C&C block leaking

im at a loss I haven't started the motor yet just put water in it and its leaking on the back drivers side.i used the permatex copper coat and the recommended tork that came with the c&c block.heads and block were machined the surfaces looked good I started in the middle then went out on each side of the tork sequence.

I tried the commetic gaskets years ago I had a problem with sealing on a different build cast iron block in the same area.what are you guys doing to get these gaskets to seal?

Standard block prep is not enough.  The MLS gaskets have to have a SMOOOTH deck surface on head and block.  Conventional machining doesn't leave a fine enough finish.  OK for graphite laminate gaskets, not good for the MLS type.  Depending on application and use, you can always fall back to the old modified Cleveland head days...

Build it, knowing it leaks, when your ready to use it, ceramic seal it.  Get some liquid glass, and after you've set cam break in and such, fill cooling system so the liquid glass stops the leak...  good till next rebuild.

Or.... let it leak.. I run copper with stainless steel wires, mine pisses water when cold............. when hot its dry. Don't take a cold engine to the starting line.

^^^^ this has always been the deal with copper I run. I haven't had a cometic Mls to leak but I did have an intake gasket leak that made me think it was the head.

Are the flanges of the sleeves above the deck?

When the surfaces are not smooth enough for sealing an MLS gasket, a light coat of "spray High Tack' on both sides of the gasket usually works.

update:its not the commetic gaskets leaking the water is coming from the back of the block.i have a tci mid plate for the powerglide trans.the back of the c&c blocks bolt pattern does not use all of the tapered bolts for the mid plate.i did use hi tack sealer on the bolts I put in the plate incase they were in a water jacket so I know they are not leaking.i had 2 bolts left over from the odd pattern and I suspect that the water is coming from one or both of the bolt holes.

this is a hard earned lesion not looking in the holes.

Stock block?I got a D9 under the table, it would take some digging, but IM pretty sure unless someone did some drilling and tapping, trans bolts don't hit water. Drivers upper hits oil, it punches through to the lifter galley, but none that I remember are into the water jacket.

it is a c&c aluminum block the bolt pattern is not like the stock cast iron blocks.i had this same plate on an a460 block previously.

Larry T wrote:it is a c&c aluminum block the bolt pattern is not like the stock cast iron blocks.i had this same plate on an a460 block previously.

Ok... then I don't know shit... because your playing a league above me. Good up to the A460 block.....

I have a c&c block in mine. I have a JW ultra bell I don't have mid plate bolts in the block. I don't remember any holes going into water jackets. Maybe keith can chime in may have been installed before I got it ? It did have to have one of of the internal plugs where it was tapped too deep and they struck water.

dr's wife racing wrote:I have a c&c block in mine. I have a JW ultra bell I don't have mid plate bolts in the block. I don't remember any holes going into water jackets. Maybe keith can chime in may have been installed before I got it ?  It did have to have one of of the internal plugs where it was tapped too deep and they struck water.

Same here...never seen the bell bolt holes into a water jacket.

update#2: I took out the tranny and behind the mid plate on the drivers side it has a pin hole that is in to the water jacket it is not leaking at the bolt holes as previously thought now on with a fix.i am going to plug it with a 1/16 pipe plug hopefully that will do it.

Damn you pay that much for a Block and it comes with a hole in it ? Unless it was bought used It would be Freaking going back for that Price....

I bought my block used. It was only used for a short time. Mine was onthe inside where one of the oil restrictors is at. It was just tapped a little too deep. Keith made a special plug for it. Hasn't leaked a drop since. It is in a no stress area.

I bought my block used. It was only used for a short time. Mine was onthe inside where one of the oil restrictors is at. It was just tapped a little too deep. Keith made a special plug for it. Hasn't leaked a drop since. It is in a no stress area.

Sorry to hear about the leaky casting.
Aftermarket blocks have one thing in common. A company with good intentions, contracts a foundry to cast them on a rather small production run. I think that is why we experience some of the fruity issues with castings.
Although it is an expensive pain, it is a great idea to carefully pressure test and triple inspect these things prior to machining and assembly.
Another of my favorite things to do before rolling to the dyno, is to cap off the water pump connections, fill the water jacket with water and use a little regulator to pressure test the assembly before oil is poured in. You can catch embarrassing things early on.
Hope the repair goes well.
Keith

update #3:at the moment the repair has stopped the leak.i used my die grinder to go down about .015 below the surface and filled it with JB weld.i waited 24hr then leveled the area even with the block and used some paste permatex over the area just in case.

I talked with the guys at c&c Friday they didn like the idea of the pipe plug fix so I did the JB fix.i understand they weld a plug in that area and then machine over it.it looked like the weld just didn penetrate that small place in the block.next time I have the block out I will have it welded.