yeah I'm serious, though I've done just about everything else on an L-series except remove the head, and done a head on another make. Another thing, I didn't remove the manifolds, it was only 8 nuts to remove the carb and turbo - saved a lot of time!
----- Original Message ----- From: "Bob" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, February 18, 2003 11:53 AM Subject: Re: L6 Head Removal/Refitting > 3 hours?? It took me and a make about 4 to just get it off - though we > were working at hangover speed.. Ill second the quality of the info I > have received on this post, it makes the job heaps easier. The head is > going into a shop tomorrow minus the cam etc to be serviced, I was going > to do the valves etc myself, but have decided to leave that bit to those > older, wiser, and more qualified. > > On Sun, 2003-02-16 at 12:22, Zac Campbell wrote: > > Bob, how did you go doing the head work on the L6? I did mine on the L20b on > > saturday and surprised myself by having the car running again in no longer > > than 3 hours! Mind you Terry's walk through helped. > > > > > > > > ----- Original Message ----- > > From: "Terry Rudd" <[EMAIL PROTECTED]> > > To: <[EMAIL PROTECTED]> > > Sent: Sunday, February 16, 2003 3:19 AM > > Subject: RE: L6 Head Removal/Refitting > > > > > > > Andrew, > > > > > > Thanks for pointing out - yes I did mean to say always change the valve > > stem > > > seals. We occasionally went to the considerable trouble of changing the > > > guides on a few heads in the early days - pretty expensive back then too > > and > > > not really worth it for a street engine and cheaper to toss the head and > > go > > > downtown to the wreckers and grab another - I guess it really depends on > > how > > > much has been put into other mods like big valves and porting etc. I'm not > > > sure how it's done these days, back then you had to dunk things in a very > > > hot oil bath, as I said tres exy as it was very labour intensive and no > > way > > > to do it without the correct gear. Stem seals seem to be made out of a > > > better class of materials these days also, I've seen genuine seals totally > > > stuffed in 70-80K kays, my last set on the old L engine have done 100K > > kays > > > and still no signs of anything getting down past them, but the guides are > > > absolutely kangaroo teds brother, sorry that's probably a 30yo > > colloquialism > > > (roo ted). > > > > > > regards > > > Terry > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED]]On Behalf Of GREENBURY, > > > Andrew Robert > > > Sent: Saturday, 15 February 2003 4:19 PM > > > To: [EMAIL PROTECTED] > > > Subject: RE: L6 Head Removal/Refitting > > > > > > > > > Terry, > > > > > > Excellent informative post. > > > > > > You mention: > > > "change the valve guides (always with an old L head as the guides wear)" > > > Do you mean with every head removal the valve guides should be renewed? Or > > > just the valve stem seals? If you meant guides, have you got an indicative > > > price for this work, figuring its not DIY. > > > > > > Thanks > > > Andrew > > > > > > > > > Bob, > > > > > > The L6 heads are much the same deal as the L4 - I have a feeling that this > > > is going to turn into an essay, writing about playing with heads > > > invariable > > > does. It's always a good idea to get hold of a workshop manual for > > > reference > > > when doing this sort of thing for the first time too. Good quality tools > > > especially the tension wrench make a rough job into a good job. > > > > > > Here's a bit of a technical guide to pulling a head the correct way, i.e. > > > make that the way that an SOB like me was taught to do it on a L engine 30 > > > years ago by one of the best rally teams around. > > > > > > Remove the bits and pieces to allow you to remove the rocker cover - I'll > > > start from there. > > > > > > Remove the plugs and rotate the engine by hand to exactly TDC induction > > > stroke on #1 cylinder; if you go past TDC, then rotate the engine thru 700 > > > plus degrees i.e. nearly twice more to do it again - it's not nice to turn > > > an OHC engine backwards, if we got caught doing it in my learning years it > > > was worth a swift kick up the bum accompanied with a good verballing. When > > > satisfied it's in the correct position, check that valves on #1 are both > > > closed, to be sure you can check that the valves on #6 are open. > > > > > > Note the position of the V in the timing wheel in relation to the notch in > > > the cam thrust plate, the V to the left of the notch is valve timing > > > retarded (possible stretched chain), in the centre is neutral as in stock, > > > and to the right indicates the timing is advanced; > > > > > > Note which position (i.e. P1, P2 or P3) the dowel in the cam is positioned > > > on the timing wheel; factory is Pos 1, if it's anywhere else then it's had > > > the human touch applied to it, i.e. the valve timing has been advanced for > > > some reason sometime in it's past. > > > > > > OK, if the cam dowel is in P1 and notch in centre of the V is as it left > > > the > > > factory and indicates that the cam chain isn't stretched. You may wish to > > > consider using P2 when putting it back together for a small amount of > > > valve > > > timing advance (4 degrees on a L4 anyway, I think the L6 is the same but > > > I'm > > > not absolutely certain of this). Just a word of caution with playing with > > > valve timing on the L6, they seem to be a lot more sensitive to minor > > > advance, if you don't change anything else then things like heaps more > > > grunt > > > mid revs and then absolutely out of breath at 5000 rpm can happen - it's > > > happened to me a few times on carbie fed L26 engines, and by returning the > > > timing to stock it revs to 6000 + as before - could have been just this > > > engine, jury out on that one and I haven't had a L6 apart in 20 years to > > > play some more. > > > > > > Check the position of the rotor i.e. is it pointing towards the front > > > (true > > > #1 position) or the rear (180 degrees out) - useful to know when you're > > > trouble shooting. > > > > > > Collecting this information before you pull it apart gives you a good > > > insight into getting a nicely performing L engine after a head rebuild. > > > > > > Use the trusty old solid wooden chock (don't use particle board and the > > > like) to hold the cam tensioner in place - dimensions are 160mm long, 32mm > > > high along one end and 45mm high along the other - thickness is important > > > too - around 10mm is good. A little trick to aid removal after the wheel > > > and > > > chain is re-installed is to drill a hole in the top of the 45mm end so you > > > can get the tool out - it's prone to sticking so you can thread something > > > fairly strong through the hole eg a leather shoe lace is good (I nearly > > > lifted an engine off its mounts when attempting to get it out once). The > > > straight edge of the chock goes in along the straight guide i.e. passenger > > > side; > > > > > > As a bit of insurance, you can mark a link and it's position on the timing > > > wheel, so you know for sure you re-install it in the same place, providing > > > you don't change the location of the cam dowel in a different P number. > > > Undo > > > the cam retaining bolt and remove the timing wheel from the chain. It's > > > important to keep track of where you remove bits from as everything should > > > be returned to where it came from - this really only applies to head > > > bolts, > > > valve springs and seating washers, collets, rockers etc. Bits like mani > > > bolts etc are not important. Make sure that you know the head bolt removal > > > sequence, on most engines it is the reverse of the tightening sequence as > > > shown on the VRS set. > > > > > > Once you've removed the head then remove each valve, (remember to label or > > > use some method to identify where it belongs), check the valves aren't > > > bent > > > i.e. slide in the guides easily, change the valve guides (always with an > > > old > > > L head as the guides wear), de-coke the valves, check the seats for blow > > > by > > > and correct as required, check that the head is flat and serviceable, by > > > serviceable L series head has all of the letters in "NISSAN" along the > > > lower > > > edge towards the front cylinder visible, if it's on the limit and you need > > > to shave it further to true, then it's head saver time, or better you will > > > need to source another head. > > > > > > Don't forget check that the cam dowel is tight in the end of the cam, grab > > > hold of it with a pair of pliers and check that it's tight i.e. it wont > > > rotate in it's hole and there's no sign of cracking around it where it > > > locates in the end of the camshaft. It's not usually a major problem in a > > > Datto L but none the less they'll grenade real bad if that dowel comes > > > adrift. > > > > > > Re-installation is pretty much the reverse, make sure the surfaces are as > > > clean as you can get them. After the head is torqued down, pay particular > > > attention to relocating the cam timing wheel in the correct or chosen > > > position, as this is the part that ppl find difficult - it's not really > > > that > > > hard if you follow the tear down tips. If it's not in the correct position > > > on an L engine it's going to show up as the engine is turned over during > > > the > > > valve adjustment process. I recommend that the crankshaft is turned over > > > by > > > hand thru a further 720 degrees after completing the rocker adjustments to > > > be sure before the starter is hit for the first time. If you changed the > > > dowel position to adjust the valve timing, it is quite normal to have to > > > rotate the cam a fraction (around 4 degrees for each number) to refit the > > > timing wheel. > > > > > > I would only recommend that you get stuck into the inlet ports if you have > > > had some experience - we practiced this sort of stuff on a stuffed as in > > > cracked or something head to explore the limits and perfect technique. The > > > novice can fairly safely use a dremel and some fine wet & dry to polish > > > the > > > ports, but that's all I'd do unless you are comfortable with delving > > > further. > > > > > > if you're still reading this you will have a bit of an insight into a > > > routine L series head service. > > > > > > Have fun with it, > > > > > > regards > > > Terry > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED]]On Behalf Of Bob > > > Sent: Monday, 10 February 2003 9:57 PM > > > To: [EMAIL PROTECTED] > > > Subject: L6 Head Removal/Refitting > > > > > > > > > Hi All, > > > > > > Ive ordered in my VRS kit and will be changing the head gasket > > > shortly. I have only taken a head off once before, are there any > > > special tricks with the L series that I should do? I looked throught > > > the archives and saw plenty of trouble with the chain tensioner > > > slipping, how can I try to avoid that? Also, is it worth cleaning up > > > an E88 head at home with a die grinder, is there anything worthwhile > > > that can be achieved by a backyarder? > > > > > > Regards, > > > Bob > > > > > > > > > > > > > > > > > > > > > > > > -- > Bob <[EMAIL PROTECTED]> > > --membersozdat------------------------------------------------------- OZDAT Mailing List Please Note:- Send (un)subscribe requests to [EMAIL PROTECTED] Send submissions to [EMAIL PROTECTED] No unauthorised redistribution of this email http://www.ozdat.com/ozdatonline/index.htm http://www.ozdat.com/ozdatonline/listindex.html http://www.mail-archive.com/[email protected]/ ---------------------------------------------------------------------
