Engine internals - getting started on the rebuild

[martym00se72]

Hi Folks,
I finally got my 3.0 out of storage and it is sitting on a pallet in my shed awaiting my undying attention. I bought the engine sight unseen. I was told when i bought it that it was from a running 75 that got totalled. It is from Qld Brizvegas so I guess I want to check that it is not a flood damaged wreck - what should I look for?

It looks like it has not been running for quite some time – took the passenger cam cover off and it smelled a bit like varnish so thinking the internals need a really good flush out – thankfully everything looked straight. I plan on taking the sump out to give that a clean out – what else should be done to get it cleaned up and moving again? I don't want to have to pull it to bits if it can be avoided – I am trying to not stretch my tech skills beyond their limits just yet.

I understand the size of the main pulley is 41mm – how much force is required to crank the engine manually? I intend changing timing belt, tensioner and water pump straight up, but want the engine at TDC – dizzy arm points to #3 at the moment. I can't see a timing main on the main pulley – is it cast/stamped into it or a painted mark? The pulley is surface rusted.

Also, engine came minus starter and alternator – keen for an alternator upgrade – any suggestions? Starter motor source?

There will be a guaranteed shit load more questions – can already think of a number, but figure so long as I take my time and do my research (with the kindly assistance of your good selves), it should all be good!
Cheers
Marty

[Duk]

I intend changing timing belt, tensioner and water pump straight up, but want the engine at TDC – dizzy arm points to #3 at the moment. I can't see a timing main on the main pulley – is it cast/stamped into it or a painted mark? The pulley is surface rusted.

There are timing marks on the camshafts, also, but you have to take the head covers off to see them.

Also, engine came minus starter and alternator – keen for an alternator upgrade – any suggestions? Starter motor source?

5 litre V8 VT Commodore apparently have a very good alternator.
1 thing that a modern alternator will bring to the party is an ability to deliver HEAPS of current at idle speed. http://autospeed.com/cms/title_Upgrading-the-Alternator/A_111306/article.html it will require some mounting point changes and remember, 120 amps at 14 volts is 1680 watts of electrical power. To make sure you can transfer the mechanical power, think about mounting points that would have to withstand twice that amount, to be safe (that's 4.5hp!)

[wankski]

u need to take the spark plugs out... using a normal 1/2 ratchet wrench you can turn it by hand...

you should ALWAYS confirm TDC (via dial gauge). i don't care what the pulley says.


yes, i know 24v is different, but like so...



you can get away with sticking a large screwdriver in there and watching for it's apex of it's travel, then cross referencing that with the pulley mark if there is one.  dial is very accurate tho...

[martym00se72]

OK - so I have started tinkering - cleaning off 25 years of grot and crap. Every thing looks straight under the cam covers. Got my 41mm socket from the UK and tried to crank by hand using my breaker bar. Zero movement. Also, took the oil filter off. Had plenty of liquid, but it sure as shit isn't any oil I am familiar with - runny like water, smelling somewhere between petrol and varnish and highly flammable. I don't know what to make of it. but I am guessing that might have something to do with the failure to crank? Any thoughts? Suggested strategies? I bought the engine intending as a straight swap in - not intending to do a full tear down. Anyone have thoughts on how that might still be achieved? Beginning to think I bought myself a bit of a dud 

[wankski]

the only way to take off an arese crank nut is by a very good impact wrench and an impact socket.

the tightening torque is something like 230Nm on a lot of them + age and getting seized = no hope.

my aircat impactor ripped it off in 3-5 hits... that tool is of course is rated @ 1100ft/lbs @ 120psi. invaluable for suspension work too...

anyhow.... your only other hope is to lock the engine by the fly wheel and use some scaffolding pipe or similar and slip that over your breaker bar... not ideal with the engine out of the car... likely just rock the whole motor than move the cranknut... really - u need an impactor...

at this stage, forgive me, but i think it was niave to expect to plug in a 25yo motor, no matter what condition it was sold at...  (unless professionally rebuild of course!)

at minimum strip the sump and find out what you're looking at... inspect the big end bearings numbering everything and putting them back where u found em....

i would also as a matter of course rip off the heads, perform a leak down on the pistons to ensure compression rings are good opr at least equal, clean out the carbon and inspect the heads - refit new head gaskets after cleaning out and inspecting the head...

again invert head and perform leak down after gently cleaning out the combustion chamber.. rebuild and retime.  with the engine already out of the car - really shouldn't take too long...

[wankski]

obviously, if you wanted to take it a step further, you could, once u have ejected the big ends from the sump and removed the heads... extract the pistons from above... inspect cyl bores and perform a light hone after cleaning with ATF. then inspect ring gap to determine wear - you can re-order new rings from IAP...

i probably wouldn't do this unless u were embarking ona  full rebuild as the old SOHC per bank arese runs wet liners and honing the bores will likely break the liner seal - meaning you'll have to buy new ones and clean out and reinstall.. if you do this, apply a fine layer of gasket cement to the new liners to ensure a good seal... this things are a pain when they don't work...

if it were me tho, i'd limit it to extracting heads and sump - bit of cleaning - and inspecting crank and bearing shell condition... obviously if you detect a problem there... it's rebuild time... otherwise if it passes leak down on the pistons and inverted head after light cleaning - good enuff with new head gaskets...

all sorts of crap has come out of filters in my time on perfectly good engines.... no need to preempt things... crack it open and see... that's the fun part!

[dehne]

hi there
I had a 2.5 with a similar prob and found that fuel had some how leaked into the oil, i drained it out and put some old oil into it and then cranked it over (engine was still in car) MMM would be a bit annoyed with it not turning over, maybe with all fluids out and some crap new stuff might help, have also seen a plate that you connect to the rear of the engine where tailshalf goes and has a big nut welded to it and has been used to crack the engine( slight seize) then engine has moved again.
Hope everything works out for you