89ci S&S Sporty engine into 1990 frame

[arizona]

Hello all,

Recently purchased a 1990 four speed Evo Sporty for the sole purpose of replacing its stock 883 engine with a complete 89ci S&S Hot setup kit .Which also includes the S&S Super Stock cases. On paper this S&S engine in .465" taller than stock. The 1990 bike in mind has .650"clearence !!!!!!!!(most bikes are lucky to have .250” clearance ) at the tightest location (aft rocker box/frame tube).Removed 883 stock engine and tried to install the S&S to no avail. Looks as if we need to remove at least .250" off of the top frame rail directly above the aft rocker box .What went wrong?? Is the 4 speed evo frame different than the 5 speed? Is the kickstand area different?? S&S claims their slightly taller engines should fit 1986-2003 Sporty frames.
Thanks in advance, BC

[Dakin Engineering]

5 speed engines have the alternator up front right where the 4 speed kickstand mount is. I saw a Zipper's 100" in a modified frame. He shaved the underside of the backbone and welded in a flat plate above the rear head.

Sam

[arizona]

Good point...noticed a bit of scratching on the underside of clutch cover where the kickstand area is as we manhandled the engine onto the 1990 frame.I would do the same with the welding option on the backbone but first want to ensure engine will drop fit into frame.So far its a no-go.

[A 4 liter V8 eater]

Originally Posted by arizona

Hello all,

Recently purchased a 1990 four speed Evo Sporty for the sole purpose of replacing its stock 883 engine with a complete 89ci S&S Hot setup kit .Which also includes the S&S Super Stock cases. On paper this S&S engine in .465" taller than stock. The 1990 bike in mind has .650"clearence !!!!!!!!(most bikes are lucky to have .250” clearance ) at the tightest location (aft rocker box/frame tube).Removed 883 stock engine and tried to install the S&S to no avail. Looks as if we need to remove at least .250" off of the top frame rail directly above the aft rocker box .What went wrong?? Is the 4 speed evo frame different than the 5 speed? Is the kickstand area different?? S&S claims their slightly taller engines should fit 1986-2003 Sporty frames.
Thanks in advance, BC

Please keep us updated on the build

[arizona]

...before I start looking for a 1991 and newer solid mount 5 speed Sporty, you can bet I will do all that could be done to stuff that 89" into that 1990 4 speed frame.

[norseXL]

It´s a pretty tight fit at the rear cylinder on the four-speeds so you may have to heat that area of the frame and get the big hammer out to fit aything higher.
Just my opinion though.

[arizona]

If thats all thats needed than I can comply...I have been also told a heavy duty hydro jack can come in handy with the heat to just tweek the frame tubbing.Eventually,think I just might remove the aft rocker box top cover and try and fit S&S motor just to see how all else falls in place.

[norseXL]

Be shure, what ever you do, measure twice before starting banging to se if flattening will give you anough space.

Thankfully though, HD did not use any fancy steel alloy in those frames ( and the scale will tell) so some heat and force should not do any harm.

By heating just the area you are flattening, the rest of the frame should be OK.

[arizona]

I have a good pulse on where the frame needs to be shaved and yes, will measure 30 times before and metal work begins...some folks even shave off some metal from the aft rocker box cover.BTW,here is Spain, a used Sporty (any year) costs at least 5k USD and I got a "deal" on this '90 for 3k Euros ($4k)

[rontech]

89ci S&S Hot setup kit .Which also includes the S&S Super Stock cases.

Is this an S&S sportster engine or a big twin EVO style? I didn't know S&S made a sporty engine. Should be interesting.