
Getting expensive too ,if you can find one .
Looking to have one rebuilt , who is doing yours ?? Have a 63 and a 66