Shovel Perfcormance Limits : V-Twin Forum: Harley Davidson Forums

Rhinopkc · 10-08-2005, 07:36 PM

What is the maximum amount of power that can be achieved with a Shovelhead and still have a reasonably reliable bike? What would it take to swap in an evo-style engine into a '78 FXS? I would like to keep it a shovel, but if I can't get reliable performance out of a shovel I may have to do an engine swap. I don't mind wrenching (hell, I kind of enjoy it), but I would like to keep it reliable enough for medium-length (500-1000 mile) rides. I already have an evo for long runs, but the wife is getting her license and now I have an excuse to build something that hauls ass.

LittleBear · 10-08-2005, 07:50 PM

The best combination of power and relibility comes from a 93" S&S Shovelead motor. How much money do you want to spend?
The biggest problem with a Shovelhead build, if you can not do the work yourself, is finding sombody who can. I lot of people say they can work on Shovel's but very few really can. That is why the S&S motor is a good thing.
I do not think a "80 EVO will not fit in your frame, the motor is too tall.
Welcome to the forum

FL84FXWG · 10-08-2005, 07:51 PM

Check out Truett & Osborn , Wichita KS. EXCELLENT high perf Shovels for years and I mean years!

Web www.truettandosborn.com

Friendly folks that know their stuff.

"I'm older now but still running against the wind"

frankencat · 10-08-2005, 08:13 PM

93" S&S Shovelead

newultraclassic · 10-09-2005, 12:00 AM

Quote:

Originally Posted by Rhinopkc

What is the maximum amount of power that can be achieved with a Shovelhead and still have a reasonably reliable bike? What would it take to swap in an evo-style engine into a '78 FXS? I would like to keep it a shovel, but if I can't get reliable performance out of a shovel I may have to do an engine swap. I don't mind wrenching (hell, I kind of enjoy it), but I would like to keep it reliable enough for medium-length (500-1000 mile) rides. I already have an evo for long runs, but the wife is getting her license and now I have an excuse to build something that hauls ass.

IMHO, most anything you do to a Shovelhead will affect reliability negatively. Cetainly power will be higher but there are limitations to the design. Increase compression too much and the hemispherical chamber will cause detonation unless you also add dual plugs which create even more complexity in the ignition. Stock flywheels are extremely heavy, lending themselves more to lower speed, high torque operations.

One of the greatest limitations in the engine though, is the lubrication system. It has a lizard-like flow of oil which is prone to overheating when performance is pressed to the limit.

If you really want reliability, keep it stock. These comments are based on owning a Shovelhead for close to 15 years and having tried various performance modifications. Finally decided that I like it stock the best. Do I like Shovelheads? Sure do. It's my favorite HD. I just prefer to keep it running. Put 100 miles on it today and it still runs great.

As to EVO engine in a Shovelhead frame...the only one that will take an Evo is the rubber-mounted FLT or the late FXR.

(Putting on my flame suit to protect from the Shovelhead High Performance League.

)

springer- · 10-09-2005, 12:16 AM

Quote:

Originally Posted by newultraclassic

Shovelhead High Performance

Isn't that an Oxy Moron?

newultraclassic · 10-09-2005, 01:31 AM

Quote:

Originally Posted by springer-

Isn't that an Oxy Moron?

Good point.

I know you ride one and probably you would have more to say about a performance Shovelhead than I, Springer. I know that they can be made to go rather fast. That said, it's got to be at the expense of something.

I intend to keep my Shovelhead until I drain it and put it in the living room to set a beer on. It will make a good conversation piece when I can't ride anymore.

That said, really, the only thing I do care about is keeping it running and that pretty much implies that I will keep it stock.

95 FXST · 10-09-2005, 11:44 AM

This had two Shovels.

http://www.guinessrecords.com/conten...recordid=43614

FL84FXWG · 10-09-2005, 08:17 PM

Ditto on keeping it stock. My only upgrades are: newer Harley CV Carb, Ramjett clutch retainer, Shimmed my rockers to quieten it down and added
a Spyke Single fire ignition and coil.

I can run crap gas on 7.5 CR and it stays nice and cool.

They can be made to go really fast but I like it low and slow.

newultraclassic · 10-09-2005, 10:59 PM

Quote:

Originally Posted by FL84FXWG

Ditto on keeping it stock. My only upgrades are: newer Harley CV Carb, Ramjett clutch retainer, Shimmed my rockers to quieten it down and added
a Spyke Single fire ignition and coil.

I can run crap gas on 7.5 CR and it stays nice and cool.

They can be made to go really fast but I like it low and slow.

That's great. Mine is set up exactly the same: CV Carb, RamJett, Rockers properly shimmed and 7.5:1 C.R. I love the low compression. I also have the stock 1982 H cam with hydraulics. I have Paughco dual exhausts and, like you, I have the Spyke single fire with the Spyke coil.

With this combination the torque is perfectly flat and starts at 1,400 rpm and, as you say, you can run it on any fuel at all. Mine also runs very cool and starts and idles nicely.

Alte314 · 10-09-2005, 11:01 PM

Have to say that making a high performance shovel is pretty much a waste of time and money. The S&S is your best bet. Shovels are for those of us who don't even LIKE to go fast, I'm the guy with a line of cars BEHIND me on a windy road. That being said, (my bike is obviously stock), I trust it completely and won't hesitate to get on the road for a 1000 mile weekend, it's never let me down. I guess you can do a reasonably good build on a shovel, lots of people have, but the longevity won't be there.

newultraclassic · 10-09-2005, 11:04 PM

Quote:

Originally Posted by Alte314

Have to say that making a high performance shovel is pretty much a waste of time and money. The S&S is your best bet. Shovels are for those of us who don't even LIKE to go fast, I'm the guy with a line of cars BEHIND me on a windy road. That being said, (my bike is obviously stock), I trust it completely and won't hesitate to get on the road for a 1000 mile weekend, it's never let me down. I guess you can do a reasonably good build on a shovel, lots of people have, but the longevity won't be there.

Absolutely. I couldn't agree more!

bigal51 · 10-10-2005, 07:45 PM

I had a shovel for over 12 years. The best build I had with it was 7.5 compression, andrews # 2 cam(hi lift and short duration), mild port and polish with duel plug heads, dyna single fire ignition, s&s super E and drag pipes. I prefered this build to the s&s 93 inch kit I had put on later.-Al

Bosco1962 · 10-10-2005, 10:13 PM

Quote:

Originally Posted by FL84FXWG

Check out Truett & Osborn , Wichita KS. EXCELLENT high perf Shovels for years and I mean years!

Web www.truettandosborn.com

Friendly folks that know their stuff.

"I'm older now but still running against the wind"

Ditto on Truett and Osborn. Talk to Paul he know's all about Shovels
I have owned 6 Shovelheads and bought my first new one a 1978 FXS Lowrider
I have had few problems over the years with them and think they respond well to mods.
Most riders that rag on Shovels have never owned one.
Of course what do I know I never owned an EVO.

Steel City · 10-11-2005, 02:14 PM

Quote:

Originally Posted by bigal51

I had a shovel for over 12 years. The best build I had with it was 7.5 compression, andrews # 2 cam(hi lift and short duration), mild port and polish with duel plug heads, dyna single fire ignition, s&s super E and drag pipes. I prefered this build to the s&s 93 inch kit I had put on later.-Al

Have to agree with that one mate... mine is almost exactly the same as that one, except the ignition is now a crane H4..and i have S&S barrels.. I love it... never misses a beat, now i have changed to the crane system... sounds fantastic, drives very well, esp. at low revs..... and is different to all the bro's on the evos out there..super engines...