I set the bore gauge to the cylinder reject size of 3.567 in. The cylinder was unbelievable consistently 1.5 thou more than this.
As much as I would like to keep this engine I have no need for it and a plastic shroud, muffler, and dip stick will be way more then the $10 I have into it now. The logical thing to do is to ebay the parts.
The question now is do I just part it out or have some fun making it run first. Expectations is that parts are worth about the same either way. It will be interesting to measure the difference between the virgin cylinder bore and the worn area.
There prices based on what similar parts sold for on ebay
035 carb $4.95Economy Shipping
025-$69.99 crank list for more $10.00Standard Shipping
012 stator
<20 head
090 block $18.00Economy Shipping
025 piston and rod $5.95Expedited Shipping
075 flywheel #698282 mod $12.95Expedited Shipping
g50 oil pan $12.65Expedited Shipping
007 Push rods
025 cam shaft and gov
005 oil filler tube
025 pulley $11 shipping
010 head bolts $6 shipping
010 other bolts $6 shipping
020 carb linkage $6 shipping
They total to $348.
There may be parts I did not think of and ones that are in bad shape and cannot be sold.
It is too cold so I brought the go-putz engine 28M707 and the 31P777 into the house. Now that they have warmed up I am going to take another shot at measuring the cylinders. In this post I will only be dealing with the 28M707.
Nominal bore is 3.440. Used gauge block to verify and lock digital caliper at 3.440. Setup bore dial indicator to zero at the caliper setting. A real pain. Then verified the virgin cylinder wall below the piston travel. It may be faster to set the dial indicator on the virgin wall. Not sure.
Checking the bottom of the bore verified the setting of zero as 3.44. The wear along the axis of the crank travel is .012 over so we will need to bore this one to .020 over.
The bore below the piston is consistent as expected and will allow the hone to follow the center of the original bore.
Bought a naked 31ci inch single cylinder BS engine today. 31P777-0237-G5. I am seeing a lot of different HP figures for this engine so we will call it north of 15 and south of 20. 18 or 18.5 seems to be the the most common numbers. Rumor has it that it has a cast iron bore. 18.5 is correct.
It is missing the starter and there is dirt in the filler tube which is missing the dip stick. Need to figure out how to rinse the engine out. I am not too worried with the pressure lube system.
To the left is an image of a similar engine on ebay.
I should part it out but am tempted to get it running if possible. One never knows why a 'found' engine is take out of service.
Starters from the old L-Head engines look like they might work.
The good news is that she is an oil burner and it has a cast iron sleeve! It is too cold to inspect the bore. The head gasket looked good.
Learned on the web that one can file the ends of of .010 rings and use them as .003 rings. If it is out of round or tapered I will bore it out to .010 over and either get a rebuild kit or sell the block and bits on ebay.
Piston with rings is B&S 796173. $87.52 with shipping from tewarehouse. Service manual (missing images should be good one in repair books. 276781 Single Cylinder OHV .pdf
To gain experiance with the dial bore gauge I decided to characterize the engines I have the heads off.
standard min 2.4990" max 2.500"
Crankshaft is along the '2' axis
dial reading adjusted
A1 -0.0005 2.5025
A2 0.0000 2.5030
B1 -0.0010 2.5020
B2 0.0000 2.5030
C1 -0.0015 2.5015
C2 -0.0003 2.5027
2.4" anvil with .12" washer
Briggs says:
If the bore is more than .003” (.08 mm) oversize, or .002” (.04 mm) out of round on cast iron cylinders, or .003” (.06 mm) out of round on aluminum cylinders, it must be resized, or see NOTE below.
The bore has reached but not exceeded the wear limit in the '2' direction.
This is an aluminum cylinder so the larger out of round applies. The worst level is level C at ( 2.5027" -2.5015 ") or 0.0012". This is not quite half of the allowed 003" allowed.
In the 2 direction we have a taper from bottom to top. According to Oklahoma State "Taper in the top half is cause by dirt ingestion through the air filter. Taper in the bottom half is caused by dirty oil.
This is all based on trusting the digital micrometer I am using. Would be nice to have some way to check it.
Measuring GoPutz 's cylinder indicated that it needed to be sized up to .010 over. It took a long time to make the six measurements needed. So I bought a Fowler Cylinder bore gage in addition to the Lisle boring hone. I also purchased #240 and #500 grit stone sets. While I was at it I bought a better digital micrometer.
A boring hone should not be confused with a flex hone. The boring hone has the stones mounted solid to a rack and pinion arrangement that allows the hone to be precisely sized and expanded.
After reading the honing instructions I found out that I really needed a long reach micrometer to ensure the stones remain flat.
My first idea was to hone the block in a tub of kerosene resting inside the parts washer. Once I got it setup I found that there is a lot I did not like about it.
My plan B is to mount the hone in the drill press. This way I can set the speed using the belts and limit the stroke using the dept stop. It does make recycling the kerosene harder but that is a minor compared to what is gained.
The engine has been removed and torn down. I have not removed the valves which seem to be well seated.
The exhaust valve seemed a bit loose.
Found a plug gauge for briggs 5/16 valve guides on ebay for under $10 with shipping. It is NOS and a bit rusty in spots but should work. Will use it to see if the exhaust valve guide on go-putz's briggs 13hp needs replacing.
Sunday, October 19, 2014
The plug gauge does not go in to the valve guide so it should be OK.
The plug gauge seemed large and I wondered if was the correct one but it is only .012 larger then the 5/16" specified for the valve stem diameter.
I measured the cylinder with snap gauges. It seems every time I use these thing I need to relearn their proper use. This motor looks to be well cared for. The insides are about the cleanest I have seen in an old briggs. The cylinder out of round 0.0035 and taper 0.003 are not horrid but the larger dimension of the cylinder is too large for standard rings and both are too small for 10 over.
I removed the parts from the molasses and cleaned them up. The procedure was recorded with 2 cameras but there is a lot of video and and it will take some time to edit it.
The parts were in the molasses for a long time and a crust formed along the top of the parts. The good news is that it looks like there is no damage from this and a significant amount if not all of the buildup is gone from all but the worst cylinder. The lesson here is to use a deeper container or rotate the parts every week or so.
The next step is to take the snap gauges and determine which cylinders to use.
Someplace on the web I read that a place which rebuilds compressors honed the cylinders by media blasting. No details. The idea is that it prepares the surface to better hold oil.
For some months now the WinCo Generator has been sitting on this overloaded cart. The intention had been to attach the chain to the ceiling so it would prevent the WinCo from hitting the floor should the cart fail. That was lame and never happened.
This cart was originally an AV center at the local high school. It was buried in clutter over at the other shop so I liberated it to hold the WinCo.
The AV cart is much more suited to the WinCo. Tomorrow I will get a picture of the generator on its new cart.
Attached to the generator was this service tag. It was an even shade of brown but a light brushing revealed the name of service shop still in business in Amarillo Tx.
Loosely following the method used by ShopDogSam in his IH 1 1/2 HP build I polished the rod journal which is shared by all 3 rods. It is a 1" journal and measures quite close to that. Have to see what it reads when I finish polishing it. That strip was too wide but the only one I took a picture of..
The polished crank is not an easy thing to photograph. It looks a lot better in person. Here it looks like I polished rust.
In the sunlight it looks like this. Still needs work.
This rod journal had been hammered so bad that there was some mushrooming which I flattened. Need to figure out if this has increased the play between the rod and crank too much. If this was a car I would send the rods out to be reconditioned. Maybe carefully taking a few thou off the matting surface of the cap and or rod would be enough. Note the chamfer where the rod and cap join.
The rods and caps have a bump on one side to indicate orientation. Neat. The parts manual show 3 part numbers for the rods. Other then the tube pressed into the center cap and the oil slinger that bolts to the back cap they look identical. Still need to compare some more. But I know which rod was in back because of the scoring.
I am pulling the rings from the pistons and removing to grease like buildup in the lands and on the rings. Not sure if it matters with these rings but I am taking care to preserve location and orientation. The compression rings have nice sharp edges which is good because I plan to reuse them.
It would be nice if I could get that last ring out of the center piston.
On the original compressor the top ring has a notched end and the 2nd ring does not. This makes cleaning them a bit easier because there is no problem telling them apart. They have a dimple on the top too.
The table was a mess by the end of the day. I need to clean off the low workbench and use that and keep the table just for the parts.
I started cleaning compressor parts this morning. Because the heater on the ultrasonic cleaner has died I am using an old hot plate to heat the water. Shortly after I got started the neighbor came over and asked me to dig a foundation for her room addition. The backhoe blew a hydraulic line with just 4 feet left. We finished off the AM with a trip to the carwash.
A picture to remind me where the oil slinger goes. The rod cap with a tube hanging out of it goes in the center.
The good news is that all the compressor parts have been clean enough to access their condition.
Feb 16th
This table should make it easier to keep track of the bits. All the parts except for the body and one piston are on the table..
I am continuing to clean parts. One of the rod journals must have been oil starved or had something get into it that lightly grooved it and the crank. With luck emery cloth or wet/dry sandpaper will clean it up. Rods can be had from grainger at about $90 each.
There is gunk behind the rings that is not coming out. I may have to remove the rings to do a proper job cleaning the lands.
The AENLD is now off the stand I need for sand blasting so I can get to that when ready.
Yesterday I cut 2 new pan baskets. My gasket stock is thin so I often use two layers.
Prior to installing the oil pump I primed it using the bottom half of a one gallon tea jug (like milk jug) to hold the oil. The pump was easy to reinstall.
To get the pan on I had to block up the bottom of the engine to get a bit more clearance. Keep in mind the dry weight for the engine is 110 1lbs. The manual say to torque the pan bolts at 7 to 10 ft lbs. I used 100 inch lbs.
Next the engine gets attached to the heavy steel plate you see in the lower right quadrant of the picture. I wanted to do it this evening but my back betrayed me. I dumped the bolts for the base into the green towel which then dumped them on the floor. I was not into crawling around and sorting them out.
Feb 16th
It is a good thing I did not get the base bolted on I forgot the oil screen! Only 12 little bolts to pull and replace
OK inspected and did some final cleaning of the screen with a tweezers. Pulled the sump and installed it then replaced the sump and bolted the engine to the heavy metal plate it came on.
6.5HP OHV Briggs moves to the running list. It still needs an exhaust gasket and a elbow installed in the carb but that can happen when the parts come.
Today I took another shot at lapping the intake valve. Last time I tried it was below freezing and nothing seemed to work including my hands and the suction cup so I gave it up as a bad deal. These are pictures borrowed from a previous post.
Try as I might I could not get a grinding noise. So I checked the valve clearance and there was none. My guess is this is a botched repair job with the heli-coil sticking up and what looks like a freshly ground valve seat and a valve that was never adjusted.
Part of me wants to replace the seat but then that would possibly mean a new seat and valve. I think the right thing to do is to grind off the valve stem and see what we end up with after a light lap.\
Feb 19th
The trouble I see with that is the valve will be too far now in the seat and the contact patch will be on the upper edge of the valve instead of in the middle. The question is do I need a new valve, valve seat or both.
I wanted to see how another valve would work so I grabbed the intake from Little Briggs #2 which what has a bad exhaust valve guide. But as you can see the 10 ci engine uses a larger valve. Duh!
Need price both and do some more thinking.
Ordered a new valve and seat off ebay for $10.50! Going rate is abou5t $25 each at the parts houses.
Not much is going to happen until after I get the AENLD off the stand I need for the sand blasting enclosure.
To have a complete set of parts I needed to remove the connecting rod from the piston rusted into its cylinder. It had been soaking in for about 10 days. I was ready to take it to the band saw and split the cylinder in two.
A box of compressor parts arrived today from Kam1973, Helping me with this was an act of kindness that I must acknowledge. We meet on "The Garage Journal" forum in this thread.
With these parts I should be able to restore the compressor without resorting to JB Weld to fill the pits in the cylinders.
My next step is to free the piston from my worst cylinder so I can reuse the rod. But now I don't have to worry about saving the cylinder or piston.
I have to say the newer Briggs and Stratton parts manuals cover so many engine configuration that they are confusing. You might find the part number you are looking for but they give little clue how the engine goes together. I suppose one needs a service book for that.
This engine had a carb clean and a bath at the car wash. The exhaust port is busted out but it looks like I can cut threads and put a 1" galvanized or black pipe in it.
Added the carb which leaked when I got it outside. I had to take it off again to change the bowl gasket because the new one was a bit small and would not seat in the bowl but did work if slipped over the carb body.
Earlier I had the shroud and the throttle/governor assembly at the car wash. I did a fair job on the inside of the shroud but not so much on the outside.
Not sure why this merits a picture but hey it did need oil.
Feb 12
The head took a bath. I also chased the threads in both exhaust port bolt holes. There is enough threads in the busted part to maybe work if I use a wire to tie the bolt down aircraft style. Or I may try sold alumaloy to fill in the missing area and redrill the hole. Need to see how much exhaust gets through the gap between the muffler insert and the block.
Cylinder bore looked good and head was clean.
Reassembling the head. From the engine users manual: Head bolts torque to 210 in/lbs. Intake at .005 in and exhaust at .010 in.
Feb 13
Lapped the valves and put it all back together.
Did some testing. The muffler seems like it will be OK. Got the governor closer to useable. May have a gas leak at the carb but will not know till I switch to the correct gas line.
Feb 14th
Mounted gas tank. Short a few screws for the trim. Added correct fuel line and it still leaks. Need to try changing elbow on carb. Soon this will be moved to the running list.
All this engine needs is a gasket for the muffler and maybe an elbow for the carb. I will tear of the carb and muffler when I get the gasket. But it is essentially done so it is moving to the running list.
This is an interesting engine in that it is my only OHV but it is also one of Brigg's weakest engines. I should have checked to see if it had a cast iron sleeve when I had the head off but i expect it does not. Maybe I will check when I have the carb and muffler off.
Anyway if all this engine is going to do is sit on the shelf there is no point in addressing the minor smoking problem. But I may try to solder a lead to the busted off low oil sensor.
Aug 1st 2019
Asking about a metal camshaft on facebook need a few pics.
The cap would not come off the gas tank. The filler neck turned with it. Neither ultrasonic cleaning or heating with a propane torch helped. So I cut the cap off with a dremel cut off wheel. Unfortunately I now have a slit in the filler neck but I am sure I can solder that to look like new. I do have a new cap in stock but I may use an old one to keep the look. May have to repaint and weather the tank.
The tank is now soaking with acetone and a few rocks to shake around. The tank weighed about twice what it should have when I started so it could take a while.
