Case of the missing shroud...

Silverbear, I don't think you'll have any problems replacing valves. Easier than a Volkswagen, heck there's only two. Just remove your top cover and they are there. The pushrods might be a different story, I know they get unseated and can bend at high revs. But as for valves, just pull the head remove the valves and pop the sucker back together and adjust. Not much simpler than that. I've done valve replacements on honda generator engine as well a B&S, not a big deal. Personally I don't think you'll ever have to do it, heat is not that much of an issue, unless you sitting there still and rev high for an extended period, highly unlikely.
 
I didn't really mean it like that Mike, head gaskets, base gasket, etc. I said you could pull the head apart and replace them. Its not that hard. No you can't just pull the head off like a china girl, its attached to the top part off the case. But its only a few bolts to pull apart the case. These are not like auto engines, they are easy to pull apart and put back together. I've done several crank replacements, bottom end replacements, bearing fixes, etc. I have run go carts for over 20 years, since I was a kid. Replacing the valves would take me an afternoon, so I don't consider it a big deal at all. BUT!!!!, I still run my engine with the covers on. Personally, its a "generator engine on a bicycle", who cares what it looks like or what its performance is. If you want to do that to an engine, get an Animal or performance engine from B&S, or stick to the Morini or the China girls. But I will tell you that I ran a Honda 50cc for years without a fan or shroud and it only burnt the valves once, during a long race, on a hot Florida afternoon, no BS. Fixed it the next day and was racing the next weekend, long live the Honda!!! It's still sitting in my garage, I might rebuild it one day, but its hard to find parts for the older engines, there's just a few on there you can't get anymore, like the entire bottom half, lol.
 
SB, Been gone for a few days and have just read the 5 pages of this thread. Great work on your part and the comments from everyone are wonderful as usual. While I could fabricate a fin cover I think your idea is perfect for the job and it sure does look great. I won't be long going that way with mine. Ordered the wide 3-piece crank, but will still have to get mor width to clear. May look for a smaller pedal sprocket to clear the motormount I made. In the end I'll probably have to modifiy it to let the sprocket clear. When I get this all worked out I'll have my wife show me how to post some pictures so you guys can see what I'm trying to do. Good Luck, Dan
 
Hi Tad, well I dunno if you realize at this point,. that the HS is a ONE piece casting? The guts are all loaded in from the bottom.

I was disappointed to see the whole concept of remove the shrouds and air diversion systems again. Just so it is absolutely clear to all reading I will not be doing ANY warranty on ANY engines that I have sold that have been subjected to cooling system parts removal, or modifications.

Guys, do anything you want, paint them purple should you so please, but know this, Warranty is void on modified engines from the MFG down thru whoever sells them, myself included, when the engineered cooling system is bypassed, reduced, or modified in any way that reduces its efficiency, warranty is over for the complete engine, end of story.

I hope I have not hurt anyone's feelings, nor their creativity, but I need to make this point indelible.

Thanks for your understanding,

Mike
 
Mike,
It is very clear that this kind of modification voids the warranty. Everyone should be aware of that. Still, I am not at all convinced that this is going to wreck my engine. I can see how the engine in a stationary situation would need that shroud and the benefit of the flywheel fins pushing air up there. I do not understand how heat shields help cool the engine. It seems to me they would make it hotter than if they weren't there, especially on the other side of the engine where the air pushed by the flywheel could not reach. Aren't the heat shields really for protecting your hands from getting burned? Just trying to understand. The warranty part I do get. That it will wreck the engine... I'm not convinced. As for hurting my feelings, not a problem. Stopping my creativity? Not a chance. I know you're being the responsible adult around here and that's good. Some of us are just bad kids. Ha!
SB
 
Tinsmith said:
SB, Been gone for a few days and have just read the 5 pages of this thread. Great work on your part and the comments from everyone are wonderful as usual. While I could fabricate a fin cover I think your idea is perfect for the job and it sure does look great. I won't be long going that way with mine. Ordered the wide 3-piece crank, but will still have to get mor width to clear. May look for a smaller pedal sprocket to clear the motormount I made. In the end I'll probably have to modifiy it to let the sprocket clear. When I get this all worked out I'll have my wife show me how to post some pictures so you guys can see what I'm trying to do. Good Luck, Dan
Click to expand...

Hey Dan,
You can also get pedal extenders to get a little more width for pedal clearance. Or bending the crank arms out near the 90 degree bend already there and then bend it back toward the bike further up the arm. I had to do that on the Motorbike build. You'll figure it out. Look forward to pictures...
SB
 
MotorbikeMike said:
Hi Tad, well I dunno if you realize at this point,. that the HS is a ONE piece casting? The guts are all loaded in from the bottom.
Click to expand...

Only the top part is a one piece casting, the engine is two pieces, the top half and the bottom half. Its a diagonal split design, and yes you load all the parts in from the bottom, after you remove the bottom half. Really easy, the piston and crank pull right out and then you have access to the cylinder and valves. Like I said an afternoon project for an experienced person, maybe a day or two for a semi-mechanically inclined person.

And who cares about a measly 6 or year warranty. Yes I'll probably keep mine stock till the warranty runs out, but at $200 bucks an engine, if you want hot rod chopper styling.... do what you frickin want, no parenting allowed!!!
 
And not to belittle anyone on here, but if you don't have any experience rebuilding small engines, buy a new one after your warranty runs out! Yes these are workhorse engines, for running water pump or generators, they are not designed to be used this way and will have mechanical problems from time to time, especially right after your warranty runs out, lol. They are however very easy to work on compared to any automobile/motorcycle engine, and can be a real learning experience in small engine mechanics.
 
Has anyone considered a clear cover? I'd like to see someone mold out these covers in clear plastic that way you could see the fan spinning!
 
Hello SB, here is the engineering. The fins on the flywheel are designed to create a certain (unknown to me at this time) CFMs of ambient air, sucked in through the rope starter, and blown upwards above the rope starter.

This air is channeled by the flattish tins on the rear, side, and front (if so equipped). The air circulates through the TOO SMALL cooling fins on the barrel portion, and head portion of the engine.

The left front opening between the tins is the "exhaust" portion of the airflow design. I have already mentioned the EX. valve and seat being the hottest points of the engine. Now, wherever you would like to take a temp reading, it will NOT be at the hottest point, which ultimately will be the point of failure.

Much time, money and experience goes into the design of the actual shroud, and how much finning, the angles of the fins, even the shapes of the fins, and ultimately the distance between flywheel fins to not burn too much HP, be in balance, and still properly cool the engine for even extreme service.

As I ride in 100+ F temps, the air from that front vent section, at times, is a bit unpleasantly hot on my bare leg (shorts not "skinny-driving").

This engine will NOT get enough passive cooling, as it does not have enough square inches of finning. This was replaced by the fan action so that the engine, no matter how it was used, would not overheat. Idling, pulling hills, or any other activity that increases heat production, without adequate cooling, whether fan-forced, or passive, puts the engine at a higher risk.

I am not saying that the lack of the cooling system may damage your engine, I am saying it Will damage your engine, I just cannot predict exactly when.

I hope this helps all understand the theory, if not, please ask, and I will elaborate, or try to get some engineering data for you.

Mike
 
MotorbikeMike, No offense, But I'm calling shenanigan's on it having any damaging effect on one of these engines being used on a motorbike. consider these are STATIONARY engines, meant to be sitting still to power a generator or a water pump or something similar, usually in an area with minimal ambient airflow, and yes, the shroud serves a purpose. However, that being said, these are not stationary. Their mounted into open air frames travelling at 25-35+ mph, producing plenty of ambient airflow over the heat fins.

Take into consideration that if you read the warranty on any motor meant to be a stationary engine and you'd realize that merely the act of using it in a non-stationary fashion alone voids the warranty. Removal of the shroud in no way modify's this motor, and as such if anyone DID have an issue, and wanted to attempt to try and get their factory warranty out of it, all they need do is bold the damn thing back on before shipping it in. And if they thought that was an issue, as soon as they tell them it was mounted on a bike and not in some compressor somewhere their up the creek anyways.

While I'll grant that if your sitting in the desert sun, at a red light for a full solid 5-6 mins with this thing running without the shroud on, sure you'll have heat issues, but so did old Harley's and any rider worth his salt would know, if your gonna be sitting there a while, turn the damn thing off. These bikes have pedals after all, and if we need to move when the light turns green, just simply pedal to the shoulder, pull start (or install an electric start) and be on your way.

Even better, if your running a 4 stroke, and your worried about desert heat, install and oil cooler. you can pick one up for less then 20 bucks just about anywhere. All this fuss of something so simple as realizing that a motor meant to be stationary doesn't need some ugly piece of tin when its no longer stationary. geesh.
 
sparrow69 said:
MotorbikeMike, No offense, But I'm calling shenanigan's on it having any damaging effect on one of these engines being used on a motorbike. consider these are STATIONARY engines, meant to be sitting still to power a generator or a water pump or something similar, usually in an area with minimal ambient airflow, and yes, the shroud serves a purpose. However, that being said, these are not stationary. Their mounted into open air frames travelling at 25-35+ mph, producing plenty of ambient airflow over the heat fins.

Take into consideration that if you read the warranty on any motor meant to be a stationary engine and you'd realize that merely the act of using it in a non-stationary fashion alone voids the warranty. Removal of the shroud in no way modify's this motor, and as such if anyone DID have an issue, and wanted to attempt to try and get their factory warranty out of it, all they need do is bold the damn thing back on before shipping it in. And if they thought that was an issue, as soon as they tell them it was mounted on a bike and not in some compressor somewhere their up the creek anyways.

While I'll grant that if your sitting in the desert sun, at a red light for a full solid 5-6 mins with this thing running without the shroud on, sure you'll have heat issues, but so did old Harley's and any rider worth his salt would know, if your gonna be sitting there a while, turn the damn thing off. These bikes have pedals after all, and if we need to move when the light turns green, just simply pedal to the shoulder, pull start (or install an electric start) and be on your way.

Even better, if your running a 4 stroke, and your worried about desert heat, install and oil cooler. you can pick one up for less then 20 bucks just about anywhere. All this fuss of something so simple as realizing that a motor meant to be stationary doesn't need some ugly piece of tin when its no longer stationary. geesh.
Click to expand...


Couldn't have said it any better man!
 
silverbear said:
I don't much care for sardines, so don't have a can. I'd rather eat fresh walleye. Maybe this winter when I have time for refinements I'll invest in a can of sardines. The dog will either like them or roll in them or both. Right now I'm happy with having the fins covered up and the heat shields removed. It sure looks better. Mike is right, I'm sure, that warranties go out the window by removing them, but I haven't noticed any tendency for the engine to get hot on my bike. If I were a dealer like he is, I'm sure I'd be telling my customers that altering the engine in this way is not advised and that doing so voids warranties and leaves you on your own. I would like to know what is involved in replacing the valves, etc. if they were to go bad. If I only get ten thousand miles on this motor instead of twenty, at least I don't have to look at that shroud. Gotta be cool even when you're a geezer.
SB
Click to expand...

A LITTLE MORE SPENDY but salmon and maybe hearing come in them cans I think. I will have to check when I go to the store
 
Or if you want to go full shiny shroud without he fuss, just get a Hormel or DAK canned ham.....perrrrrrfect! You know the one...shaped like a shroud. Then eat the ham for Thanksgiving or something.dance1
 
Well, to tell the truth I had already thought about the canned ham for the transmission cover, but don't think it could possibly be the right size. On the other hand, look how nicely the tomato can fit. I'm still scratching my head about the transmission cover, although to be honest I'm getting used to it. Down the line I'd like to make one out of copper, make an in frame copper gas tank and have it be a kind of visual theme on the bike... this is for a HF motor/EZM tranny on a 51 Schwinn cantilever frame sometime off in the future. Copper exhaust pipe... Maybe this winter. If you were going to make a custom cover for the transmission, how would you do it? I don't weld, so something like stainless is out. Diamond plate would look sharp.
SB
 
Just about to kill off a tin of smoked herring. Can I mail the tin {washed}?
Two different styles. Will send sizes and shapes if desired. Recommend herring in tomato sause. Larger tin.

I'll keep it until further notice.

Steve.
 
professor said:
You can use a thermometer that has a probe end on it and put it in the passage to fill oil to check it after running. My HF was 170 degrees after running in 70 degree weather with all stock tin on. Do keep your oil below 230 or so.
Click to expand...

I used my wife's thermometer from the kitchen. The cylinder head registered just above roast beef after idling the engine for fifteen minutes. I figure things will be just fine until it gets above meatloaf........
 
Put the herrings on hold for now, please.
Yes, meatloaf could be trouble.
I think I'll order the cold cuts, cheese and a Lost Lake beer. Thanks. And some of that hot mustard...
SB
 
You must log in or register to reply here.
Back
Top