We drilled it out to 21/64" and we will use a flat washer and 5/16" bolt on the inside side of the ear with a finger painting on both sides of the gasket of grey high-temp RTV and on the bolt as we push it through the back and under the washer in the header hole in front with a flat washer and nut. We have the hardware of sufficient non descriptiveness to look at a glance like a stud. A 5/16 bolt fits in the 21/64" hole slightly loose, so it should not weld itself again and it can be moved around to be straight. The other tops will get a stud and washer. It is straight as free handing can do, and the little wiggle room of of the 21/64" hole with the 5/16 bolt and washer through the back and a washer and nut in the front should allow enough wiggle to get a straight bite. At 18 lbs ft a 5/16" should be in its element.
It isn't what I wanted, but it will do. Hopefully case closed, any comments?
This message has been edited by 65Galaxie394 on Jun 16, 2012 7:06 AM This message has been edited by 65Galaxie394 on Jun 16, 2012 7:05 AM
I am going to put studs on the top row of the other 7
June 16 2012, 7:36 AM
with a washer and nut, it should fit right in and not look as "ghetto" I didn't want to push our luck going to 3/8", since they never torque over 20 ft lbs. Using the bolt as a stud through the back it 5/16" should tighten down fine I hope. 21/64 made a nice fitting hole. A 5/16" with a short shank ought to work well.
What do you think of Grade 8 vs Grade 5? I am thinking 8 would get brittle with the heat. Grade 8 would torque better, probably either, I use a stubby little wrench to tighten headers anyway, I told him just use what you can do with your palm and wrist with a little wrench as it pulls up. All 8 tubes are independent slip-fit too. That should help.
This message has been edited by 65Galaxie394 on Jun 16, 2012 7:38 AM
Actually grade 8 bolts will "temper" with heat. They will become softer...
Some grade 8 vendors are not up to standard in their fasteners and that may precipitate a heat related failure. For exhaust manifold bolts it is not so critical, but in other applications it can be deadly.
Lead based anti-sieze compound will take the most heat.
Grade 5 or another standard. I don't want it to anneal to the point that it welds to the ear again, this is what killed original header bolt. If I had used one the stayed in the boss, the heat would have dissipated through the iron properly instead of welding the protrusion to the ear after 10 years of heat cycles.
I use stainless...
It seems that the problem is simple corrosion/rust that locks the fastener in there in the first place. My theory is that no corrosion, no problem. At least it hasn't been for me in the about twenty years.
I also do not tighten them very tight, factory specs.
And I use never seize, Lead or Nickel for stainless.
Billy is camera shy, he took advantage of the cool morning
June 16 2012, 8:10 AM
drilled it out fitted a 5/16 shank bolt through it and I am satisfied it has enough "wiggle" to work well. Then he swapped mounts and put it in the wind. It is still on the stand in the garage. We have some detailing to do before it is ready for prime time. It is going to be 95° this afternoon. I believe his afternoon involves a girl, a 12 pack, three inner tubes (one for the beer and the empties) and a local river.
I broke a stainless steel 3/8 bolt off at intake manifold. Machine shop used a diamond bit to remove it (after several attempts by me) and charged $75 or back then 1 hour labor. I use all grade 8 intake & exhaust with anti seize now. No problems since. Leland I'm going to use studs for the ex. on my next FE build though. It just sounds right! LOL.
With a softer bolt like a grade 5, you have a better chance of removing it. And since we'r
June 16 2012, 8:13 PM
e talking about the upper bolts here, a 5/16" grade 5 in a larger hole is NOT going to get stuck. Unless the head sits immersed in salt water for several years. Then all bets are off. A grade 8 bolt will be harder to drill and remove, since it seems nearly everyone here chooses to forego the welded nut over the broken bolt method of removal.
I really wanted to build my "good" engine, but I am thankful for my son's help getting
June 16 2012, 3:31 PM
this one in. It will likely be the last one. I wanted to build a roller cammed 4.08X4.08 with ported C8AE-H heads and a PortOSonic. But this engine has served me very well and is a very strong runner. I believe it will overachieve just as it did in the truck.
Dreams are what they are. I started collecting parts for the other one before I lost my sight. A false start because of a thin block delayed it just enough.