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Ultima engine cases

12K views 19 replies 9 participants last post by  troqed 
#1 ·
Looking around on e bay this evening I found Ultima engine cases that say Evolution bottom end Twin cam top end. Would this be a good way to go for a big inch Evo build?
 
#2 ·
I have to ask-why TC top end?
Most all their heads have smaller valves then an EVO
Great for max velocity at HD road RPM...
I don't know if they are the best choice for performance

I would talk to some REAL performance shops B4 I transposed into the unknowns.
The Net is full of people who repeat what others have said and yet have done nothing themselves.
 
#7 ·
Very good way to go. The TC heads and cylinders in their oem form have much better cooling thanks to larger and more cooling fins. The heads are much more efficient and will typically be in much better condition that even the most cherry evo castings and have potential to support a lot more horse power than factory evo castings. Plus there is the improved head vent system, leak free rocker boxes, abundance of inexpensive heads and cylinders, etc, etc. Everything about a FATVO is better than an oem based EVO engine. Everything.

The Ultima castings (heads, cylinders and cases) are known to be of pretty high quality. Much better than any of the evo stuff harley ever put out their doors.

I have built two FATVO engines. One using Ultima cases and another using the now unobtainium Delkron cases. Each had their pros and cons but I think the Ultima was the better of the two right out of the box. This could be a simple bolt together engine, but an good machinist will get a lot more than someone just bolting one together.

Do yourself a favor and search 'FATVO' on this forum and every other harley forum you are on. This forum has two full pages of threads to read. Everything about this engine has already been said countless times here.
 
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#8 ·
I did a little Fatvo recon before I went 106" with my Evo. The TC top end will get you to 100" if you have a 3.875" bore on the TC cylinders using the 4.25" stroker crank, but you have to have the pushrod tube holes in the head modified to fit the new pushrod angles.

Probably why it's going for pretty cheap on eBay, nobody builds them anymore.
 
#14 ·
Personal Opinion Here:

I would never build another Evo, regardless of the crankcase. If you leave one in completely stock form, or at least Stage 1, you'll be ok, but anything after that should be avoided. Also considering I easily managed to get a 2000 Twin Cam engine and transmission into my 1994 Road King, why not get rid of older technology and go with newer?

PM me if you want more details on my opinion and why the TC is just a better engine.
 
#15 ·
Matt
i don't think anyone needs to PM you-
You are allowed to agree/disagree with other thoughts on here.
You might have a good one.
Or I might disagree with it .
No matter.
It would great if you just say whatever is on your mind.
It is all a learning curve.
We all have different experiances to draw from.
As for me, so far I have run with a passion from the Twinks!
It seems the net is overwhelmed with out of phase wheels, cam chest that is good for about 30K.
As I always say "no matter what HD you choose they all come with congenital defects and it is a matter of what you are familiar with and what you want to fix.
The M8 has already had a ration of problems.
My favorite engine case would be a Delkron 4 cam Big twin .
Albeit I have never owned one it would seem to be the best of all worlds.
They are just not available anymore.
 
#17 ·
Having fully rebuilt both engines, while also not being a professional engine builder but I am a mechanical engineer, the following is exclusively my opinion. I believe the TC is a better overall engine design for the following reasons (in no particular order):

The oil pump is on the inside of the engine
The breather system is actually filtered before it leaves the engine
The cylinder base gaskets aren't gaskets at all but o-rings
The engine actually comes with piston cooling oil jets
The pushrod angles are in better alignment with the rockers
The aluminum casting of is more porous and more prone to cracking and failure on OEM Evo castings
There is more integrity in the mating surface between the engine and transmission
The ignition system is self-contained (no timing cup to adjust)


That's all I can think of right now. Granted there are a couple of small pros with the Evo, but they pale in comparison to the faults.

Just keep in mind, the Evo is based heavily on the Shovel, which was originally designed in the 60's. The TC is new from the ground up (even though a LOT of Evo stuff bolts right onto it).
 
#16 ·
EVO with a little cleaning up in the heads a reasonable cam exhaust, AC and tune is a darn good running almost bullet proof engine. Start jacking with it more than that it could be a time bomb. There are some out there that built Big EVO's . The Shark is one they kicked ass even would today and held up. But those deep pockets were empty when done.
1996 Fb Engine stock still going strong engine never touched.
 
#18 · (Edited)
Agreed the harley evo cases in particular were a rough break. I know whent through the whole cylinder stud nightmare myself. I think what was said is accurate even though I'm a big fan of the evo the S&S evo cases bring another aspect. I cannot attest with any experience with a twin cam. Was always told if your building an up top screamer than the evo has an edge. Opinion olny with no real world experience. Honestly you couldn't give me stock evo cases after what I went through. But again if left low power both motors work
 
#19 ·
I've been riding for 59 years and always love tinkering changing front ends etc. I just recently decided to make my 01 fxst chopper with 3 over tubes harder to ride so I built my on parts for sucide clutch/ jockey shifter. But I just have never been clear as to why people want bigger engine's. I did own a Big dog Ridge back 117 cubic power plant. It was fun just for me it was unnecessary. Plus my most portant reason is money and skill. Not saying anything against big engine's I just never had the need. Oh by the way thanks for the great forum. Snake out
 
#20 ·
The look from the guy on his 30K$$$ plus bike as you pass him going up 4th O July is worth every penny!
He now has to question everything.
EGO.....I like to pass people.
I will admit I have the disease.
 
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