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Low compression stroker pistons

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  • Low compression stroker pistons

    I bought an '81 Low Rider a few years back and have a lot of problems with fuel. According to the engine build sheet it's an 89'' stroker with 10.5:1 pistons with an S&S 514 cam it has 2'' intake valves with solid lifters and is running on points and a CV carb. It's kick only. I recently rode from Alberta to BC and as soon as I filled up in BC I had a hell of a time kicking the engine to life due to the poor fuel even with octane boost. Does anyone know of a reasonably priced low compression cast piston maybe 7.5 or 8:1 that I could use so this engine would run on regular 87 or 89 octane fuel. I believe part of the issue is cam shaft overlap so the cam has to go as well.

  • #2
    An 89" Shovel is a 4 5/8" stroke engine with 80" barrels. IIRC, the S&S 514 is the same as an Andrews #3, which is a low compression stroker cam. Contact S&S to see what is still available for the 4 5/8" stroke. My brother has an 88" Shovel with this cam and low compression, and it a nice torque motor.
    VPH-D

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    • #3
      Thanks again VPH-D yes I looked at this 514 cam and it is for LC engines and I'm 10.5:1. I was thinking to save some loot I'd put in stroker plates to lower the CR I'd like around 8:1 as long as the engine will still fit in the frame but there is still the problem of the overlap and the kicker. I have a #1 in a stock 80'' engine I'm assembling and thought of the # 2 or # 3 Andrews. IIRC?
      Pete:::::::;;;;;;;;;

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      • #4
        My brother doesn't have any problem kick starting his 88 motor, but usually hits the button. If it were me, I'd replace the cam with something small...
        VPH-D

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        • #5
          I had a '79 Low Rider 4 5/8" stroke with an Andrews B grind , if I remember correctly it's been a while, and 7.5:1 pistons and it ran and kick started fine on any gas in the U.S. I rode it all over the country. I loved that bike and should have kept it. But it did have alot of torque, if you beat that bike hard you had to fix stuff. I got the pistons from S&S, I don't know if they still have them.

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          • #6
            Thanks Flathead and VPH-D. Our fuel here in Alberta is pretty good it starts and runs fine on 91 with some octane boost but as soon as I fuel up in British Columbia it's nearly impossible to start and it's kick only with a 3'' open belt drive, I love to ride in BC with my tent and sleeping bag so I have to do something. I'll get a hold of S&S and use your guys's advice.
            Thanks again
            Pete:::::::::::::;;;;;;;;;;

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            • #7
              Howdy Pete,The combination I had on my '79 worked great for me but remember that was before we had to burn alcohol based fuel, you can probably compensate for that with your carb jetting. When I first built mine I was running a 3" open belt too but I had to switch to a closed primary and a chain due to my frame flexing, that also made it possible to run an electric starter. If I was to build that bike today I'd run the closed primary with a belt,it was hard on chains, that's just me. Good luck and let us know how things work out.

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              • #8
                Where was your frame flexing? I love my open belt, I've been running them since the mid '80's they're kind of like a shovelhead you don't see them very often anymore. I am installing a stock engine I've assembled 8:1 compression, Andrews # 1 cam, points igition and a CV carb. This should be a dream to start on the kicker compared to that stroker. I'll find some pistons and change the cam and put the original engine back in the bike this winter and have a low compression mild cam stroker next summer.
                Thanks again
                Pete:::::::::::;;;;;;;;;;;;

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                • #9
                  When riding with freinds if I rode it hard my riding buddies would pull me over to tell me they could see my trans moving when got on it real hard. I checked it out several times for a loose trans, or trans plate, frame cracks or broken welds nothing, so I went back to a closed primary. I'd run the 3" set up on the bike for several years before I stroked the motor with no issues. Remember that motor had alot of torque. That set up was recomended for a full dresser with a sidecar or pulling a trailer, I had it on a light weight Low Rider. No problem starting though. I had a freind of a freind who had the same set up and nitrous on his Evo dresser with a sidecar and trailer and he ended up breaking the end off of his cam.

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                  • #10
                    S&S 514 is a higher lift/ short duration solid lifter style cam sold with 84" kit. I ran one and liked it a lot but since then I've made the jump to Velvas and Evo cam but that is another story. The fact that you are able to kick start suspects cylinder pressure is not too high and the "10.5 to 1 CR" is a ballpark reference. Couple variables are head gasket thickness and whether head surface has been faced off. Strokers like timing pulled back a couple degrees and are supposed to run just fine on premium pump gas. Good luck.

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                    • #11
                      Thanks
                      Our fuel up here is good in Alberta but BC fuel is so expensive that no one can afford premium and it has likely lost its fire power sitting in the tanks. The gas in BC is about 6 bucks a gallon for regular.

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