V-Twin Forum banner

1 - 20 of 20 Posts

·
Registered
Joined
·
51 Posts
Discussion Starter #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?
 

·
Registered
Joined
·
69 Posts
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.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #4
Thanks. I was just curious about them. I’m pretty ignorant to building HD motors . Actually I’m getting fairly well educated through this forum and YouTube. There is a build in the near future for me. Just not sure which direction I’m going to go yet.
 

·
Registered
Joined
·
69 Posts
There two schools of thought-
Bolt on the inches, or massage what you have.
The latter takes more finesse.
In either case, if you shoot for one to one you will have a lot more then HD. They are about 60 to 70 %
 

·
Registered
Joined
·
246 Posts
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?
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.
 

·
Registered
Joined
·
126 Posts
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.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #9
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.
Thanks Mattbastard. Why do you think nobody is building them anymore?
 

·
Registered
Joined
·
246 Posts

·
Registered
Joined
·
126 Posts
Thanks Mattbastard. Why do you think nobody is building them anymore?
I don't THINK they're as popular as they used to be now that S&S has created their Special Application cases that come with piston oil jets and it bolts right up in a stock Evo location, and go all the way up to 124".

Think about it, when it comes to feasible, tried and true builds you've got:

96" in the stock, Evo cases with case boring
100" in the Fatvo with some head work and a longer pinion shaft in Evo crank w/ .927 end rods
Up to 124" with the S&S SA cases

The Fatvo case is similar to the SA case, it's just got cylinder stud spacing for the TC top end where the SA case is spaced for the S&S cylinders and top ends. You've still gotta modify the heads to work with the Evo pushrod geometry, and you have to have the 1/4" longer pinion shaft and Fatso rods installed on your Evo crankshaft (and subsequently trued and balanced) to make the Fatvo bottom end work. All that adds to the costs, and you're still stuck with an engine under no warranty. The S&S engines come with one, and bolt right up with no downtime. Granted, the 124" is MUCH more expensive depending on your build specs, but after my 106" Evo build I've given up building engine combinations that aren't very popular. Call it what you will, I just feel better building engines that many other people have done rather then me being a guinea pig.

Having said all that, Ultima also offers a Fatso short block that comes with the crank and proper rods and all you need is a TC top end (with proper pushrod holes).
 

·
Super Moderator
Joined
·
19,319 Posts
Back when 113's were at the top of the evo food chain, Fatvo's gave you 100 inches for less money out of pocket.

Then when the 120+ inch evos showed up, the Fatvo's died right along with the 113's.
 

·
Registered
Joined
·
126 Posts
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.
 

·
Registered
Joined
·
69 Posts
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.
 

·
Registered
Joined
·
2,937 Posts
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.
 

·
Registered
Joined
·
126 Posts
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.
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).
 

·
Registered
Joined
·
1,312 Posts
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
 

·
Registered
Joined
·
1 Posts
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
 

·
Registered
Joined
·
69 Posts
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
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.
 
1 - 20 of 20 Posts
About this Discussion
19 Replies
9 Participants
troqed
V-Twin Forum
V-Twin Harley Davidson forum. Discussion on V-Twin Harley Davidson motorcycles including Dyna, Electra Glide, Softail, Sportster, and more.
Full Forum Listing
Top