Mercruiser Setting Timing on 3.0L

[Scott06]

Perfect thanks!

This is what the block looks like in between the two cylinders. Not sure how good you can see it but I'm assuming this is what fire slotted means?

could be cant tell from the pics if the block surface is eroded or not. As mentioned below you need a long machinist flat bar to check the whole surface. You can put dykem or machinists dye on the block surface and sand with long sand block to see if the block is fire slotted- the dye will stay in low spots when it gets sanded off the high spots.

Use the sealant mention on the heads bolts and just reuse yours. I have never had an issue reusing head bolts unless these are torque to yield style

 

[kd4pbs]

I actually did that while I was cleaning the bolt threads, but with a tooth pick just so I dont damage anything around... But yeah there is absolutely nothing under the head bolts, it goes straight through to the block cooling system. Which makes me wonder if I should put something on the bolts so water doesnt go up them...

Yep - as I suspected like Scott wrote, but the manual seemed to indicate otherwise - you'll want to put sealant on the bolt threads. The only reason I have recently used the specialty sealant is because I have it; like Scott wrote, Permatex 2 will work fine... I've never had an issue using that either.
Glad you've gotten this far now and found the culprit. There's your problem! That sucker is really blown.
The damage to the deck between #2 and #3 is quite suspect, but I have run worse. I hate to admit. If it were me, I'd probably coat the new head gasket with some spray on copper coat to give the fire ring a good chance of sealing adequately. Many people poo-poo the use of spray on copper coat on composite head gaskets, but I've never had an issue - and I've used it on countless heads, both air and water cooled motorcycle head gaskets and a few automotive aluminum head on iron block applications.
Congratulations!
Now, as they say, assemble in reverse order (after checking things of course)

 

[kenny nunez]

You have to read closely on the gasket if sealant can or cannot be used.
I once saw a head gasket blow completely out from under the head when someone used Copper Coat when no sealant was to be used.
I learned from an old engine machinst about Chrome Aluminum spray painting the gasket which penetrates into the pores of the head and block. If sealant can be used that is the only thing I use.
It grabs so good on a composite gasket that when the head is pulled both sides of the composite seperate from the metal core if there is one.

 

[kd4pbs]

You have to read closely on the gasket if sealant can or cannot be used.
I once saw a head gasket blow completely out from under the head when someone used Copper Coat when no sealant was to be used.
I learned from an old engine machinst about Chrome Aluminum spray painting the gasket which penetrates into the pores of the head and block. If sealant can be used that is the only thing I use.
It grabs so good on a composite gasket that when the head is pulled both sides of the composite seperate from the metal core if there is one.

Thanks for the warning - I'll have to remember that.
I have seen on one head after years of assembly (2.4L L-6 Datsun engine) the same thing happens on a copper coated composite head gasket. It sure was a PITA to clean, but man, that thing sealed well! That's the first time I had ever seen that done, and the reason I've used copper coat on a handful of suspect applications since.

 

[kd4pbs]

Now that I think about it... I wonder if it was just a copper colored spray paint that I experienced on that head gasket. I've never had to go back into anything I've used the copper coat on. It either worked fine (my '05 Jeep Liberty CRD is still in the stable) or I eventually sold the vehicle.
Has anyone taken a head off that they know had copper coat spray on it and experienced the same kind of sticking that Kenny describes?

 

[alldodge]

Kenny knows what he is talking about, do only what manufacture recommends. No sealant is needed on head bolts of a 3.0 but if you want to go for it, just don't use a lot

If OEM says use nothing, use nothing

Ever see a gasket come out from under a valve cover because someone used silicone on the gasket, similar goes with head gaskets.

To the OP, remember you will find all kinds of info on a forum, the one who bangs on the desk and repeats the same thing, may not be the one who actually knows, they are just the loudest

Note to self, I may be the one not to listen to

 

[ESGWheel]

Dan,
Congrats on getting this far, you should be proud! So now for some additional How Tos.

• 5.1 Flatness > already explained and need to compete.
• 5.2 Cracks > I will provide a brief explanation but I am suggesting jump to 5.3 first as if an issue with valve sealing and needs to go a machine shop, they can check for cracking. Cracks in heads and blocks can be hard to see, obviously a large crack easy but usually the type of cracks we are looking for need some ‘magic’ to get them to reveal themselves. You may think that micro cracks are not an issue but that is not the case in engines. There are several methods to reveal cracks, and the home brew version is to use dye penetrant (called dye pen). Here is a quick vid explaining the process link
• 5.3 Valve sealing integrity. A valve obviously is intended to open can close and when closed have a good seal. How to know it has a good seal? For your situation where the valves are still installed, use the acetone test. Set up the cylinder head is such a way as the bottom of the head is facing up and as level as possible. Fill each cylinder head cavity (where the valves are) with acetone up to the level of the head, i.e. as much as possible. Now wait some time, like an hour. Did the level drop? Leaking valve. Which valve? Look at the passages (intake and exhaust) and see which one (or both) are wet with acetone. Since it does evaporate quickly if the leak is slow may have to sit and watch for where its leaking from. Note: spark plugs need to be installed. Here is a vid showing the concept link. Other methods exist with using a compressed air but hard to get a seal to pressurize the intake / exh ports without fixtures. The key here is (1) no excessive leaking for any given valve and (2) they all behave the same (as in no leaking or only very slightly). Post your results of valve sealing. Note if only slightly, can potentially lap the valves at home and save on the machine shop costs.

More: soon, when all back together, as Scott mentioned in post #63, the root cause of the blown head gasket must be found. My point is post getting it back together need to figure this out and not go jetting around in the boat. Said another way see this link.

 

[DanOnTheBoat]

Thanks a lot for all the good info and support guys!!

A lot to reply to so I'll try to do it all in one post lol.

So I got a 90* carpenters square and I measured the block in every single way possible. Sideways, vertically, left, right, across, etc. 0.06mm was the lowest that would not go under the carpenters square. I think I'm in spec? I also tried to "force" it in between the block and the carpetner square and it would still not go through(Unfortunately I wasn't able to take pictures I needed 2 hands)

For the gasket sealant, I honestly ordered a bottle of Permatex 80019 JUST in case IF I need to use it. I'm not sure if it's any good but will check if MANHLE requires any sealant on their gaskets.(I'm sure I won't need it)

Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant, 4 oz. : Amazon.ca: Automotive

Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant, 4 oz. : Amazon.ca: Automotive

www.amazon.ca

Also, as for the head. I took it to a machine shop today. They'll clean it up, pressure test it, check the valves, check for cracks, recurface it all in one. To me the valves looked pretty good, but you never know.

And lastly, I was checking over my blown headgasket, and I remember someone saying in this thread that blowing a headgasket could be from timing issue. So I was inspecting it and I saw that in between cylinder 1 and 2 it was getting ready to punch another hole through the gasket. So maybe I was wrong about the engine being over heated? Maybe it was due to incorrect timing?

Oh and also, lets say my block is warped just a little. Than how would I sand it down?

Does anyone know if the head bolts are torque to yeild? Or are they reusable(DON'T STRETCH), because I read a lot online and different people have different opinions. Just want to do things right the first time.

 

[ESGWheel]

I will try to answer but not in the order asked.
I will start off showing my age with a quote from the past but with an element of modern times. Here it is:

• I put your comment of “Also, as for the head. I took it to a machine shop today” into the latest AI ChatBot and asked for a translation and here is what came back (link) J

The point is I was operating with the understanding you were looking to do this as cheap as possible as well as learn from it. I am sure you are getting good learnings but clearly you have allocated more budget for this which is great. So, it’s my misunderstanding and will adjust my thinking accordingly.

I am uncomfortable with the idea of using a carpenter’s square unless it’s a couple of feet long. Did you do that pencil line test with it first? Also do not need pictures of you doing the measurements, but making a diagram with those measurements would be helpful. Another alternative is mentioned by Soctt in post #61. While I suspect all is good, I am pressing in on this point because its important, and doubly so given the pictures of the head gasket where it looks like was about to bust thru into the other cylinders.

AD in post #28 provided the max overall spec is 0.007” which is 0.178 mm.

If flatness is out of tolerance the ONLY way to fix it is pull engine and take to machine shop. You CANNOT ‘sand’ this flat. See posts # 29 and 30 where this is discussed.

Timing or overheat, still do not know yet, will need motor back together.

While you head bolts are probably fine, the new ones you found seems like good insurance. Can also talk to your machine shop for this advice as well. Example if they had to shave a lot off the head (indicating an overheat), they may suggest new bolts.

 

[Scott06]

Thanks a lot for all the good info and support guys!!

A lot to reply to so I'll try to do it all in one post lol.

So I got a 90* carpenters square and I measured the block in every single way possible. Sideways, vertically, left, right, across, etc. 0.06mm was the lowest that would not go under the carpenters square. I think I'm in spec? I also tried to "force" it in between the block and the carpetner square and it would still not go through(Unfortunately I wasn't able to take pictures I needed 2 hands)

For the gasket sealant, I honestly ordered a bottle of Permatex 80019 JUST in case IF I need to use it. I'm not sure if it's any good but will check if MANHLE requires any sealant on their gaskets.(I'm sure I won't need it)

Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant, 4 oz. : Amazon.ca: Automotive

Permatex 80019 Aviation Form-A-Gasket No. 3 Sealant, 4 oz. : Amazon.ca: Automotive

www.amazon.ca

Also, as for the head. I took it to a machine shop today. They'll clean it up, pressure test it, check the valves, check for cracks, recurface it all in one. To me the valves looked pretty good, but you never know.

And lastly, I was checking over my blown headgasket, and I remember someone saying in this thread that blowing a headgasket could be from timing issue. So I was inspecting it and I saw that in between cylinder 1 and 2 it was getting ready to punch another hole through the gasket. So maybe I was wrong about the engine being over heated? Maybe it was due to incorrect timing?

Oh and also, lets say my block is warped just a little. Than how would I sand it down?

Does anyone know if the head bolts are torque to yeild? Or are they reusable(DON'T STRETCH), because I read a lot online and different people have different opinions. Just want to do things right the first time.

View attachment 411681View attachment 411682

you might be better off if the boat is on a trailer to take it to the machine shop and see if they have a machinist rule to look at the block.

 

[kd4pbs]

Note the old gasket is a FelPro. I don't know that Mercruiser used those OEM, so that's likely a replacement. Might want to look up the part number just for kicks to see if that's a marine set - not that if it isn't this would be the cause for that blowout. For sure the other spot was on it's way out.

And as far as the listening to people on the internet thing... agreed! Do your own research and develop your own common sense filter. There's lots of BS out there, but there's also tons of unconventional advice from those who have been around the block a few times (no pun intended). And remember... not one AI bot has ever even held a screwdriver, much less repaired a blown head gasket.

 

[DanOnTheBoat]

I will try to answer but not in the order asked.
I will start off showing my age with a quote from the past but with an element of modern times. Here it is:

• I put your comment of “Also, as for the head. I took it to a machine shop today” into the latest AI ChatBot and asked for a translation and here is what came back (link) J

The point is I was operating with the understanding you were looking to do this as cheap as possible as well as learn from it. I am sure you are getting good learnings but clearly you have allocated more budget for this which is great. So, it’s my misunderstanding and will adjust my thinking accordingly.

I am uncomfortable with the idea of using a carpenter’s square unless it’s a couple of feet long. Did you do that pencil line test with it first? Also do not need pictures of you doing the measurements, but making a diagram with those measurements would be helpful. Another alternative is mentioned by Soctt in post #61. While I suspect all is good, I am pressing in on this point because its important, and doubly so given the pictures of the head gasket where it looks like was about to bust thru into the other cylinders.

AD in post #28 provided the max overall spec is 0.007” which is 0.178 mm.

If flatness is out of tolerance the ONLY way to fix it is pull engine and take to machine shop. You CANNOT ‘sand’ this flat. See posts # 29 and 30 where this is discussed.

Timing or overheat, still do not know yet, will need motor back together.

While you head bolts are probably fine, the new ones you found seems like good insurance. Can also talk to your machine shop for this advice as well. Example if they had to shave a lot off the head (indicating an overheat), they may suggest new bolts.

LOL. Well I looked at it i didnt just take it off the block, I still inspected it it and took a look at all yhr valves which looked great to me, which they were. But yeah I mean I assume everybody took their heads to thr machine shop...

I've done the diagram yes with the measurements I got. And I didn't just measurements ones and called it a day, I went over the entire surface of thr block over and over to really make sure I didnt miss anything. And those are the results I got. I hope I did it right lol.

As for the carpenter square I used a 16 x 24". It's not flexible or flimsy it's pretty solid and thick.

View attachment 411699

 

[DanOnTheBoat]

Note the old gasket is a FelPro. I don't know that Mercruiser used those OEM, so that's likely a replacement. Might want to look up the part number just for kicks to see if that's a marine set - not that if it isn't this would be the cause for that blowout. For sure the other spot was on it's way out.

And as far as the listening to people on the internet thing... agreed! Do your own research and develop your own common sense filter. There's lots of BS out there, but there's also tons of unconventional advice from those who have been around the block a few times (no pun intended). And remember... not one AI bot has ever even held a screwdriver, much less repaired a blown head gasket.

I've noticed that as well and I'm not sure if that's OEM or not... However I just got in the new gasket kit and I have som questions and posibble concerns... I took a side by side picture, and I've also placed the head gasket on the block. There are 4 small(circled in RED), they seem pretty small on the gasket compared to the block and my old head gasket... Also the big water port in the back(also circled RED), the gasket sort of goes a little over the port. Is that okay/normal?

Also is the dimensions in between the cylinders on the gasket okay? They aren't too thin/small? The material is also different, the Fel-Pro feels more like "metal" lol, but this one feels softer and sort of rubbery. Maybe that's normal? I'm sure it won't blow out on me...

Other than that, everything seems to line up good.

 

[kd4pbs]

There will be no issue with the differences. Looking at the old gasket, every spot between cylinders were bad. I think you'd be well right to have the head milled and verify correct timing upon reassembly. That's what we call down in these parts, "Blowed up big time!"

 

[DanOnTheBoat]

Question about head bolts. So I think I'm going to reuse mine, they dont look stretched or rusted. I also showed the machine shop mechanic, where I had my head resurfaced and he said they are good to be reused. Also said they reuse head bolts all the time when rebuilding engines. Now, about the thread, i got Permatex 2 Form A Gasket Sealant. Its slow dying and non hardening. Temperatura range: -54°C - 204°C. Water and chemicals resistant. Is this stuff good and would it work? Or should I use Permatex High Temperature Thread Sealant?

 

[Bondo]

Ayuh,.... That's perfect,....

 

[nola mike]

the aviation sealant would be fine as well

 

[DanOnTheBoat]

I went to the store and got the Permatex High Temperature Thread Sealant just to be safe. Already installed the head, hopefully I get it all done today.

I have a few questions about the pushrods and how to adjust them. Ive watched countless videos online, and a lot of people do it different ways and I'm confused on what is the right way. I get that you have to wiggle them around until they have no lash and than make a half turn to tighten it, but the part I dont understand is which pushrod am I adjusting since I have to be TDC?

 

[ESGWheel]

Reread posts 41, 42 & 43….

 

[DanOnTheBoat]

Okay so in short, everytime each cylinder is ATDC I adjust both intake and exhaust for that cylinder