Intake manifold installation question / 4.3L vortec

[Spiderhole]

Good morning. I am in the final stages of putting my motor back together. I am at the point where I need to install the manifold. I have the new marine gaskets ready to go. I do have a few questions.

The manual says 35lbs of torque, but I had read somewhere that a bulletin was released that it should only be 11lbs of torque - is that correct?

I have the grey gasket maker stuff ready. Am I supposed to put the manifold in place first with the gasket maker on the front and the back of the motor and let it dry first before torquing it down in sequence?

Do the bolts have to have gasket maker on them as well for installation?

Should I put the carb on the manifold before I install?

I think that's all?

Thank you,

 

[Bt Doctur]

If you only have 8 bolts, 11Lbs is correct
I put Permatex Aviation on the heads water ports, then the gasket, then Permatex on the water ports of the gasket
Grey or Black RTV front and rear ,about a 1/4 inch and also on the bottom end of the gaskets
using guide pins, install the manifold and lightly tighten the 8 bolts
Let RTV cure and then torque to 11 lbs using the correct pattern
Permatex Aviation on the bolt threads

 

[Rick Stephens]

I have never let the RTV dry first before setting the manifold and starting the bolts.

 

[Spiderhole]

Thank you very much. I had read that there was not a need to put gasket maker on the actual heads and gaskets, but that is what you recommend? Is Permatex Aviation available off the shelf at any parts store? Thanks

 

[Bt Doctur]

Rick, I`ve had a leak or two by squishing the rtv, letting it cure first gives me a 1/8 inch solid rtv gasket. It will still compress when torqued
Personal preference ,been doing that since my first 283 motor WWWWWWWWWAAAAAAAAAYYYYYYYYYYYY
back

 

[Rick Stephens]

Rick, I`ve had a leak or two by squishing the rtv, letting it cure first gives me a 1/8 inch solid rtv gasket. It will still compress when torqued
Personal preference ,been doing that since my first 283 motor WWWWWWWWWAAAAAAAAAYYYYYYYYYYYY
back

Gotcha. Thought I would bring it up so I could think about my own process and the difference. Thanks for the feedback!

Rick

 

[Rick Stephens]

Thank you very much. I had read that there was not a need to put gasket maker on the actual heads and gaskets, but that is what you recommend? Is Permatex Aviation available off the shelf at any parts store? Thanks

Yes, you usually can find it at auto parts stores. There is a Mercruiser branded identical product for lots more. I use the Loctite stuff and it is identical. The idea is a coating that never gets hard and brittle.

 

[Spiderhole]

Yup, my local shop had it on the shelf. I am hoping to get to this project later today or tomorrow.

To put this motor to TDC when I reinstall the distributor is all I am doing sticking my finger in the spark plug hole and waiting for a rush of air to come out? Does it matter what position the valves are in?

 

[Bondo]

Does it matter what position the valves are in?

Ayuh,..... The valves on #1 have to be closed, to cause the pressure you'll feel,.....

That's also why you only feel the pressure, every other pass of the timin' mark on the crankshaft,.....

 

[Lou C]

Rick, I`ve had a leak or two by squishing the rtv, letting it cure first gives me a 1/8 inch solid rtv gasket. It will still compress when torqued
Personal preference ,been doing that since my first 283 motor WWWWWWWWWAAAAAAAAAYYYYYYYYYYYY
back

I did it your way when I did my top end overhaul 2 years ago. No leaks....so it works! On the pre-Vortec a bit of Permatex Aviation on the front and rear end of the gasket helps keep in in place because the old pre-Vortec does not have the handy locating pins that the Vortec design has...

 

[Spiderhole]

Last question... I followed the instructions that came with my head gaskets, and I hope this is correct. I torqued everything in the proper sequence. I did not use any gasket maker on the head gaskets which I believe is correct for marine head gaskets on this motor.

 

[Lou C]

That is correct no gasket maker for the HGs.

 

[Spiderhole]

Last, last question... I ordered a thermostat kit. The previous owner had completely removed the thermostat from the boat. In the instructions it appears there is some sort of brass sleeve and that the thermostat mounts inside of the housing, not directly on the manifold. Is that correct? I am having a hard time finding the specifics on the correct way to assemble. I also am reading 21LBS on the housing to the manifold when I get to that step.

 

[Spiderhole]

Last, last question... I ordered a thermostat kit. The previous owner had completely removed the thermostat from the boat. In the instructions it appears there is some sort of brass sleeve and that the thermostat mounts inside of the housing, not directly on the manifold. Is that correct? I am having a hard time finding the specifics on the correct way to assemble. I also am reading 21LBS on the housing to the manifold when I get to that step.

...Actually, I think I figured it out. My has the two lines on the top of the housing. The thermostat mounts inside and that brass sleeve holds the thermostat in place. I think I have it correct. I found the sleeve in a box that came with the boat, it's whipped, but it holds the new thermostat in place. I think that with those two lines on top its designed so that a little water always flows into the rest of the housing until the thermostat gets to 160 degree, then it opens and the water starts flowing completely free.

 

[achris]

In future, if you could include a better description of the engine, rather than just 4.3L vortec. Merc have been using the vortec version of the 4.3 since 1997. Something like year, serial number and configuration (carb/MPI, alpha/bravo, raw/closed cooling, etc)

Thermostat housing screws, 30lb-ft.

Here's the assembly order...



Make sure the gasket is the Merc genuine, with the brass rivets in it, or your temp gauge will stop working....

Chris.......

 

[Spiderhole]

Thank you. Sorry, I will keep that in mind in the future - my motor is a humpty dumpty unfortunately. It is all marine equipment, but it's not the original motor to the boat. My housing is a little different than that one in your picture, but I believe it's a similar install. This is a carburetor motor, two barrel.

 

[achris]

6 hoses? Try this picture. (and in the case of FrankenMercs, photos, photos, photos....)