Was trying to remove a broken head bolt and drilled through the block straight down. Do I need a knew block or will the head bolt seal that area, or are there any other options?

 

Good luck, I don't know. I'm sure someone can help you.

 

I have worked on some older engines where the head bolt hole was not closed off and extended into a coolant passage, as long as there was sealant applied to the threads everything was fine


Most likely it will be ok, I dont know what is under there so I cant say 100% but there are other engines designed that way, if I remember correctly the ol small block chevy motors are that way.

 

Which hole and how straight did you drill?

 

driver side, second cylinder bolt in valve cover, lst long bolt, hole that went through is straight and about 1/4 inch in diameter.

 

I sorry it's the second cylinder bolt, 1st m11 long bolt on drivers side were valve springs are.

 

If the hole is only a quarter inch and straight, you should be fine. Here is a photo of where you drilled through. That little dome section to seal the head bolt is often times broken anyway.

 

can you heli coil the threads, also the threads are M11x1.75pitch which i cannot find anywhere the only thing I can find is m11x1.50. Also if I am to this point should I pull the block and let a machine shop do this or can I make a guide to square the drill and heli coil tap? and will the heli coil be able to hold to proper torque for the cylinder bolt? Can I use a m11x1.50 bolt if I cannot find the m11x1.75pitch

 

The thread diameter and pitch is 11 mm x 2.0. You can get a Time Sert in there but the kit is expensive to purchase to install one insert.

I would go with a 7/16" x 14 stud with a long heli coil in that hole. That would be the least expensive fix if ARP or A1 has a long enough stud in that size.

Steve

 

I would put plenty of sealer on the end of the bolt, and I'm sure you would be fine. I've done that with a header bolt that someone had drilled into the coolant jacket, and the customer didn't want to buy a new head. It's been a couple years, still no leak. The problem with a helicoil is that it won't seal the bottom.

 

whats the longest heil coil I can get in that 7/16 14 size? the longest one I found was .656, I also found the 7/16 bolt from arp, they had 2 sizes 4.50inches and 3.75 inches.

 

It's not going to work. Have you ever used one?

 

Shouldn't cuttings from this operation falling thru the hole that got drill be a conceren?!?

 

Hello Steve I was wondering were you get the m11x2.0 time sert that you mentioned, I checked arp and the longest head bolt they have in 7/16 14 is 4.5 inches a the bolt size is 5 inches.

 

any info on this, i'm in the same situation....