engine rebuilders

[pwood]

my 6.2 1984 diesel is getting tired and smoky i live in australia and the cost of rebuilding one here is very expensive . i have found the diesel depot on the internet there prices seem reasonable can anyone refer other engine builders.

[colinr]

G'day, I'm in Melbourne. Nearly any good machine shop can do a bore, hone, crank grind and valve grind. Getting the bits ain't hard as american ebay is full of bits for the chevs. I imported all my stuff except the pistons and rings which I got from Brunswick Diesel in W.A.. $850 freighted to Melb, ouch, putting it into a Toyota so cooling is a problem and they were good quality with all the coatings. The importer I used had a Californian address to post to and then in the container to Melbourne where I am. Heaps cheaper. I'll be honest though, with all the friggin around and the cost of buying a stuffed 6.5 here it would have been easier and much quicker to buy a reco motor from the states and ship it here. About $500 plus bloody GST to get a motor here. Downside, at least 3 months shipping time and then hope there is no red tape delays with customs. As you would have read there is some gremlins with the 6.2's. Linquip in Qld and Dewars on the NSW/VIC border also deal in chev bits. There are a few more but they are Ned Kellys. Where are you in Oz? Plenty of people on this website that know the way around these donks, so if it is advice you want, your at the right place. Will yours get away with a freshen up or do you want a reco. Some good motors for sale in the states, and the 6.2's are cheaper than the 6.5's, I'd pay the extra and go for the extra grunt of the 5 but how deep are your pockets, and you already have a 2 block. Good luck. Colin.

[pwood]

I live in Adelaide travel to Melb [Spotswood] 6 times a year. My 6.2 runs excellent, a bit rough on warm idle as you give throttle smooth as, 12 lt per 100km hyw. Runs cool 180, oil pressure warm 40-50 psi 60km 20-30 psi idle. whisper of smoke at idle put your foot down heaps of bluish white smoke. Has new injectors and IP. Hard to say how much oil it uses rear main seal leaks. I have noticed that when you first load it heaps of smoke get going [road trip] after a while seems to get better. Just a theory could this mean idling around town oils up in head through valve seals and then sucks it in on hard throttle, meaning just a head job i wish. Like you mention these 6.2 are not the pick of the bunch and could start rebuilding and find all the nasty aspects present. Diesel Depot offer a reconditioned performance long motor for just over $4000 on there web sight. Did you rebuild your motor or send it out, and do you know the year and casting number. My conscious says don't be weak and step up to the plate and take on the heads with all the help from the diesel page your really not alone.

[colinr]

Except for the rear main and the smoke out the back everything sounds OK. The gurus on this page will have more of an idea of how good/stuffed it is. What mileage has it done? There's a mob called Clearwater that sell after market heads on ebay, about $400 a head by the time you pay for shipping to Oz. New injectors and pump means your a fifth of the way there. The biggest problems with the chevs is the crap metal of the blocks and heads. If your block and heads are crack free, with a rebuild they will with luck, stay that way. After a certain year (2001 I think) some other mob did the castings, put better metals in and the engines stay crack free. If you are gunna put out the hard earned for another motor, pay the extra and get one of those. Your motor in my limited know how sounds rebuildable. But again, how deep are your pockets and can you do without wheels while the rebuild gets done. If you need something unexpected for the build you either wait for it to be shipped or get lashed for bits in Oz. You can bore a 2 out to a 5 without a problem. The early blocks were the same for both. When are you coming to Melb next. Catch up for a coldy. Best of luck.

[pwood]

I am getting prices for new heads shipped over, will pull mine, after news years if there worth doing up will just get the parts and change over to stamped rockers. If not park it up and wait.

If still smokey must be bottom end, i guess i wont die wandering where from. Still believe valve seals, oil builds up around valve idling, then gets sucked in on hard throttle. Hard throttle a few times in a row no more smoke, as sucked all oil in around valve. Idle again builds up open throttle smokey again.

I will be in Melb in the new year, have a beer or two with ya and see what another chev idles and pulls like, would not know any other. I should have bought a toyota those 24 valve twin cam 4.2Lt diesel turbo straight six are great, chevs have excellent HWY miles but suck around town like all big V8. I also would not have this love hate obsession with the chev to expensive.

[DmaxMaverick]

Smoky exhaust from engine oil must be post-combustion, such as leaking into the exhaust port after combustion. If it gets into the cylinder, it's just fuel like #2. Diesel engines don't know the difference. By the time you see smoke from engine oil, you'll have other issues present, such as a run-on engine, excessive consumption (adding 2 or 3 quarts with each fuel fill), and it'll stink so bad there'll be no doubt. Short of head or block cracks, there'll be no evidence of it. Oil won't "suck" along the exhaust valve guide. Your smoke sounds like injector, injector pump, or timing related. Do a compression check. If it's good, look to the fuel delivery or valve timing (worn chain).

[pwood]

Thanks for the reply DmaxMaverick your theory blows my theory out the water. I went looking in another direction as i have had new injectors, reconditioned IP and new timing chain installed by so called reputable injection shop.

I will investigate your suggestions, as maybe i have a faulty injector out the box. If the pump has been turned up and timing is correct i assume that would blow black smoke. Can you get the timing that wrong when installing new chain
and still run so sweet? or is it a matter of moving IP for advance or retard.

Thanks again will post out come.

[DmaxMaverick]

If all these components are new, check for air getting in somewhere. The presence of air can be confirmed/excluded by installing (temporary) a clear hose at the IP return exit fitting, with a loop that will catch any air passing through. Once the line is in place, run the engine. If air is passing, it will collect in the loop, which should be obvious. Air in the system does 2 things: Displaces fuel; and retards injector timing (the air cushion delays the event).

Things that can cause smoke when it shouldn't (in no specific order):

Retarded combustion timing.
Poor injector spray pattern.
Low injector pop pressure.
Low compression.
Low fuel supply pressure/volume (lift pump, collapsed/crimped line, filter, fuel pick-up in tank).
Leaking EGR valve, if it has one.
Excessive resistance at the fuel return circuit (line blockage or failed/incorrect fuel filler cap).
Dysfunctional HPCA (timing optimized for good cold starts).
(other things I don't think are related to your issue)

If it were mine, I would first try advancing the pump timing 1/8", and repeat everything that caused the smoke before. If it seems to improve, or the smoke color changes (gets black), the problem is most likely retarded timing, and possibly coupled with overfueling. Turning up the pump on a N/A engine more than the tiniest bit is almost always an exercise in futility. Any black(ish) smoke indicates enough or too much fuel for that load (it's already using up all the available O2 for the current fueling). Advancing the timing will offer the greatest opportunity for the best combustion efficiency, until the timing limit is reached. Excessive knock/noise and hard starts (detonation) means it's a bit too far. If the pump volume has been increased (turned up), the throttle timing advance should be adjusted to compensate for the "new" curve. Even most "good" shops don't do this, and their customers end up with a smoker and higher EGT's.

Take one thing at a time and work through it. Start with whatever is easiest for you. The fuel lift pump should provide 4-7 PSI at idle, and never be less than zero at any load.

[Robyn]

I have had personal experience with the clearwater heads, good stuff, top quality fit and finish.

Be sure to use 6.5 head gaskets as they have the metal reenforcing pieces around the end water passages that make them better. (MORE GOODER) :D

Missy

[pwood]

I had already advanced the timing once on Robyn's advice, just under 1/8 i was scared to go more not knowing the consequence. So i tried for more after your advice and 3/16 is the magic number. I have to really stand on the go pedal and i get just a little bit of smoke and more blackish in colour. Do i leave it at that or go for more, are you saying advance it till it knocks then back of till its sweet again.

Thanks for the advice Dmaxmaverick and Robyn, other wise i could have been another lamb for slaughter at the re builders

[DmaxMaverick]

3/16" isn't unusual. I've seen significantly more. It depends on the pump build, and how it was originally timed on the engine. At some time in your near future, it would be a good idea to loosen/tighten the injector lines on the rear of the pump to relieve the stress from the adjustment turn. Your "test" sounds about right, after the adjustment. How's the power and rattle?

[pwood]

The power seems like it has improved, or that could be my perception like the way they seem to go better after a wash. The sound is the same always smooth except on idle, seems to run like a petrol with a misfire soon as you give it a hint of throttle smooths out. It has always been like that, no other ones around to compare it with.

Thanks again

[Edahall]

I should have bought a toyota those 24 valve twin cam 4.2Lt diesel turbo straight six are great, chevs have excellent HWY miles but suck around town like all big V8. I also would not have this love hate obsession with the chev to expensive.

Hmmm, wondering if your poor around town economy could be a symptom. However, you have to remember that you've got a heavier vehicle to get up to speed and the GM diesel is not direct injection which means it is not as efficient at idle.