Looking at upgrading my 80 to something bigger. I don't want to tear down the lower end. But I want as big cu as possible. What do I need? ideas thoughts?

 

You are not gonna get much without tearing down the lower end and either boring the cases or putting in a stroker.

 

yup not happening........evo's cant really go big bore on stock cases either

 

If you want to go big, Evos are not the best to do that with. Increased compression is not the best for them eaither. I would match a cam to head work. Stay around 9.5:1, Make that work horse breath and suck fuel and you can blow away any 88" or 96". Air and Fuel is the Key to the EVO's. Not inches.

 

"If you want to go big, Evos are not the best to do that with. Increased compression is not the best for them eaither. I would match a cam to head work. Stay around 9.5:1, Make that work horse breath and suck fuel and you can blow away any 88" or 96". Air and Fuel is the Key to the EVO's. Not inches."
I like this can you match what you say in parts etc... I need a starting point...

 

I found a Harley mechanic that has his own shop near me in CA. Someone I got hooked up with and only trust him to work on my sled.

The plan for my bike is to take the heads off and send them to a machine shop near Fresno CA. The guy there races for S&S and also machines his own parts. I am goind to have him port and polish the heads and machine the valves out and put larger ones in. Then have him choose a cam that would match his work.

There are ton's of kits out there that you can just bolt on but I am looking for reliability and I want the motor to look like a stock sleeper.

I have been told that the evos don't respond well to 10:1 compression and messing with the lower end.

Find a trustworthy mechanic and research a recipe for what you want.

 

Others that have responded know more than I but if you don't already have them, here is a suggestion
to wake up your 80' evo:

EV-27
torrington bearing upgrade (needed)
new hd lifters ( needed)
ez-change adjustable chromoly pushrods (should do)

even more to make it better:

good single fire ignition
possible head work
9.5:1 pistons

If you do the work yourself and shop wisely, the cost for parts related to the cam upgrade is not too bad, guessing maybe $120 for a EV-27, torrington bearing $10, ez-change chromoly adjustable pushrods $100 stock HD "B" lifters another $100 - A few hundred more you can have a good local indy shop do it and not have any worries afterwards. Be careful though, if the estimate starts going up pretty high , keep in mind a new Ultima engine delivered to your door costs less than $4000.00


This will give you pretty good performance and you can still save up for and buy a new Ultima motor for less than $4,000. delivered from Jireh. With Ulitma , you determine how big you want to go 100-107-113-120

 

If you have an early Evo, you can increase bore size safely only to max rebore, which comes out at around 83 inches. Otherwise you cannot change your engine size without stripping down the entire engine!

There is not enough metal around the crankcase mouths to bore them out any further. You can stroke it, as I did to my 1990 motor, to 89 inches, or around 91/92 with max rebore. I ran my motor with 10:1 pistons and it was a real peach! I had the work done by a UK Harley specialist, including porting/gas flow, new cam, etc.

If you have a later Evo, from 1992/3 on, the cases have more metal and you can both stroke and bore it out to around 106/107 inches. When I investigated that route I eventually decided to go with an S&S V107T!

Stroking your current motor is likely to be quite expensive if you get a specialist to do it, as there is quite a lot of labour involved. There are threads here on HDF from many riders who have replaced their engine, as I have, with a bigger one.

You will find that once you get into serious spending, it will get easier! Once you get to the 'other side', you will find life gets really sweet and a new engine will have been worthwhile after all....

 

Here's my take on this .When I had my '93 ultra, it ate a lifter wheel and trashed the motor.I had Harley do the reman deal on it to the tune of almost 4k. Now after I had time to digest this expense, I could have had a larger aftermarket motor with a longer warranty, then Harley's for about the same $$$.I then could have sold the original motor to offset the cost of the new one, and had a bigger more powerful motor for about 3k. To make an evo over 100cu in, will cost alot more then that with no warranty.,,

 

+1 on

"...I then could have sold the original motor to offset the cost of the new one, and had a bigger more powerful motor for about 3k."

My old engine was 80": stock bottom end, 5 over KB pistons, SE heads and cam, S&S E, HI-4 and Supertrapp 2-1 and made a little over 80 HP. Lots fun, very reliable, but not very economical (30-35MPG) .

Put in a 6 speed last summer and needed more power. Talked with a local shop about stroking it out (89 max) and it would have been $3000 +.


I'm curently finishing up a 113" install. $3499 delivered to the garage door in about 4 days. Got a grand for the old engine (140K on original bottom and 40K on top) and will have about $3000 total into the change out when I am done.