Head studs vs head bolts comments LBrumfield?

[mrtexas]

Pete's Machine Shop in Albuquerque, NM built my new engine using a diamond block. He installs grade 8 head bolts rather than studs. He told me that good strong studs are available but strong nuts aren't. For a high compression head he says torque the bolts to 70#. I got my studs from Brumfield when I bought the high compression head. He was out of nuts so I got them at a swap meet from a Model A vendor.

Head bolts or studs? I'm sure there will be some lively discussion on this one.

[Kevin in NJ]

Let me take a stab a this one. The following is really my best guess.

The course threads in the cast iron are great for putting a stud in with no tension and holding a static stud. The cast iron threads are not good at allowing a moving under tension for proper torque. I also think that the cast iron would wear too much after a bunch of uses.

The cast iron is a course metal and is not good at fine threads. The course pitch threads will give you more tension per degrees of rotation. So the torque values you use for nuts may be completely wrong for generating the correct tension needed to hold the head down. I also believe the friction in each hole may vary more due to the course structure of the cast iron leading varying tension on each bolt.

I would also throw in that some the cast threads have issues from use over the years. I would be afraid that during torquing into cast iron with a bolt you would strip a marginal thread.

That is my intuitional guess as to why bolts should be frowned upon.

I have a hard time believing that hard enough nuts are not available. Something does not sound right from a couple of angles in Pete's logic. It seems that Brumfeld and others have been using studs successfully on some fairly high compression applications for quite some time. People like Larry probably have engineered the correct solution so they have checked the real numbers.

Lets hear from someone that has a proper answer.

[George Miller]

Originally Posted by mrtexas

Pete's Machine Shop in Albuquerque, NM built my new engine using a diamond block. He installs grade 8 head bolts rather than studs. He told me that good strong studs are available but strong nuts aren't. For a high compression head he says torque the bolts to 70#. I got my studs from Brumfield when I bought the high compression head. He was out of nuts so I got them at a swap meet from a Model A vendor.

Head bolts or studs? I'm sure there will be some lively discussion on this one.

Studs are going to be stronger. I think you will find they use studs in racing engines, they also use them for the mains. As far as the nuts not as strong that is not true. You have to by grade 8 or better, not the import butter bolts.

[1931 flamingo]

I believe Larry has commented on this in the past AND says studs. Try a search on this topic as it has been covered extensively in the past. It has to do with coarse studs in the block and also being 80 yrs old. JMO
Paul in CT

[MrTube]

I remember the previous thread and the out come being stick with studs.

I have to assume Ford used studs for a reason, and it certainly wasn't because they took longer to install.

[ABento]

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Studs hold and clamp better than bolts and there are hard washers and nuts from the stud manufactures ERA, I believe the name is the one I use, common problem when doing just a head gasket, is not cleaning everything correctly, remove each stud run a tap in the block and a die on the stud and nuts to clean all the threads now you can clean the top of the block, when putting the studs back in use a high heat teflon, in the squeeze tube, to seal the studs in the block and a drop of oil on each nut to torque.

[MrTube]

Whats the best way to tighten studs into the block?

[Doug in NJ]

Originally Posted by MrTube

Whats the best way to tighten studs into the block?

With your fingers!

Doug

[MrTube]

Originally Posted by Doug in NJ

With your fingers!

Doug

I really need to stop over complicating things

[mrtexas]

Originally Posted by 1931 flamingo

I believe Larry has commented on this in the past AND says studs. Try a search on this topic as it has been covered extensively in the past. It has to do with coarse studs in the block and also being 80 yrs old. JMO
Paul in CT

Someone have a lilnk to the above?

[bobH]

Comments from a guy that knows 'nothing'... First, I've been reading here for a long time that the 'usual' reason for bolts, is for ease of disassembly... nothing else.
Secondly, studs are generally thought to give a stronger, more predictable 'clamping force', if that has any importance (as for 'race' engines).
Thirdly, I'm having trouble understanding the '70-lb-ft'... MUCH lower values have been posted by the experts. What's the compression of this engine?
Forthly, aren't 'decent' nuts available from places like MMC (McMaster-Carr)?
Lastly, some of the experts have opined that (quality) grade 5 is plenty adequate. Again, what is the compression of this engine?
JMHO

[George Miller]

Originally Posted by bobH

Comments from a guy that knows 'nothing'... First, I've been reading here for a long time that the 'usual' reason for bolts, is for ease of disassembly... nothing else.
Secondly, studs are generally thought to give a stronger, more predictable 'clamping force', if that has any importance (as for 'race' engines).
Thirdly, I'm having trouble understanding the '70-lb-ft'... MUCH lower values have been posted by the experts. What's the compression of this engine?
Forthly, aren't 'decent' nuts available from places like MMC (McMaster-Carr)?
Lastly, some of the experts have opined that (quality) grade 5 is plenty adequate. Again, what is the compression of this engine?
JMHO

Probably 70 ft lb because course threads would take more torque to get the same clamping force as a fine thread like on a stud.

[mrtexas]

Originally Posted by bobH

Comments from a guy that knows 'nothing'... First, I've been reading here for a long time that the 'usual' reason for bolts, is for ease of disassembly... nothing else.
Secondly, studs are generally thought to give a stronger, more predictable 'clamping force', if that has any importance (as for 'race' engines).
Thirdly, I'm having trouble understanding the '70-lb-ft'... MUCH lower values have been posted by the experts. What's the compression of this engine?
Forthly, aren't 'decent' nuts available from places like MMC (McMaster-Carr)?
Lastly, some of the experts have opined that (quality) grade 5 is plenty adequate. Again, what is the compression of this engine?
JMHO

Brumfield 6:1 head

I'm not trying to generate conflict, I want all opinions.

[mrtexas]

ttt

[Chris in WNC]

"He told me that good strong studs are available but strong nuts aren't."

last year when replacing a head gasket & a loose helicoil in our recently purchased Town Sedan I had 3, count em 3, allegedly grade 8 nuts strip out when torquing to 65 foot-pounds.

replaced them with used grade 8's I had on hand and 4000 miles later they are still hanging on.

[Bruce Lancaster]

One thing to keep in mind about SAE hardware is that there is no sort of enforcement of standards out there...if someone wants to mark his grade-Z parts and boxes Grade 8, all he needs is to put the marks on. Those who supply low end retailers* have doubtless figured out that it is good to put plenty of lines on bolt heads. There is even counterfeiting of high grade aerospace hardware that is supposed to be traceable through every step of manufacture and heat treating...
Read Carroll Smiths classic book on hardware for car people... some of it is terrifying, all is informative.
If you have Grade 8 nuts stripping out, you need a different supplier, not a higher grade! Somebody sold you out to the lowest bidder!
There is much stronger stuff than SAE hardware out there, but of course none of it is going to look right on and old car.

*I recently saw a sign in the hardware aisle of Home Depot stating that their graded bolts were now connected to traceable standards...this is probably a good development, and probably a result of something labeled "Grade 8" breaking and doing something nasty to someone with a lawyer.

[tmiller6]

There is enforcement on SAE standards. The United States fastener quality act of 1999 placed controls on the marketing and marking of fasteners. This is the reason that carriage bolt heads are no longer smooth unless you find some old stock. The manufacturer has to place his mark along with the grading. All fasteners and containers have to be accurately marked with grades and country of origin. A decade ago, people were killed or injured because of counterfeiting. If you find something marked Grade 8, that isn't Grade 8, you can go after the manufacturer.

[just plain bill]

Originally Posted by tmiller6

There is enforcement on SAE standards. The United States fastener quality act of 1999 placed controls on the marketing and marking of fasteners. This is the reason that carriage bolt heads are no longer smooth unless you find some old stock. The manufacturer has to place his mark along with the grading. All fasteners and containers have to be accurately marked with grades and country of origin. A decade ago, people were killed or injured because of counterfeiting. If you find something marked Grade 8, that isn't Grade 8, you can go after the manufacturer.

What if the manufacturer is from China or some where else. ISO and SAE are just symbols to some manufacturers offshore. My son works for a large manufacturer that buys threaded parts from offshore manufacturers. When they receive a shipment of special bolts they have to experiment with different speeds and feeds to finish machine them as the composition of the metal varies from shipment to shipment.

[brum1]

The use of studs is a method to aid the manufacturing process. It helps to hold the gasket in place and align the head during assembly,

[Mike V. Florida]

Originally Posted by bobH

Comments from a guy that knows 'nothing'... First, I've been reading here for a long time that the 'usual' reason for bolts, is for ease of disassembly... nothing else.
Secondly, studs are generally thought to give a stronger, more predictable 'clamping force', if that has any importance (as for 'race' engines).
Thirdly, I'm having trouble understanding the '70-lb-ft'... MUCH lower values have been posted by the experts. What's the compression of this engine?
Forthly, aren't 'decent' nuts available from places like MMC (McMaster-Carr)?
Lastly, some of the experts have opined that (quality) grade 5 is plenty adequate. Again, what is the compression of this engine?
JMHO

The original post stated;

"For a high compression head he says torque the bolts to 70#."