Sanborn cooling hole mod leakage, what to do

[RapidRob]

360 oe iron block iron 308 heads felpro 8553PT gaskets. 4th try! what am I doing wrong. geyser starts in the coolant after several minutes. can I use a touch of sealant around these added holes?. visual on the fire ring appears OK. thank you for your time. RR EDIT the dark perimeter is where I had to slightly dremel to remove the fluff from the hole drilling & that is what I am wondering if I need to fill with something (the right stuff cement? or ? I gotta get it taken care of this time!

[JVMopar]

Get yourself a set of gasket punches. Got mine from Harbor Freight. Just sharpen them up, place the gasket on a clean, thick, flat piece of steel or better yet aluminum. Place the punch where you want it and hammer the punch. I've done it to several sets of gaskets. Works fine.

I took an old gasket and used the imprints on that gasket as a template on where to punch the holes.

Honestly what you did there looks good enough for me. I'd run it.

[RapidRob]

I had a heck of a time with this. actually first I did use HF gasket punches but they distorted the gasket on the bottom side too much but in hindsight I think I used a soft board underneath as I was worried about dulling the punches when I should of been more concerned with the gasket it self & used some aluminum plate. then I tried drilling em with a regular drill bit but when it went thru (I did go slow) it pulled up the gasket & grabbed it & made a mess. finally I used these bits & got the result posted. however this is my 3rd set of gaskets modded this way as the first 2 set leaked combustion into the cooling system (I drilled holes per Sanborns' cooling mods). I'll see how it goes this time as I used a very light smear of "the right stuff" gasket maker around the added gasket cooling holes. I'll post how it turns out. here is a pic of the bit I used this time. thank you for the reply above. RR PS what do they call these bits? bought em from a member here

[RapidRob]

fired it up & still leaking (boils coolant out the radiator within minutes).

[JVMopar]

Better check that gasket real careful when you get it apart. If you can't find the source of the leak, have the head checked.

[RapidRob]

thanks bro. I'm on it now.

[dirttrackracer]

Are the locating dowels in your block to long. Could be holding the head up. You should not be getting combustion in the coolant from the gasket mods you are doing. Leaking outside the block maybe but the fire ring seals the combustion chambers. Have to done a compression test before and after running the engine. I'm thinking you have some others problem causing your symptoms.

[Krooser]

Originally Posted by dirttrackracer

Are the locating dowels in your block to long. Could be holding the head up. You should not be getting combustion in the coolant from the gasket mods you are doing. Leaking outside the block maybe but the fire ring seals the combustion chambers. Have to done a compression test before and after running the engine. I'm thinking you have some others problem causing your symptoms.

Good point...

[dirttrackracer]

I just finished up my factory stock motor and punched coolant holes in my cheap engine-tech head gaskets with a step drill bit. fired it up yesterday zero leaks ran it about 20 min and 180deg so again inspect those heads for cracks or some reason why they are not pulling down all the way.