That's what I'm aiming for.. Think one of the other two dirty ones I bundled in the boot are like that.. though one has missing valve seats...hopefully tonight I'll find the other is good to take new valves. Leaving the guides well alone this time My collection of heads is getting out of hand! ..
..... although perhaps another vanagon head would give me two with bigger inlets and I could suck more fuel in ... then.... I think I may need help with my parts buying addiction... I knew I should have stuck to fly fishing and that was expensive enough
Just in case anyone was wondering inlet manifold (well gasket for it anyway) and heat exchanger from CJ engine appear to fit ok onto the later 39mm inlet valve (CU 81-83? - The 071.101.371) heads... Now to get back and see what's under the gunk on those others!.. I know they're 029 heads anyway... just means I'm going to have to try again on getting valve guides in on at least one head!..
Not sure what people are bouncing around inside their combustion chambers but it appears to be a popular thing to do!
Well still don't have a pair of matching heads with guides so going to stop sulking and get those guides in while other options develop! Done some homework on tolerance fit machining and for this size of hole for an interference fit shaft needs to be 0.02mm bigger than hole for about 1.5tonne of pressure to push it in or a head at 150deg C to push in... Going to make sure head hole is clean and oiled and polish guide down to be 0.02 bigger and see how we go with a bottle jack to push if I can't get access to the oven again... Then hope hole is close enough to seat centre to get away with lapping in ... What else is there to do on a rainy bank holiday!
You really want to heat the heads up to 250c+ Freeze the guides too Heads will need to be in the oven for an hour to heat them through fully Get it right and the guides drop straight in
Do you size the holes first at all? Did the 250c for an hour and a half (where my over goes to) and freeze guides last time and got well stuck half way in! Will be cooking them again to help this time but thought getting sizes in the right ball park or at least tidying them up might help! Just don't want to make them too big and have lose guides!
Ordered std for exhausts which measure at 13.04ish with micrometer but oversize for the intake I'm replacing which came out with valve.
Only tried the one std exhaust guide.. went so bad thought I'd better stop and re-group! Cold sweat moment.... just had to check photo to make sure I wasn't ramming an exhaust guide into the intake hole ( no @snotty that's not a euphemism)... wasn't
Do you have oversize exhaust guides (1st oversize should do it) for if I fancy fixing the head I dropped. .. the bore for the one that got stuck defo needs tidying now...
Ah.. technique. . I was going down the brute force line first. .. Perhaps too much thinking now... oil might help too . I though dry fit way the way to go as it needs to stay in there but having seen how tight it was don't think that would have been an issue. Need a stocktake of heads now to see min work to get a matched pair...getting bogged down.. might call after weekend re guide ..do you do machining of heads too..need skimming chamber to get a good sealing face and get rid of pits from whatever was dancing in there on a couple if worth doing for spares...
Yeah, brute force will bugger the heads and guides... Just for ref, std size guides are 0.04 bigger than the holes. This keeps them in place, as the ally will expand quicker than the phos bronze... Over-sized guides will either need sizing, or the holes in the head resizing. And yes, I machine heads... I'm now pretty much set up to do the majority of machining in-house Machining a type 4 case for Porsche cooling the other day. I've got a T25 case to do for type 1 cooling too.. Need to build a case jig so I can bolt it down level to the mill bed
No stuff in post yesterday to get going on heads again... Have to do some cleaning up and other prep instead. ...
First out of the diesel bucket. . De- crudding And inspired by @paradox and his painting.. Then pushrods If like me your rock assembly keep together system fails Bentley shows them going together like this Longest reach rockers on the outsides.. blocks with bevels out and slots down.
Definitely renew the pitted one; I’d replace them all with these: http://www.tp-technologie.de/produkte ventileinstellsch en.htm
Cheers .. was just browsing 'tinterwe on these but mostly seems to be on adjusting not condition advice!.. Will have a look at them
