Building a 100 inch Sporty.

delcrossv · #1 08-06-2023, 10:44 PM

Oldest son expressed a desire to build a high output engine for his late model ('08) XLH. I used to do some sporty builds back in the 80's (mostly with shovelheads on sportster cases) so I thought, what the heck, let's give it a go.

Man, times have changed- S&S doesn't do stroker flywheels for sportsters anymore, and unless you have a 50 ton press, the cranks aren't serviceable anyway.

So Plan B- got a set for S&S "special application" cases with some shot 4" cylinders and some nice STD stage 3 , dual carb drag heads.

All cleaned up. Long studs will go as we're going with ductile cylinders.

All set for 4" bore.

Did a mockup with the old cylinders for grins.

We decided on magneto ignition so found a old school XLCH timing cover. The points drive is the same as a magneto drive. Going to trim off all the extra material outside the cam box. The cases will need some welding for the additional screws and the generator idler gear bushing.

Cylinders and pistons on order. More to come.

Fishinfool · #2 08-06-2023, 11:06 PM

Looking good. I am sure that Sporty will get up and go.

I bought a 883 Sportster back in 1991, I think, when they were $3995.00. The throttle seemed more like a sound rheostat - It got louder, but did not go much faster. That was OK, as I didn't plan on leaving it stock.

1200 jugs and pistons, higher compression, along with an S&S carb, some tuning and loud pipes. What a difference. Quicker than my buddies on their stock 80 inch big twins.

Larry

delcrossv · #3 08-06-2023, 11:30 PM

Heads:
As these were drag heads, there is no provision for oiling. The rockers were greased before each run. I do have a good spot to tap for an external drain and will have to go old school with external feeds to the rockerboxes too.

Intake is 2.09, exhaust is 1.75. The groove for the fire ring is 4.25 OD.

Triple valve springs.

I've been talking to Jesel about a lightweight valvetrain so I can reduce the spring pressure. Shooting for 8000 rpm redline, with an 8500 rpm overrev. Probably going to go with titanium valves and retainers to reduce sprung weight.

ladder13 · #4 08-07-2023, 08:23 AM

……following…….

Engineer1911 · #5 08-07-2023, 08:32 AM

Frightening what an Old Man with tools and knowledge can do to Milwaukee's finest. Squeeze firmly, twist, and hang-on!

Autonomous · #6 08-07-2023, 02:43 PM

That is gonna raise hell! I'm especially intrigued with the twin carb setup.

My first HD was a 1980 XLH with minimal engine mods.
The only one I did heads, bore, cams, etc. on was a Twin Cam Ultra.

1sailor · #7 08-07-2023, 02:58 PM

I've been riding Harleys for just a tad over 50 years now. I was never a big fan of the sporty's but I did once own a K model. It was the flathead forerunner of the Sportster. They have come a long way since they first came out. Motors getting bigger and also the introduction of rubber mounted engines. I'd be willing to bet they can be made to scream with the right mods. Your project looks to be quite a bit more complex than your average "build".

delcrossv · #8 08-07-2023, 04:50 PM

Update: The stock 1.25" crankpin has a tendency to flex under high load making the flywheels spread.
Stock pin:

This leads to broken pinion shafts. HD's solution on the XR engines was to go with a 1.5" pin like this:

So far so good, but the XR pin is not presently available and took a narrow 1.35" rod set. Carrillo can't make these as the narrow female rod races tend to separate from the rod ends

Badness.

So I was able to find this pin from S&S (new old stock)that's Sportster length, takes a full width 1.49" rod set and is 1.500 in diameter. Drive side is welded, timing side is tapered. Nice and stiff.

Seeing how Carrillo is making the rods to order anyway, the only additional pieces I need to have custom made are the roller cages.

Yay!

Autonomous · #9 08-07-2023, 05:07 PM

This is giving me the strangest *****.

Keep it coming!

1sailor · #10 08-07-2023, 05:24 PM

I'm going to guess here that you have a lot of equipment that is not commonly found in most garages. I've never known anyone who made their own bearing cages. I'm impressed.

delcrossv · #11 08-07-2023, 05:37 PM

Quote:

Originally Posted by 1sailor

I'm going to guess here that you have a lot of equipment that is not commonly found in most garages. I've never known anyone who made their own bearing cages. I'm impressed.

Oh, not me. That'd be a CNC job. I should have said "have made".

Making one by hand would be a whole 'nother level of tedium.

Fixed. Thank you.

Should be cost effective as it's a Carrillo nitro rod cage, just narrowed to sportster width.

1sailor · #12 08-07-2023, 06:01 PM

You know, in all the years I've been riding and hanging out with other bikers, I have never heard one ever say "cost effective" before. I didn't even know those two words could fit together. At least not when talking about custom builds.

Marshwheeling · #13 08-07-2023, 06:10 PM

Not much of a Harley fan here, but this one holds a strong fascination. Calls to mind Steve Hamel’s Vincent work.

delcrossv · #14 08-07-2023, 06:18 PM

Quote:

Originally Posted by 1sailor

You know, in all the years I've been riding and hanging out with other bikers, I have never heard one ever say "cost effective" before. I didn't even know those two words could fit together. At least not when talking about custom builds.

LOL. Must be the engineer leaking through. 🤣

S&W Fan · #15 08-07-2023, 10:45 PM

Very cool. The last Sporty I had was a 2006 XL1200R, the last of the carbed versions. I did suspension upgrades on it and had it "breathed" on by a now closed shop fairly close to me. Loved smoking the baggers (even though I eventually went back to one haha) that would look down on our "girls bikes". It dyno'd at 94hp with 97 ft lbs of torque at the rear wheel.

Sold it when I came across a really killer deal on a '14 Fat Bob.

With the original a/c cover on it

I called it Mr. Bob lol, 121ci

1sailor · #16 08-08-2023, 02:50 PM

Well since we're talking bikes and posting some pics I'm posting a pic of mine. I first built it in 1992 starting with a 1982 FLH frame that was cut and stretched to accept a Softail tranny and Evo style motor. Over the last 31 years I have traveled 11 states and crossed the Continental Divide multiple times. Happily, I was able to travel a lot of those miles with my son. I also built his bike. As it currently sits it has a 120 inch motor with a Baker DD6 tranny. When I built it my intention was to build a bike with a "classic look" but not a replica of any particular model. I also adapted an Indian teardrop headlight just to make it a little different.

delcrossv · #17 08-08-2023, 04:18 PM

Quote:

Originally Posted by 1sailor

Well since we're talking bikes and posting some pics I'm posting a pic of mine. I first built it in 1992 starting with a 1982 FLH frame that was cut and stretched to accept a Softail tranny and Evo style motor. Over the last 31 years I have traveled 11 states and crossed the Continental Divide multiple times. Happily, I was able to travel a lot of those miles with my son. I also built his bike. As it currently sits it has a 120 inch motor with a Baker DD6 tranny. When I built it my intention was to build a bike with a "classic look" but not a replica of any particular model. I also adapted an Indian teardrop headlight just to make it a little different.

That's a looker for sure. 👍

1sailor · #18 08-08-2023, 04:29 PM

Thank you.

delcrossv · #19 08-08-2023, 04:32 PM

Rods ordered from Carrillo (after many false starts)

**Plus changes: Center to Center length 7.440"
Sportster XR750 : ***Plus changes
***Center to center : 7.440"
***Pin End Width : 1.081" (.050" clearance per side)
Pin Diameter: .791"
Female Big End Width : 1.490".
Male Big End Width: .560"
Big End Bore : 1.877" semi finished

The longer rods give a 1.86 rod to stroke ratio which is pretty much in the sweet spot at close to 2 to 1.

So a longer XR 750 rod with an H beam, instead of an I beam, with a wider big end and standard XL diameter rollers. 21 instead of 16 like a normal XL.
All about compromises. Glad that's done!

Mike0251 · #20 08-08-2023, 04:44 PM

Looking good so far! I had a 1957 sportster for 25 years. All stock except for my engine. 4 5/8 stroke, .020 over, S&S L series carb, Andrews close ratio gears, Andrews cam, ported polished heads w/stainless valves and bronze guides, Trock billet trap door (a must!), and Barnett slipper clutch. I also obtained another cam gear cover, removed the 4 bronze bushings for the cams and replaced with Torrington needle bearings (exact same as whats in the case half and they fit the bores perfectly too). Machined off the bushing part and kept the head for spacers and then shimmed accordingly. When I would take it to the 1/8 mile drags I added wheelie bars, racing slick, and an air shifter. Best time was 7.02 @ 98mph.

I tried a belt drive for awhile until a holeshot ripped every tooth off the belt LOL. Went back to chain. I also used to rebuild many older engines for several years, FH, PH, SH. I assume you still have to true your flywheels? Had a truing stand and was very good at it. It's an art.

Best of luck, keep us posted!

1sailor · #21 08-08-2023, 05:06 PM

So, was 1957 the first year of the actual Sportster. As I recall my KLH (flathead K model) was also a '57 so your sporty must have been one of the first of the overhead valve models.

delcrossv · #22 08-08-2023, 05:28 PM

Quote:

Originally Posted by Mike0251

Looking good so far! I had a 1957 sportster for 25 years. All stock except for my engine. 4 5/8 stroke, .020 over, S&S L series carb, Andrews close ratio gears, Andrews cam, ported polished heads w/stainless valves and bronze guides, Trock billet trap door (a must!), and Barnett slipper clutch. I also obtained another cam gear cover, removed the 4 bronze bushings for the cams and replaced with Torrington needle bearings (exact same as whats in the case half and they fit the bores perfectly too). Machined off the bushing part and kept the head for spacers and then shimmed accordingly. When I would take it to the 1/8 mile drags I added wheelie bars, racing slick, and an air shifter. Best time was 7.02 @ 98mph.

I've gone round and round between rollers in the cam cover or bushings, On this I think I'll start with the bushes and see how they wear.

I used to get cylinders from Ron Trock, he's pretty near me. His son, Ron Jr. is supposed to get the business going again, but not yet. Went with Axtell for the cylinders. Don at Axtell is a great guy. The cases came with an S&S trap door so I'm good there.

Quote:

I tried a belt drive for awhile until a holeshot ripped every tooth off the belt LOL. Went back to chain. I also used to rebuild many older engines for several years, FH, PH, SH. I assume you still have to true your flywheels? Had a truing stand and was very good at it. It's an art.

Best of luck, keep us posted!

Yeah, not too keen on belt primaries. The dragbike guys blow them up regularly. Sticking with chain.

The wheels will need to be "trued" twice as the pin is welded on one side. So, verify the is pin normal to the wheel and parallel to the sprocket shaft then weld, then put the other wheel on the taper and true the assembly like usual.

Little weird, but 🤷‍♂️

BKLooney · #23 08-08-2023, 05:54 PM

I love bike builds, haven't done one in years. Can't wait to hear how stout that Sporty is when you're done!

The last bike I built was in 1999, didn't build the engine as I just went with a stock 1340. 4 speed, kick only, 4 over wide glide, Paughco rigid, etc...lots of good stuff. I rode that bike for about 3 years, a guy with a lot of money wanted to own it more that I did!

Building a 100 inch Sporty.-harley-6-14-01-5-jpg

Mike0251 · #24 08-08-2023, 07:17 PM

Yes, it was an XL overhead valves. SN 57XL1374. I'll dig for pics as this was quite awhile ago lol.

delcrossv · #25 08-09-2023, 04:24 PM

Update:
Closed the loop with Jesel, they'll need a set of valves, locks, retainers and lash caps to do the valvetrain.

Trading calls with Del West for Ti parts. Only the lash caps will be steel, valves, locks and retainers will be Ti.

🤞🤞Should be able to get my seat pressures down below 200lbf!

Going to set up the heads for the new valves and then send them to Jesel for remachining to fit their rocker assy.

Looking at Redshift for cams, but I have to see if they can make a #2 cam that has the drive gear in the end for the magneto. Cam guy at Zippers is out for a few days but did trade emails .

Stay tuned....

1sailor · #26 08-09-2023, 05:17 PM

That's one thing about those Sportsters. They do have a box full of cams in there. Having 4 cams made should be interesting. I used to work next door to a machine shop whose owner was a big Indian fan (the originals). He actually made his own cams which I though was pretty cool. This project of yours is going way beyond what most would consider a custom engine build. Most of the engine builds I've been familiar with are done using available aftermarket parts with some custom fitting. Looking forward to the updates.

delcrossv · #27 08-10-2023, 10:04 AM

Quote:

Originally Posted by 1sailor

That's one thing about those Sportsters. They do have a box full of cams in there. Having 4 cams made should be interesting. I used to work next door to a machine shop whose owner was a big Indian fan (the originals). He actually made his own cams which I though was pretty cool. This project of yours is going way beyond what most would consider a custom engine build. Most of the engine builds I've been familiar with are done using available aftermarket parts with some custom fitting. Looking forward to the updates.

Thing is, a lot of the parts that used to be available from bigger vendors like S&S now just aren't. And, of course, if you want to color outside the lines a little, you've always had to make parts.

The drag bike folks have to do this kind of thing pretty regularly. It's half the fun.

delcrossv · #28 08-10-2023, 08:22 PM

Talked to the Kid and we decided that it's easier to replace valve seats than cam bushings.

This resulted from the following dilemma:

A. Steel valves and seats are more durable, but to control the valves at high RPMs you need a lot of spring pressure- present set up probably is 1000 lbf open pressure. Lots of spring pressure means a lot of wear on the cam bushings, lifters, etc.

B Titanium valves require softer Ni/Al bronze or Cu/Be valve seats, but are 40% lighter. So that 1000 lbf goes to 600 (saving the bushings and lifters) but the seats need replacement more often.

Now going down the rabbit hole to decide between Beryllium-Copper or Nickel-Aluminum bronze seats to match the duty cycle to make things last as long as possible.

Mike0251 · #29 08-12-2023, 07:06 AM

I'm still looking for my sportster pics lol.
But since we are talking 100ci I thought you'd enjoy my current go fast bike. (I left the HD family a couple of decades ago) 2009 Vmax 103ci (1700cc) with quite a few mods and pushing well over 200hp. The fuel tank is under the seat (oem) and this is what lurks under the cowl cover. Wife and I made a sandwich run yesterday.

1sailor · #30 08-12-2023, 02:18 PM

How things have changed. I remember when I bumped my Shovelhead up to 80". It was all any of us could talk about. That was considered a pretty big motor back then.

delcrossv · #31 08-14-2023, 05:03 PM

Quote:

Originally Posted by 1sailor

How things have changed. I remember when I bumped my Shovelhead up to 80". It was all any of us could talk about. That was considered a pretty big motor back then.

Well, you know what they say: "There is no substitute for cubic inches".

delcrossv · #32 08-21-2023, 03:21 PM

Heads going off for machining for new titanium valves, locks and retainers, bronze seats and guides. May have to go with Inconel for the exhausts. They'll be flow tested so we can determine the best cams.

Then they go to Jesel for more machining to accept their rockerboxes.

Got some 4 speed cams for test fitting and some welding/machining needs to be done on the cases as well.

Needs some clearancing. Not as bad as it looks.

Autonomous · #33 08-21-2023, 03:42 PM

As you have pistons on order, I assume you have a target compression ratio in mind. Maybe I missed it, what kind of fuel are you planning on using?

delcrossv · #34 08-21-2023, 03:50 PM

Quote:

Originally Posted by Autonomous

As you have pistons on order, I assume you have a target compression ratio in mind. Maybe I missed it, what kind of fuel are you planning on using?

Trying for about 11:1 static. Dynamic compression of course will be less due to overlap. We'll try to cam it so we can run 91 octane pump gas mostly. 🤞

Bonneville cams will have more advanced intakes so higher dynamic compression then we'll run race gas.

Heads guy will cc the chambers then I'll have hard numbers to share. Mostly I need to fix the cam lift so I can fix the geometry (stem length). I can mess around with duration to get the dynamic compression where it needs to be.

Autonomous · #35 08-21-2023, 08:03 PM

Bonneville cams?
This just got more interesting!

delcrossv · #36 08-21-2023, 09:07 PM

Quote:

Originally Posted by Autonomous

Bonneville cams?
This just got more interesting!

Shhhh. Verwy seecret.

delcrossv · #37 08-26-2023, 11:27 PM

.030 change to width of male rod to match stocked races a Carrillo. Dropping cases off Labor day weekend for machining.

Now a couple months wait.

wood714 · #38 08-27-2023, 12:14 AM

Back in 2000 I had a Sportster and was a member of the Sportster List. There were a lot of us from SW Ohio. Four months before this race we all went on a ride to Hocking Hills together. Dale originally bought that bike for his wife. Sportsters can go fast.

delcrossv · #39 09-12-2023, 12:24 PM

Update:

Dropped the cases and cam cover off with the machinist:

New pad and case bushing for generator idler gear
Cases trimmed to fit idler gear
New bushings installed and line bored for cams, idler and pinion shaft
Oil passages aligned between cover and case
Cover trimmed to just cover cambox
New cam and main bearings and races
Cases machined for thrust bearing on timing side "anti spread"

As the later oil pump doesn't have a timed breather and the earlier cam cover needs one, making a reed valve breather insert to go in the cam cover across from the generator oil slinger. Probably aluminum body with a steel reed. If it still spews, I'll need an external secondary separator.

He's already doing the rotating assembly (flywheels & rods) Saw the flywheel blanks when I was out there.

Next, I need to get the rod rollers to to Carrillo guy so his machinist can make the bearing cages and the intake manifolds to the heads guy for flow testing. Pack them tonight, mail them tomorrow.

delcrossv · #40 09-19-2023, 04:27 PM

Running some numbers.
Finally CC'd the heads and got dome volume off the pistons.

With .040 squish (assumed)

Static compression is 13.6:1

Dynamic is 12.6:1 with big overlap cams (Redshift 723V2's)

Looks like this one is going to run E85 (alcohol) -fortunately available pretty much everywhere around here.
🌽🌽🌽🌽🌽🌽🌽🌽🌽🌽🌽
Should get a good power boost as stoich is around 8:1 for E85 as compared to 14.7:1 for gas. Wheee!

Edit: Cranking compression is 289 psi. Probably should start thinking about compression releases.

delcrossv · #41 10-15-2023, 09:21 PM

Update. We flow tested the STD heads, and they aren't up to the task. Even at .700 lift we can't squeeze more than 250 cfm through the intakes.

However, there is a solution. Since the cylinders are custom built, we're not limited to the Sportster head bolt pattern. So, for maximum flow we're going to use modified 4 valve Milwaukee 8 heads with 2.5mm oversize valves. We expect better than 400 cfm from these.

This is starting to look like an updated version of the Shovster (shovelheads on Sportster cases) builds I used to do in the 80's.
New pistons ordered as M8 pistons have a larger wrist pin than the rods we ordered. Also going with titanium pins to save on reciprocating weight.

Autonomous · #42 10-15-2023, 09:42 PM

This complicates the twin carb scheme you had planned. Sure sounds like it will be worth it though.

delcrossv · #43 10-16-2023, 12:36 AM

Quote:

Originally Posted by Autonomous

This complicates the twin carb scheme you had planned. Sure sounds like it will be worth it though.

Simplifies it, actually. We'll be going with one BIG carb.

Autonomous · #44 10-16-2023, 02:19 PM

Will this affect your cam choice?

My Road King had the Magneti Marelli fuel injection with separate intake runners. Obviously, they didn't pan out as HD went back to the 1-2 intake manifolds.
The dual Weber dyno charts I've seen didn't seem to offer any real advantages. I suspect the biggest issue is the necessarily short intake does not allow realistic wave harmonic tuning. It would be interesting to see what ~18" second or ~12" third wave intake runners would yield.

delcrossv · #45 10-16-2023, 05:45 PM

Quote:

Originally Posted by Autonomous

Will this affect your cam choice?

My Road King had the Magneti Marelli fuel injection with separate intake runners. Obviously, they didn't pan out as HD went back to the 1-2 intake manifolds.
The dual Weber dyno charts I've seen didn't seem to offer any real advantages. I suspect the biggest issue is the necessarily short intake does not allow realistic wave harmonic tuning. It would be interesting to see what ~18" second or ~12" third wave intake runners would yield.

Cam choice s definitely affected. We're now looking at 575's with the lobe placement on the cores to be tweaked and then sent back to Redshift for welding. Supposedly, high lift doesn't gain anything but more charge loss with M8 heads. Of course there are significant durability gains at very high rpm going with lower lift, provided the flow is sufficient.

Tuned runners would be nice, I will bring that up with the heads guy, but his initial take with talking with his M8 guru is that there's not much gain to be had. All the drag bike folks run fairly short runners. The bigger issue is keeping short radius turns out of the intake for obvious reasons.

The recommendations are all pointing to a bored D carb for the salt and a black body G carb for street- the D carb having an extended bowl to keep up with alcohol consumption. Even with the D carb with a 2.25" bore it'll be somewhat undercarberated at full power.

👍😁

delcrossv · #46 10-24-2023, 03:48 PM

Short update:

Heads guy and machinist will meet up at Rockingham for the drag races. M8 head cores go to the machinist to move pushrod holes to Sportster geometry, cam cores go to the heads guy.

Heads build sheet

1 M8 head cores (front and back)
8 2.5mm over Premium Steel valves
1 Ultra Premium Ti Conical spring kit
8 Bronze guides
8 Viton valve seals
4 Moldstar 90 exhaust seats
4 Nickel Bronze Intake seats
1 M8 intake manifold core
1 New S&S 11-0112 D Carb
1 Extended bowl and emulsion tube

1 Max effort port of M8, install guides
size and valve job
1 install 8 oversize seats
1 Xl pushrod Machining (R&D)
1 Build custom manifold for D carb
1 machine external oil drains
1 Degree cams in my SB100 mock up case for altered timing (4 valve head)

2 intake to carb mounting bolts
2 Intake flange to head kit
1 Chemical strip heads
1 Custom timed redshift cams built on cores you send me
1 Freight to send cores to Zippers
1 Rocker box gasket set
* comp b/t 13.5-14.5:1 compression
*E98 Eth fuel is the plan today for race
*E85 for street
**

Edit: I'll still need to get roller rockers and a rocker stud kit from S&S as well as a black G carb. also need to find rockerboxes off the 'bay.

Autonomous · #47 10-27-2023, 07:46 PM

That is gonna be wild!

delcrossv · #48 11-16-2023, 01:13 PM

Did bore measurements and it just fits into the 1650cc class. 4.002 with the bore honed. 1649.03cc swept displacement. Phew!!

New pistons: (3.997" nominal)

delcrossv · #49 01-09-2024, 01:56 AM

Short update:
Custom bearing cage design is complete. Machinist should have those done by 2/15.
Talked to inspection committee at SCTA and it looks like I'll be able to have the engine measured and sealed here so I won't have to disassemble it at Bonneville.
Still have to order magneto, wires, trans gears and primary drive parts.

Decided to go with piston coolers, not so much that the pistons will need cooling with E98, but I'm concerned the cylinders might get oil starved at the piston speeds we'll be operating at.

Also, the rollers tend to slide around the crankpin oil holes at high rpm as there's too much oil there. The sliding makes for flat spots on the rollers and premature failure. To alleviate that, I'm machining slots fore and aft of the oil holes- about 1/8 long and .010 deep to encourage the oil to spread out away from the feed holes. That's a FAFO experiment. Seems to make sense though. We'll see how that works out.

delcrossv · #50 02-09-2024, 01:38 PM

Short update:

Just got off the phone with Morris Magneto. Type F mag, custom advance cams, remote kill, and this will be the first one they've made with an electronic tachometer send. Should arrive in 4-6 weeks

And they have cool t-shirts