It's time for me to replace my exhaust manifolds and risers. When I put a socket on one of the exhaust manifold bolts, I was shocked to see that the heads on the bolts have seriously corroded over the damp winter we had this last year. I am just amazed at what has happened in the last 8 months. Someone suggested I may have had a really hot boat near me, which would be par for the course since I'm surrounded by sailboaters. I may end up having to pull the heads on both motors and thought as long as they are off, I might as well have the valves redone.
Can someone give me a rough idea what it should cost to have the valves done if I take the heads into a shop. Also, is there any reason why I should stay away from a regular auto shop to have the valves done? I have the original 1978 454 Mercruisers @ 330 hp.
It just figures that a) right after I spent $5K on a new enclosure, window covers, and a cockpit cover and b) right after albacore just showed in a big way over the weekend that I would be yanking the heads. Ordinarily, I would have been fishing salmon for the last two months, but with that fishery closed (probably for the rest of my life) I don't get a preseason to tune the boat before the albies get here.
As always, thanks in advance.
What should it cost to have my valves done?
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JohnV8r
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What should it cost to have my valves done?
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Harry Babb
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Hey John
If your engines are running good I would make every effort to remove the manifolds and NOT remove the heads.
Of course if the valves are leaking then you have no choice but to do a valve job. Run a compression test if you are in doubt.
You may want to try using an air tool to grind the remaining portion of the hex head off of the bolt.....then slide the manifold off of the bolt shanks. after the manifold has been removed it should be easy to remove the remaining bolt shank from the head using Vise Grips.
I was faced with the same situation on my old 350 engine and this method worked good for me.....rotary file as shown below and prybars.... saved me from having to remove the heads.
If you must remove the heads and grind the valves a good automotive shop will be able to do the work. Around here I believe that they charge about $80 per head (4 cylinders per head) to disassemble, vat, grind the valves and seats.
If the bolts are not to far gone you may be able to use a 6 point socket to break them loose and not have to grind them like I described above. You may even try using a smaller socket (9 MM)and drive it onto the bolt with a hammer then break it a loose.
If your engines are running good I would make every effort to remove the manifolds and NOT remove the heads.
Of course if the valves are leaking then you have no choice but to do a valve job. Run a compression test if you are in doubt.
You may want to try using an air tool to grind the remaining portion of the hex head off of the bolt.....then slide the manifold off of the bolt shanks. after the manifold has been removed it should be easy to remove the remaining bolt shank from the head using Vise Grips.
I was faced with the same situation on my old 350 engine and this method worked good for me.....rotary file as shown below and prybars.... saved me from having to remove the heads.
If you must remove the heads and grind the valves a good automotive shop will be able to do the work. Around here I believe that they charge about $80 per head (4 cylinders per head) to disassemble, vat, grind the valves and seats.
If the bolts are not to far gone you may be able to use a 6 point socket to break them loose and not have to grind them like I described above. You may even try using a smaller socket (9 MM)and drive it onto the bolt with a hammer then break it a loose.
hb
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JohnV8r
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Harry,
Thank you so much for the grinding idea. I will definitely try the six point and the 9 mm before grinding. I have been "prepping" the bolts with copious amounts of red label Corrosion X. We'll see what happens.
As for the heads, I'll check the compression. I hear a little valve train noise, but nothing that makes me concerned about heading offshore. In fact, I have always been pretty happy with the way my engines have run. I just thought if I was going to have to take the heads off, I would have the valves done.
Thanks for the response!
Thank you so much for the grinding idea. I will definitely try the six point and the 9 mm before grinding. I have been "prepping" the bolts with copious amounts of red label Corrosion X. We'll see what happens.
As for the heads, I'll check the compression. I hear a little valve train noise, but nothing that makes me concerned about heading offshore. In fact, I have always been pretty happy with the way my engines have run. I just thought if I was going to have to take the heads off, I would have the valves done.
Thanks for the response!
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chris pague
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John; That valve train noise may be the push rod for the fuel pump? Like mine I have one that makes a slite tap and with the vintage of these engines it somewhat normal. Only prob is if it gets real bad then the cam is wiped for the fuel pump lobe. Go electric. If you do the compression test do a dry test and record your readings. Then a wet test and record your readings.. This will tell if you have a valve prob and or a ring prob. Get a buddy to help it will save a ton of time.
Chris
Chris
I have found that life can be short. Hope I am not late?
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chris pague
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chris pague
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chris pague
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Tony Meola
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John,
There is no standard price.
A standard valve job would be guides, seals and reseating the valves to the seats and checking spring tension and surfacing the head.
Now that on average should be 250 or less a head.
Now if you have to start replacing valves, springs, installing new seats the price can go up from there.
A good quality machine shop is imperative to getting a good and fair job done. I'm really lucky I've got one down here.
Ask around at auto repair shops and marinas where they get their work done. Whne you start seeing one name more than others, go there.
The most important parts of R&Ring heads is geting the block deck surface cleaned of all gasket material and use a straight edge to check for warpage. If its out of spec, it will pop a head gasket. Block deck(head mating surface) should be like new in appearance whne finsihed cleaning.
Check all head bolt holes and chase with a tap to clean. Buy a new set of head bolts and oil the threads when installing to get even torque readings.
If a head bolt goes into a water passage, then sealer on the threads is needed.
Torque in 3 steps to the pattern. If any of the bolts don't feel like they are tightening properly or feel like they are pulling out don't stop and say that is good enough. Its not.
It means the threads in the block are crap and won't allow a proper torque and you'll pop a head gasket.
You have two choices at this point. Replace block or heli coil the hole or holes.
I've done the latter to some degree of sucess in the past.
A properly torqued bolt should snap a torque wrench crisp.
There is no standard price.
A standard valve job would be guides, seals and reseating the valves to the seats and checking spring tension and surfacing the head.
Now that on average should be 250 or less a head.
Now if you have to start replacing valves, springs, installing new seats the price can go up from there.
A good quality machine shop is imperative to getting a good and fair job done. I'm really lucky I've got one down here.
Ask around at auto repair shops and marinas where they get their work done. Whne you start seeing one name more than others, go there.
The most important parts of R&Ring heads is geting the block deck surface cleaned of all gasket material and use a straight edge to check for warpage. If its out of spec, it will pop a head gasket. Block deck(head mating surface) should be like new in appearance whne finsihed cleaning.
Check all head bolt holes and chase with a tap to clean. Buy a new set of head bolts and oil the threads when installing to get even torque readings.
If a head bolt goes into a water passage, then sealer on the threads is needed.
Torque in 3 steps to the pattern. If any of the bolts don't feel like they are tightening properly or feel like they are pulling out don't stop and say that is good enough. Its not.
It means the threads in the block are crap and won't allow a proper torque and you'll pop a head gasket.
You have two choices at this point. Replace block or heli coil the hole or holes.
I've done the latter to some degree of sucess in the past.
A properly torqued bolt should snap a torque wrench crisp.
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