Fly cutting a cylinder head - GIF

**Altair** · Sep 3, 2023, 10:27 AM

Fly cutting a cylinder head.

Previously:

Engine cylinder honing tool - GIF
Making cylinder sleeves/liners for engines
Fly cutting a cylinder head - GIF
Flycutter resurfacing a motorcycle engine part - GIF
Laser removing oil from engine block - GIF

**Frank S** · Sep 3, 2023, 12:39 PM

.004 cleanup is not bad

**mwmkravchenko** · Sep 4, 2023, 05:56 PM

I have to do my Tacoma block. It'll be an adventure.

Mark

**Frank S** · Sep 4, 2023, 08:51 PM

Originally Posted by mwmkravchenko

I have to do my Tacoma block. It'll be an adventure.

Mark

Several years back I rebuilt a 22rt that had been seriously overheated. .018" on the head and .012" on the block for a total of .030" That was too much in my opinion to maintain long term reliability. But the Machine shop just provided a thicker head gasket. and said have the customer bring the truck back to have the head retorqued after 10K miles and it should be fine. They didn't and at 50K miles the head gasket let go Some Toyota engines can take that much machined off and still retain the original thickness head gasket. other cannot, if you have to go with a thicker head gasket or even a standard one Retorque the head/s after 10 K And always use new head studs/ bolts after any rebuild. If your engine has torque stretched bolts replace them 1 at a time when retorquing.

**IntheGroove** · Sep 4, 2023, 11:11 PM

On all the old flat heads I've done, new or used gasket, run it to temperature, let cool, re-torque...

On used head gaskets, spray them with high-heat aluminum paint then soak them in water. Many of the old ones had asbestos in them...

**NeiljohnUK** · Sep 5, 2023, 05:17 AM

Originally Posted by IntheGroove

On all the old flat heads I've done, new or used gasket, run it to temperature, let cool, re-torque...

On used head gaskets, spray them with high-heat aluminum paint then soak them in water. Many of the old ones had asbestos in them...

Old 1920's Rolls Royce's used a single sheet of brown wrapping paper as a head gasket, not to seal as such, but to prevent the head and block wringing together, both being hand scraped to FLAT in the factory, a friend rebuilding one couldn't believe it when he took the head off, we blue checked both on a surface plate and still flat after 80 years!

**mwmkravchenko** · Sep 5, 2023, 12:25 PM

Originally Posted by Frank S

Several years back I rebuilt a 22rt that had been seriously overheated. .018" on the head and .012" on the block for a total of .030" That was too much in my opinion to maintain long term reliability. But the Machine shop just provided a thicker head gasket. and said have the customer bring the truck back to have the head retorqued after 10K miles and it should be fine. They didn't and at 50K miles the head gasket let go Some Toyota engines can take that much machined off and still retain the original thickness head gasket. other cannot, if you have to go with a thicker head gasket or even a standard one Retorque the head/s after 10 K And always use new head studs/ bolts after any rebuild. If your engine has torque stretched bolts replace them 1 at a time when retorquing.

Thanks Frank.

My rebuild experience is 7 VW diesels. A simple motor but all the principals are there. I am not sure if the Toyota's use stretch bolts. But the VW did. And I agree replace with new. I am pretty sure that this was done before and buggered. I may even try my hand at building up the block and head because it has overheated a few times. That I will determine when I get it apart. have to clean up my shop to get it in there in the first place. Winter is coming and here is starts in December until April.

Mark