WBXmayo

[itchyfeet]

Heads next

These are two used AMC heads that I bought and bartered, the valves on one are not in great condition and so they are going to get swapped out with valves from some old scrap heads I have, the other, valves look OK and with some replaced guides so I doubt AMC cheese valves.

first job was to remove two steel studs, one snapped so had to drill it out and helicoil.

I then cleaned all other threads to find that six more exhaust threads were either striped or very worn so helicoiled those too, perhaps the AMC aluminium is softer than VW?

P1090210 by Paul_Barr, on Flickr

P1090211 by Paul_Barr, on Flickr

P1090212 by Paul_Barr, on Flickr

P1090215 by Paul_Barr, on Flickr

P1090213 by Paul_Barr, on Flickr

some of the outer head stud seats were badly indented and scored so improvised a cutter from a tap seat cutter. It looks like somebody tightened them far too much or the AMC aluminium is softer than VW, not seen this before.

P1090206 by Paul_Barr, on Flickr

P1090208 by Paul_Barr, on Flickr

valves next

P1090218 by Paul_Barr, on Flickr

[itchyfeet]

Fine grinding paste & wd40 as a lubricant on an old barrel helps to remove and find any imperfections, always the same number of turns on both chambers of each head.

P1090223 by Paul_Barr, on Flickr

P1090224 by Paul_Barr, on Flickr

clean up the green o ring seal surface

P1090226 by Paul_Barr, on Flickr

water jacket surface, again paraffin or wd40 as a lubricant

P1090227 by Paul_Barr, on Flickr

grinding valves the easy way, clean guides with lots of parrafin/wd40, then oil stems, when removing the valve never touch the paste onto the stem.

This is a a set from a VW head that was toast but the valves are good.

P1090228 by Paul_Barr, on Flickr

reassembled

P1090229 by Paul_Barr, on Flickr

I decided not to use the old valves on either in case they are AMC valves, I pulled appart my last duff head and recovered the valves,

ran out of time tonight to grind and fit job for tomorrow...


P1090230 by Paul_Barr, on Flickr

[itchyfeet]

I have Not used AMC heads before but the reason for removing the valves is that they could be AMC. The end of AMC valves (where the collets hold it) fail in time ( picture from Marco Mansi) good but worn valve on the right for comparison

AMC Valves by Paul_Barr, on Flickr

[ajsimmo]

I hear that AMC have addressed the problem of the poor quality valves, and the new ones I buy now look to have different valves to the older ones (I bought a pair of NOS AMC heads so could compare old-new with new-new). I hope the change has cured the problem. The only way to find out is to fit the new-new straight out of the box, but it might be a few years before we know the results.

Sent from my ONEPLUS A3003 using Tapatalk

[itchyfeet]

Thanks Andrew, lets hope so although I suspect most people will take a while to trust them again.

finished the other head off this morning, get lots more done when it's raining outside.

checked valve guide play on this one as it was more worn, still well within limits

P1090232 by Paul_Barr, on Flickr

ground and assembled, then gave them all a whack to make sure they are seated.

P1090235 by Paul_Barr, on Flickr

one rocker stud thread was damaged so came out when I tried to fit a nut, removed it and cleaned it up and threadlocked it back in

P1090233 by Paul_Barr, on Flickr

rocker gear from the VW scrap heads....finished

P1090237 by Paul_Barr, on Flickr

[itchyfeet]

Crank bearings this afternoon

woodruff key out with a screwdriver and hammer

P1090239 by Paul_Barr, on Flickr

clip off ( needs the right tool)

P1090240 by Paul_Barr, on Flickr

crank gear puller on and some heat on gears and it comes off

P1090241 by Paul_Barr, on Flickr

P1090242 by Paul_Barr, on Flickr

mark the parts so its easy to reassemble

P1090244 by Paul_Barr, on Flickr

measure journal it's spot on blue

P1090247 by Paul_Barr, on Flickr

measure old and new bearings and they are the same, seldom any major wear in the main bearings but I'm changing them anyway.
About 0.1mm difference between bearings and journals is normal although I have never seen a spec.

P1090249 by Paul_Barr, on Flickr

flywheel on temporarily makes it easier to refit gears, bearing on with assembly lube making sure it the right way ( I photographed and marked the old one)

P1090250 by Paul_Barr, on Flickr

heated the gears in the oven for about 20 mins on high then they just drop on, I have a sleeve ( a scaffold joiner) and hammer ready in case I need it but I didn't.

P1090251 by Paul_Barr, on Flickr

[itchyfeet]

measure up, check and fit bearing 4

P1090252 by Paul_Barr, on Flickr

P1090253 by Paul_Barr, on Flickr

P1090254 by Paul_Barr, on Flickr

woodruff key hammered back in with block of wood and check pulley fits

P1090255 by Paul_Barr, on Flickr

checked all other journals all spot on blue crank dims, excellent condition.

P1090256 by Paul_Barr, on Flickr

removed old spigot shaft bearing with a M8 Rawlolt

P1090264 by Paul_Barr, on Flickr

P1090263 by Paul_Barr, on Flickr

fitted new one

P1090269 by Paul_Barr, on Flickr

that's it for now con rods on later after I have checked cam shaft play.

P1090270 by Paul_Barr, on Flickr

[itchyfeet]

Finished cleaning up the case mating surfaces tonight with some wet and dry and paraffin taking care to clean up as I went and not to contaminate any oilways.

P1090274 by Paul_Barr, on Flickr

took the razor sharp edge of the oil pump inlet and outlets, I will be O ringing pump and this can damage the o ring on insertion, rag in the oil way to catch any grit off the wet and dry.

P1090273 by Paul_Barr, on Flickr

ran nuts down all threads to make sure they are free and remove any dirt on both threads.

P1090278 by Paul_Barr, on Flickr

ready to drop the crank in and start rebuilding

P1090277 by Paul_Barr, on Flickr

[T25Convert]

Looking good, lots of attention to detail!

Makes me want to build another one. Just done a 1600 Aircooled lump, its so similar it really does show how crude the water jacket is.

[itchyfeet]

^^^ Thanks, you know you want to build another

Cam bearings need modifying as usual as there is an extra tab, filed it off

P1090279 by Paul_Barr, on Flickr

cleaned up all the cam screws and threads with meths, let it dry then threadlocked them in, this is high strength, high temperature and suitable for engine oil......I hope

did the screws hand tight then tried to centralize the gear, it would not move but backlash was under 0.05 at worst and zero at best point so it's OK.

P1090281 by Paul_Barr, on Flickr

tightened to max torque on the data sheet

P1090282 by Paul_Barr, on Flickr


P1090283 by Paul_Barr, on Flickr

[T25Convert]

Now don't do what I did and leave the other halves of the cam bearing shells out. It's a right pain when you find them after you've sealed the case!!

Find myself looking at a van on eBay with a blown water jacket, it's only a matter of time before I'm swearing at head studs again!

[CJH]

tightened to max torque on the data sheet

P1090282 by Paul_Barr, on Flickr

I see cap heads there. Did you try grinding the tip of your 4mm hex bit flat (that's the same advice he gave me), or did you just go straight for the cap heads with their 5mm hex head? I still find it odd that he (and presumably all his other customers) can get the 4mm dome heads up to torque without rounding the slots, and I was a long way short.

[itchyfeet]

yep ground a allen key off and got much higher torque but I still rounded it out at 19Nm so fitted cap heads, I borrowed a calibrated torque wrench so do doubt there.

[itchyfeet]

Now don't do what I did and leave the other halves of the cam bearing shells out. It's a right pain when you find them after you've sealed the case!!

Find myself looking at a van on eBay with a blown water jacket, it's only a matter of time before I'm swearing at head studs again!

As you have the skills it's a good way to pick up a cheap van, my Pop top was a bargain because it had mayo engine.

[itchyfeet]

Refitted con rods to crank tonight, looked back at the pictures I took last year of the numbers stamped in so they are in the same place.
Fitted new big end shells and torqued up to 45Nm these are non stretch bolts 113105425B that I swapped and binned the old stretch bolts.

P1090284 by Paul_Barr, on Flickr


P1090287 by Paul_Barr, on Flickr

note all pips on the con rods facing upwards...

P1090290 by Paul_Barr, on Flickr

then what should have been a 5 minute job turned into an hour, popped the dizzy drive gear in and it jammed, took me an hour to coax it out with an old dizzy, I think it must have a burr and shaved a bit of aluminium off as it went in, there was some swarf on the way out, I think I will try a different one tomorrow, no more time tonight.

P1090292 by Paul_Barr, on Flickr