Fitting a stroker
Fitting a stroker
Teach me something guys. I'm already having dreams of someday building a 93" motor (after a transmission rebuild). Right now my 80" BARELY fits. Less than 1/4 inch clearance between rear rocker box and frame. What would i need to do if i ever got my hands on a stroker that is 1/4" taller?
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From: Cental, MI
Teach me something guys. I'm already having dreams of someday building a 93" motor (after a transmission rebuild). Right now my 80" BARELY fits. Less than 1/4 inch clearance between rear rocker box and frame. What would i need to do if i ever got my hands on a stroker that is 1/4" taller?
Or... I do Not spend that kind of $$$ on Shovelheads anymore... Hell an Evo BT is about $1000 around here... leaves plenty of "meat" for Much less expensive upgrades...
If it is Only Speed, that you Need...Get a 1200 Evo Sporty... or get used to seeing their Taillites!!!!
It did occur to me that if you are intent on a Big Inch Shovelhead... the 4 speed EVO frame [1985 and 1986] will fill the Bill for Fitment, and once assembled... still a 4-speed...
Last edited by Racepres; Apr 24, 2020 at 10:18 AM.
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From: la la land jerzey
twisted on the site has driven both the big bore 3 5/8 bore - and then again with 4 1/2 stroke for 10s upon 10s of thousands of miles from one end of the USA to the other and back many times
the problem is the cost - the companys today get $250 for the pistons alone then the jugs then the block needs to be bored and the heads need to be bored and NO going back
I don't believe - or I should say I don't remember - but 93 can happen ( actuall 92,886 ) in a stock frame as S&S sells wrist pin re located pistons < I believe they are still available
the problem is the cost - the companys today get $250 for the pistons alone then the jugs then the block needs to be bored and the heads need to be bored and NO going back
I don't believe - or I should say I don't remember - but 93 can happen ( actuall 92,886 ) in a stock frame as S&S sells wrist pin re located pistons < I believe they are still available
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From: Niles Canyon Ca.
My current 93" is 4-1/2" stroke X 3-5/8" bore @ 11.7-1 compression which I seriously need to drop to 10-1 or lower, sit's in my stock frame comfortably. You can still get long stroke flywheels from a couple places like Truett & Osborn and S&S still but 4-3/4" stroke wheels in a stock bore will only give you 88" and you still end up modifying a few things like the cases and the cylinders oil ports to make them work. Pistons will be a special order kinda deal so good luck with that. Didn't think anyone's still selling stroker kits for shovels anymore.Stroker plates no clue where you'd find them anymore, been a while since I've seen or heard of those too. Last ones I used I made.
Years back when long stroke bikes were the rage it was common to either heat and flatten the frame & downtube for clearance or cut a chunk out and weld flat bar in, done both with no issues. As John says with going bigger bore you do have to open the cases & heads but I have put stock jugs back on opened cases before just don't use the old garlock gaskets, MLS only.
I will add this my last 88" shovel with stock 4-1/4" flywheels X 3-5/8" bore @ 8.5-1 comp and balanced was the most reliable comfortable engine and a torque monster. Wasn't a street light racer but put a load pack on and 2 up for a trip it would out pull any hot rod evo on the hill's. Got over a 100K out of that build before I spun the output shaft in the flywheel doing the burn out from hell after a 3 day weekend of too much fun. Funny part was rode the bike 150 mi home. Went to start it the next day and found that spunt shaft.
Years back when long stroke bikes were the rage it was common to either heat and flatten the frame & downtube for clearance or cut a chunk out and weld flat bar in, done both with no issues. As John says with going bigger bore you do have to open the cases & heads but I have put stock jugs back on opened cases before just don't use the old garlock gaskets, MLS only.
I will add this my last 88" shovel with stock 4-1/4" flywheels X 3-5/8" bore @ 8.5-1 comp and balanced was the most reliable comfortable engine and a torque monster. Wasn't a street light racer but put a load pack on and 2 up for a trip it would out pull any hot rod evo on the hill's. Got over a 100K out of that build before I spun the output shaft in the flywheel doing the burn out from hell after a 3 day weekend of too much fun. Funny part was rode the bike 150 mi home. Went to start it the next day and found that spunt shaft.
Last edited by TwiZted Biker; Apr 24, 2020 at 09:29 PM.
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From: StLouis
Thanks so much for this question SparkyD. My 83 FLHT frame will support a stroker from what I have been told, about 2 inches of clearance above and in front of the rocker boxes. I have a base gasket leak on the front cylinder and plan on riding it like is and a tear down next fall winter. I thought of tricking it out with something like a stroker it, but the responses you have gotten so far have convinced me to leave it a 80 ci, another words stock. Everything is original and I don’t want to ruin it. Keep the knowledge and information flowing, there are guys here that have forgotten more about Shovelheads than I will ever know.
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From: la la land jerzey
just know this about an oil base gasket leak - when the pair of pistons are going in a down ward motion pressure has built up in the lower unit - this happens when the breather valve is not in the open space ( timing location ) - then when the pistons are moving upwards suction develops - this suction reverses the oil being pushed out and instead is sucking oil back in With the outside dirt and debris
this over time will wreck the lower unit and score the breather valve cavity - you should re think your repair logic
this over time will wreck the lower unit and score the breather valve cavity - you should re think your repair logic
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From: Niles Canyon Ca.
Took that into account, I pulled an evo stunt, used a large high temp o-ring out of a hydraulic cylinder, miced out .010" oversize, sealed it between the spigot skirt and the cases nicely but too tight to sucked down in. Was still intact with no sign of leakage 3 years later when it got a proper R&R.
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Tourer
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From: Hudson Valley
Ross Pistons are readily available for stock height 96” shovels that make decent power and are reliable
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Seasoned HDF Member
Joined: Jul 2014
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From: Cental, MI
Thanks so much for this question SparkyD. My 83 FLHT frame will support a stroker from what I have been told, about 2 inches of clearance above and in front of the rocker boxes. I have a base gasket leak on the front cylinder and plan on riding it like is and a tear down next fall winter. I thought of tricking it out with something like a stroker it, but the responses you have gotten so far have convinced me to leave it a 80 ci, another words stock. Everything is original and I don’t want to ruin it. Keep the knowledge and information flowing, there are guys here that have forgotten more about Shovelheads than I will ever know.
Think what it Cost to Rebuild a Shovel... then what the dollar figure is on a Pretty Potent EVO....
Note that I much prefer a Shovelhead in the Chassis they came in... but... Circumstances sometimes Dictate Actions... Plus, I learned a little Something!!!
One last Edit; Having Owned an '83 FLHT, I can say if that Motor was the one that went South... It should be a Match made in Heaven with an Evo!!! But it just took a Lickin, and Kept on Tickin!!!
Last edited by Racepres; Apr 25, 2020 at 08:06 AM.
This post is more about wanting to learn. My idea was to start building a stroker based on either S&S or Ultima cases while I'm riding it the way it is. My stock cases have VIN# that matches the frame so i don't want to mess with the original cases. Funny you guys mention EVO, I've recently been starting to look at the EVO as my next bike. Maybe I'll build one while riding the shovel.
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