Making a Harbor Freight engine look vintage/antique?

Discussion in 'Motorized Bicycle General Discussion' started by Mr.B., Mar 12, 2011.

  1. Mr.B.

    Mr.B. Well-Known Member

    Joined:
    Oct 21, 2008
    Messages:
    1,185
    Likes Received:
    27
    I’m sure most are familiar with Harbor Freight’s affordable 2.5 & 6.5hp engines, but I’m curious if anyone has ever “antiqued” one?

    My biggest question would be “Can you rotate the engine so the cylinder is vertical without effecting performance or durability?

    I realize you would have to make a new intake manifold to keep the crab level.

    BTW: I tried searching and didn’t find anything, but admittedly I’m not skilled with the feature.

    Looking forward to seeing your mod's or hearing your ideas!

    Thanks,

    -Kirk
     
    #1 Mr.B., Mar 12, 2011
    Last edited: Mar 12, 2011
  2. wheelbender6

    wheelbender6 Active Member

    Joined:
    Sep 4, 2008
    Messages:
    3,816
    Likes Received:
    10
    I haven't done a Briggs or HF, but I can tell you what I have seen, Mr B. They remove the fan shroud (they to have rig a rope start or something). Intake manifold mods are often made with copper plumbing. Exhausts are made the same way.
    Check out the "DIY and non-kit" subforum to see a lot of HF & Briggs builds.
     
    #2 wheelbender6, Mar 12, 2011
    Last edited: Mar 12, 2011
  3. Mr.B.

    Mr.B. Well-Known Member

    Joined:
    Oct 21, 2008
    Messages:
    1,185
    Likes Received:
    27
    Yep, I can think of lots of cosmetic stuff, but with the cylinder sticking out the back at a shallow angle, that may be a deal breaker...?
     
  4. wheelbender6

    wheelbender6 Active Member

    Joined:
    Sep 4, 2008
    Messages:
    3,816
    Likes Received:
    10
    I see. If you spin the engine around so that the cylinder leans forward, the crank turns the wrong direction.
    Maybe you could mount the engine tilted forward as 45 degrees, so that the cylinder is vertical. That could adversely affect the oiling of the engine.
    The HF builds I have seen, rack mount and frame mount, have been level with the cylinder tilted rearward.
     
  5. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    These Honda clone engines you are speaking of will NOT last around a city block if you tilt them in the angle your asking about here, all of these type engines have what is called a "dipper oiling system" this means they have a slim finger like probe that extends down from the rod cap on the con. rod, which when the piston in the engine is at BDC will be down in the engine oil, as the engine is running this dipper actually slings oil all over the inside of the enine and there is also a hole in the Con rod cap which will allow oil to be pushed between the crank journal and the Rod while the engine is running.

    If you tilt one of these engine at that angle you will prevent the dipper from reaching the oil which will cause the engine to lock up and be wrecked in a matter of a minute or two at the most, I have built High performance Kart engines using these Honda Clones and so I know these engines very well, I have not built the little 2.5's but they are just smaller versions of the 6.5HP Honda GX200 clones.

    And if the oiling wasnt an issue you would have a carb issue as well, because at that angle it would either flood with fuel or starv for fue also.

    If you want that vintage look, get a briggs Flat Head and build it up, you can still buy the 3.5hp engines which would be plenty for a bike if set up correctly, mill the head down .010-.012 put an offset flywheel key in it to advance the ignition timing about 6 degrees, build you a cool straight pipe exhaust and you'll have a cool running and cool sounding engine with that old time flat head look.

    Good luck on what ever you do, but dont tilt the overhead valve engines back very much or you will lock it down real quick...... guarranteed
     
  6. wayne z

    wayne z New Member

    Joined:
    Dec 5, 2010
    Messages:
    1,746
    Likes Received:
    0
    Have you seen Mrsfans briggs bikes? He tilts his engines about 45 deg, and has had years of use with no oil related problems.

    I think you could tilt the Clone engines successfuly if you took the effort to figure out how to keep the oil level thesame distance from the crankshaft as it is in the stock positon. As long as the dipper hits the oil, yer good.
    If you dont wanna fuss with a special manifold, you could use a diphram carb like on the old Tecumseh 2-strokes.
     
  7. wayne z

    wayne z New Member

    Joined:
    Dec 5, 2010
    Messages:
    1,746
    Likes Received:
    0
    i've been contemplating on finding a way to mount on of these with the cyl foreward and reversing the output with some kind of gearbox.
    Got an idea for a fricton gearbox made from Snapper mower fricton tranny parts. Be a clutch and gear reduction all in one.

    A solid steel flat pulley on the motor, and a Snapper fricton wheel, on a jackshaft, against it.The motormount could be hinged, to move the pulleys apart/together.Or maybe a modded cent clutch on the motor with a flat pulley instead of sprocket teeth?
     
    #7 wayne z, Mar 13, 2011
    Last edited: Mar 13, 2011
  8. Mr.B.

    Mr.B. Well-Known Member

    Joined:
    Oct 21, 2008
    Messages:
    1,185
    Likes Received:
    27
    Yes, my thoughts exactly...

    And yes despite my low post count I’m a daily visitor and have seen many wonderful builds here using Briggs, Tecumseh, and upright Hondas.

    In fact I’m getting close to finishing my first build that uses a vintage Wisconsin engine. I’m thinking about the next build now and looking for a easy to find, reliable, and inexpensive power plant

    -Kirk
     

    Attached Files:

  9. Russell

    Russell Active Member

    Joined:
    Apr 19, 2009
    Messages:
    1,186
    Likes Received:
    8
    I have seen some 4cycle engines made to look retro. Although I cannot recall the post. One of the honda conversions made me drool. However it took a lot of imignation and a heck of a lot of machining. But dam, it looked great.
    I am working on a much more modest retro look conversion. Hope to finish in a week or two, will post pictures. Of course it will be mounted on my new and first BTR tribute bike.
     
  10. msrfan

    msrfan Active Member

    Joined:
    Sep 17, 2010
    Messages:
    1,714
    Likes Received:
    8
    Thanks, Wayne Z, for the referral to my bikes. You're exactly right about tilting the motors while retaining a certain oil level. The dipper action is violent the way it sprays oil everywhere inside the engine. If you want to see how much it splashes, just start one up without the oil cap. I made that mistake inside my garage and it took several days to find and clean all the oil up, and it almost emptied the crankcase. Also, inside oil splash engines there are feed holes and passages that rely on gravity for the lubricant to run down into the shafts and bearings. Tilting will probably not change that dramatically. I recommend taking off the side cover and looking at the oiling system before deciding to run at an angle. The engines I've seen are over-oiled for two reasons I can think of. First, why not? Any excess oil just runs back to the bottom and gets splashed again. Second, all motors burn a certain amount of oil and the mavufacturers know that a lot of people let the level get dangerously low. So just like they go overkill on the cooling fins because they know people don't clean the grass out of them, they do the same to make sure the motor will oil even when very low. We don't treat our bicycle motors like mowers. Most of us keep an eye on our oil levels. Can't afford to burn up a motor 20 miles from home. I've found that the Briggs motors use the same quantity of oil tilted or not. True, the bottom is flat and tilted puts the corner at the bottom, but the dipper still reaches into the oil deep enough. Personally, I own a couple of GX120 Honda 4hp motors along with a clone 6.5 hp and I tried to think of ways to make them look older. No matter how you tilt them, you still have a flat mounting base to hide or cut off, and a valve cover to deal with. As mentioned before, levelling the carb or going with a diaphragm type would be required. I conclude that there are plenty of old motors available for our use that look old. I also own a Wisconsin model AB like the one used on the 1910 Pierce clone by Louie MCman in the DIY category and I would never have thought to use it on a bicycle. Just shows great imagination. One of the problems with "real" old motors is weight to hp. Most are cast iron with low power output. The Wisconsin is rated aroud 3 hp and weighs over 50 pounds. It depends on the look and performance you're after. On the other hand, plenty of Techumseh, Lauson, Jacobson, Briggs, Power Products, Clinton, and many others are still lurking at yard sales, scrap yards, swapmeets and landscape shops that will yield enough power and are fairly light weight and inexpensive to acquire. I have bought complete machines for $20 just to get a motor. Kohler, Wisconsin, Onan, etc are usually heavier. So quit looking at cheep chinese knockoffs and get the local Greensheet or Pennysaver and check the adds for what you can look at near your home. Then scout the older lawnmower shops and wrecking yards. There's nothing like a vintage motor in an older or homemade frame. Not to mention "Made In USA".

    [​IMG]

    [​IMG]

    [​IMG]

    [​IMG]

    Creative trimming of sheetmetal and cooling finns can make a motor look vintage. My goal was to make them look unrecognizable.
     
  11. matthurd

    matthurd New Member

    Joined:
    Dec 13, 2010
    Messages:
    817
    Likes Received:
    0
    i find hammers and dragging it in sand from a baseball park are a good way to make anything look antique.
     
  12. myke

    myke New Member

    Joined:
    Mar 23, 2009
    Messages:
    43
    Likes Received:
    0
    those are some great looking bikes
     
  13. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    Well, let me ask all you guys who think the overhead valve engines can tilt at a very extreme angle and be OK a question or two......

    How many of you have ever been into one of these OHV engines?

    I say dont be so quick to give advice to someone on this matter if you have not even had any xeperience with one of these engine....these are NOT the very mechanically simple flat head engines, I built one of these GX200 clone a couple years ago and put a custom made billet con rod in it not knowing that the crank journal in my engine was about .001 -.0015 to large and this was enough to not allow it to oil properly and I cooked a high dollar custom Billet rod because of it, these clone engines are much tighter tolerenced engines than the old flat head briggs engines and I've built a truck load of them in my life along with the old Tech. HS 50's ect. and from my personal experience the Hoda engines are by far the best, even the clones are better than a Briggs most of the time but they are very picky about the oiling.

    Dont get me wrong here, I'm NOT saying it cant be done but because I have not seen one of these engines placed in that kind of an angle and ran successfully there is and was NO way I would tell someone that it is OK to do it or that I think it will work because the briggs engiens are OK with it, these aint briggs engines and just because they have a dipper oiling system doesnt automatically mean you can get away with it, I know a slight angle will work because I've seen these engine mounted on Rcae Karts at a slight angle, but if the cylinder is positioned vertically the rod itself, and the counter weights on the crank shaft will be what is plunging down into the oil and not the dipper, this could actually cause too much oil to be slung up through the push rod channels and cause way to much oil on top of the head under the valve cover and if it does this, the crankcase pressure will likely push large amount of oil into the PCV hose and right on into the airfilter housing or out on the ground if the hose isnt hooked to the housing, these engines build a good amount of crankcase pressure and tend to put some oil in the filter housing as it is when they are mounted the way they were intended to be.

    Please understand that I'm not bashing anyone elses opinions here, but I have a good amount of experience building and working on these engines so I'm pretty familiar with there strong points and the things that are potential problems if things arent right.

    I just will not give advise on something like this that is unproven and risk telling someone that something will work and then they cook an engine because I told them I think it will be ok because it works on a completely different designed engine.....

    I would like to know if this will work or not but having the crankshaft actually running in the engines oil supply is not a good thing on one of the overhead valve engines IMHO, but I'll take back everything I said here if and when I see one of these runing and holding up well mounted with the cylinder veritcal or close to it.

    As to the quality issue raised about the Clone engines, these GX200 clones will probably out last 2 or 3 of the old aluminum bore briggs engines and unless several things are upgraded on the old Briggs the clones will run circles around them STOCK also, way more torque and potential horsepower with only slight mods. so these engines aren't junk as many may think and if someone wants to build one and make it scream out 10-14 HP here is a site that offers many upgrades and How to info. on everything about these GX200 Clones, Affordable Go Karts - Home page - AGK - http://www.affordablegokarts.com and if you can get one to work at a major tilt, the carb issue can be solved by using a Tilitson Carb and a custom intake that is available on this site I have listed, browse around and just see what all can be done to these clone engines and they run like a scaulded ape with a few mods.

    Dont mean to upset anyone with this post, just not gonna tell someone something will work if I dont know for sure it will thats not very ethical at all and could cost someone a lot of money and trouble.....!

    Peace

    dnut
     
  14. msrfan

    msrfan Active Member

    Joined:
    Sep 17, 2010
    Messages:
    1,714
    Likes Received:
    8
    Good points, mapbike. I'm glad you cleared up some questions. I was hoping someone with more experience with these engines would post. I know when a crank and rod hit oil, it may foam. and where there's air, there's no oil. No one has mentioned the Honda 5hp OHC motor. The GC160 is an upright motor that may be a good candidate for a bicycle.
     
  15. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    Yes the GC160 might be a very good engine for the bikes, and thank you for understanding my points, I was not trying to come across as hostile to anyone at all, I just thought there were a few things to be considered on the overhead valve engines that might cause an issue when or if they were mounted at to much of an angle, I could be completely wrong in my thinking on this but knowing these engines pretty well is why I posted the points I have on them being mounted at what could possibly be to great of an angle.

    I hope if someone comes across one of them that is working great at such a severe angle, they will post that information with some pics so we can know for sure whta the answer is to these questions I have on the topic.

    Thanks for the input here msrfan, matbe we will all know the answer on this for sure in the near future.

    Peace
     
  16. wayne z

    wayne z New Member

    Joined:
    Dec 5, 2010
    Messages:
    1,746
    Likes Received:
    0
    OK,
    if you tilted one of these engines vertical, and accuratly devised a way to check and keep the oil at the same distance from the crank as stock, and there is no oil pump involved, there's no logical reason that I can see why it won't work.

    If the oil is at the same level as original, the counterweights won't hit the oil.

    Heck we DIY builders are all experimenters Can't be worried too much if something don't work as planned. Can't find out if it works or not by following the naysayeres LOL. Edison had a lotta trouble wit that. When his experiments didn't work, he would say something like" thats just one more way that don't work".
     
    #16 wayne z, Mar 13, 2011
    Last edited: Mar 13, 2011
  17. dmb

    dmb Active Member

    Joined:
    Dec 4, 2010
    Messages:
    1,359
    Likes Received:
    0
    check out b&s j.r. dragster motors.. i'd dig in their dumpsters anytime. talk about getting a speeding ticket on the freeway!
     
  18. Mr.B.

    Mr.B. Well-Known Member

    Joined:
    Oct 21, 2008
    Messages:
    1,185
    Likes Received:
    27
    I do appreciate your experience & opinions. Thank you.

    My goal is to just simply discuss the possibilities of using one of HF engines...

    I really didn’t want to show pictures of my current project until it was more complete but for illustrative proposes here it is. The engine is a 1939 Wisconsin model AK. Yes it does weight 55 lb’s but is rated at 4.2 HP at 2400 rpm’s and has a long throw, I expect good torque.

    It suits the era I’m most interested in perfectly and seems to run well (although not road tested yet).

    But I do feel I was very fortunate to find it very cheap at a garage sale, I’m not sure I can count on doing that again.

    So for my next build I wanted to use something that’s easily available, reliable, and inexpensive, budget is a big issue for me.

    -Kirk
     

    Attached Files:

  19. Mr.B.

    Mr.B. Well-Known Member

    Joined:
    Oct 21, 2008
    Messages:
    1,185
    Likes Received:
    27
    Another blue sky thought about the dipper...


    Perhaps removing the cast “finger” and replacing it with a simple piece of flat stock that weights the same but is at an angle closer to the original orientation would make it splash more correctly?

    What say you?

    -Kirk
     

    Attached Files:

  20. mapbike

    mapbike Active Member

    Joined:
    Mar 14, 2010
    Messages:
    5,380
    Likes Received:
    1
    The engines you speak of here are Briggs reproduction " CLONED " engines and for the most part.

    They also run on Methanol and run extremely hot, it would last maybe twice around the block if put on a bike as it is run on the Jr. Dragsters.

    but if it were toned down a bit and put on gasoline with a good overall set up oh..........! Yeah...........! it would take one heck of a bike to handle one of those custom " Briggs design cloned " Blockzilla engines, they are wicked fast, but only actually run that good if set up on Methanol and a big cam grind with larger valves and very high compression and advanced ignition timing.

    amazing how they push that liitle rail at 80+MPH
     

Share This Page