mmorellicamaross

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?

ABQ99TA

iTrader: (17)

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

00pooterSS

iTrader: (40)

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.

Steve - Race Eng

iTrader: (1)

Which hole and how straight did you drill?

mmorellicamaross

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

mmorellicamaross

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

Steve - Race Eng

iTrader: (1)

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.

mmorellicamaross

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

Steve - Race Eng

iTrader: (1)

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

84ls1_transam

iTrader: (11)

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.

mmorellicamaross

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.

84ls1_transam

iTrader: (11)

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

Nabdrill

iTrader: (19)

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

mmorellicamaross

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.

LS1INSIDE

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