If no one comes up with an answer, call Briggs at (414) 259-5333 and ask to talk to a customer service rep. They should be able to assist you

 

I called them and talked to them. He just basically reaffirmed the part number of the shim gasket, but could not offer any technical advice on why the change was made or if I could run the thicker gasket. Guess I'll just order another steel one and go with it. I would still be interested in knowing if anyone successfully made the switch or has experience with which one is better for future reference.

 

Look, I've used both with no problems.
As with any head gasket / head work, ya gotta make sure the head surface is FLAT. NO WARPAGE. I use a small granite slab and self stick DA discs or sandpaper to true 'em up.

 

You did read this, right ? :

Please Read Before Posting New Thread

When posting a thread about the problems you are having with your equipment:

Please give a full and accurate description of the problem you are having and what you have already done to correct the problem. It will also benefit you to post all model and specification numbers off your equipment.
Machine problem - machine numbers.
Engine problem - engine numbers.
This will aid in letting everyone know exactly what equipment you have and to give you a quicker and more accurate response to the problem at hand. We do have some Service Technicians here on Lawnsite and some have Technical Support at their fingertips but need model numbers to access proper information.
Thanks For Reading.
Good Luck

 

Fish, Sorry, I thought I was fairly detailed in describing the issue. But just in case, Model# is 303771, Type is 0141-01, and SN starts with a 91, indicating 1991 date of manufacture.

For the record, I went ahead and ordered another steel shim head gasket, just to be on the safe side. I will use a machinist's straight edge and feeler gauge to check for flatness. If needed I will sand it down a little, but hopefully it won't need it. Can anyone give me the torque specs for the head bolts? If not, I will dig them up.

Thanks!

 

Can anyone give me the torque specs for the head bolts? If not, I will dig them up.

In the manual : https://rich.homeunix.com/gravely/pro16/272144 Vanguard Twin Cylinder OHV BRIGGS & STRATTON.pdf
I usually torque the lubed bolts to around 190 inch lb.
I have never used hondabond on any head gasket, period. No way.
If yer gonna use the steel gasket, I always use a spray sealer , either Permatex copper coat or preferably silver spray paint, yep...silver spray paint ! I've used that chit on all my bike head gaskets since the sixties. Then on small engine metal head gaskets. Works great.
I use the copper coat spray on all the other types.

 

You were detailed. Unless it is a special circumstance that must must must have a certain material, I do not think it will matter. I've used all of them like bigfish. Make sure your surfaces are clean and free of debris. You can also put some honda bond or copper bond on the gasket to help get that good seal. In fact, I always recommend using copper gasket on head gaskets.

 

Thanks for the info, guys, and thanks to BigFish for the link to the service manual. Definitely saving that one!

Are the grafoil gaskets a better way to go? If so, maybe I should just use those. Checked flatness with a machinist's straight edge and a .003 feeler gauge, and I'm good there. Went ahead and sanded head surfaces with some 180 grit just a little just to be sure.

 

The reason the gaskets blew was because the lower head bolts had worked loose over time. Top ones were tight, bottom ones were barely hand/finger tight.

 

Glad you determined the root cause. As for the valve cover, I dont think you need to put the grease on to facilitate easy valve cover removal in the future. It wouldn't hurt anything if you did, its your call.

 

Last question for you guys - when I have built big and small block Chevy's, I used to just use heavy axle grease on the bottom of the valve cover gaskets so I could pull a cover off easily if I needed to do valve adjustment. Has anyone done this on the mower engines?

 

Walker, just as long as they will seal without any gasket sealer. I want to be able to remove them without tearing up the gasket, but don't want oil leaking everywhere either. It is a rigid, cast aluminum cover, so it should clamp down pretty tight.

 

As long as the mating surfaces are clean, I install gaskets dry. Others may differ in their approach. You could always put a little film of rtv if you want.

 

I personally installed them dry until I discovered hondabond and such. I would use some sort of copper sealer but it is definitely personal preference. No scientific evidence suggesting to silver paint or hondabond or anything like that. So use what ya want!

 

Tommy, thought I should clarify - I was discussing the head gasket early in the thread, but was bouncing the idea on what to do with the valve cover gaskets as well to allow easy removal. Were you talking about using silver paint or Honda bond on the valve cover gaskets too, or just the head gaskets?