My dad has a 740 gle wagon with a blown headgasket and our local volvo dealer wants $2000 to replace it.I can only assume this includes a complete reco of the cylinder head but my dad was going to scrap the car because of the cost.I am going to try to do this myself and am after as much info as possible such as cam timing diagrams and tensioner diagrams. Also can you re-use the head bolts on this model?

 

First thing, dealers are always expensive.

Pulling the head and reinstalling it is going to save you a bunch of money. Once you got the head off, you can't do alot, so if I were you, I'd find an auto machinist. Make sure its a machine shop and not a repair shop, a repair shop will just take it to the machinist, and mark up what ever the machinist is charging. I've seen people attempt their own head jobs, and they ussually end up bringing to a machinist. I worked in an auto machine shop for a year a few years back and I think the average rate for a 16V 4 cyl. was $400. Don't quote me though, thats just a ballpark figure. That would include cleaning in a hot tank, resurfacing the head, glass beading the valves, new guides and seals, 3 angle valve job(valve faces and stem ground, and re-assembly which included cold valve lash adjustment. You could also have the head pressure tested for an additional fee. Pressure testing is done by apply air pressure to the coolant passages and spraying the head with soapy water, if you see bubbles, theres a crack. Simple, but effective. Basicly, if you bring the head to a shop, they'll give it back ready to go on your shortblock. depending on how worn your head is, you might get out with just having to pay 50 bucks and you can put it back together. As far as the head bolts, bring them in to your machinist and he'll tell you. I myself always replace headbolts, connecting rod bolts, and mainline bolts with a reputible aftermarket brand(ARP is my favorite) when I rebuild a motor of my own. Even if they're $50 for a set, its something you know will not break. A chain is only as strong as its weakest link.

One quick word on machine shops, there are good ones and there are bad ones. If you can, try to find one thats been around a long time, or one that freinds have had sucess with. The guy I worked for had been building motors for about 40 years, and he didn't cut corners. Don't be afraid to ask questions, find out exactly what hes going to do, and ask for the old parts that he had to throw away. If he gets irritated at your questions, you shouldn't be there. If he wants to resurface your head on a beltsander, or "lap" your valves, you shouldn't be there, valves and seats should be ground and never lapped. Also ask him how much he took off the face of the head when he re surfaces it, because that will affect your compression ratio and you may have to shim your head gasket to make your electronics happy. We built alot of race motors because guys knew that they could beat their motors hard and they would still win. The local racers trusted our machine work, and you should trust your machinist, even if your not racing. Hope it helps

 

Thanks for the advice Dingbat.I Should have mentioned that i was a cylinder head reconditioner by trade but i left the industry about 5 years ago.I was mainly after the tourqe settings for the headbolts manifolds ect and the timing gears alignment as these are not a free running engine and don't want to get it wrong.The cylinder head has been reco'd a year ago when the timing gears packed it in.My only concern is that the head maybe either bent or gone soft or cracked due to a water pump failure but as you said i will get it pressure tested and checked for all these things.I am also considering putting a turbo on the car with the computer airflow meter and all necessary parts from the turbo version.

 

All the torque values and timing gear positions should be in any off the shelf repair manual(If you don't want to drop $20 bucks on one, go to the library and look it up) or your machinist will have that info. If your motor overheated, your head is most likely warped and if it overheated really bad, its likely cracked. Might want to have the intake and exhuast port vacuum tested too. Sometimes when a head overheats and warps, it will actually warp the seats too, causing valve leaks and when they overheat REALLY bad, the valve guides can warp causing the valves to stick. I wouldn't worry about the metal going soft unless you take a torch to it. Hardened aluminum can withstand alot.

If your going turbo, you might end up needing a different head as most motors have a standard version and a turbo version(different displacement, thicker chamber walls, more coolant passages, etc.). Hope it helps