Looper head studs

[H2OPERF]

Don't think I would attempt that by hand . even if you make some type of alignment plate and use a gh2 tap still not like a mill, 3/8 would be nice but no need if u go gr8..

[powerabout]

perhaps grade 8 threaded rod and stick with unc thread, at least you will have the correct torque as you can use the original spec.
Anyone know how to convert unc torque to unf to get the same clamp force?

[BarryStrawn]

Making studs from ARP bolts like I mentioned in post #5 is a crap load less work than drilling and rethreading the block accurately, drilling the heads, and altering the gaskets. All with zero mistakes. One person I know who went up to 3/8 told me it wasn't worth the trouble. And they were running big bore, big compression, big RPM, and winning big drag races. If you try this, use a junk block for practice.

If you have a mill I expect you have a lathe. If no automatic die head just grind up a HSS threading tool and single point them. Slow but its simple enough manual lathe work. And each mistake just costs you one $3 ARP bolt.

[H2OPERF]

Agree...Allens fasteners has all the arp by the piece, get most of mine from them.

[gfinch]

ME TOO !
To Berry's post.
Try This... (If I Remember Correctly)...maybe not... I've slept since then... Check all the holes the the cylinder head...
IIRC... there are a couple that are larger in diameter. If I were to do it again...which I wouldn't...I would use the... a junk head... as a drill guide. Then have a whole lot of fun drilling tapping and then drilling larger holes in all the heads that will in the future go on to this engine.

IMHO Just regular sized STUDS SUCK!
BTDT !!!

[Steve Pope]

If all you want to stud the head fasteners is to save the block threads each time you want to read piston tops then why not leave the factory screws and buy a bore camera. I have one that connects to a tv set so you can get a really good pic!

[baja200merk]

I have used mc master carr never had an issue with the studs. 6 bolts per cyl is the key, studs are probably a bit overkill but we ran 150psi and over 8k rpm. Actually we ran 180psi and over 9k rpm in stock bolts with no problem.

Etec head bolts are stainless never seen a head gasket problem, ever..... torque spec only 17lbs I doubt they stretch, if they did they probably wouldn’t recommend reusing them.

[powerabout]

I have used mc master carr never had an issue with the studs. 6 bolts per cyl is the key, studs are probably a bit overkill but we ran 150psi and over 8k rpm. Actually we ran 180psi and over 9k rpm in stock bolts with no problem.

Etec head bolts are stainless never seen a head gasket problem, ever..... torque spec only 17lbs I doubt they stretch, if they did they probably wouldn’t recommend reusing them.

the right type of stainless

[H2OPERF]

New ones are 17-4 same thing the tiller bolts are made from and I think the old v8 mount bolts too.. strong stuff depending on heat treatment.. very susceptible to improper heat treatment probably why tiller bolts have poped heads.

[baja200merk]

Makes sense thought it was weird they r magnetic. Probably why I have never seen one break or be frozen from corrosion. Used to break the old looper ones even with heat never had a Etec break no matter how salty.

[Captain75]

Recieved my studs today, think they will fit fine.
Some pics:


Amount of threads compared to stock bolts

Some additional threads added(in middle)
Black line on the stock bolt indicates the engagement dept.

[billybob]

my personal opinion is, do not try to read piston tops. just read the spark plugs. it,s easier & just as effective. I have run studs on merc. & omc. they are a hassle, even for changing heads for diff. classes. all omc loopers need, are remove air box internals,increase main jet 8 or 10 sizes, relieve exh. at top of gearcase, & plane heads, 20 to 25 thousands, & run premium fuel. I have run these motors to 8,900 rpm. all day long.

[Captain75]

my personal opinion is, do not try to read piston tops. just read the spark plugs. it,s easier & just as effective. I have run studs on merc. & omc. they are a hassle, even for changing heads for diff. classes. all omc loopers need, are remove air box internals,increase main jet 8 or 10 sizes, relieve exh. at top of gearcase, & plane heads, 20 to 25 thousands, & run premium fuel. I have run these motors to 8,900 rpm. all day long.

Ok! I agree with your airbox opinion, it wakes the motor up!
When it comes to jetting by plugs, this is where the opinions on this board are divided...
I have recieved many warnings concerning plug jetting.

[Captain75]

I decided to extend the threads a bit further in order to have full engagement of the block threads:

Slightly over 1” of coarse threads

[Steve Pope]

piston tops. Ask Jay Smith.