Moparts

Tips on replacing head gasket on 360???

Posted By: twister360

Tips on replacing head gasket on 360??? - 10/15/09 02:39 PM

It has been determined by an old Mopar mechanic that the head gasket on my 360 Magnum motor is bad on the drivers side and I have purchased the parts to replace. What are the steps to disassemble and reassemble? I would like to start on this this weekend.

Thanks
Posted By: stumpy

Re: Tips on replacing head gasket on 360??? - 10/15/09 04:40 PM

I would suggest going to the library and looking at a repair manual.
Posted By: JoesMopar

Re: Tips on replacing head gasket on 360??? - 10/15/09 04:56 PM

Disconnect your battery

Drain as much of your coolant as possible.

Remove your carb, kickdown to intake linkage, intake etc.

Remove the ground from the front of the head, the exhaust manifold, possibly from the pipe too if you need to.

Remove the valve cover, then the rockershaft assembly.

Take the pushrods out and make sure you mark or put them in an order so they go back to the right lifter AND the correct end down (I like to do that anyway).

Loosen your head bolts but try not to remove the, so you don't get them mixed up, some coolant will probably spill down into the cylinders. Take the head off, you may need to wack the sides gently with a rubber hammer, or there may be a tang you can't pry from a little with a big flatblade screw driver.

Soak up all the anitifreeze off the tops of your pistons. Cover the rest of the motor good and spray some WD-40 on the tops of those pistons and blow it with an air blower from your compressor, just to make sure most the fluid is out. Put a little oil around the edges to keep it from rusting while your working.

Clean the top of the block thouroughly, make sure no trash got into the cylinders, is so, remove it. Do the same to the face of the head.

Clean the top of the block with a good solvent like laquer thinner or etc.

Then do the oppoisite for reassembly. Torque to specs and in recommended sequance for heads, rockershaft, intake, etc.

After your done, do an oil change to make sure no coolant is left in your oil and fill it back up with coolant.
Posted By: west

Re: Tips on replacing head gasket on 360??? - 10/15/09 06:04 PM

Quote:

Disconnect your battery

Drain as much of your coolant as possible.

Remove your carb, kickdown to intake linkage, intake etc.

Remove the ground from the front of the head, the exhaust manifold, possibly from the pipe too if you need to.

Remove the valve cover, then the rockershaft assembly.

Take the pushrods out and make sure you mark or put them in an order so they go back to the right lifter AND the correct end down (I like to do that anyway).

Loosen your head bolts but try not to remove the, so you don't get them mixed up, some coolant will probably spill down into the cylinders. Take the head off, you may need to wack the sides gently with a rubber hammer, or there may be a tang you can't pry from a little with a big flatblade screw driver.

Soak up all the anitifreeze off the tops of your pistons. Cover the rest of the motor good and spray some WD-40 on the tops of those pistons and blow it with an air blower from your compressor, just to make sure most the fluid is out. Put a little oil around the edges to keep it from rusting while your working.

Clean the top of the block thouroughly, make sure no trash got into the cylinders, is so, remove it. Do the same to the face of the head.

Clean the top of the block with a good solvent like laquer thinner or etc.

Then do the oppoisite for reassembly. Torque to specs and in recommended sequance for heads, rockershaft, intake, etc.

After your done, do an oil change to make sure no coolant is left in your oil and fill it back up with coolant.


you forgot the gasket
Posted By: scratchnfotraction

Re: Tips on replacing head gasket on 360??? - 10/15/09 06:33 PM

what yr and vehical is it?

magnum 360?

Dak...ram 1500...older car ans swaped in the manum?

still got the manum keg intake and serp belt?

little more to it than an older LA 360,basics are the same but there is a little tid bit of info thats need for the mag stuff

like intake bolts only torque to 144 inch pounds..things like that..

Posted By: MoparforLife

Re: Tips on replacing head gasket on 360??? - 10/15/09 07:25 PM

Two of the big thing in a succesful head gasket replacement one is cleanliness and the other is making sure that the head is true. Thake it to a good machinist and have him check it and make sure that it is perfectly flat. The head is the most likely to get slightly distorted.
Posted By: RapidRobert

Re: Tips on replacing head gasket on 360??? - 10/15/09 09:22 PM

Quote:

Thake it to a good machinist and have him check it and make sure that it is perfectly flat.

you want it good the 1st time. the intake bolts are numbered 10-6-2-4-7-11 front to rear on the pass side. 9-5-1-3-8-2 on the drivers side front to rear. torque bolts 1 thru 4 in 12 INCH lb increments to 72 INCH lbs then the remaining bolts (5-12) to 72 INCH lbs (in order). Check that ALL are at 72 INCH lbs by (re)torquing them in order, then torque ALL to 144 INCH lbs in sequence & recheck all of them in order for 144 INCH lbs.
Posted By: Bill MeLater

Re: Tips on replacing head gasket on 360??? - 10/16/09 01:04 AM

Shop vac comes in real handy for getting the crap out fo the cylinders/etc. Too...
Posted By: scratchnfotraction

Re: Tips on replacing head gasket on 360??? - 10/16/09 01:55 AM



I use the shop vac as I am scraping the gasket surface to keep it clean and junk out of the cyls

Posted By: twister360

Re: Tips on replacing head gasket on 360??? - 10/16/09 03:14 PM

Quote:

what yr and vehical is it?

magnum 360?

Dak...ram 1500...older car ans swaped in the manum?

still got the manum keg intake and serp belt?

little more to it than an older LA 360,basics are the same but there is a little tid bit of info thats need for the mag stuff

like intake bolts only torque to 144 inch pounds..things like that..





The engine is in a 74 Duster and the motor is a 360 Magnum from a ram truck, dual plane air gap intake and holley 3310 carb. Also has headers and PS and PB. Will the headers and power accessories be much of a problem. What is the torque for the head bolts and should I resue them? I plan on taking the head to the machine shop to check if it is square and check the valves. Anything else I should do? Thanks
Posted By: MoparforLife

Re: Tips on replacing head gasket on 360??? - 10/16/09 03:38 PM

105 foot lbs. In x pattern starting in center and working end alternating side to side top to bottom, small increments.
No need to replace bolts.
Posted By: stumpy

Re: Tips on replacing head gasket on 360??? - 10/16/09 03:41 PM

To save future grief you need to do both at the same time. While you already have most ecverything off it's not that much extra work or cost.
Posted By: cptn60

Re: Tips on replacing head gasket on 360??? - 10/16/09 03:43 PM

Don't forget to get the cylinder head checked for cracks. we have seen more than a few cracked.
Posted By: 65signet

Re: Tips on replacing head gasket on 360??? - 10/16/09 08:45 PM

I would be looking at why the head gasket failed
Posted By: RapidRobert

Re: Tips on replacing head gasket on 360??? - 10/16/09 10:21 PM

Quote:

I would be looking at why the head gasket failed

Exactly. Pay him to come over & check the decks w his straight edge also.
Posted By: twister360

Re: Tips on replacing head gasket on 360??? - 10/19/09 02:30 PM

Thanks for all the info.

Too busy this past weekend to get started on the repairs.
Posted By: twister360

Re: Tips on replacing head gasket on 360??? - 12/01/09 07:34 PM

Quote:

Don't forget to get the cylinder head checked for cracks. we have seen more than a few cracked.



I took the head to a machine shop and the head gasket was definetly blown. Had the head checked and had 2 cracks in that particular part of the head. The spark plug was black and it was not firing at all. The machinest said the head cracked because of the failed head gasket. Had to get a replacemant head and had a valve job done and had the head checked to see if it was perfectly flat. I put it all together this past weekend and fired it up. It actually runs pretty good now even with a lopey cam. It is now running on 8 cyclinders and not 7 as before. I let the engine run for about 30 minutes, looking for leaks etc. and checking for anything out of the ordinary. Is there anything I should do to assure myself that everything is in order, as I have never done this type of job on the car before?

Thanks for your help.
Posted By: stumpy

Re: Tips on replacing head gasket on 360??? - 12/01/09 08:40 PM

Runs good, no leaks, you're done.
Posted By: d100clubcab

Re: Tips on replacing head gasket on 360??? - 02/28/15 04:14 PM

Quote:

Disconnect your battery

Drain as much of your coolant as possible.

Remove your carb, kickdown to intake linkage, intake etc.

Remove the ground from the front of the head, the exhaust manifold, possibly from the pipe too if you need to.

Remove the valve cover, then the rockershaft assembly.

Take the pushrods out and make sure you mark or put them in an order so they go back to the right lifter AND the correct end down (I like to do that anyway).

Loosen your head bolts but try not to remove them, so you don't get them mixed up, some coolant will probably spill down into the cylinders. Take the head off, you may need to wack the sides gently with a rubber hammer, or there may be a tang you can't pry from a little with a big flatblade screw driver.




Any "easy" way to get these bolts out?
I was able to use my cordless impact on a few of them but the ones I need to to do by hand are STUCK

ideas?
Posted By: RapidRobert

Re: Tips on replacing head gasket on 360??? - 02/28/15 05:41 PM

Quote:

Any "easy" way to get these bolts out?
I was able to use my cordless impact on a few of them but the ones I need to to do by hand are STUCK ideas?

use a 1/2" breaker bar & a cheater pipe on the end of it if needed. maintain the socket/extension in line with the bolt head (pretty much vertical) & the breaker bar/cheater out horizontle at a 90 deg angle & jerk the handle rather than a steady pull to break (em) loose
Posted By: HotRodDave

Re: Tips on replacing head gasket on 360??? - 02/28/15 06:08 PM

Use a 6 point socket NOT made in asia or you will have round bolt heads

Also use the mr gasket .029 head gaskets, they are cheap, good and give you the most compression and on magnum motors help mpg/tq. Kind of like shaving the heads .020 for free.

If you have magnum heads don't bother looking for cracks, it has them. If you are concerned get them pressure tested, they don't cause any issues because the water is so far up above the cracks.
Posted By: d100clubcab

Re: Tips on replacing head gasket on 360??? - 02/28/15 06:54 PM

Quote:

Use a 6 point socket NOT made in asia or you will have round bolt heads

Also use the mr gasket .029 head gaskets, they are cheap, good and give you the most compression and on magnum motors help mpg/tq. Kind of like shaving the heads .020 for free.




1. got the half-inch 3/4" socket from Home Depot because my Crafstman hand sockets are only 3/8"

2. been looking for the 1121G but cna't find anyone with them that can get them to me quickly. even called nine local dodge dealerships with no luck.

3. i have old school heads so i will have them checked for cracks and flatness
Posted By: Supercuda

Re: Tips on replacing head gasket on 360??? - 02/28/15 07:02 PM

http://www.summitracing.com/parts/mrg-1121g

Odds are no one close stocks it so you may as well order it.
Posted By: d100clubcab

Re: Tips on replacing head gasket on 360??? - 03/01/15 12:15 AM

Quote:

use a 1/2" breaker bar & a cheater pipe on the end of it if needed. maintain the socket/extension in line with the bolt head (pretty much vertical) & the breaker bar/cheater out horizontle at a 90 deg angle & jerk the handle rather than a steady pull to break (em) loose



trip to harbor freight solved this
loosened those bolts up like warm butter
didnt even need the extender pipe

i HATE harbor freight but for something like this, it works well
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