REPRINT FROM OLD HTT: EVO CASES AND HP?

[ClassicRider2002]

DISCLAIMER: THIS IS A REPRINT TOPIC FROM "OLD" HTT

I have saved many great topical discussions as "links" over the years and would hate to see these lost, so I am reprinting this TOPIC here, which may "perhaps" help some.

TOPIC:  EVO CASES AND HP?  09-08-07


From: reddog74usa  (Original Message) Sent: 9/8/2007 9:45 AM
How much power can ya build up on a set of 1990 cases?

[ClassicRider2002]

From: Dave_Hath Sent: 9/8/2007 11:31 AM    Message 2 of 16 in Discussion
As much as your wallet can handle.....I have built 90 HP 80 inchers on stock HD cases. I'm sure there are otheres who have done more. I am always a bit cautious when asked to do a big bore kit on Evos from the mid 90's I've seen a few crack. But I have seen many early evos...84-91 run as 89 and 96 inch motors, I have an 85 evo I am building to 88 inches stock stroke and bige bore(if you can still call 3.625 big anymore) You would be surprised how fast a 90 HP bike feels with more than 80 ftlbs of tourqe from 2000 rpm up. Hell my friends FXR is making 79hp and 84 ftlbs and is a blast to ride. I hope this helps. But a well set up 80-88 inch Evo with 9.5:1-10.5:1 pistons, some very basic pocket porting the right valves, 5 angle (blended) valve job and cam like a woods W-6, Andrews EV-38/EV46, or a Mackie DM 500 or DM 500X will make really good tourqe. It will run very hard and make power where it is needed. If this was a really light bike with the right gearing I might go to a DM 530 or a EV51( or something similar). For build ideas check out the nightrider site.   Dave


From: reddog74usa Sent: 9/8/2007 1:30 PM   Message 3 of 16 in Discussion
Yep, Bike is a light bike. 1990 FXLR


From: Tommy_FXLR Sent: 9/8/2007 3:05 PM   Message 4 of 16 in Discussion
The right exhaust, a set of SE heads, & a Wood W-6 cam oughta put out around 84-86 HP & 90-92 TQ.


From: reddog74usa Sent: 9/8/2007 6:45 PM   Message 5 of 16 in Discussion
This all sounds good but my real question is how much power has anybody been able to get out of a set of stock EVO cases without them cracking. I seem to remember this being a problem for anything over say 80 HP


From: JohnS_Rosamond_CA Sent: 9/8/2007 7:20 PM   Message 6 of 16 in Discussion
I wouldn't want to go much more than 80 hp.  It's not that you can't go higher than that, but I would have serious reservation about a bike higher than that being any good at high mileage or daily riding to work.


From: Tommy_FXLR Sent: 9/8/2007 10:14 PM   Message 7 of 16 in Discussion
I wouldn't go over 90HP with stock cases. IMO, if you ride it civilized (keep the RPM's under 6000, ride it easy until it warms up, & don't wind 'er up & dump the clutch) 85-90 HP will be fine.
   

From: reddog74usa Sent: 9/9/2007 2:36 PM   Message 8 of 16 in Discussion
Well truth is I just picked up a 1990 FXLR bone stock with 6900 unmolested miles on it. All it has is a set of H-D slip on mufflers with the oem header pipes on it and it runs great and gets 48-52 MPG with not even one oil leak. Ya know how it goes I'm just thinkin of ways to improve it but me thinks I best just run it the way it is.
     

From: norton8502 Sent: 9/9/2007 4:56 PM   Message 9 of 16 in Discussion
Good choice there reddog. '90 Evo cases are prone to all sorts of problems, even on stock engines. And it only gets worse on modified engines.   


From: SUPERDAVE8404 Sent: 9/9/2007 5:43 PM   Message 10 of 16 in Discussion
Well if you don't bag on it you can have lots of power and drive a daily route to work.
The 90 FL I have is puhing just around 100 hp and I drive it to and from work.It is hard sometimes not to crank on the throttle but it can be done.


From: reddog74usa Sent: 9/9/2007 6:40 PM   Message 11 of 16 in Discussion
Since this engine runs so good it may a good idea to build a hot rod engine on a set of delkron cases. Theres a lot to be found for these Evo's.


From: easyricer Sent: 9/10/2007 7:39 AM   Message 12 of 16 in Discussion
I know it cost more, but I would rather just swap the motor out with an S&S 96 incher, install a 34 tooth front pulley and ride the snot out of it! The stock EVOs are good engines but with a 90 model I wouldn't want to build it too much. They have some case issues on the 89-94 models because they changed from sand cast to a different process.
The S&S also comes with a good warranty and is designed to be tortured on the road. For the money, it's a good deal. You can keep the stocker for another small bike project or as a spare. You can also recover some of the S&S money by selling your old motor.  EASY 
   

From: reddog74usa Sent: 9/10/2007 5:35 PM   Message 13 of 16 in Discussion
Easy, Maybe I'll do another one of these.


From: reddog74usa Sent: 9/10/2007 5:39 PM   Message 14 of 16 in Discussion
The 96 S&S is definitly a consideration as it is a proven design. I did the TC in a FXR but the Evo's are a very nice engine also. to me either way is a winner.


From: hd96 Sent: 9/16/2007 3:36 AM   Message 15 of 16 in Discussion
well lets see power well I have a friend that 136 hp not sure on tork bigger pistons and a 5" stoke the bike was an i think 84 fxr he raked it  and changed a few things he stood it on the back wheel 1,2,3 4, out of 6 gears then that wasn't enough he added nos he finely blew it up on the drag strip so the cases will take alot just don't go to big on the bore flow the heads you can get lots of power doing the heads up right hd97@telus.net  Decker daryl                                                                                                                         
ps I have a 96 ulta with v-thunder can stock heads a 2000 i ign. with a mukuni 42 it dineoed at 74.8 horse and 82 foot lbs Its a heavy bike but it goes  real good I also took the belt off and put a chain on kept blowing belts,So I put spockets on to give me a better bottom end


From: hd96 Sent: 9/16/2007 3:43 AM   Message 16 of 16 in Discussion
I've had the v-thunder can in my bager for 5 years it is a really reliable bike so if you want a bike to go better with just a little horses power like 75 horse with 82 ft lbs doesn't cost much go with the v-thunder cam and the 2000 i ign.cb carbs are good so are ss  or mukuni put a 2 into one thunder header and your set Decker Daryl 

[ClassicRider2002]

Anything added beyond this point is new information.

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"Classic"