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Briggs vanguard conversions

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blane.c

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The head will likely require an external line. Nothing really wrong with this idea as long as vibration is taken into account during the design.

Piston squirters might be done with nothing more than a couple of aimed drillings in the rod big end. The oil holes in the crank can be slotted for more oil as needed. It's common on VWs to grove the crank journal 360 deg for full time oil to the rods. Same kind of idea here.
View attachment 89092
I can see how that will require more oil quantity, but how is it going to get there in the same size line? Or do you ream out the line somehow?
 

Vigilant1

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I can see how that will require more oil quantity, but how is it going to get there in the same size line? Or do you ream out the line somehow?
The assumption is that the bearings (tight clearances) are the "bottleneck" in the existing setup, and that the lines can flow more oil if it is available.
The ugly answer would be just to tap some new external lines from that filter adapter shown earlier and run them wherever you need them (esp the heads, if run with "heads up).
As with the stock setup, the pressure bypass valve doesn't open unless pressure is too high (usually due to thick oil below expected normal operating temps). If a wider pump or a two stage pump is fitted, it would be necessary to insure the bypass valves is up to the task of handling the new, higher flow rate.
For me, if extraordinary cooling steps aren't shown to be needed for my required output, I won't be taking them.
 
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pictsidhe

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The head will likely require an external line. Nothing really wrong with this idea as long as vibration is taken into account during the design.

Piston squirters might be done with nothing more than a couple of aimed drillings in the rod big end. The oil holes in the crank can be slotted for more oil as needed. It's common on VWs to grove the crank journal 360 deg for full time oil to the rods. Same kind of idea here.
View attachment 89092
I'd rather use fixed squirters. A 360 groove in the big end would drastically reduce the load capacity, and it is already on the marginal side. I'm fine with using unfiltered oil for cooling, so tapping into the cooler adaptor or cooler return line would work for me. I haven't looked into the pressure drop in the feed line to the filter, yet. Even if I have to take my cooling oil from the pump, that's not insurmountable.
 

Hot Wings

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run them wherever you need them (esp the heads, if run with "heads up).
/QUOTE]

For those that want to run 'heads up' this is going to be a real problem to solve.
My spare heads have a vestigial casting running up the side of the head next to the intake valve that is not drilled. On the vertical engines this is for an oil line from the block to oil the upper end. The oil then fills up the space around the valve springs until it flows over the top into the push-rod valley. The intake valve has a valve stem seal - required if the stem is constantly surrounded by oil.
 

Vigilant1

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I think the heads-up oiling issues have already been addressed in the SE33 build, right? ( some pix and discussion earlier in the thread). Now, if the heads are bathed with lots of extra oil for cooling, maybe we'll have new issues to address.,
 
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Hot Wings

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I think the heads-up oiling issues have already been address in the SE33 build, right? (
Now that you stimulate my memory - I do remember a pic of an external oil line into the head between the valves and under the rocker arm cover flange. Maybe not all of the heads have the vestigial casting?
 

TiPi

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I think the heads-up oiling issues have already been address in the SE33 build, right? ( some pix and discussion earlier in the thread). Now, if the heads are bathed with lots of extra oil for cooling, maybe we'll have new issues to address.,
In the heads-up installation, the oil is for lubrication of the moving parts. Most industrial engines use just the oil vapour floating around (one of the reasons they have the crankcase breather on the valve cover). Lubrication only requires a very small amount of oil. Check VWs and Jabiru, had some issues if not addressed.
The oil circuit on the 49 is very conventional: oil pump (with relief valve) - oil cooler - oil filter - lube points.
Many people don't understand how a hydraulic circuit actually works. The oil pump does not create the pressure, the pressure is the result of the downstream restrictions. In an engine, the restrictions are variable with temperature, base oil viscosity, rpm and clerances that can change with rpm and temperature. The pump output is pretty much linear with rpm.
At operating temperature, the oil pressure is not cotrolled by the relief valve, it is just a funtion of oil volume delivered by the pump and the leakage rate of the circuit. It balances itself at what we know as "normal oil pressure". For the Briggs, this is 1-3.5bar
 

Vigilant1

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Now that you stimulate my memory - I do remember a pic of an external oil line into the head between the valves and under the rocker arm cover flange. Maybe not all of the heads have the vestigial casting?
The pictures are earlier in this thread, from a slideshow. I'll find them later and link to em (I'm on my phone now).
With the production move of some of the assembly lines and incorporation of new equipment, it wouldn't be surprising to see subtle differences between older/ present engines and model lines.
 

Vigilant1

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Now that you stimulate my memory - I do remember a pic of an external oil line into the head between the valves and under the rocker arm cover flange. Maybe not all of the heads have the vestigial casting?
The post here has some pictures of the oil lines on the SE33 (and a link to slideshow with other pictures on the SD-1 and engine installation).

You posted here, inserted the picture below, and said:


At the top (bottom in my case) of the block there is a drilled oil passage (near the red arrow) from the camshaft to feed the flywheel end crank main bearing. It looks like they tapped into that to feed the top end. On the vertical shaft engine this area gets it's oil from splash. When converting to Horizontal this is a logical way to do it. Inverted should not need any supplemental top (bottom) oil, but something similar may help with the heat. The roundish casting under the green circle is an oil passage that is not drilled on either sets of my vertical heads. I presume that it is drilled and fed with pressure oil if the head is used on a factory horizontal engine. I'll have to do some more looking to see if this vestigial oil line is also duplicated in the block of the vertical engine.
There isn't a lot of room under between the valve cover and the top of the intake port to put the fitting, but it should be possible with a 10mm or less thread.
The gray box on the valve cover looks like an oil separator. The stock engine has a little reed valve oil separator crankcase breather near the red arrow. I don't know why they wouldn't have used it and just added the overflow tube there.

Edit:
Only one set of my heads has the vestigial oil line. My block and it's head do not.
TiPi, from looking at the pictures above, it looks like oil lines have been plumbed to the heads of the engine (whether the oil is for lube or cooling) and that the oil comes from a new tap into an in-block oil passage. Do you think we've got that wrong, that the rockers/etc depend on oil mist and that these AL lines are for something else?

One observation: In the SE33, the crankshaft bearing on the flywheel end is also the propeller bearing. It already has an area smaller than the PTO bearing, so I would think that when it is under load (e.g. gyroscopic prop forces, etc) that the need for solid delivery of high pressure oil is pretty important. Using that particular oil channel to supply both heads would require some careful research to determine that the oil supply to that critical bearing remains sufficient. Maybe that concern has already been considered and this approach (possibly including restrictions in any spray "nozzles" in the heads, etc) indicates that it wasn't found to be a problem.
 
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Hot Wings

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You posted here, inserted the picture below, and said:

Yah, my brain is kind of mushy today. Too many hours in front of the CAD screen.:rolleyes:

Took a look at my 810 and it's heads are different than the spares I got of eBay by part number. The new heads do not have the casting material for a top oil port.
 

pictsidhe

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The existing breather on the end of the cam tunnel would be one good drain point. I'm pondering dry sump, but don't know enough about oil/air seperation and would like to see if I can get by with wet sump first.
 

TiPi

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I think people are over-thinking many areas. These engines are designed to work hard in zero-turn mowers, used by professional mower mobs. The engines have achieved 2,000h and more in those applications.
What is required for a successful conversion is to maintain the status quo:
  1. adequate cooling (engine & oil)
  2. uninterrupted oil and fuel supply
  3. address any issues arising from turning the engine

  1. Needs to be addressed by the installation
  2. Requires the modification of the oil sump, oil pump pickup, oil level indicator to meet original operation. Fuel delivery has to meet 125% of max flow
  3. Identified issues: valve gear lubrication: a dribble of oil at the right point will fix that
Anything else is to reduce weight (flywheel) or facilitate the prop mounting (taper shaft, adaptor etc).
There are a couple of reliability improvements from the racing people:
- Billet valve retainers
- Replace the alu pushrods with steel pushrods (intake)
- Keep the ignition coils and rectifier/regulator cool
 

blane.c

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Why the weldments? Couldn't you just have oil lines from the valve covers to the reservoir (in green on your drawing) and another to the suction side of the pump? Then the reservoir can go on the firewall, be lashed to the engine mount, etc.
Seen a lot of those oil line connections. They all leak like sieves eventually. Near the bottom of the gravity well not good.

Notice that the idea is to have the oil level below the "O" ring level. And to the extent possible mimic a wet sump. Also riding on "O" rings the idea is not to add any additional weight (or at least not much) to the valve covers, the reservoir will have "independent suspension" regards vibration and will be held in place at the heads or block. Also this is a crude drawing of an idea (dare I say) and refinement will raise the reservoir up quite a bit I am sure and shorten the pick up tube.

I do not want a scavenge pump. Weight and another thing to break.
 

Vigilant1

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Notice that the idea is to have the oil level below the "O" ring level. And to the extent possible mimic a wet sump. Also riding on "O" rings the idea is not to add any additional weight (or at least not much) to the valve covers, the reservoir will have "independent suspension" regards vibration and will be held in place at the heads or block. Also this is a crude drawing of an idea (dare I say) and refinement will raise the reservoir up quite a bit I am sure and shorten the pick up tube.
I'm probably just not following your concept well. But I do think the area under/around the heads will be pretty valuable/crowded real estate in a heads-down installation with the induction runs, a carburetor, fuel lines, exhaust pipes, etc. Putting 1/2 gal tank down between the heads, too, will be something.
An unrelated question regarding maintenance access and oil leaks--did you happen to design any British Leyland products in the 1970s?:)
 
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