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FabianRW

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I'm making a budget bandsaw mill.

Got a V-twin Briggs and Stratton Vanguard 16hp horizontal really cheap, only £50.
Taken it apart, looks in good condition inside, dated to 1993 but not ran long I reckon, just simple fixes as they'd not changed the oil, ran it and it wore the cam shaft back in it's solid bearing so eventually it had a slight knock, luckily minor damage and not much wear otherwise, just needs shims on the engine-casing end of the crankshaft to take wear I think.
Minor water ingress, I'm getting rid of surface rust and basically reconditioning each part.

It's a 290000 series model, fairly standard hand start, petrol tank on-top and not much more to it. Could be missing a fuel pump which is how the water got in I think. No electric, never had a starter but is also missing any kind of on/off switch, I'm guessing the petrol valve does that instead?

So great base to start from, I'd like to get a bit more power without downgrading reliability.
These are my thoughts but I'm only a woodworker, only done one rebuild on a 076 chainsaw.
Anyone got any input on-top or good alternatives/suggestions please?:

First off I'll remove exhaust rings inside the heads exhaust output, limiting output size, didn't think the 16hp would have them but they seem to be there.

I'd like to upgrade the carb from the Aisian to a Mikuni 28mm (probably a copy of or second hand) I'd fabricate a 90° elbow so the carb and filter face forwards and sit above the pulley but nice and high, maybe starting 100mm/4" above the manifold depending on if I'm using gravity petrol feed or fuel pump. (Not sure it ever had a fuel pump, there is limited info)

I am not sure if I'd add a fuel pump, possibly an original, what are people's thoughts on which one to go with if any?

I would add a kill switch ideally but not sure how best to do it, fuel on/off is fine as an on/off but I'd like to run the thing on propane.

In terms of running it on propane (and petrol) I would consider suggestions, I can get a tri/dual fuel kit fairly cheap in the future so all mods have to be suitable for this.

I'd quite like to keep mods minimal in cost, already got to get a gasket set etc and spend ages cleaning and restoring it so must be either low cost or stuff I can do myself/fabricate. I can weld etc.
 

JRM

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The 29mm Mikuni is what is used on the18hp Vanguard version and the only real difference I'm aware of between it and the 16hp, with the exception of possibly the cam. I'm not sure how much extra hp you'll be able to make without valvetrain upgrades anyhow as those engines will start floating the valves much past the governed rpm. I'd try the carb first and see how it does for you.
 
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I'm making a budget bandsaw mill.

Got a V-twin Briggs and Stratton Vanguard 16hp horizontal really cheap, only £50.
Taken it apart, looks in good condition inside, dated to 1993 but not ran long I reckon, just simple fixes as they'd not changed the oil, ran it and it wore the cam shaft back in it's solid bearing so eventually it had a slight knock, luckily minor damage and not much wear otherwise, just needs shims on the engine-casing end of the crankshaft to take wear I think.
Minor water ingress, I'm getting rid of surface rust and basically reconditioning each part.

It's a 290000 series model, fairly standard hand start, petrol tank on-top and not much more to it. Could be missing a fuel pump which is how the water got in I think. No electric, never had a starter but is also missing any kind of on/off switch, I'm guessing the petrol valve does that instead?

So great base to start from, I'd like to get a bit more power without downgrading reliability.
These are my thoughts but I'm only a woodworker, only done one rebuild on a 076 chainsaw.
Anyone got any input on-top or good alternatives/suggestions please?:

First off I'll remove exhaust rings inside the heads exhaust output, limiting output size, didn't think the 16hp would have them but they seem to be there.

I'd like to upgrade the carb from the Aisian to a Mikuni 28mm (probably a copy of or second hand) I'd fabricate a 90° elbow so the carb and filter face forwards and sit above the pulley but nice and high, maybe starting 100mm/4" above the manifold depending on if I'm using gravity petrol feed or fuel pump. (Not sure it ever had a fuel pump, there is limited info)

I am not sure if I'd add a fuel pump, possibly an original, what are people's thoughts on which one to go with if any?

I would add a kill switch ideally but not sure how best to do it, fuel on/off is fine as an on/off but I'd like to run the thing on propane.

In terms of running it on propane (and petrol) I would consider suggestions, I can get a tri/dual fuel kit fairly cheap in the future so all mods have to be suitable for this.

I'd quite like to keep mods minimal in cost, already got to get a gasket set etc and spend ages cleaning and restoring it so must be either low cost or stuff I can do myself/fabricate. I can weld etc.
You're looking for more HP, propane is not the way to go as you will lose around 20 percent right there! Fresh rings, lap the valves, make it fresh will help a lot. I bet there's a group of Briggs guys that would have some real mods that can bump that up considerably.
 

FabianRW

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You're looking for more HP, propane is not the way to go as you will lose around 20 percent right there! Fresh rings, lap the valves, make it fresh will help a lot. I bet there's a group of Briggs guys that would have some real mods that can bump that up considerably.
I have read propane gives more power and longevity compared to 85 petrol which is now the standard here, used to be 95 until very recently. I'll put additive in.

I was hoping one of the lawnmower mod guys or similar experience may be able to help but I don't need a racer engine, need reliability and economy to be same or better than original more than anything.

Propane may work out considerably cheaper but I'd be running it just on petrol to begin with.
 

FabianRW

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You're looking for more HP, propane is not the way to go as you will lose around 20 percent right there! Fresh rings, lap the valves, make it fresh will help a lot. I bet there's a group of Briggs guys that would have some real mods that can bump that up considerably.
I did read up again on propane, you're correct in saying it is less powerful, sorry about that.
It is higher octane, I think people mix that up with higher power, so it runs cleaner but that's all.
I'll probably use petrol just on wide cuts when I need more power, the prices nearly doubled recently!
 

Lightning Performance

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The power is in the head and cam along with lobe timing. Your gong to need to clean up the ports and know what your doing or flow will decrease. The valve springs and installed heights will be your big issue getting the rocker arm geometry correct to keep the valve guides from looking like an egg. Shaving the head some will add compression but watch what else you moved like the stock location points of all your add on parts. The correct push rod length is a must.

Getting a fresh valve job is best with a known good source doing them. The lapping is just a temporary fix that will pound down the seats eventually. Your valve springs will need replacing more than likely. Have the head setup by a known good builder is your best bet to add power across the curve.
 
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I ran my exhaust into a turbo style auto muffler which is the biggest gain. Some of them had NPT threads into the muffler which is OK. Take some mandrel bent tubing and run into about a 1 1/2'' collector will also help it stay cool. Thanks
 

Lightning Performance

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I ran my exhaust into a turbo style auto muffler which is the biggest gain. Some of them had NPT threads into the muffler which is OK. Take some mandrel bent tubing and run into about a 1 1/2'' collector will also help it stay cool. Thanks
Maybe he'll try that, good deal or never come back again.

Many don't want to hear when you're looking for more power under the curve not necessarily more RPM it's best left to others. If you don't know how to achieve that by many means your just wasting time. Having an informed well thought out plan before lifting any wrenches is always the best bet. Assuming you can somehow know more or learn more than people with decades of experience isn't the best approach most times. Spending money can be far more rewarding as a cost saving measure in the long run. The big gain is not making mistakes that take you backwards like most do. Everything from flow around the valves to choosing the wrong intake/carb system does just that. The bigger picture keeps you from destroying parts or the whole motor but we know nobody ever burns one down 😐
 

FabianRW

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The power is in the head and cam along with lobe timing. Your gong to need to clean up the ports and know what your doing or flow will decrease. The valve springs and installed heights will be your big issue getting the rocker arm geometry correct to keep the valve guides from looking like an egg. Shaving the head some will add compression but watch what else you moved like the stock location points of all your add on parts. The correct push rod length is a must.

Getting a fresh valve job is best with a known good source doing them. The lapping is just a temporary fix that will pound down the seats eventually. Your valve springs will need replacing more than likely. Have the head setup by a known good builder is your best bet to add power across the curve.
That's more like the answer I was anticipating, thanks. All makes complete sense and I'm aware of these kinds of upgrades. Unfortunately my budget limits what I can do but I am only wanting to get minor increase in hp.

Although I'd like to leave it mostly factory as it seems to have had very minimal use, I am considering just basic flow improvements; cleaning and minor porting, lapping valves are definitely things I'll be doing. The springs seem fine, everything is 'low miles' from the look of it, someone let the entire block get filthy with oily dirt and it may well have overheated but the damage is minor and only related to the oil. (To explain the condition it's not had much use, the previous owner(s) didn't change the oil and it got thick and blocked up in use, the cam wore into the front of the engine block (solid bearing front cover side) as a result and would have started to knock, there is minimal damage from this, they must have stopped as soon as they heard it, or it just stalled maybe).

So I need to add a shim for the cam shaft to locate in the proper place, I may use an oilite washer for that.
Nothing else is damaged aside from the gaskets, it's got some very minor oxidation from open pipes where they stored it outside, I've been dealing with that.

It has an original Mikuni carb but not like the Mikuni's everyone is familiar with, more like the usual type that is on these engines. Anyway it's probably a good carb but I'm looking at a 22mm normal Mikuni that's come up cheap, 23mm is the size of the intake manifold coming out of the carb. I understand that I'd only get more power like this by increasing speed, which I don't mind doing a little so long as I can keep timing and heads setup etc factory.

I want to think about this now because it decides the exact pulley sizes I'll need.

My actual bandsaw is going to be extremely strong and rigid, aluminium construction because I've managed to find some cheap used heavy duty industrial aluminium parts.
In terms of expense as you say it's only worth spending so much or fully going for it in a planned manner. That is what I'm doing, my plan is to run this engine until I can afford a larger more powerful engine like a Honda gx690. So I'm thinking ahead with the frame and duty of the bandsaw mill.
So happy to leave the engine factory if that's what makes sense, maybe just minor porting.
The cylinder honing I may not need to do but I've not found my acetone to be able to clean them out yet, they're fairly full of hardened oil/carbon looking deposit and they actually had grit in, despite no scoring. Glad I didn't try to start it beforehand.
 

FabianRW

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Any progress?
Hi mate,
Just been cleaning it one piece at a time, obtaining missing or damaged parts. It is currently boxed in parts.

I will port the intake manifold and exhaust outlet etc but otherwise I plan to leave it original.

I have made progress with the plans though, I aim to get it running well first as from what I understand it is far more important to have the correct gearing for the type of bandsaw blade and cut depth/type and hardness of wood.

So I plan to use 5-step aluminium v groove gearing, which I have a set of already.

I think gearing is probably far more important than an extra one or two hp and maybe that can be a next step.
 

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