what , change a head in 16 minutes, change a gear box in 12---- no way i say...
mark k ----- Original Message ----- From: "Lach" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, February 18, 2003 4:49 PM Subject: RE: L6 Head Removal/Refitting > In the '70s, we were running a 1600 for Greg Carr in one of the Castrol > Rallies here in Canberra. On the final day, the car blew a head gasket. > Two of us changed the gasket and had the car out of service in 16 > minutes. He went on to win the event. Did a gearbox in a BDA Escort in > the Queensland mud in 12 minutes, but that's another story. > > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] On Behalf Of James Fitness > Sent: Tuesday, 18 February 2003 2:23 PM > To: [EMAIL PROTECTED] > Subject: Re: L6 Head Removal/Refitting > > > Back when I was 18, I was driving from Melb to QLD and had the > headgasket blow on my 1600 just out of Lismore (ok so I was going the > long way :) > > I ended up stopping at the local Nissan dealer and begging them to let > me use their tools cause I had none and little money... anyway to cut a > long story short - 3 hours later and $50 for a new gasket and I was back > on the road... > > They were still shaking their heads as I pulled out of their driveway > casue they still didn't believe that I had gotten it all done in that > time ! > > > > > Zac Campbell wrote: > > > 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]> > > > > > > > > > > -- > ----------------------------------------------------------- > > James Fitness > Director > Data Scribe Australia Pty Ltd > http://www.datascribe.com.au > Computers, Peripherals and Supplies > > > Ozdat Online > Webmaster > http://www.ozdat.com > > > --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]/ > --------------------------------------------------------------------- > > > --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]/ ---------------------------------------------------------------------
