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SmilinSam

16 HP cast iron Briggs heads- maybe block

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SmilinSam
The head on my 1972 Briggs 16 HP Engine is warped and I have a good head off a late 80's or early 90's 16 HP with the magnatron iginition. The two heads are not the same. The newer head is different where the three bolts go that hold the air shroud piece on top. The old head has the castings around the holes go all the way up to the top of the cooling fins, while the newer head has the castings only as high as the bottom of the cooling fins. Other than doing something different with the air shroud piece on top, can the new head be used on this older block?

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SmilinSam
quote:
Originally posted by Storm7012
Your head's warped.....lol.?
:D ...and my wife reminds me constantly As to lapping, I dont know how bad, other than bad enough to leak at one corner. Put a new head gasket on and blew that pretty quick. I did look at the block and Block seems OK though. I'll get a chance to examine this this weekend and see, but I wanted to get info on the other head too.

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ReedS
I had a newer 16 hp BS that was missing that piece of the air shroud, found a replacment from an older engine and used some spacers and washers to get it to fit. My spacers were old GM disc brake slide pin bushings used on most older GM's approx 1/2 in length with about a 3/8 id.

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Brettw
Sometimes, if not too bad, you can put a sheet of sandpaper on a large, flat piece of steel, or a piece of glass on a very solid flat surface, and work the head around and flatten out the high/low spots. Takes a bit of work, and you have to keep rotating and working the head, but eventually you will see a flat surface again. This assumes it isn't too bad and your arms will fall off before you accomplish the goal. Hey, at least the cost is right.......

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HubbardRA
I milled a couple on a lathe. The ones I milled, I removed .062 inch off of them. The engines ran great with those heads. That much increase in compression would cause overheating in a heavy worker, but I was using the engines for tractor pulling. Anyway, you do not need an end mill, you can turn them in a lathe and do a face cut.

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SmilinSam
quote:
Originally posted by Brettw
Sometimes, if not too bad, you can put a sheet of sandpaper on a large, flat piece of steel, or a piece of glass on a very solid flat surface, and work the head around and flatten out the high/low spots. Takes a bit of work, and you have to keep rotating and working the head, but eventually you will see a flat surface again. This assumes it isn't too bad and your arms will fall off before you accomplish the goal. Hey, at least the cost is right.......
Try lapping old Stanley wood planes flat, thats when your arms fall off;) I have plate glass with fine emery cloth glued to it already for doing planes. So, if need be I can do the lapping, but would like to try the other head. If I dig around I may have some similar spacers as Reed mentioned off a Kohler.

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HubbardRA
Sam, One thing I forgot to say. If the bolt pattern is the same, you can use the new head to replace the old one. Spacers can be used under the heads of the bolts to take up the space on the newer head. I have the head from a 10 HP Kohler that I have been running on my 14 Hp engine. In fact, I had two 12 Hp heads, one had the high bosses around the holes and the other had low ones. Head bolts were different lengths on the two engines they came off of.

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SmilinSam
This isnt looking too good. Apparently the head isnt the problem. Tryed this other head , which is known to be good, and within a few minutes of running the engine another leak developed in the same location as before. Seems the block must be worn a little between the head bolts above the flywheel. I have had engines before that were worn so bad from running with a leaky gasket that the damage is clearly visible, but this one is almost invisisble. The only thing I see is that the gasket isnt getting quite as compressed in this area as the rest. I put one new gasket on and it was a soft type gasket and it blew it completely out. I have used two used hard typr gaskets and it seems to be blowing them out between the top and bottom facings. Do not know what to do. Maybe play taps and bury the engine?sm00

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thedaddycat
Take it to an sutomotive machine shop. They should be able to do what we used to call "decking the block", which is checking it and then milling it flat. I have access to a surface grinder at work, it's a precision machine that you can adjust the height of the grinding wheel by .001" increments and the table is on a two-axis carriage. You run the table back and forth (left to right) to make a pass and then move it inwards to make the next pass. It takes a while to make a complete pass over the whole thing at the set height, then you lower the wheel and do it again and again until you have taken off enough to make the surface flat. You know it's completely flat when you get at least a little contact with the wheel over the entire surface. Any low spots and the wheel will not touch in that area. If you can't find someone out there to do it, ship it to me and I'll take care of it for you Sam.

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SmilinSam
Back in from the shop again. Took the head back off and went over the heads I have and the block with a nice straight edge and the only thing I found out of sorts anywhere was a rather large burr along the edge of one of trhe bolt holes in the block. This is one of the two between where the gaskets keep failing. I ran my finger over all the bolt holes and could feel a couple more, but the one I hit with the straight edge made the straigt edge stop and ride up and over it. I took a sharp chisel and carefully de-burred the bolt hole, along with any other catches along other holes. Now the straight edge has a uniform sliver of light all the way across no matter where I set it on the block or heads. I know this is not precision, but ... Whats the chances that a simple burr like this could be the problem? Dont have any gaskets left , so I have to order some more.

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thedaddycat
OK Sam, here's one of those shade tree mechanic fixes for you. Go dig through that $30 drill bit set in a plastic case and find the countersink. I'm sure you know what it is but for those who don't it's kind of like a cone shape and used to make a depression in wood so the screw head sits below the surface of the wood. Give all the bolt holes a quick hit with the countersink, that should take off any burs and also leave you with a slightly tapered hole to make the bolts "find" the holes easier. At this point you have nothing to loose by trying it.... Then just reuse one of the old gaskets to give it a quick test(unless they are completely toast).

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acfarmer
Another shade tree trick is to smear JB Weld thinly where the leak is located just before you put the head on and tighten down.Then let the JB Weld sit for 24hrs before cranking engine.Never done it on a flat head but its worked on a couple overhead valve engines for me

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