welding up a 400
 

ok so i ran my 400 lean and ended up with about a 1/8 to 1/4 deep groove between the #3 and #5 cylinder on the block and head.Many people have been telling me i can have this welded and it will be fine.It is bored 40 over already so more boring after welding is not a option.Is it possible to sleeve a siemese bore engine?

Sleeving a 400 blocks is not a good idea as we have seen them crack from the bolt hole to the cylinder many times cause a 400 has thin decks and thin cylinders plus you will distort the cylinders on each side of the sleeve.

http://speedtalk.com/forum/viewtopic...ing+400+blocks

Would it work better if the block were half filled? Seems that the block would be more stable.

Welding
 

Do the right thing. Thank your block for it's service, give it a good burial, and go get another one. Don't be tempted to try and save it when you know better.

If you machine another stock block, you may have enough invested in 2 stock blocks to own one good aftermarket block.

An SHP Dart would be a good investment over the next few racing seasons.

I also strongly agree with Mark.
I was going to reccomend the SHP block last week but before posting rememered that SHP only comes in 350 main journals.
If you already have a 400 block and ratating assembly you have the large journal mains, so you would have to start all over again with a new crank to fit the SHP and rebalancing your rotating assembly.
For all that, I would just step up to the Little M Dart block with 400 mains, and you will have an awesome block to build on for many years to come (that is if you don't put windows in it...?)
Yes, it is a few more dollars now, but will save you a lot in the long run and you will have a brand new block of new design rather than a 30 year old block on its last leg...

X2....would be money well spent.

only thing is money!!!! I can get a stock block for around $3-400. Dart blocks are $2300

A Dart SHP block all machined is 1795.00

welded deck
 

I welded a 350 block between the cyl and decked it and put 700 passes on it as a 385 before the crank broke and I buried it then . used a high nickel rod .Later J.Smith 4621 racing

welded block
 

The oil pan you see in my pic is unded that block. Later J.Smith 4621 racing

Then putting the 400 crank on the shelf and buying a new 350 mains crank is at least another $600 for a good one, then taking the rotating assembly in for rebalancing is another $400 or so, so now we are up to what...? $2795.00 ... whatever... you get what you pay for, pay up now or pay up dearly later...? How comfortable do you feel with your luck ...?

Speed and reliability cost money......don't got the dough, ya can't go"Savin' my nickels, savin' my dimes so I can go and buy that 409" :D :D

i have to agree saving nickels to spend dollars sooner then later doesnt make sence

heres a gm 400 block for ya on elbows up...

http://www.elbowsup.com/viewtopic.php?f=13&t=34613

Re: welding up a 400
 

there are some pretty good welders out there for sure. this is the key. if the welder can repair the void, you will then have to have it decked, then you will need to plate hone the one side, then a good hot wash. so lets say you spend $75.00 to weld the block, you can clean it up with a die grinder and tootsie roll yourself, take it back to the machine shop and have them deck the one side lightly, you have 100.00 in that then a good plate hone costing from 75.00-150.00. so all in all, your most likely going to spend a little more if it needs a sleeve. installing a sleeve in the block will be another 100.00 i have seen people weld stock blocks and you never would know it.

you could just spring for one of those chinese blocks that is 10 times better than a stock gm casting for under 1000.00 bare and spend 795.00 to race prep it i would take it to a machine shop and get the answer there and not here. if he says he can fix it and he will stand behind it, you choose then. your budget is what you are working with, not someone else.

Re: welding up a 400
 

Those chinese blocks are junk have one brinell tested as they are only about 107 compared to an SHP or stock block that is 190 JUNK JUNK JUNK

I seen that one coming...lol

Look up Rays crack repair in Hodgensville, KY. He uses a cold repair process that doesn't distort the block from heat and requires very little decking afterward. (270) 358-0932, Ray Shepherd.