Ultima 113" cam

[Deye76]

From my Ultima owners manual.
displacement Ci 100Ci 107Ci 113C
Cam Lift: Int      .520" .625" .640

.640 seems like a lot of cam for a 113" Wonder if it's a misprint.

[turboprop]

Not really. I ran a Wood W6HF in my 106" Taj-Mah-Motor. It had .650" lift but a short intake closing. That engine ran very well. Spring technology has changed. Back in the shovel days .500" seemed like a lot. Don't fear the reaper.

[Deye76]

Have heard it might have something else. Getting in touch with Ultima is like winning the lottery. Was hoping someone knew.

[turboprop]

I think Ultima roller rockers have a non standard ratio that makes comparing their cams to most other brands somewhat tricky. If that 113 Ultima does indeed have .640" lift at the valve, the cam would most likely compare to a cam with less lift. I bet whatever cam is in that engine is simply rebranded or copied from one of the major cam manufacturers.

[Deye76]

Yup, I just found out it has a 1.675 rocker arm ratio vs stock evo 1.6., so it's more like a .625 cam. Makes sense now.

[JW113]

I have a SE-264 (.640" lift) cam in my HD 113. No problems so far. Also have 1.67:1 roller tipped rockers, so the actual valve lift is a little more than .640.

-JW

[Hybredhog]

  I kind of figured it out once, and it came up to be approx. .015" extra lift. Not a massive deal, but could make lobe clearance easier. I'm sure there is somebody here that may have done dyno test between the two. As for the Ultima 113, I've sold & installed a bunch of them , they're all doing well, and they squeeze ST into a stock frame. Well one guy is pretty bad at abuse & maintenance, and the rest of the bike is falling down around it, & I won't work on it anymore. 

[jsachs1]

Very easy to figure out the lift in a cam.
1 - Measure the base circle of the cam. 2 - Next Measure from the bottom of the lobe to the top of the lobe. 3 - Next subtract the base circle measurement from the overall lobe length.( # 2 measurement ). 4 - Multiply answer # 3 by the rocker arm ratio. This will give you the lift of that lobe with the  rocker arm ratio you're using.
John

[jsachs1]

Another thing to remember is: the different rocker arm ratio length is either added or subtracted from the center pivot to the pushrod cup area of the rocker arm. This can affect the pushrod hole in the head, and the push rod tube clearance.
John

[Deye76]

Thank You John.

[Reddog74usa]

I ran the Ultima 640 in my 113 that I had John do the heads on and it made great power. 133TQ 139.8 HP. It was a stock 113 right from Ultima and the only mods were Sachs heads, bored super G By Sachs and the rest was as from the factory. Really made that FXR a lot of fun. I ran an engine oil cooler and it never went over 190 on the oil temp even on hot days and got like 43 MPG. It was the perfect combination for dependable street performance with no PMS.

[Deye76]

John Sachs, have any thoughts on a S&S .600 cam with 1.6 rockers, in a Ultima 113"?

[jsachs1]

John Sachs, have any thoughts on a S&S .600 cam with 1.6 rockers, in a Ultima 113"?

They're not a bad cam, but IMO, there's better.
John

[pwmorris]

I ran the Ultima 640 in my 113 that I had John do the heads on and it made great power. 133TQ 139.8 HP. It was a stock 113 right from Ultima and the only mods were Sachs heads, bored super G By Sachs and the rest was as from the factory. Really made that FXR a lot of fun. I ran an engine oil cooler and it never went over 190 on the oil temp even on hot days and got like 43 MPG. It was the perfect combination for dependable street performance with no PMS.

I remember that bike and motor Dog-
That was a hell of a 113"! Damn sad you got rid of it....

[Deye76]

John Sachs, have any thoughts on a S&S .600 cam with 1.6 rockers, in a Ultima 113"?

They're not a bad cam, but IMO, there's better.
John

Any suggestions?