Ok, so I've been away from the scene for the last 10 years.

The bike is a 1980 FLH80, 80 cube 20 thou over, S&S e series, and running drag pipes.

I wanted to go 88 cubes, but after talking to some people, I'm being told to upgrade the ignition instead, as the newer ignition systems will give the same result.

Is this true?

Cheers TC.

.

 

Big dollars to bore an 80" out to 88", split the cases and bore out, new pistons and cylinders, open up head, might as well rebuild bottom end while its all in bits.

My opinion, a good single fire ignition, 40mm CV carb, exhaust with good muffler volume, rebuild heads and shave to increase compression 1 point, rering or rebore cylinders. you might find the bottom end needs rebuilding but more than likely will.Stock H grind cam,

New fork springs, rear shocks and later model brake calipers.

You have to bore cases and open up head to go 3 5/8" bore for 88" or swap the bottom end for stroker flywheels. either way you have to split the cases.

 

had my ol shovel went 20 over an only cleaned heads up went to mild andrews cam an made inlet manifold so i could run a mikuni 42 mill flatty had 38 inch drag pipes an made some short baffles used a dyna / ultima ignition and cant rember the cam but wasnt to big ran solids too ran sweet as kept up with all the evos was in a ridgid frame then in softy frame but sure ya got a oil cooler on it

Thanks for the replies. When I got the top end rebuilt I was told the bottom end was going to need a rebuild next.

So I will be getting the bottom end done. Looks like I'll do the ignition upgrade aswell.

Thanks guys.

 G'Day T.C.,

Good advice all round, though as Kiwidave recommends,  the option to keep it simple and reliable is IMHO the better way to go.

A few points for you to consider:

1- Definately go for a single fire ignition. Kick start capability limits you a bit, but as Dave said the good old HI-4 in either it's past

or current form is a good choice.

2- You mention that a bottom end rebuild is on the cards. If this is the case I would suggest a couple of improvements.

  a)  81- 91 Oil Pump or if you have the $$$ an S&S unit.

  b)  Early Evo (to 86) Flywheel assembly, if you have the $$$ S&S have a set  available for this conversion. This saves you

        over 3 kg's of weight in the lower end,  plus the Evo style wheels are clearanced correctly and won't go out of true as the cast iron 

        Shovel ones can.

  c)   Change the lifter blocks and lifters to Evo type, the bolt pattern is the same. Use adjustable pushrods.

  d)  Change the oil supply line to the rocker boxes to a T line feeding both boxes from the middle, replacing the transfer line .

        (plug the rear supply hole with a 1/8 npt plug.)

  e)  If you can afford it bathtub the heads and use flat top pistons.

And run the primary as a sealed unit, this together with a good filter should keep it cleaner for longer.

 

Cheers,

Cris.

 Thanks Dave and Cris for your input, I really appreciate it.

Cris, thanks for the mod tips, I'll definitely look into those. A couple of questions though, does the Evo flywheel have to be modified in any way to fit or straight swap??

And any suggestions on where to get these parts from??

Cheers TC.

You can spend the $$$$'s and get S&S Flywheels or hunt around for a second hand set from somewhere. They fit straight in your cases, but need to be done by someone who knows what they are doing. Dave might pass on a number to you seeing as you are in Victoria.
Cheers,
Cris

Enjoy it stock, Harley's were made to be cruisers