Stupid question # 427

[C4ME]

What size are the head bolts? Are they SAE 1/2-14 thread pitch or are they metric M??-1.75 thread pitch? I am believe the block stuff is standard and the other stuff is metric, but I don't know and do not want to run the wrong tap/die down a hole or up a bolt!

Thanks,
Joe (AKA Chief stupid question asker)

 

[Ken]

Somebody's countin' stupid questions and numbering them? :L

Class identification should be embossed on the head of the bolt. There should also be a manufacturer's identification there as well on some bolts.

By the way, you know there aren't any stupid questions, right?

Although there may be stupid answers, such as mine where I answered thinking in terms of grade strength, not thread pitch.

 

[wishuwerehere82]

Joe,

The easiest way to make sure you have the right tap is to place the tap against the bolt side by side. When they are the same pitch the threads will mesh together along the length of the tap. The diameter can be matched by using a micrometer or a vernier caliper.

 

[WhalePirot]

My thread checking tool had my head bolt at 14 threads/inch, at .391". This is close to 25/64" and a shade under 10mm. The bolt I measured is used and may be slightly stretched.

 

[SSTibet]

I would consult a reliable handbook for that matter. Whalepirot is right, the bolt may be stretched over time and give you the incorrect pitch. O.D. of the bolt may also be worn out and give incorrect diameter.

 

[C4ME]

First, thanks for the feedback. Second, there is a numbering system for my stupid questions so that if the # gets really big, I will be billed by the question!

Third, I used a 5/8" socket to remove the bolts which makes them SAE (I think) but I am always nervous as I believe that there is very little difference between a 16MM wrench and a 5/8" and I do not have a 16MM wrench to check against. Now, that being said, the reason that I do not have a 16MM wrench is likely that this is not a popular size. I shall believe that the bolts are SAE as the engines were made in the USA I believe and some of the ancilary parts were made in Canada.

The real question is why can't we just stick to one standard and leave it at that! Why two on the same car!

Incidentally, the bolt strength is not that clear to me. The top of the bolt has a large circle with a smaller circle in the center with either a horizontal or vertical...or diagonal line through the smaller circle...sorta like a upper case theta.

Now one can see clearly why my stupid questions need counting!

Thanks again,
Joe

 

[SSTibet]

Joe, most designer do not have the after sale support notion, that's why they come up with all sort of standards in a product. You are darn right; there should be as few dimensions & standards in a product as possible. I hope USA converts to all metric system as soon as possible and our grand kids do not suffer from this stuff.

Cheers,

Selim

P.S: I live in Turkey and I am a metric type guy.

 

[C4ME]

Joe, most designer do not have the after sale support notion, that's why they come up with all sort of standards in a product. You are darn right; there should be as few dimensions & standards in a product as possible. I hope USA converts to all metric system as soon as possible and our grand kids do not suffer from this stuff.

Cheers,

Selim

P.S: I live in Turkey and I am a metric type guy.

Selim,
Having grown up in the era when there was going to be a conversion to metric by the government, I recall the real confusion. Like most attempts at converting slowly, there was resistance from industry as the tooling cost would have been high. Instead of a clean break, I believe a weening process was attempted and that was really crazy. I would tend to simpathize with industry as that would make the cost of many things increase.

I am more comfortable with the English standard, but would be willing to change if there was a clean break...instead of the comparison method of teaching kids that 2.42 CM = 1 inch. That only confused me as a kid and I wish that a CM would have been equally to a....CM and messed with the comparison.

All this being said, I do not think there will be a conversion anytime soon. Again, I do not mind english units or metrics, I just don't like a mix!

Joe

P.S. Never been to Turkey, only in the Neighborhood somes years back with the Navy.

 

[WhalePirot]

RE: UR original question

Are you just cleaning up the holes or is one stripped?

If you're replacing head bolts, Chevy head bolts are Chevy head bolts. They 'neck down' from the larger diameter just below the head, as you see. I measured the thinner section.

BTW, my 16mm and 5/8" sockets fit the head about the same.

The mix of metric/english bugged me when I first got my Vette, but now I kinda know which is which; rather like how experience delivers the judgement that allows me to grab the right-sized wrench/socket the first time.

 

[SSTibet]

I grew up in an era when math was tought in the old British system in Turkey. Damn, being an 12 year old kid I had to know penny, dime, sterling, stone, inches, pounds... What a mess!!! Fortunately they started metric soon enough and we learned kg, meters, liters, etc. Later the British converted to metric and we got even at that point And it was all metric system when I studied college in UK

 

[Lucky 3]

Head bolts should be 7/16 - 14. At least any Chevy I have ever had apart was.

 

[C4ME]

I grew up in an era when math was tought in the old British system in Turkey. Damn, being an 12 year old kid I had to know penny, dime, sterling, stone, inches, pounds... What a mess!!! Fortunately they started metric soon enough and we learned kg, meters, liters, etc. Later the British converted to metric and we got even at that point And it was all metric system when I studied college in UK

You've gotta have the coolest car in Turkey!

Joe

 

[C4ME]

Head bolts should be 7/16 - 14. At least any Chevy I have ever had apart was.

I sorta figured that all the GEN I would be the same, but was nervous to charge on cleaning out holes and threads without more confirmation. I am reading the same, but got spooked on the 1.75 pitch when I was checking. Thanks.

Joe

 

[C4ME]

Are you just cleaning up the holes or is one stripped?
I am cleaning bolts/holes for reinstall.
If you're replacing head bolts, Chevy head bolts are Chevy head bolts. They 'neck down' from the larger diameter just below the head, as you see. I measured the thinner section.

BTW, my 16mm and 5/8" sockets fit the head about the same.
That is what bugs me about mixing!
The mix of metric/english bugged me when I first got my Vette, but now I kinda know which is which; rather like how experience delivers the judgement that allows me to grab the right-sized wrench/socket the first time.

Thanks for the info, I am learning more and more everyday! Can't imagine not learn about these cool cars .

Joe

 

[67HEAVEN]

Stupid question # 427

If you're going to ask a question, what better number could there be?

 

[C4ME]

If you're going to ask a question, what better number could there be?

Precisely!

 

[C4ME]

And now a little humorous light on the conversion subject.

CONVERSIONS MADE EASY


For those who thought the hardest part of Physics101 was the constant conversion from MKS or CGS units to English units, here are some useful English system conversions:

Ratio of an igloo's circumference to its diameter: Eskimo Pi

2000 pounds of Chinese soup: Won ton

1 millionth of a mouthwash: 1 microscope

Time between slipping on a peel and smacking the pavement: 1 bananosecond

Weight an evangelist carries with God: 1 billigram

Time it takes to sail 220 yards at 1 nautical mile per hour: Knot-furlong

365.25 days of drinking low-calorie beer because it's less filling: 1 lite year

16.5 feet in the Twilight Zone: 1 Rod Serling

Half of a large intestine: 1 semicolon

1000 aches: 1 megahurtz

Basic unit of laryngitis: 1 hoarsepower

Shortest distance between two jokes: A straight line (think about it for a
moment)

453.6 graham crackers: 1 pound cake

1 million-million microphones: 1 megaphone

1 million bicycles: 2 megacycles

365.25 days: 1 unicycle

2000 mockingbirds: two kilomockingbirds (work on it....)

10 cards: 1 decacards

1 kilogram of falling figs: 1 Fig Newton

1000 grams of wet socks: 1 literhosen

1 millionth of a fish: 1 microfiche

1 trillion pins: 1 terrapin

10 rations: 1 decoration

100 rations: 1 C-ration

2 monograms: 1 diagram

8 nickels: 2 paradigms

2.4 statute miles of intravenous surgical tubing at Yale University
Hospital: 1 I.V. League

100 Senators: Not 1 decision