I'll preface this by saying I'm just an internet-educated hack with some tools and a decent barn where I can work on things. Plus two teenage boys with a propensity to tear stuff up so fixing up an older, inexpensive car to keep around as a spare has a certain appeal.
The car is a 1998 Saturn SL2, 1.9L DOHC, 170xxx miles that blew a head gasket after overheating. Car is in decent shape but has been parked in the barn for the past 6 months because it's not worth taking to a professional shop and spending $800-1000 for repair. Thinking I might try to fix it myself, I priced a set of bolts and gaskets at $60. Decided if I can't fix it, I'll just trailer it to a junkyard and sell it for a measly Benjamin.
Took the head off. Checked flatness and found it out about 0.008". Filled chambers with water and found 9 out of 16 valves leaking to one degree or another. Checked top of block and found flatness to be out 0.002". Decided it would be silly to slap the head back in with leaking valves. Not sure about the lack of flatness.
Talked to a couple local places about rebuilding this head. They are quoting $200-300 and anywhere 3 weeks to 3 months to get it in for a rebuild. I can afford the money but don't really want to wait 3+ weeks. Found another shop who said he could machine it to make it flat next week. Found an online rebuilder in a neighboring state that can ship me a rebuilt head for $300 within a few days. Found another head for $125 at a local scrapyard but I'm assuming there are no guarantees that it is in any better shape than mine. I'm guessing the scrapyard would frown on me measuring flatness and dumping water in it on their counter before purchasing.
Decided to start by lapping valves and see if I can get my head to stop leaking. Watched youtube videos. Bought a Lisle tool to remove the keepers from the recessed bores. Lapped valves and put it back together. Several valves are still leaking. Watched more videos. Decided I didn't do a good enough job so I pulled the 4 valves out of one cylinder and tried again.  Leak rate is now down to maybe a few drops worth in 15 minutes or so on that cylinder.
Questions:
1. Let's say my goal is not perfection but just to just get it running again to last for another 30k miles or so. Is a couple drops of water in 15 minutes enough to worry about?
2. Everything I read says if the flatness is out more than 0.001" per cylinder over the entire length (so 0.004" for this 4 cylinder head) then it should be machined. I'm seeking real world experience to see if I can get by with 0.008" or is 0.004" a pretty hard and fast rule?Â
3. Any suggestions if I can't get the valves sealed good enough on my head? I can get a new set of exhaust and intake valves delivered for about $60 (Enginetech brand from Rockauto) so I'm debating between trying to find a machine shop to also machine the seats and then buy and then put new valves in myself vs. just buying a complete remanufactured head.
Thanks for reading and any feedback you may have.
The car is a 1998 Saturn SL2, 1.9L DOHC, 170xxx miles that blew a head gasket after overheating. Car is in decent shape but has been parked in the barn for the past 6 months because it's not worth taking to a professional shop and spending $800-1000 for repair. Thinking I might try to fix it myself, I priced a set of bolts and gaskets at $60. Decided if I can't fix it, I'll just trailer it to a junkyard and sell it for a measly Benjamin.
Took the head off. Checked flatness and found it out about 0.008". Filled chambers with water and found 9 out of 16 valves leaking to one degree or another. Checked top of block and found flatness to be out 0.002". Decided it would be silly to slap the head back in with leaking valves. Not sure about the lack of flatness.
Talked to a couple local places about rebuilding this head. They are quoting $200-300 and anywhere 3 weeks to 3 months to get it in for a rebuild. I can afford the money but don't really want to wait 3+ weeks. Found another shop who said he could machine it to make it flat next week. Found an online rebuilder in a neighboring state that can ship me a rebuilt head for $300 within a few days. Found another head for $125 at a local scrapyard but I'm assuming there are no guarantees that it is in any better shape than mine. I'm guessing the scrapyard would frown on me measuring flatness and dumping water in it on their counter before purchasing.
Decided to start by lapping valves and see if I can get my head to stop leaking. Watched youtube videos. Bought a Lisle tool to remove the keepers from the recessed bores. Lapped valves and put it back together. Several valves are still leaking. Watched more videos. Decided I didn't do a good enough job so I pulled the 4 valves out of one cylinder and tried again.  Leak rate is now down to maybe a few drops worth in 15 minutes or so on that cylinder.
Questions:
1. Let's say my goal is not perfection but just to just get it running again to last for another 30k miles or so. Is a couple drops of water in 15 minutes enough to worry about?
2. Everything I read says if the flatness is out more than 0.001" per cylinder over the entire length (so 0.004" for this 4 cylinder head) then it should be machined. I'm seeking real world experience to see if I can get by with 0.008" or is 0.004" a pretty hard and fast rule?Â
3. Any suggestions if I can't get the valves sealed good enough on my head? I can get a new set of exhaust and intake valves delivered for about $60 (Enginetech brand from Rockauto) so I'm debating between trying to find a machine shop to also machine the seats and then buy and then put new valves in myself vs. just buying a complete remanufactured head.
Thanks for reading and any feedback you may have.