Machine Head Project

[S2central.net]

Yeah the cam bearing worries me a tad, but I'm assured it could be TIG'd and drilled (the stud hole) to make it good again.

I might take you up on the offer of a junk head - best to practice on that with a grinder than this thing.

Dunno the story on how those IN valves get mooshed but there is no damage visible to the head - might regret those words after closer examination.

I'll post the head p/n later - it was flukey that the EM studs are right.

Hopefully see you last week of October down in the Dub when I'm there again - PM me back if any particular evening works for you. I hope to have this head ready for dropping into Westwood for 1st bench run.

Paul

[Jamo]

I'm sure somebody on the forum have got away with swapping a single cap

MartinJS was it?

[volcano rs]

Yeah the cam bearing worries me a tad, but I'm assured it could be TIG'd and drilled (the stud hole) to make it good again.

I might take you up on the offer of a junk head - best to practice on that with a grinder than this thing.

Dunno the story on how those IN valves get mooshed but there is no damage visible to the head - might regret those words after closer examination.

I'll post the head p/n later - it was flukey that the EM studs are right.

Hopefully see you last week of October down in the Dub when I'm there again - PM me back if any particular evening works for you. I hope to have this head ready for dropping into Westwood for 1st bench run.

Paul

i had 10 of them like that couldn't even get the valve compressor on them they were wedged in .

[S2central.net]

All VSOS removed now - bit of a PITA without a 'proper' tool for that - man they are tight... A squish with long nose pliers, then another squish from the other direction seems to loosen them up so they can pulled out with the pliers.

On the 7A head, there is another metal disc below the valve spring retainer which is easy removed with the now infamous magnastick

I think on the parts system it shows *all* 20 valves on the 3B/ABY/AAN/ADU having this extra disc - must be a heat thang.

Photos to follow...

[S2central.net]

Heres the disc after removing the VSOS.

[S2central.net]

Photo from inlet side - clearly showing 7A head number - 034 103 373 K

[S2central.net]

Got flukey light with this snap of one of the inlet ports that shows up the casting marks and surface bumps which I aim to remove. The bronze coloured bits are the tips of valve guides.

I know its not good practice to polish the inlet ports and/or make them too smooth as the fuel can just condense on the walls, but these ports can only get better with a little TLC.

I noted that there is not much of a 'step' in the port shape where the valve seat approaches the manifold faces - its pretty reasonable so I'm not gonna go crazy in that area - there is risk to the valve seats in this area if the grinder slips !

Better photos with a closeup lens on a real camera to follow - the EX ports are naturally pretty black and hard to get a goof pic from right now


Paul

[mcandmar]

On the 7A head, there is another metal disc below the valve spring retainer which is easy removed with the now infamous magnastick

I think on the parts system it shows *all* 20 valves on the 3B/ABY/AAN/ADU having this extra disc - must be a heat thang.

Now thats weird, my version lists x10 of them for the intake valves on a 7A, and x20 of them for all valves on NM/3B/ABY.

I dont remember seeing them before

[S2central.net]

Just checked - yes family album says 10 for intake side, but I'm pretty certain that I found them on EX side. COuld be wrong though - you know what its like when you have the head this way, that way on the bench. I'll look at the photos again to see if that proves it one way or another.

[S2central.net]

Heheh - just looked at pic ***248 again - that IS the inlet side - the nut visible in bottom right corner is for the dissy clamp, which is on IN side. D'oh. Well spotted Mark - no flies on you

PAul

[mcandmar]

You had me worried, did i forget to fit a bunch of washers

In relation to porting i found some interesting pics if you want me to post them, i have very few of the ported head but plenty of close up on the stock one.

I would also be interested in compaire pics of your 7A ports to my ABY as i'm convinced the 7A is a better quality casting. Will try and take a few pics and explain.

Mark.

Heres a good one showing the stock intake ports on an ABY, rather arty isnt it

[S2central.net]

Those seam lines in the centre are apparent on the 7A head but much less so at the edges of the port.

I think the one I have is an early variant - as the family album claims not to know what it was replaced by. Currently shows the 7A head as 034 103 151 B (as opposed to N suffix for 3B or ABY).

[martinjs]

I'm sure somebody on the forum have got away with swapping a single cap

MartinJS was it?

No wasnt me but i remember it being talked about, think it was someone Jas knew.

[Error404]

great project Paul, really interesting... how are you planning to do the actual porting? have you had advice / experience on the size and shape?

Hoep that broken cap doesn't cause you too many headaches

[mcandmar]

Paul, incase you missed it this was just posted in another thread...

http://www.20v-sauger-tuning.de/kanalbearbeitung.htm

Found this little gem