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Sat Nov 30, 2002 2:39 pm

hi y'all!
just wondering that when the face of the cyl head is re-faced do you need to flycut the chambers by the same amount as what is taken from the face.

Sat Nov 30, 2002 4:58 pm

Some machinists will do it for you at no additonal charge IF they are familiar with VW heads and engine building... or ( if they don't ,or want to charge extra) you can add cylinder shims under the cylinders in various sizes ( about 10.00 US a set) to replace what was cut off the head and what was cut off the case decking (cylinder seating surface) if you by chance are having that done too....

Sat Nov 30, 2002 6:16 pm

just doin heads to make sure no warping has occurred due to running with loose lower cyl head nuts for what could be sometime.
ah women owners.
this is gettin done at same time as checkin if i have unleaded heads as the engine builder ain't sure.

Sat Nov 30, 2002 6:32 pm

Yeah we talked about all that in some of our e-mails... I have always read/heard that any VW heads after about 1968 came with hardend seats capable of running lod lead or unleaded fuel...
Are you putting on new pistons and cyls?? anyway I need to e mail you some stuff, catch you then... K

Sun Dec 01, 2002 6:02 am

not doin new pistons and cyl.she done bout 20k on these ones so should be fine.
heads are meant to be new castings so s'pose depends on the company that did the castings.
reminds me to e-mail the engine builder again.

Sun Dec 01, 2002 8:40 pm

psimitar and keifernet,

ALL VW heads can use unleaded fuel! In the UK (no where else I've seen) there is a habit of advertising to "convert your VW to unleaded" which is not exactly untruthful but it in fact misleading. Since you guys have only recently switched to unleaded, they are playing on your fears.

In the USA they have been using unleaded fuels now for over 15 years. Here in Australia - over 3 years. No changes to the VW engine at all - just fill up and keep driving. And in the UK, even the octane number is no problem since 95RON is the lowest you have - that's better than the miminum specified by VW.

The "unleaded" thing is a nonsense for VWs, since every single VW head has hardened steel valves seats, so they don't need the protection of lead in the fuel which was needed for cast iron heads (where valve seat recession is a problem).

In about 1965 VW changed to a harder steel for the valve seats, but the earlier ones are still HARD, and can still cope with unleaded fuel. It's THIS fact (the harder seats) that the UK advertsers tend to play on - as all modern replacement VW heads have the extra hard steel, they can (sort of truthfully) say "oh yes - these modern heads have the hard steel you need to run unleaded..."

There's more info in this article
http://www.geocties.com/aussiebug1970/octane1.html

And re the head refacing. It's the flycut which is the actual head resurfacing, as THIS is where the cylinders seal on to the head. Any cutting of the face of the head is just so it won't bind on the cylinder fins when the head is put down over the top of the cylinder. So getting the heads "resurfaced" is a nonsense unless they are flycut too.

Rob
Rob and Dave's aircooled VW pages
Repairs and maintenance for the home mechanic
http://www.geocities.com/aussiebug1970/