Online: Hilly

80" Evo upgrade

1/2
  • contractor
    contractor
    11 years ago

    merry xmas everyone.

    been emailing T-Man Performance regarding there street performer upgrade.

    he told me that because iv done 38000ks is would be better to go with the S&S 88" motor with 4 5/8 stroke on my stock bores.

    what do you think guys?

    B

  • jacko88
    jacko88
    11 years ago
    I did my Evo myself, split the cases, replaced all the bearings, put 10thou oversize high comp pistons, EV 46 cam, ceramic coated the combstion chamber ,valves piston skirts etc,black diamond valves, black teflon coated the motor and tranny, high KW starter etc etc etc for around 5k which incleded a scorpion clutch and 5 speed kicker kit plus new regulator and starter solonoid. The only oversight was compression release as the compression was too high to kick. The motor went great and had no trouble keeping up with twinkies. I did the numbers and at the time for all that I did it would have cost me that for just the S&S motor alone however if you cant take such a project on the new motor option will be cheaper cos labour will kill you on the road I took good luck anyway
  • contractor
    contractor
    11 years ago

    gday jacko,
    im no sloach in the engine department, i have built some nice v8s and rebuilt the odd old dirtbike.

    i havent touched a harley though and to be honest the whole process frightens me a little, altough if done during winter i could take my time.

     

    I did see he menchions 4 5/8 88" stroke? how des this suit my standard bore 80"??

  • Krash Kinkade
    Krash Kinkade
    11 years ago

    Well up to you m8, but I would keep stroke stock as strikers have a high piston speed & the stock evo barrel liner don't have that much meat . Also strokers vibrate a lot more. Piston skirt shorter so rock n roll. I ' seen some very quick 80 inch evoz but your bike so your call. Good luck

     

  • contractor
    contractor
    11 years ago
    so what do you suggest krash? obviously no stroker? bigger piston, cam, head work, 5k sounds like alot of money, although i am comparing what i could do with say a 308 and 5k.
  • daddyracer56
    daddyracer56
    11 years ago

     @ 38,000 klms  the bottom end sould be still good unless you were slack on the oli change's + flogging her arse off,   i change the oil in the tank  tank every 2.500 & the filter every 4-5000 , just don't let the oil go black,   it depends what year EVO 80 you have 1988 to 1992/3 have the weaker cases & could be a bit of a gamble on the fast  hi comp list they can crack behind the front lifter block + the main case race can come loose in the case's ,       1994 & up you would be O.K., if worried about crank do a run-out check on the pinion shaft + feel the big end  with the top end + the alt rotor off & see what she feels like 

  • tussuck
    tussuck
    11 years ago
    Throw a turbo on the thing! 110HP at the back wheel for a 1/4 the cost of the big bore kits, plus you run 8.5:1 compression for 95% of the time!
  • contractor
    contractor
    11 years ago
    yer badcooky mines an 88 softy.
    i guess the biggest problem is are the kms legitimate? hard to say.
  • tussuck
    tussuck
    11 years ago
    Pull one of the heads and have a look into the cylinder. If the hone marks are still quite clear then it's a genuine mileage. I pulled my jugs at 50k and could still see a faint hone marking....lol
  • contractor
    contractor
    11 years ago
    ok il do that on the weekend.
  • contractor
    contractor
    11 years ago
    good post bangkok bob, i also thought about those mods.
  • tussuck
    tussuck
    11 years ago

    +1 there. I would do some mild hop-ups to the current engine before dumping a chitload of cash on a larger engine. Being an EVO there are some tried and true setups that will give you some great performance. Such as:

    • EV27 or EV3 cam
    • Single Fire ignition
    • Carb upgrade to an S&S Super E or mikuni HSR42 (although I feel the HSR42 is too big for an Evo)
    • Free flowing pipes - take your pick here! Just STAY AWAY from shotguns - they sound the best but suck performance wise unless your running WOT all the time
    • Adjustable pushrods will help as well - at least you do not need to pull half the engine apart to replace things

    If your super keen you can shave 50thou from the heads (or use thinner head and base gaskets) to give the compression a nice bump upwards

    Cheers

  • Dave81
    Dave81
    11 years ago

    Cheers for all this advice as well fellas, looking at going down this path in the new year.

  • Burnzi
    Burnzi
    11 years ago
    Reading this with interest, how old is too old to do all of this on an 80 cube (pipes, ignition, coil, cam, original carb rejet and thunderslide) My leckyglide has 80,000 on it.
  • tussuck
    tussuck
    11 years ago
    Never too old...I have been running the above setup on my 86 FXR since about 1990! I now have a turbo on the machine as well and it goes!
  • jacko88
    jacko88
    11 years ago
    Mikuni's are fine on an Evo Tussuck you just need to go down a size on the pilot jet, accelerator pump nozzle and change out the jet needle cos they are set up way too rich at stock. Once you do these mods they are a great trouble free carb I swapped over about 8 years ago and not one issue in reliabilty or performance etc.
    Another bit of advice I followed was dont go over 10:1 compression if you want streetability and a trouble free build there is a school of though that going over this in a daily rider wont give 200k of engine life etc
  • contractor
    contractor
    11 years ago
    excellent read fellas, thanks alot for your advice, now im thinking about the cam and carb/exhaust, so more fuel and better breathing.
  • tussuck
    tussuck
    11 years ago
    Have run with the genuine Harley oil in the primary and engine for the past 10 years as its not too bad. Over the years I have run many different types of oil (even tranny fluid in the primary at one stage) but the harley stuff is not badly priced and works well in my motor.

    I checked my oil the other week and it was as black as heck! So I figured that now that I'm running the turbo the good old harley dinosaur oil is probably getting a bit stressed. So I went and bought a 6 pack of Mobile 1 V-Twin fully synth to see if it holds up to the heat a bit better. On my first ride today so it's too early to tell if its better or not. I am comfortable that its going to work well as the write ups on synth oils is good... It may be that I see no physical difference in things but I know that it's going to hold up well over the upcoming summer.
  • tussuck
    tussuck
    11 years ago
    What's your current setup on the bike? That will drive the next steps more than anything else. Generally it's pipes, carb and then cam in that order if your doing the job over a length of time. If you have the money then do all three at once and the bike will really sing!
  • contractor
    contractor
    11 years ago

    i do have an aftermarket set of pipes although im not sure what they are, other than that im looking at a carby at present and air intake.  im going to run the mobil oil as well, my girl got fairly hot on the weekend plus im 130kgs so it works hard <img src=" border="0" src="/DesktopModules/NTForums/themes/_default/emoticons/smile.gif" />  have a look at my pics and you will see the bike.

1/2