Oh oh, titanium again ;)

[Jacques]

So, is there any chance that a 6Al4V titanium bolt in size M8 * 35mm will hold as engine mounting leg bolts, of which there are six?

I know they are widely used for engine mounting on some other cars and motorcycles, but is there any experience on the Esprit like mine (Stevens Turbo SE)?

I think the standard factory item on the Esprit for this particular application is 8,8 grade steel alloy bolts (like in normal ones). I may be corrected, though

A bit of info below:

Grade 5 6AL-4V Titanium (Tikore's preferred material):
Yield Strength: 128,000psi
Ultimate Tensile Strength: 138,000psi
Shear Strength: 79,800psi
Density: .160 lb/in^3
Additional note: Titanium has an extremely high resistance to corrosion.
As presented above, titanium bolts/nuts have a strength that is very comparable to grade 8 steel bolts/nuts that are used in high strength applications. Furthermore, based on the density figure above grade 5 titanium is 45% lighter than steel components.

Grade 5 Alloy Steel (commonly used on automobiles for lug nut and lug bolt applications)
Yield Strength: 92,000psi
Ultimate Tensile Strength: 120,000psi
Shear Strength: 72,000psi
Density: .284 lb/in^3

Grade 8 Alloy Steel (used for lug nuts and lug bolts in high strength applications):
Yield Strength: 130,000 psi
Ultimate Tensile Strength: 150,000psi
Shear Strength: 90,000psi
Density: .284 lb/in^3

 

Kind regards,

jacques

 

[fjmuurling]

Based on the numbers above I would only be a little concerned about the shear strength of Ti.

Based on the little information I could find about the galvanic corrosion between Ti and Al I would not be worried. however I could be wrong.

 

Some usefull information:

Ti Bolt Information

If I read the above correctly you can substitute the 8.8 bolts for their Ti bolts. (maybe worth to give them a ring / send email)

[Jacques]

Thanks Freek. I share the same opinion.

I'll go forward with this and try to install them and see how they perform, once I have them ordered.

Kind regards,

jacques

[fjmuurling]

There are some nice ones with holes in them for the use of lockingwire.

[fjmuurling]

The "strength" of Aluminium is much lower than that of Steel or Ti, so if somethings breaks / shears it will be the Aluminium and not the bolts.

One less worry for the use of Ti bolts.