First time adding displacement.

Discussion in 'Projects/Builds' started by kirrbby, Dec 10, 2012.

  1. kirrbby

    kirrbby Well-Known Member

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    I have been all through stock Honda motors, 49 & 72cc. Made my mistakes and had successes. I'm considering building a 110, But I've never even installed a 88 kit yet. I would probably be easy to impress. So I'm wondering if I should start with the 88. I bought a slightly used race head kit and I have a good H motor to start with. The kit is missing a few things that I will buy. The first question is, 88 or 110. Next question is what else will I need besides the obvious gaskets and seals. Depends on what I decide to build. Here is some pics, motor, frame, kit. 110 build 001.jpg 110 build 003.jpg 110 build 005.jpg 110 build 004.jpg 110 build 006.jpg 110 build 002.jpg 110 build 007.jpg
    110 build 008.jpg 110 build 009.jpg 110 build 010.jpg
     
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  3. cjpayne

    cjpayne Well-Known Member

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    I think, if your going to modify for performance, the bigger the better. Go for it. You'll probably have to modify the suspension too, to put up with the increased speed. The stock front suspension might(God forbid!) get the Death Shakes after 65mph. I'm sure Racerx is going to chime in. I would take his advice over mine.LOL
     
  4. ez50

    ez50 Well-Known Member

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    IMO - Going over 50mph on a CT is overkill and it is about where the 88 tops out. But then again, the $400 that it took to go to the 110 is what stopped me. I spent that $ on going to 12v too.
    Going from 72 to 88 sure is fun. 72 to 110 = 2xfun?
    One thing to think about, can you get the oil passage back to original once it's drilled out on the H case?
    Thrust washers, shift drum pins, clutch kit, timing chain & parts, build your own throttle cable parts, lft. turn out intake, jet kit, air filter, a can of 08707-NH35M Cloud Silver just to name a few.
    Cool project
     
  5. kirrbby

    kirrbby Well-Known Member

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    I've been thinkin about this pretty seriously (finally) for the last week or so. Was gonna go big but now I'm hedging. I have nearly everything I would need for the 88. Couple hundred bucks maybe, is all I would need to spend. I already have the washers, pins, timing chain, paint, gaskets and seals. I would rather use the stock carb and throttle if I do the 88. I guess I'm just lookin for some extra zip more so than top speed. If I could pull the front wheel in 2nd and 3rd easily I would be happy, for now at least. I also have a K1 front end that I'll paint to match the frame. The 88 seems like a better choice me to start with. It would also allow me to buy a complete 110 kit when I'm ready for one rather than have to piece it together.
     
  6. Gary

    Gary Well-Known Member

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    I have a H motor with a 85 kit on my ct. It has a supposed warmer Honda cam,can't remember which one, but stock exhaust and carb. I run a 46 tooth rear sprocket on a hilly and wooded 12 acre "yard". Very happy with what it does for me, but next time will be bigger. I already have another H lower end and when it's time,I plan to build a stroker.When thats done,since I do have a title plan to license to ride around on the back roads.
     
  7. kirrbby

    kirrbby Well-Known Member

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    I plan to plate this one also. My vision for this bike is to be able to take it down the road and pull off onto the trail, through the cornfield, cross the creek, back out onto the road. If I decide to take the jump, well... I'm not gonna do that, but the bike should be disappointed. Take it home, hose it off, then to the local car cruise and have it look like a nice, classic Honda CT70. The 88 is the build which will keep the classic look. A stroker is definitely in my future, and I'm sure a pristine princess as well. Right now tho I'm leanin toward a simple 88. I can tweak and tune it until there is nothin left but to stroke it.
     
    #6 kirrbby, Dec 11, 2012
    Last edited: Dec 11, 2012
  8. OLD CT

    OLD CT Well-Known Member

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    88cc's is the limit for the stock exhaust,if you dont like the free flow's stick with 88.Although you want to keep the stock carb you will lose a few mph not going with a bone stock no jetting required in most cases,25 dollar webllc PZ19 coupled with a dratv 20mm turn out and ''real'' free flow K&N from him also,not the 10 dollar cheapies.They dont last.You will need to drill out the oil oriface for a hi vol oil pump.EVEN IF YOU WANT TO GO BACK TO STOCK A HI FLOW PUMP CAN ONLY HELP NOT HURT ANYTHING.Ooops didnt mean to caps lock.88cc's is the end of the road for not needing a oil cooler.A must on a 110.Oh almost forgot a 110 style carb in most cases is going to need the dratv remote 1/4 turn quick release throttle.The stock dead man isnt a good choice.
     
    #7 OLD CT, Dec 11, 2012
    Last edited: Dec 11, 2012
  9. fatcaaat

    fatcaaat Well-Known Member

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    I'm not sure if I've ever chimed in on the topic relating to building the 110, but I may as well. I've built nearly every combination of parts, brands, etc from 106-110cc. I've done complete Honda trailbikes kits, dratv stroker crank, high compression piston, stock head with cam, race head, kitaco crank, flat piston, 49.5mm stroke and 54mm top for 115cc...xr70 head, chinese e22 head, etc etc etc...blah blah blah.

    The best, and most impressive motor out of all of them was configured as follows. This particular motor outclassed a lifan 140 all over the place, and was a pleasure to ride in all bands of the RPM.

    Base: Honda CL70 motor with 4-down transmission (avoid the 1dn 3up xl and sl transmissions at all costs IMO)
    Crank: DRATV 52mm crank...it was a 6v version but doesn't matter
    Head: E22 race head from greece. This head had the same combustion chamber as the stock ct70 and same valves, but used a cam with bearings...basically the same thing as the dratv ultra head but using the chinese style camshaft. Head was ported.
    Intake manifold: Honda ATC125m. This is a bolt on intake and was port matched to the head and deburred throughout.
    Carb: Mikuni VM20 carb and kn filter pod
    The electronics were stock ct70 with advance flywheel and points.
    Piston 52mm dratv high dome piston. Cylinder was a steel 85cc that I bored to 88cc but marked 72cc
    Clutch was stock pack but using 3 plates from trailbikes and dratv hd springs
    HV oil pump from takegawa.
    I also ran an oil cooler on it at the time, it was a home made style I created from a temp-a-cure transmission cooler.

    For some reason, this motor was just absolutely incredible. It was perfectly dialed in. It would run 55 all day except up the most steepest hills in 4th gear. Topped out around 65mph

    To this day, I have not replicated the performance of this motor for its size. Not with CDIs, larger carbs, more agressive cams, or better quality materials.
     
  10. Gary

    Gary Well-Known Member

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    I'm curious on why you like the 4 down pattern? Easier to find neutral?
     
  11. fatcaaat

    fatcaaat Well-Known Member

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    Because I've grenaded 3 6v 4-spd trannies with 1dn and 3up patterns on 106-114cc configurations.
     
  12. kirrbby

    kirrbby Well-Known Member

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    I may go for the webllc carb, turnout and K&N if for no other reason than to try one out and compare it to the stock setup. I will keep this bike asthetically as stock as possible for the most part, and go with the 88 and K1 front fork setup. I'll paint the stock K0 triple tree for good measure when I do the rest of my painting and then keep it on the shelf. When I step up to the 110, I'll go for the oil cooler, disk brake, big pipe, 12v etc. I like those bikes also, when they are big and obvious and in your face. I forgot to mention the head has been ported. I'm not sure if that will affect the jetting or the choice of carb and intake. Thanks for the advice.
     
  13. kirrbby

    kirrbby Well-Known Member

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    fatcaaat that sounds like a golden nugget of information from a man who knows. Do you still have that motor? Are you considering building it again? .... I should just cut to the chase... I'll give you ONE MILLION DOLLARS for it.
     
    #12 kirrbby, Dec 11, 2012
    Last edited: Dec 11, 2012
  14. OLD CT

    OLD CT Well-Known Member

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    What cam are you going to run?Cam choice is key.For better mid and top end the old 99 dollar dratv ''monster cam'' 6mm lift cam would be best.Versus the mini monster cam he sells which is equal/comparable to the hot honda cam.Too bad he doesn't sell it anymore,you would have to get it overseas.You will be fine with the ported head and the PZ.Hurry up and get started,i want to hear the performance difference between a jetted stock carb and the pz out of the box from the horses mouth.

    Well it's getting late,12:30am,time to hit my other workbench.LOL.
     
    #13 OLD CT, Dec 12, 2012
    Last edited: Dec 12, 2012
  15. fatcaaat

    fatcaaat Well-Known Member

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    I'll build another one just for you for a Million Dollars. Sadly, I no longer have that motor. In my quest for even more power, I have gone the large PRC motors and eventually came to settle on Honda Nice motors. I do plan on building another one though...not exactly the same, but similiar. I have a 1993 CT70 with a stock motor in it. If I do go this route, I'll go dratv 120cc, which is a 54mm top end with the 52mm bottom end, but keep it automatic. For the head, i'm not sure what I'd do, but the carb will stay VM20.
     
  16. racerx

    racerx Administrator
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    If the existing crank isn't in tiptop condition, a 52mm stroker crank may be cheaper than a crank rebuild. Who's going to know that your engine is packing a long arm, unless you tell `em? :3: Going to 54mm bore requires having the cases bored. However, the larger bore further unshrouds the valves, an advantage at high rpm...which translates into peak hp/mph. With the right head & cam choice, 70mph is possible.

    As for the assertion that anything above 50mph is "overkill"...huge can of worms, open to lengthy discussion and individual opinions...it just depends. Death wobble is highly unlikely, unless you're running a worn K0 front end. IMO, the K0 pogo sticks are unsuitable for anything much beyond stock speeds, unless you ride on the worlds smoothest pavement. With a properly setup K1-later front end and some good aftermarket rear shocks, a CT can cruise along drama-free at 50mph over reasonably decent pavement. The real rough stuff can bottom-out the front suspension a little too easily, at speed. Stock brakes become progressively ineffective as you go beyond 50mph. Rider judgment, in the form of avoiding potholes and knowing to compression-brake down to the low-50s, before grabbing a handful of front brake, can be sufficient for most riding situations as well as the occasional banzai blast into the low 60s.
     
  17. kirrbby

    kirrbby Well-Known Member

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    The stroker crank alone would be a easy upgrade for a couple hundred bucks. But I was under the impression that it would also necessitate the oil cooler, free flow exhaust, billet clutch. These would definitely add to the time and money budget and blow my nearly stock K0 cover. Can I get away without the cooler and exhaust without cookin the works? If I am really nice and easy with the break in maybe? If the possibility exists it would be good to know at the very least.
     
  18. OLD CT

    OLD CT Well-Known Member

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    Nooooo, you cannot get around the oil cooler or the exhaust,''especially'' at break in.Which is another long disscusion of going about that.Some here may differ but a 110 needs to breath and a stock pipe will not allow that.And if you do that you will have to fiddle with jetting all over again.I am certain that running a stock pipe would add fuel to the fire to the already hot running engine while breaking in.You will be dissappointed with the performance in a big way running a stock exhaust.Go with fatcaaats carb choice recomedation for a 110 not a PZ19 that is for a 88.A TB billet clutch is a must for a 124cc but would be a damn good investment for a 110 for true piece of mind @ 11000 rpm.No one is going to judge you when you park your bike,if you have a cooler or loud exhaust.I'm speaking from experience not a manual of how to's.
     
    #17 OLD CT, Dec 12, 2012
    Last edited: Dec 12, 2012
  19. kirrbby

    kirrbby Well-Known Member

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    I thought that was the case. The oil cooler and or exhaust are the breaking point for me as far as this particular build. I'm really not concerned about those who would judge, I only have to please myself. I'm shooting for a bulletproof all purpose stocker...ish K0. I am fired up to get started on the motor but I have to tell you old ct, the weather here in Michigan will prevent a lot of true comparison on the carbs and such until spring. Time is definitely on my side. I'm the kind of guy who, if possible, likes to have a project very well thought out before I even draw the plans. I am definitely getting there.I have spent some years now gaining confidence and experience with these engines and it's important to me that I do my best. I'll definitely be asking for you're expertise. My project is not that tough but I hope to learn a lot towards the next. The 110. I may even get to that one in time for spring.
     
  20. racerx

    racerx Administrator
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    You're taking what began as a 49cc motor out to 110cc+. It's amazing that there's enough fin area to handle 88c, in the first place. Beyond that level, consider an oil cooler & dipstick thermometer mandatory. If you decide to go along the lines of fatcaaat's build, then 11,000rpm should be easy enough...making the billet clutch cheap insurance. You did say you wanted reliability. An all-new TB clutch, billet basket, oil cooler kit & dipstick thermometer total ~$350, not dirt cheap but about as inexpensive as reliable pieces get.

    If you retain the stock 6v head and use a relatively mild cam, like the SL/"fast road" profile, the motor may be incapable of 11K, thus eliminating the need for a billet clutch basket. That'll cost you some peak hp and top end, but torque will be relatively unaffected. Without a doubt, the stock muffler becomes a restriction beyond about 7hp/50mph.

    This would be easier to address if your goals were clear. If "...the oil cooler and exhaust are the breaking point...", then you've pretty well limited this project to 88cc. However, you've not mentioned an mph target (sustained & top speed) or budget number(s).
     
  21. kirrbby

    kirrbby Well-Known Member

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    For this bike 88cc and keep the stock look. 50 MPH sounds really fast to me and I'm sure to be happy with that for now. I would however like to get to 50 very quickly. I'll spend the necessary cash to make sure I can be proud of the finished product, and I'm all ears. The cam that came with my bore kit is tb's 189 I am told. He also told me that with this cam I would lose a few mph on the top end but keep good performance on the low end. Do you guys also like that cam? I need to put together my order list and get some parts on the way. I'll pull the motor apart this weekend and start cleaning it up.
     

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