mikesimpalass

Well, bad news, I was bolting my new Texas speed cylinder heads down onto my Lq4, and I noticed water leaking out somewhere. I looked closer, and water was leaking from the side of the block. Oops. There was some coolant down in the head bolt holes, and it cracked the block when i started tightening down the head bolts. Lesson learned.

So, my plan for repair? I called Kyle at Thompson motorsports and ordered up a 370 with forged pistons. Great guy to deal with by the way, extremely knowledgeable on lsx engines.

sepsis

iTrader: (7)

Good fix. lol

ls1 1990 VN

35th camaro

a customer at the shop cracked his block in 3 different place doing his heads, water in the bolt holes, he took out the bolts and coated them with liquid Teflon past and never had a problem after 3 years.

mikesimpalass

Certainly gives me something to think about, but i already have a short block on the way from tms. If anyone wants to take a chance on my old long block, ill make you a smoking deal!

mikesimpalass

In fact, im gonna make a post in the for sale section about this

ss performance

iTrader: (17)

There is a company named Lock N Stich that makes a way to repair blocks with out welding.

I use to race turbo Buicks the 4.1 blocks. It was common for the to crack between the head bolt holes and the water jacket. I fixed several blocks with Lock N Stitch. I boosted these blocks into the mid to upper 20 psi range with no troubles.

It's a nice system you might want to check it out.

Good Luck.

JakeFusion

iTrader: (7)

Lesson learned. But for folks reading this: this is why you unplug both coolant drain plugs, let the car drain a day or two, and then run ARP thread chasers down into the block the get the gunk out.

slt200mph

iTrader: (42)

A couple days......I do head swaps in a few hours not a couple of days. I never have drained a block the way you describe. Just twist up some paper towels and soak up all the coolant out of the holes and then blow them out good with compressed air. Then
chase the threads with a groove cut in a old head bolt. That method has been working great for the last dozen plus years I haven't lost a block yet ....

JakeFusion

iTrader: (7)

I don't like sticking paper towels down in the head threads. That's just me. The compressed air works though. And I highly recommend everyone use the proper ARP thread cleaner vs an old bolt. The old bolt works, but the ARP thread cleaner works better and refurbishes the threads.

But gravity works too. And it's not hard to remove the drain plugs. It's a good way to get all the old coolant out of the engine anyway. Just draining the radiator doesn't do it. A couple of hours is at it needs or help it along with compressed air in the water pump holes.

csmc711

iTrader: (4)

I always take the heads off and then get some plastic fish tank air hose, shove it in the back cylinder, start a siphon and let her drain. Not all blocks have drain plugs and I get a little nervous removing the ones that do after so many years in service. I guess I am stripped, ripped bolt gun shy,lol.

joecar

The head bolt holes are blind... if they contain any fluid/gunk/trash then when the head bolts are tightened there is a risk of cracking the block at the base of the bolt holes (regardless of coolant being present in the block).

Edit: i.e. simply draining the coolant from the block does not guarantee preventing bolt hole cracking.

( yuck... ls1tech is hyperlinking keywords to ads )

csmc711

iTrader: (4)

No, but it is not there at surface level either when you put the heads back on. It is well drained and I would HOPE everyone cleans their threads and bolt holes before installing new ones. Heck, I am retarded and even "I" do that, lol.

Paul Bell

iTrader: (9)

You cracked an LQ4 (IRON) block?

Q-tips to suck out water from the bolt holes then plenty of compressed air.

ckpitt55

iTrader: (4)

I don't know why they don't use vented hardware from the factory to prevent hydrolocking at the bottom of the hole.

But this is why I like head studs -keeps wear off the aluminum threads in the block and also gives you a better feel for how clean the threads themselves are...if you can't thread it in by hand all the way and feel it bottom out then it needs more cleaning. With bolts, small amounts of friction are masked easily but a ratchet, then you start tightening it down thinking all is good and 'POP'

MuhThugga

I think the idea was to remove the plugs and drain the engine before pulling the heads.

A way I have found to work is to loosen the head bolts and then loosen the head. That way, the seal is broken and coolant will flow out, but the bolts are still in the holes, so coolant shouldn't run down in there. You still need to blow them out and chase the threads for good measure, but this ought to cut down the amount of time needed for soaking up the fluid in each hole.

LilJayV10

iTrader: (39)

Because when the engine is designed engineers aren't thinking about nor do they care about some guy that is doing a head swap in his driveway that doesn't take the time to learn how to do things properly.

IRONFIST

This is what I do too... but it's so annoying. I think maybe going over to head studs is what I'll be doing next time.

Paul Bell

iTrader: (9)

Mike, I'd still like to know that this was an iron block that your cracked.

chevynut

I am working on a LH6 alum block and just had 3 of the head bolts "pop" when installing them. The bolts were not even close to the bottom when it happened. It was a little hard to turn then the pop occurred. After they went in easy. I don't know how it could have been water in the bolt holes. The truck has been sitting without the heads on for a week with radiator drained. The fluid level in the block was down, I didnt drain the block but I hit all the holes with a wet dry vac twice. just before installing the bolts. There should have not been any fluids. I think I cracked the block but i could not see any cracks on the outside. The bolts torqued just fine, so for now I will continue to get it assembled and hope for the best. It was the worst feeling when I heard that pop.
I guess the lesson is to do everything possible to ensure no fluids or debris in the hole just before you put the bolt in there and if you feel an abnormal resistance stop. back off the bolt and check and dry if there is any fluid. Wish me luck.