Head Bolts/ What in the @*^ are THESE?

[tcartwri]

It's the stretch of the bolt that keeps them from backing out. If you don't get the torque right, the bolt will either fail, or it will back out over time. You also do not want to distort the castings by overtorquing to compensate.

Post up some pics of those bolt heads.

 

[F100Panel]

Well I went to get pictures of the bolts for Tcartwri & I checked the bolt count & now I see I was wrong on the bolt count/I'm now more unsure. There are 8 number 10's & three number 13's... eight bolts surround the actual cylinders & 3 bolts are for the do nothing edge of the head surrounding the exhaust ports on the head.. Now it looks like if the number 10 represents softer bolt, the softer bolts surround the actual cylinders...
I tried to cut & paste the cylinder head picture with the bolt pattern from the manual but it's a locked document & you can't do that...

 

[Brad_Blazer]

The clamp force of the bolts is a function of torque, thread pitch and friction, not bolt strength or stiffness.

Your bolts are all M10. It's a little strange that they have different strength ratings but it doesn't matter as long as they don't break when tightening.

 

[Redneck in training]

Just to add more to the confussion. I know nothing about that particular engine but there might be different torque values depending on location of the bolt in the engine. It has something to do with temperature of the bolt versus the temperature of the part it clamps. Bolts exposed to coolant or oil will have lower temperature than the cylinder. Cylinder will stretch more than the bolt and the clamping force will increase as the engine heats up. Bolts not exposed to coolant or oil will have the same temperature as the parts they clamp and since they stretch as similar rate the clamping force will change little with the temperature change.

 

[tcartwri]

Are they magnetic? Can you stick a magnet to them...

 

[tcartwri]

Ok, after a little bit of research, these bolts appear to be JIS ( Japanese Industrial Standard ) The clue is the large whole numeral on the head.

They are not Metric, nor SAE. Thread pitch and counts are different, and there is also a difference between 'JIS Metric' and older JIS hardware, which more closely resembled BS ( British Standard ). Is that confusing enough...

I cannot find a reference online for torque values, but it was an education. :confused2:

 

[F100Panel]

Are they magnetic? Can you stick a magnet to them...?

Yup, they are magnetic.....

 

[F100Panel]

Well... I think we are rolling now... With the bolts Identified as JIS by Tcartwri... THANK YOU!!!! & a little googling...Yes GOOGLING not Ogling the neighbor... ( In reality I'm rural/have no neighbors..) I came up with a JIS Supplier in Mass. USA.. Web Liink-
J.I.S. Information and Online Shopping
there is a phone number i'll be calling either Friday or Monday morning. At the least I'm hoping for a torque setting at the most I hope to buy a set of bolts.. They explain JIS pretty well on the link & describe my bolts PERFECTLY.. I think I'm rolling. I will post a follow up & still look for any other ideas fertil minds may have on this forum. THANK YOU AGAIN!!!!!!

 

[dcyrilc]

I tried to cut & paste the cylinder head picture with the bolt pattern from the manual but it's a locked document & you can't do that...

When you have the cylinder head picture on your screen, push the button on your keyboard marked "Print Screen". Then open MS Paint. After MS Paint is opened click "Edit" and then "Paste". This will save a copy of whatever is on your computer screen into the buffer and then paste it into MS Paint where you can edit and save it. You can then post the MS Paint image to TBN.

 

[OldMachinist]