I'm wanting to up the performance of my 1990 80" FLHTCU.

It has 9,000 miles on a HD factory reman, it runs ok, but there is a issue with the rear cylinder balance. (more rpm drop when the front plug wire pulled than the rear)

Compression test shows close to the same on max pressure, but can see a big difference on the first two strokes. Put some air in the cylinders, no valve leaks.

Looked with a inspection camera, and noticed the factory powdercoated the inside of the intake ports (WTH? textured and pretty thick) and much of it came off and went through the cylinders. Can see some scratching in the cylinders, more in the rear.

This was 4,000 miles ago and does not seem to be getting any worse. Probably would run like this forever.

Anyway,,,, good excuse to dig in it.

Two up most all the time, I don't ride under 2,000 rpms, on long trips, interstate cruise speeds usually around 80.(somewhere around 3,600 rpm)

2,000 to 5,500 expected rpm range. Not concerned about max hp#'s, looking for more torque, more response, decent street manners, not a ping monster. More fun to ride factor.

Currently have a Twin Tec ignition, good AC, and a 2-1 fatcat exhaust

Open to suggestions on piston/compression, head work, cam, and carb combinations.

Right now I'm thinking -
10-1 (Wiseco?)
W6 or W6h (I can handle the noise, I'm half def anyway)
T-man stage two head package (or whatever they might suggest)
send cv to Bob Woods, also clean up the intake

Some questions.

What compression works best with the w6 or w6h, do i need the domes or could I get enough with flat tops with deck height/chamber mods (more & tighter squish, bathtub style chambers) which I think would combat pinging/detonation better?

Which lifters reliable for the w6 or w6h cam?

Knight Prowler magic on the CV or a Mikuni?
I would think the cv would get better mileage and tollerate altitude changes better, the mikuni on our sportster has excellent throttle response.


The more research I do, the harder it is to decide what might work best, especialy on a heavy bike with a small engine.

Suggestions & results from real world experiences appreciated....Schex

 

What's your budget?
Depending on how bad your jugs are it may be worth looking into a new engine.

 

Took my 98 Ultra 65,000 miles on this set up:

Weisco 10:1 pistons, EV 3030 cam with Flowed/Ported heads.

My bike was injected, but our customers carbed bikes got either a Mikuni 42, or S&S "E" Series carbs with Dyna dual fire igntions. (Your ignition is fine.)

Super reliable package with 75 - 80 HP and 80 ft/lbs torque, Target is 1 HP per Cubic Inch. ( HP varies depending on choice of exhaust.)

That's one way!

 

Rosa's Cycle, Huntington, Long Island, N.Y, tuned a Wood 6, our Stage II Heads, S&S E carb w/T/Jet, Dyna ignition to 84 hp and 93 ft/lbs, not so long ago, and we've witnessed the same here many, many times as well.
That said and having worked with those cams for almost 15 years now, it likes 10.25 cr.
Scott

 

If you are going to have some headwork done, the W6H would be the choice over a W6 that would waste port work and bigger intake valves that is common in good heads but some engine builders get good numbers out of the W6.

My opinion, stock heads with port work, chambers milled down, flat tops and a proper thickness head gasket to get 9.8-1 with a W6H, a little more compression with a later intake closing cam would work also. I did the high compression gig once and a tempermental engine was the outcome.

Currently have the compression above, John Sachs heads, W6H, Propipe in a 89" for the last 3 years and has been dependable and a wolf in sheeps clothing when the throttles start dropping. Had a CV tuned properly and nothing wrong with that carb, put a Mikuni on it but didn't fully dial it in yet but each carb has it's charactistics, the Mikuni just idles bad to the bone.

Had a set of harley "B" lifters give out with the W6H and have had the Ultima Johnsons in the last 2 years and have taken rev limiter bounces ok and a tip on the Woods cams, set the plunger deeper in the lifter bore and the noise is tamed.

Many good engine builders out there that will help with your engine setup, parts or machine work, I'm a believer in John Sachs but always keep an open mind to experiance builders and no such thing as a stupid question to someone that wants your business.

 

Thanks for the responses,
I'll tear into it after the new year, looks like 10:1 should be manageable, especially if I can get there with flattops.

1997bagger, are all the Ultima lifters Johnsons now?

PeteRock, it's not hurt that bad, minor sratching, rear cyl just a little weak, made a 1700 mile round trip to the BBB rally in Oct. and used no oil.

Hillside,I may be calling in Jan.

Stiggy, I was looking at that very cam too, with the head work, lots of cams become "drop in".

 

Not sure if this still holds true on the newer engines, but on the older ones the rear cyl. was always a little less because the timing was a little retarded on the rear cyl. campared to the front, because it runs hotter. Yours is probably good for another 100,000 miles unless you just want to upgrade.

 

Yes, want to upgrade some.
Also planned on checking rear cyl timing, just have'nt done it yet.
Your right, I would'nt hesitate to take it anywhere.

 

Happy to lend a hand.
Scott

 

Johnson is making Ultimas lifters by advertisement, Ultima seems to have their lifter problem under control, are they bullit proof, I don't know but struggle with S&S being $250 for lifters and the Ultima's are curently holding up in 640 lift engines.

Those V-Thunder cams are also proven, easy on the valve componants and alot of satisfied owners. I came across a W6H for $40 and made a decision easy, it does provide grunt, carries thru to the rev limiter and does what I ask of it but takes a little tinkering to tame it down, The Mikuni door rattle makes more noise than the Woods cam right now.

Funny story on the Mikuni, I was installing a S&S intake and Mikuni on with the support brackets not lining up, friends called and on a long ride so I did what it took and wire tied the carb and went for a 250 mile ride, never finished dialing the AFR's in but have removed the wire ties, those ties are amazing and the look on my high dollar Twinkee buddies faces was priceless but still the same result as the white bike pulled away from them.