Head Gasket Time...

[Hoges]

Casual conversation with a fellow AULORIAN yesterday and a quick engine inspection revealed a whiff of coolant, hot water level in the overflow tank on the line for "cold" level and a rock hard top radiator hose...

Bosch series, 4.6, 145k Km

Have read most of the posts (thanks PaulP38!;)) But need some advice please: Is there a complete gasket set available for such a job or should the parts be sourced individually? Supplier?

I suspect the cam needs replacing judging by the photos I took of the of the lobes when I did the lifters/rockers... Any thoughts for replacement.. Am thinking about replacing with a standard grind but wondering if there is a grind which puts max torque in a slightly lower rev range? Supplier?

Looking at studs rather than stretch bolts : recommendations pls?

Sorry about all the questions: Head gaskets I can deal with...I dare not entertain thoughts at this stage of a slipped liner! Being a "Bosch" series I'm hoping I safe on that one:angel:

All advice gratefully received...just when I have the front end sorted with new ball joints etc:mad:

cheers

[1976_michelle]

What a shame! iSN'T THAT a bit young in ks to have happened?

[MacMan]

I can recommend the ARP stud kits for the Rovers.

https://www.aulro.com/afvb/images/imported/2012/07/612.jpg

I just did my 3.9L V8 using these, sourced locally from Fabre (http://www.fabre.com.au/about-us/).

I'm not familiar with the cam options for 4.6 engines, but I decided just to go stock grind with mine (and new lifters of course). I couldn't honestly ask for more power, and really didn't feel like an experiment. The accepted wisdom with the 3.5 and 3.9 engines is that substantial differences in cam durations and timing are only worth considering if you are also willing to do head work, since flow it the limiting factor in stock form. Someone with more experience with the 4.6 engines will be able to comment I'm sure.

The only advice I can give with camshaft replacement is whatever you use, degree it in properly. I used a Rollmaster timing chain kit on my build and I was surprised to find that I needed to use the 4° advance keyway to achieve standard factory timing. I was so surprised by this that I measured timing with both the old and new cams with both the old and new timing sets more than once. All pointed towards the +4° being the true 0° mark. Had I not invested the time checking and just "chucked it in" at 0° I would have lost out on the one thing I really love about the V8 - the willingness to work right off idle.

[justinc]

All good advice above, the 4.6 also benefits from standard factory cam profile unless substantial other changes are made.

The cam timing needs to be degree checked, as stated, as 4 degrees is a quite substantial amount of adjustment to make up and no surprises the performance is way better.

JC

[David]

Hi Hoges, is your top radiator hose hard with the engine running or with it off, I too can smell coolant from my engine so you now have me worried. I have no custard in the oil filler cap?
Regards
David:(

[Hoges]

Hi Hoges, is your top radiator hose hard with the engine running or with it off, I too can smell coolant from my engine so you now have me worried. I have no custard in the oil filler cap?
Regards
David:(

Hi David,
answer is "engine off"... had just done about 50km on freeway so it was at proper operating temp. Had been parked for a couple of minutes when we made observation... Oil filler cap is clean

Good luck!

[Hoges]

What a shame! iSN'T THAT a bit young in ks to have happened?

Nope...can happen anytime... luck of the draw I guess. I would have expected it to happen a lot later but have seen examples on other marques from as low as 25,000 km though it is more common I am told on engines with iron blocks and alumiinium heads due to different coefficients of expansion. That's not the case with the 4.6 but at least the repair is DIY "do-able" with a decent set of spanners :D:

[PeterAllen]

Hey Hoges,
How is that head gasket replacement going? Would be interested to find out where the fault was located. i had to replace mine a few weeks ago but it was just a blow out of gases to the outside and didnt effect the oil or coolant.

[Hoges]

Ummm not started yet..:eek: flew to Cairns for a week to have some "time" with my new grandson! :D Should really try and get into it before SWMBO gets back from Cairns!! ;)

Peter, did you get your bits and pieces locally or did you get them from the UK?

I have started the planning and am putting a list together of what's needed..

cheers
A.

[PeterAllen]

I purchased the head gasket kit from Island 4x4 in the Uk plus new head bolts. I didnt end up using the new valve stem seals or injector o-rings plus a few other bits and pieces that were in the kit. There were two kits available and I purchased the more expensive kit at 44 pounds. It has a better head gasket. All up with the bolts and postage was less than $A140 and got it delivered within a week.
The only other costs were new oil, oil filter, coolant and the shaving of the heads. ( Heads shaved cost $220 for both). I was lucky as there was little damage to the head surface from the blown gasket and I had run the car for over 6,000 km with it as I thought it was an exhaust manifold leak. I was expecting it to be torched and in need of a weld repair as well before machining.
Have since done over 3500kms and all is sweet so far.
Admittedly I had an experienced mechanic at call when I was stuck or unsure but found the process not too difficult albeit time consuming. 1 day pull down, 1 day cleaning and get heads done, 1 day putting it all together. ( note they were short daylight days and averaged 6hrs each day with plenty of the usual coffee breaks).
In the event it happens again I would be much more confident. Apparently my heads had been machined previously (at least thats what the machinist said) so not sure how many times it can be done but hopefully I wont need to for a few more years at least.
Good luck with it Hoges and dont forget the key code sequence to re enable the engine. I did, until wife intervened and started car up.:mad:

[Hoges]

FWIW: got in touch with Fabre in Sydney: apparently the Rollmaster timing chain kit won't suit the "later" derivatives of the venerable Buick 215 :eek: i.e. the 4.6 due to clearance issues with the oil pump. this also coincides with the advice in the Google 'free read' section of Des Hammill's book which states that due to clearance issues duplex timing chains are not suitable :(---of which the Rollmaster is an example.

Question: 1. Will the ARP "Buick 215" stud kit fit the 4.6 motor?... they want $221 for the kit...don't know if this price is over the top or within the ball park.

2. Stainless Steel valves vs oem: I see TRS in Adelaide has SS valves on "special" for $28 ea which is about x2 for standard issue... are they twice as good or do they confer advantages for day to day driving?

3. If I go new valves...do I need to lap them in to the seats in the refurbed heads? (I still have the "kit" from when I did the head on my LC Torana 173.... in 1977:angel:)

Thanks for advice and patience!

suspect I'll source the rest of the bits from Turners or Paddock spares.

I'll take plenty of photos

[MacMan]

Bugger about the timing gear. I still had to modify my 4 belt 3.9 cover, especially considering my block didn't have the cam retaining plate.

https://www.aulro.com/afvb/images/imported/2012/08/1599.jpg

https://www.aulro.com/afvb/images/imported/2012/08/1600.jpg

https://www.aulro.com/afvb/images/imported/2012/08/1601.jpg

As for the studs, as far as I know (JustinC might be able to confirm) all Rover blocks use the same pattern. There was some discussion in UK forum sites about ARP studs pulling threads out of blocks because they don't engage the same number of threads as the original TTY bolts but I decided to go with them all the same. However, I ran 3 stages of 25/50/75 ft/lbs rather than going to 80 ft/lbs as specified by ARP. 3,000km in to the new engine and it's all OK so far.

As for the valves, I can't advise anything other than if you replace them, be certain that they have been cut to match your seats. My recent experience with replacement parts suggests that everything needs to be checked carefully.

[glenhendry]

You publish a schedule Hoges, for this work, as I would very much like to come and help, heckle and pass tools as much as I can!

[Hoges]

All good advice above, the 4.6 also benefits from standard factory cam profile unless substantial other changes are made.

The cam timing needs to be degree checked, as stated, as 4 degrees is a quite substantial amount of adjustment to make up and no surprises the performance is way better.

JC

Well, everything is "out", labelled, cleaned and now for the process of replacing.

Camshaft: I got a standard profile OEM supplier cam (not "genuine") from Karkraft and a new "stiff" chain, chainwheel and sprocket. There appears to be no way to adjust the valve timing even if the cam is degree checked. Am I missing something?

Crane/Crow/Piper etc all recommend a specific routine for running in a cam. My new one has no obvious phosphate coating on the lobes... should I use the CRC engine assembly lube paste and running in oil in the engine (e.g. Penrite 15-40w non friction modified) to bed the cam in. Wondering how the experts do it

Sump Gasket Kit: contains a two small black rubber extrusions just a couple of cm long in the form of a "cross"... plus a set of washers (8) large, 2 small, with what appear to be a seal on the inner surface.. I'm assuming these are for where the bearings are replaced...is this the case? What are the crosses for?

Should I put (say)Loctite 515 on both sides of rubber gaskets (rocker cover /sump) before reinstalling, or are the RAVE instructions re. the Loctite on the sump pan for example where no rubber gasket is used?

Appreciate the advice thanks!

[Blknight.aus]

Im quite a fan of MR automotives midrange cam for the 3.9 If you havent already got your bits organised I strongly suggest using them for all your parts

the 3.9s offer no factory way of changing the valve timing on stock gears and chain,

[Hoges]

Thanks Dave -PM sent

[DT-P38]

Ummm not started yet..:eek: flew to Cairns for a week to have some "time" with my new grandson! :D Should really try and get into it before SWMBO gets back from Cairns!! ;)

Congrats Hoges!

[Hoges]

time for an update...

Thanks to Blknight I learned late one Friday evening the value of 6pt impact sockets on a looong bar for moving pesky headbolts AND how to slow cook sausage rolls wrapped in foil on a diesel engine while driving... he can explain it:twisted::p

With a small soldering iron and a bit of luck I rescued my trusty 8yr old digital Pentax from the tool box...so here are some highlights.

With heads, sump pan and front cover removed in that order the following became evident:

one slack chain...

http://i1157.photobucket.com/albums/p599/chopperdoctor1/loosechain-reduced.jpg

Removing the front cover I discovered this "blank" gallery above the oil pressure switch -see 12mm screw in plug : Got me thinking that it might serve as a handy place to mount an electric sender for an oil pressure gauge...

http://i1157.photobucket.com/albums/p599/chopperdoctor1/Timingcover.jpg

Having removed cover, sprocket and timing chain, I got to work on the block and pistons with a plastic pot scrub, Lanotec "Orange" degrease and elbow grease, and finiished off with metho clean rags and then a very light application of singer sewing machine oil...

http://i1157.photobucket.com/albums/p599/chopperdoctor1/IMGP0162.jpg


I then turned my attention to the camshaft:
First had to make room to remove it: heat exchangers can be moved forward far enough to allow cam to be removed without damaging bearings etc...there's about 2cm free space to angle cam sufficiently if cam is slightly angled down towards front RHS of engine...

http://i1157.photobucket.com/albums/p599/chopperdoctor1/enginebay-oilcoolersmoved.jpg

Lobe damage most evident...


http://i1157.photobucket.com/albums/p599/chopperdoctor1/worncamshaft148kkm.jpg

http://i1157.photobucket.com/albums/p599/chopperdoctor1/worncam-closeup.jpg


Replacement Timing chain and sprocket with "stiff" option chain in place. (red dots from a small vegemite jar of poster paint I "acquired" from my wife's box of teaching aids in 1972 to mark the timing points on my Torana... hate the taste of vegemite anyway:wasntme:) Was a precision fit
with absolutely no slack...took a couple of attempts to slide it into place without upsetting the relative positions of cam and crank ...
http://i1157.photobucket.com/albums/p599/chopperdoctor1/newtiminggearschain.jpg

So, having replaced, re-organised etc and forgotten to pack oil pump with grease:angel:, I gave the block one last careful inspection and wipeover with a clean rag /white spirit and put the composite (Elgin) gaskets in place, carefully engaged the heads with the dowels and then installed the ARP head studs with an Allen key and installed the heads.

Then came the heartbreak... These rockers were replaced just 20,000km ago -obtained from a well known reputable indy workshop in Sydney... I hadn't noticed it when I took them off as I simply wrapped the whole assembly in a polythene bag and stored it...

http://i1157.photobucket.com/albums/p599/chopperdoctor1/rockerpadfailure.jpg
Damned if I know when it occurred, I had not found the wayward pad anywhere so I can only guess I was jolly lucky and it somehow disappeared when I changed the oil at some stage. At no time has there been any noticeable zwerf on the magnetic plug...

The lifters were replaced at the same time and are spotless, convex, no circular markings at all so far...which surprised me given the state of the cam lobes.

questions: (1) Are cast iron rockers more reliable than alloy?

(2) .. I note the chap who pens the Range rover world Sth Africa blog spot draws attention to the "B......h" brand of alloy rocker which he demonstrates has been over machined and allows too much oil through and floods the top of the heads thereby (a) reducing oil pressure and (b) setting the scene for future probs with sticking valves due to flooding around the stems...:(

Recommendations please on replacement rockers?

Time beat me... family commitments dictate my closing up "shop" for a month... so

http://i1157.photobucket.com/albums/p599/chopperdoctor1/Wrappedup.jpg

When the heads came back from the machine shop I put a straight edge over the valve tops: there is a considerable height difference with the end 2 on both heads (they're 0.2mm lower). I may need to shim the rocker posts... or get some adjustable push rods... thoughts?

will get back, when I "get back" :eek:

cheers

[stopover]

I have a 4.6 v8 I did my head gaskets only 5,000 miles ago but got a constant missfire after four thousand. On investigation I realised the the camshaft was worn out. As the heads were recon items and had been skimmed I didn't know how much had been taken off but with the new cam in place and with standard push rods I found the lifter preload was very high and all over the place. So decided to go for Real Steel adjustable push rods as I had tried shims under the pedestals to no avail!. The adjustable push rods were 5/16 so decided to drill out the guide holes in situ. I experimented with a spare cylinder head to see how to deal with the swarf, there was quite a lot on each. The solution I found was to have a rubber hose long enough (cut to length) to have one end tight up underneath against the hole to be drilled and long enough to be tight up against the opposite head bottom, this formed a tight bend so that when I drilled the guide the swarf would drop into the hose. I carefully released this pipe after each drill and shook out the swarf ready for the next one. At the top there is also a lot of swarf so this was collected, as I drilled, with a powerful vacuum cleaner. Obviously I had also covered every hole with paper towel, inc the long and tiny ones down to where the crank would be. I had cleaned heads prior too and after and still found some swarf in the little gulleys where the vacuum cleaner didnt do its work. So using some wd40 to wash them out and lots of kitchen roll and a pile of cotton buds to minutely go over everything including the four bolt holes which were full of oil and needed cleaning anyway, it was done! I am confident that I got it all, fingers crossed. I measured up the RS adjustables and had two millimeters removed from the ends before putting the push-on round ends (need a press). I have after some experimenting found a piece of wire to 55/thou (as recommended by RS) and have started to install them. I found that from no slack to 55 thou is one full turn and two flats then tighten the lock nut, for some reason I had calculated that it should be one turn and three flats but after tightening the lock nut got 60+ thou so I go one turn and two. RPI recommend 40 thou ie 0.040, its up to you? I have had to make very slight adjustments as I go along but not much. I mark each push rod with prit stick so the flats can be counted and then on the rocker to show I had done that one. Wouldn't want to forget one!!

Asof today 16th Oct 12 I have six pushrods to complete, am also waiting for a stiff chain as the one sent was a floppy. Very interested on how you get on?

[stopover]

Well finished the engine and she started straight away, ran her at 1500 to 2000 revs to break in the camshaft and now she runs very well. Done about 100 miles of which 50 towing a four wheel trailer with no problems. :angel:
https://www.aulro.com/afvb/images/imported/2012/11/1390.jpg