Inliners International Forums General Discussion Engines I think this 250 is a ticking time bomb...

Finally got all the parts to start reassembling the engine. Got the pistons in. One upgrade was going to ARP head studs and the better FelPro head gasket (based on what I was reading in "the book"). Being new to the Inline 6 world, I wasn't sure if the #14 head stud hole in the block was to have a "raised" ring around the threaded hole. I figured it might be something to locate the head gasket. Being that the head gasket bolt hold would not fit around this, I looked closer and it looks like it might be a threaded insert for a stripped hole. I carefully ground this flush to the block.

Then I installed the head studs and found this one didn't sit down as far as the rest. Well I think things have gone south as I was able to get a torque of 75 ft/lbs. but trying to get to 95, it feels soft and not reaching the torque.

I have a really bad feeling that I am screwed. Any thoughts?

I would remove the rest of that heli-coil and install a new one and see if that helps.

It is best to install and torque the head after the water pump is installed and tightened; it helps support the two front corners of the block, especially the drivers side....fats

Yep, did that. Thanks for the reminder.

Looks like I get to take everything apart, yet again and hopefully that threaded hole can be fixed...

Time-sert much stronger then heli-coil.

Ran into this on my flathead some time back...the heli-coil had the end (down in the hole) angled across the diameter of the coil to facilitate inserting and was supposed to be broken off after inserting but had not been, so it did not allow the stud to go to full depth. May not be your problem but I never felt very confident with the setup thou I did finally get good torqe on the head at that stud.

Where do you get your time serts?

Last time I looked for one up here no one would fess up to having any.

Yeah, I don't think this was the issue as I had looked down the holes originally and before putting the head back on, used a cleaning tap to clean all the holes in the block. It went all the way down without any problems.

Suck part is, this engine was built by an engine rebuilding company and you would think if there was a problem with a head bolt hole, they would reject the block to be used. Guess not...

Got a couple pics of what is going on

This was ground flush before I started and pull to the bottom of the head at about 75 ft/lbs.


Here is the insert I removed