H-D 120R Engine - New or not?

[GoSlo]

Maybe I've missed other threads on this, but don't remember seeing anything about a H-D 120 engine before. Don't know the specs, but was curious if others know something about it. Good or Bad? Reliable or POS? Worth the price (it does have the H-D logo, so I know you're paying extra)? Saw one in our local dealership and they said it won't void any warranties even though it says for "race use only", but that's what the SE pipes say too.

Thanks!

[geezerglide11441]

Maybe I've missed other threads on this, but don't remember seeing anything about a H-D 120 engine before. Don't know the specs, but was curious if others know something about it. Good or Bad? Reliable or POS? Worth the price (it does have the H-D logo, so I know you're paying extra)? Saw one in our local dealership and they said it won't void any warranties even though it says for "race use only", but that's what the SE pipes say too.

Thanks!

I have a 120r installed in my 2013 Trike that I just had to re-build completely due to the front cylinder intake lifter coming apart and destroying the motor completely!! I re-built the motor with the components that I wanted to have in the motor in lieu of the OEM components that came with the original factory configuration. The main things I changed was the lifters, adjustable push rods, the Valve springs, with the main thing being the cams. I basically dumbed down the performance a little to give it better street manners - i.e. the original 120r is a race motor to be used in the old "All Harley Drags", drag-gin bagger class.

The original cams were the SE 266E cams that developed their HP/TQ in the upper rpm range were I do not normally ride. I installed the motor in 2010 in my 2008 Ultra Classic bike (since traded in for the Trike). In my opinion, the SE120r is a little to much for a normal street rider with the components of the factory build - a little lazy down low but 2500rpms and above it will put a smile on your face!!!

I have been hearing rumors of a factory 120st designed for a street application with a little less aggressive cams, etc. However, I don't know much about it at this time. I did hear (not sure of the accuracy) they put the SE 259E cams in, which I think will make it a better street application - i.e. less lift, less duration and over lap, and the intake valves close a little sooner as well. Also heard that if one has the new 120st motor purchased and installed at a dealership that it can be warranted, but I would most certainly have all the above comments verified as my original 120r did not have a warranty when it was un-crated!!! The re-build was totally on me!!

Roger

[msocko3]

When they 1st come out with the 120R is was much talked about and sought after, the early ones seem to be the best ones. The later ones seem to have some issues here or there. I know of one guy who tours and drag races with a very heavily modified 120R, If I remember right he has right around 40 - 45,000 trouble free miles on it. As geezerglide11441 pointed out, it is a race engine with some pretty aggressive cams and heavy valve springs to go with it.

Harley did come out with the 120ST this year http://www.topspeed.com/motorcycles/...-ar167976.html.

The published HP and Torque numbers are with a street legal canned map, a good tuner can do more. As a good example of what can be had with a good tune vs a canned map, here is a dyno chart from a 120ST, a far cry from the published 106hp 117ft/lbs or torque.

IMO I don't think it will be long and you'll see the 120ST in the CVO bikes and possibly the 110 in some other bikes and maybe the Triglide.

[Trent]

If & when my current motor ever blows up on me {which I secretly hope it does...and I will keep trying}, I will slap in one of these and tweak with it even more. I have the 259E cams now, and am very happy with those long legs that stroll effortlessly up the mountain roads around here. A certain individual at my dealership sez he was told this 120 will come as an option in the CVO's and Trikes in the next coupla years. I know 2 guys that have 120's in their TG's, but they got 'em before the 259E cam came with them. It took several tanks of gas to dial them in as our dealer does not have a dyno for Trikes. Both riders are very conservative riding Older but Goodier Gentleman than me, and don't ride like a primate as I am prone to sometimes do.
The very limited times I have accidently been around them, I don't think they ever got out of 4th gear. I would sure like to get on one and take it for a spin though.

[FLTR2008TRIKE]

I would recommend when you decide to go to a larger engine, bore your stock cases to either a 113" or a 117". ( You get to keep the stock engine case to match the frame )

You have two options with the flywheels

A) Have your stock wheels worked over by Hoban Brothers or Darkhorse Crankworks

B) Or Buy a S&S 3 piece flywheel assembly

Have your stock heads re worked to improve the air flow for intake and exhaust to match the cams the head porter recommends based on what your wanting for power and your engine size

2 New Screamin Eagle lefty bearings for both the left and "right side"

New stock oil pump and cam plate

New S&S or GMR lifters

New adjustable pushrods

New cam tensioner shoes assemblies

New stronger clutch pack or clutch assmebly

Depending on your expectations, these might have to be factored in

New exhaust

New larger Throttle body or at the minimum a over bore of your stock TB

New larger injectors

Definitely will need to be tuned ( Figure $500-700 )

Bigger power and torque comes a emptier wallet.... be prepared

- - - Updated - - -

PS....

Currently Im running a 124" in my trike. There is something that has to be told to anyoneinterested in a long stroke engine such as a 120" or a 124"......

You cannot lug the engine in the lower rpms.......period!!

Doing that will drastically shorten the life of the engine. The 4 5/8" long connecting arm requires the engine rpms be maintained 300 to 400 rpms more than what you generally ride in.

[Trent]

I am at full stage 4 right now. If it blows up, I will not bother doing all that stuff. Just drop in a a new HD 120ST and make a few tweaks. Not concerned about the $$ thing.

[FLTR2008TRIKE]

I am at full stage 4 right now. If it blows up, I will not bother doing all that stuff. Just drop in a a new 120 and make some tweaks. I don't worry about the $$ thing.

Why bother with tweeking a 120 when you can buy a S&S 124" LC and drop it in with a 1 year warranty and run on with it??

[Trent]

Good point... I will certainly consider that as I do like what I have read about S&S,, Gotta blow mine up first!

[msocko3]

Why bother with tweeking a 120 when you can buy a S&S 124" LC and drop it in with a 1 year warranty and run on with it??

The S&S with a warranty does look like a good choice. If they had offered it before I built my 120, I'd have bought one of those.

[3rdwheel]

Well, today I was offered a super good deal on the ST120 engine since I've had more than a few major issues on the 113 I had them build. HD offered to repair again for free (tear down for the second time) or get the 120 for cost with a "no charge" installation; and they still completely repair the 113 on the bench for sale by me.
I get the 1 year warranty, and maybe at the end of that I'll do a cam change - depending on how it feels.
My goal is for dependability and "guts".
There is not much information on the 120ST available, but the local dealer has sent 4 of them out the door with excellent satisfaction and performance.
So much for a long riding season. Everyone at HD knows me too well from all of my weeks (months) of shop time.
I'll keep you posted.

[RickDeVon]

3rdwheel I would go for the 120ST....

[geezerglide11441]

Well, today I was offered a super good deal on the ST120 engine since I've had more than a few major issues on the 113 I had them build. HD offered to repair again for free (tear down for the second time) or get the 120 for cost with a "no charge" installation; and they still completely repair the 113 on the bench for sale by me.
I get the 1 year warranty, and maybe at the end of that I'll do a cam change - depending on how it feels.
My goal is for dependability and "guts".
There is not much information on the 120ST available, but the local dealer has sent 4 of them out the door with excellent satisfaction and performance.
So much for a long riding season. Everyone at HD knows me too well from all of my weeks (months) of shop time.
I'll keep you posted.

As you say, if "Dependability and guts" is your main goal, I would strongly suggest the 120ST, and if you want to drag race the bike go with the 120r!! The 120ST will be more "street friendly" than the 120r in my experienced opinion. I am extremely satisfied with the "seat of the pants" performance of my re-build, and also have decent fuel mileage as a bonus. I re-built my 120r after a massive breakdown (front intake lifter roller detonated and completely wiped out the motor) and went with the T-Man 577 cams and beehive valve springs. This cam has very similar specs as the SE 259E and pulls very hard about 200 to 300rpms sooner then the SE 266E.

Good luck with what ever decision you make, and let us know the results!!

Roger

[fuelmoto]

We have extensive experience with the Harley 120 motors and find them a really good platform to work off of. The only real weak link we have found is the SE lifters that come standard in those motors, we have seen several roller failures that have taken out the camchest and associated components. We generally recommend swapping to a better lifter right from the start. The 120 also benefits significantly from a cam swap, plenty of good options out there. We like to do some mild headwork, set the compression to 11.0 and use the Wood TW-9B cam, and they will roll in the upper 130's hp/tq with a strong hit off the bottom. For those looking for more we offer 124" kit that is bore only and with the right combo will make north of 150+HP, all depend on what the customer is looking for

[Steve Cole]

Look we are talking about a Trike. 11:1 isn't going to last long in a normal touring bike, put it into a Trike and it will be a short life. The 120R and 120 ST are the exact same engine with a few small differences. The camshaft is changed and the 120ST comes with the 58mm Throttle body and injectors for the same cost. Bank for the buck is the ST version that's for sure. If you want to bolt it in and get a warranty your going to have to let the dealership do it. If warranty isn't a concern then get the ST version and have a good builder open it up and clean up what HD left behind. You cannot build one for the cost of the ST and you still have the original engine to sell or put on the shelf. A trike needs a good low RPM camshaft as your going to be riding in the 2000 - 3000 RPM area for over 90% of the time your riding it. So match components to that RPM area have a very enjoyably ride.

[msocko3]

Look we are talking about a Trike. 11:1 isn't going to last long in a normal touring bike, put it into a Trike and it will be a short life. The 120R and 120 ST are the exact same engine with a few small differences. The camshaft is changed and the 120ST comes with the 58mm Throttle body and injectors for the same cost. Bank for the buck is the ST version that's for sure. If you want to bolt it in and get a warranty your going to have to let the dealership do it. If warranty isn't a concern then get the ST version and have a good builder open it up and clean up what HD left behind. You cannot build one for the cost of the ST and you still have the original engine to sell or put on the shelf. A trike needs a good low RPM camshaft as your going to be riding in the 2000 - 3000 RPM area for over 90% of the time your riding it. So match components to that RPM area have a very enjoyably ride.

A good many folks on the road wouldn't ride a 11:1 build correctly, lugging is the norm for a lot of riders.

[FLTR2008TRIKE]

A good many folks on the road wouldn't ride a 11:1 build correctly, lugging is the norm for a lot of riders.

Set my 124" @10.2 which is as far as I would suggest any engine for a trike. Another thing to consider, Long stroke 4 5/8" engines "HAVE" to be ridden with the rpms up higher between shifts. Otherwise the possibility of the flywheels shifting can happen lugging the engine in the lower rpms.

[dirtdobber]

When I built my super glide. It was bought for this. I struggled with either a 120r, ss124, or build a 113.
I decided to go with a 113 for several reasons. I had control of all the components. That way it was built to my specs. I really wish it would fit my trike I would trow in in quick.
What I am aiming at is this: built engines out of a crate you are solely dependent on how it is built. So, welded cranks, truing etc.... is out of the window,
I do not have a warranty I do believe it will out last any of them I mentioned.
You have to be careful with a high performance engine in a trike. I found that out the hard way.

[fuelmoto]

When doing mods of this nature you need to look at the entire combination and develop a package of components that complements each other. The SE 266 cam that comes in the 120R is not going to be trike friendly, it is going be a bit soft on the bottom, there are plenty of options there. As far as static compression it all comes down to the cam you are using and how much it bleeds off, as well as the rest of the combination. As msocko noted a high compression build is certainly not for everyone or ideal in many applications, nor is a 120R in a trike; fortunately there are many options in between. It all comes down to what the individual is looking for and putting together the right combination that fits their needs and requirements.

[eighty80]

Well,well,well, the wonders of the 120R crate motor in a TriGlide.

Just because it's a 120R motor does NOT mean that there will be no other things to consider.

Is the rider willing to keep the R.P.M.'s above 3000 all the time?

Is the rider willing to pay for a good tuner and a dyno by an expert?

Is the rider willing to pay for premium fuel at all times?

Is the rider willing to install a premium exhaust?

Is the rider willing to upgrade the clutch?

Is the rider willing to pay for the proper cooling, it's a race motor.

As you can see, there is a lot to take into consideration. I just get tired typing.

What is a blast to one person may not be for someone else.

I will say this from my experience, I will not take my 120R TriGlide on any parades or poker runs again.

There is some good people on here, (Msocko3) as an example, do your research.

Eighty80.

[FuzzyWuzHe]

I just gotta say ... I'm loving having fuel motto aboard as a sponsor .. lots of keen info coming to TT ... thanks for sharing your knowledge and experience.