Head bolt length and can the valves collide with each other

[berni29]

Hi Guys

Does anyone know what the length of a head bolt should be? Mine are 14.5 cm from the bolt shoulder and 16 cm total length. The reason that I ask is that they only screw into the block about 1.5 cm which is half of the threaded length. that does not seem like enough to me. They have quite meaty washers. I am about to put the head back on and want to avoid another blown head gasket.

Also I noticed while measuring the tappet gaps with the head off, if an inlet valve is fully open and you fully open an exhaust valve they get very close. Can they actually hit?

Many thanks

Berni

[types26/36]

There are a couple of types of head bolts,the "waisted type" and the earler non waisted type but I dont know if there are different lengths.
I just got one out and I measure 14cms from under the built in washer to the end (see pic)
As regards the valves, I dont think they touch if everthing is standard but if you have bigger valves or higher lift cams then they could BUT this can also depend on how high/low the valve is sitting in its seat. If the seat is recessed deeper then it may not, when I do tappit shims with the head off I only have one cam in at a time as I have had some valves touching and its easier to not even have to worry about it.

[types26/36]

Why dont you just drop the bolts through the head, allow for the gasket and measure how much it protrudes then work out if it will nip the head taking into consideration how far it goes into the block.

[Rob_LaMoreaux]

Yes the valves can touch if the cams are timed wrong. If the cams are timed right then the valves should not touch.

Also half to 3/4 the threaded length engaged to threads seems about right to me.

Rob