Author Topic: Fatso motor  (Read 6044 times)

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Offline stroker800

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Fatso motor
« on: Sunday, August 30, 2009. 05:00:26 PM. »
   Gettin kinda bore,,,so took inventory of spare parts...Decided to build fatso motor,,,I have help put together a fatvo (sputhe version)..The cases and pistons came as a kit..I want to use Ultima cases as way cheaper,,,so who as built one using their stuff..I will be goin for their cases and hopefully their piston kit,,I have pretty muhc everything else,,,So the question I have now ,,,,,
what is a good cam for the stock TC heads???
Is there pushrod angle issues???
Who has an evo flywheels and rods to sell???
Any & all info good,,,tell me good and the bad on your fatso....
thanks Dave

Offline choseneasy

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Re: Fatso motor
« Reply #1 on: Sunday, August 30, 2009. 08:24:04 PM. »
 I  have a set of flywheels if you are looking. I will give it serious thought if you can't find any.

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Re: Fatso motor
« Reply #2 on: Monday, August 31, 2009. 05:53:50 AM. »
The pushrod angle [just intake] will be your biggest hurdle. Welded & relocated mine. Those oversize o-rings that Sputhe uses are nice for sealing up the tubes as the angle is off a little. Or you can use the cutter [Jim's sells it now] to true up the holes to the new angle.

Offline catmcaw

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Re: Fatso motor
« Reply #3 on: Tuesday, September 01, 2009. 08:48:21 PM. »
I'm thinking   Ultima cases #206-41   $650.
                  Ultima Flywheels #98-554  $550.
                  Mahle pistons #93-880  $185.
 Has anyone used the Mahle piston in a Fatso build?

Offline Buddy WMC

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Re: Fatso motor
« Reply #4 on: Wednesday, September 02, 2009. 05:04:25 AM. »
I've got a set of 4 1/4" stroke Evo flywheels with the 1/4" longer pinion shaft and H-Beam rods. They are low mileage used, but are in perfect shape. I'm pretty sure that you'll need that longer pinion shaft with aftermarket cases. If interested PM me, they'll be alot cheaper that new stuff.

Offline gryphon

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Re: Fatso motor
« Reply #5 on: Tuesday, September 08, 2009. 09:52:38 AM. »
Dave,
   Have you done much research on the fatvo/Fatso motors. I've known of a few guys who have run them but no one who can say they've put many miles on them. Just wondering how reliable they really are. I know that Delkron has maed heads and cases for them.

Offline hardonthemerch

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Re: Fatso motor
« Reply #6 on: Wednesday, September 09, 2009. 06:41:07 AM. »
Dave,
   Have you done much research on the fatvo/Fatso motors. I've known of a few guys who have run them but no one who can say they've put many miles on them. Just wondering how reliable they really are. I know that Delkron has maed heads and cases for them.

I can't answer your question in exact scenerio, but thinking mechanically.... I don't see the longetivity being any different that any other EVO or TC (EVO bottom - TC top)




As for the rest of the thread... The angle of the pushrods (my opionon... I considered this build once too) should be corrected by someone in the know with the equipment to do it. hence the importance of knowing what you want when you have the heads ported, etc... So that once the pushrod angles have been corrected, you don't decide that the compression isnt right, etc, and then have to re-do another set of heads.

Offline gryphon

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Re: Fatso motor
« Reply #7 on: Wednesday, September 09, 2009. 09:13:45 AM. »
I wasn't thinking  about longevity so much but reliability. For instance, any changes in the geometry that might result in difficulty keeping an intake manifold sealed, does realigning the pushrod tube holes in the head correct any oil leaking problems. I've never spoken to anyone running the Ultima fatso cases, are the any problems that have crept up after some miles on the road. Who knows what else. I've also considered the build but would really like to talk to someone first who's run one for a while and as more than a weekend bar hopper.

Offline uglybiker

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Re: Fatso motor
« Reply #8 on: Wednesday, September 09, 2009. 07:48:28 PM. »
I've been slowly acquiring parts for a Fatso build also.  Doing as much research as possible.  Talked to David Olp (American Cycle Supplies)  who said he has built a lot of them.  He told me the pistons sold by Ultima will hit at the bottom if they arn't machined.  He does a realignment of the intake pushrod holes for a reasonable price. You will need a .250 longer pinion shaft and the Ultima tappet blocks have better angles on the offset case. Hopes this helps.  Good luck on your build.  Please keep us informed of your progress.

Offline Buddy WMC

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Re: Fatso motor
« Reply #9 on: Thursday, September 10, 2009. 05:26:35 AM. »
I've been slowly acquiring parts for a Fatso build also.  Doing as much research as possible.  Talked to David Olp (American Cycle Supplies)  who said he has built a lot of them.  He told me the pistons sold by Ultima will hit at the bottom if they arn't machined.  He does a realignment of the intake pushrod holes for a reasonable price. You will need a .250 longer pinion shaft and the Ultima tappet blocks have better angles on the offset case. Hopes this helps.  Good luck on your build.  Please keep us informed of your progress.

Dave,
This is what we talked about in our PM's. Did you find out anymore info on the Ultima stock bore cases? I'm pretty interested in what you find out!

Offline gryphon

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Re: Fatso motor
« Reply #10 on: Thursday, September 10, 2009. 11:36:34 AM. »
It's unfortunate that Ultima provides Fatso cases but no information beyond that. Do they use TC or EVO pushrods and tubes. What intake manifold. Late model or early model pump. What bore size can they accomodate. The early motors used TC pistons but because of the pin size the bushings had to be removed from the connecting rod ends. Is this still a problem or are proper pistons now available. Lastly, are there any real advantages anymore to the build. With Ultima now offering  economical big bore alternatives the original cost savings promised with the Fatvo/Fatso build have dwindled. By the time you buy the cases, crank assembly, and pistons mentioned earlier you are within $255 of building a 113ci EVO motor up to but not including the heads. A new set of performance heads from Ultima is $600.

Offline uglybiker

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Re: Fatso motor
« Reply #11 on: Saturday, September 12, 2009. 05:01:10 PM. »
I hope you guys are still reading this thread.  The Fatso motor uses stock Evo crank assembly with an .250 longer pinion shaft.   Alan Sputhe (Sputhe Engineering) and David Olp ( American Cycle Supplies) both sell pistons to fit the Evo rods and 3.875 TC cylinders.  The heads and cylinders are Twinkie.  Everything else is Evo.  Use Ultima's tappet blocks as they are set up for the .250 offset.  Olp is realigning the intake holes on my heads as we speak.  Hope this helps.  Would like to see a lot more discussion on Fatsos.... engines I mean.

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Re: Fatso motor
« Reply #12 on: Sunday, September 13, 2009. 06:53:01 AM. »
I built one for my bike with Sputhe cases. Uses stock flywheels. I had the extra parts laying around so I bought the cases & built one. Never had any problems with it. If you get the parts needed cheap [swapmeets, friends etc.] it's not a bad build. If you need to buy everything [or just want everything new] buy a complete motor.

Offline catmcaw

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Re: Fatso motor
« Reply #13 on: Sunday, September 13, 2009. 07:53:32 AM. »
I have a formula for building bikes or motors.  Add up the cost of parts you think you will need then double it.
    Budget x 2 = real cost

Offline gryphon

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Re: Fatso motor
« Reply #14 on: Sunday, September 13, 2009. 11:36:30 AM. »
I'm really teetering on the fence here. I've been collecting parts to build a 107" EVO. However, because of the cost of heads (hard to find S&S 4" bore heads at a good price) I could also go with a Fatso since I have most of what's required. I would have to resell my 4" bore Ultima cases to buy the Fatso cases but that's not a problem. I already have a new bottom end with T&O torque Monster wheels and a Jim's .250 longer pinion shaft. I also have the offset lifter blocks (S&S, same angles as Ultima), everything for the cam case including the cover, new HVHP oil pump, pushrods, lifters, pushrod tubes etc. I could resell my new S&S cylinders and pistons to offset some of the other costs. Do the Ultima cases use the '92 and later EVO pump. Also, Olp can provide pistons with the right pin size but they are pretty damn spendy at over $350 a set. That sure takes some of the fun (cheapness) out of the build. Any good alternatives. How much does the head re-alignment for the pushrods cost.

Offline gryphon

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Re: Fatso motor
« Reply #15 on: Sunday, September 13, 2009. 12:22:06 PM. »
Well, it looks like Ultima made my decision easy. The Fatso cases are out of stock with no idea of when they might ever be available again.

Offline catmcaw

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Re: Fatso motor
« Reply #16 on: Sunday, September 13, 2009. 02:25:13 PM. »
Gryphon
  Were you talking with someone at Jireh about the cases?  I called Jireh several months back and asked if Fatso cases were something they kept in stock and was told no that they had to call Ultima to check availability.

Offline gryphon

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Re: Fatso motor
« Reply #17 on: Sunday, September 13, 2009. 10:25:11 PM. »
Yes, I was speaking to someone at Jireh and asked if they would check on future availability. They came back and said there was no idea when they would again be available. However, in retrospect, Ultima was probably closed today so I dont know who they would have checked with.

Offline catmcaw

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Re: Fatso motor
« Reply #18 on: Monday, September 14, 2009. 06:10:32 AM. »
I would think Ultima would be close on Sunday and  don"t see how they could check on the cases but maybe they have their ways

Offline catmcaw

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Re: Fatso motor
« Reply #19 on: Saturday, September 19, 2009. 09:09:34 AM. »
Gryphon
  Did you have any luck finding cases?

Offline gryphon

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Re: Fatso motor
« Reply #20 on: Saturday, September 19, 2009. 08:00:24 PM. »
I left 2 messages with ultima but no one ever got back to me. It's the same number I used before and the recording says they'll  get back to me but it never happened. If I had to I would guess that the Fatso cases are no longer available and they just didn't want to take up their time when there is not going to be a sale anyway. I even had a guy at Jireh's say that he would email them and get back to me but of course he never did either. People may complain about S&S's prices but at least with them tech info and sales info is only a phone call away. I've been thru this with Ultima before. No big surprise I guess.

Offline stroker800

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Re: Fatso motor
« Reply #21 on: Saturday, September 19, 2009. 08:17:59 PM. »
   Sorry for not keeping up on this post,,,evo just took a sh*t so getting that done...Also tryin to get another shovel finished as have it sold and then the pan bottom end has to go back together...As far as the fatso/fatvo,,,the Sputhe set up didn't need different lifter blocks,,no offsets and possitive there was NO 1/4 longer pinion involved,,to far back,,My motor guy had done the bottom end ,,we just did final assembly on top end..Gonna have to get motorman to go thru his job book for more details...Sputhe seems to be a little more helpful than Ultima,,the Jireh website is also vague..I don't think they have techs,,just salesman...Had all this time off from surgery but slows cash flow...
Dave