New Build 120R

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New Build 120R

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paulybronco
4 years ago

Quoting speedzter on 02 Jan 2020 01:29 AM
The numbers are a little bit strange (Pistons down the hole @ .028 front and .0275 rear) ?

Also it will take a fair chunk of milling to get to 11.5:1 , it will likely upset TDC valve to piston clearance depending on Cam choice.
What Cam ? 11.5:1 would be spot on for the S&S 640, around 9.5:1 corrected @ 200psi CCP .

Quoting Phatty on 02 Jan 2020 01:52 AMedited: 02 Jan 2020 01:55 AM
.028 and .0275 is how low the piston is from TDC in the barrel at it's highest point. The rear is only 1/2 a thou difference from the front.
I was asked by Krash to see where they sat. Cams are the S&S 640 Gear Drive. I have no idea what is involved in milling and all the other maching to get the compression.
The maching wont happen till next week after he checks it all out. I'll be talking to him Saturday to get info before it all goes ahead.

I am with speedzter here , why is there a difference in the tdc between the front and rear?

Phatty
4 years ago

Quoting speedzter on 02 Jan 2020 01:29 AM
The numbers are a little bit strange (Pistons down the hole @ .028 front and .0275 rear) ?

Also it will take a fair chunk of milling to get to 11.5:1 , it will likely upset TDC valve to piston clearance depending on Cam choice.
What Cam ? 11.5:1 would be spot on for the S&S 640, around 9.5:1 corrected @ 200psi CCP .

Quoting Phatty on 02 Jan 2020 01:52 AMedited: 02 Jan 2020 01:55 AM
.028 and .0275 is how low the piston is from TDC in the barrel at it's highest point. The rear is only 1/2 a thou difference from the front.
I was asked by Krash to see where they sat. Cams are the S&S 640 Gear Drive. I have no idea what is involved in milling and all the other maching to get the compression.
The maching wont happen till next week after he checks it all out. I'll be talking to him Saturday to get info before it all goes ahead.

Quoting paulybronco on 02 Jan 2020 02:25 AM
I am with speedzter here , why is there a difference in the tdc between the front and rear?

It's Half a Thousands of an inch, 1/1000 which is SFA. Nothing to worry about.

speedzter
4 years ago

It's not the difference, but the total amount.
It seems excessive to be almost 30 thou' in the hole.
It's best to aim for close to zero deck height, and set your quench(squish) between 30-40 thou'.
If your already.030 down, you should correct it via machining the cylinder height.

FONTANA302
4 years ago

Agree with Speedzter, machine the barrels to get zero deck for squish. There's something not quite right being that far down.

11.5:1 static isn't an issue depending on cams, dynamic compression is more important. Check my build - it's 0.000" deck, 0.030" head gasket, +6.1cc dome piston, 0.5cc above top ring, 94cc MVA heads (all cc'd by me) 11.39:1 static, 9.84:1 dynamic with the 662.2. Runs on 98 pump fuel no problem.

Put it on Fred's dyno (Pro Cycle in Brisbane) to tune with the "knockometer's" installed on the cylinder heads while tuning to check for added feedback re detonation.

Phatty
4 years ago

My Bad ( too many beers ), Mate said those measurements weren't for deck height ( Deck Height is 0 ) they were how much the clay got squised by the valves to check clearance in the piston valve cutouts. We still have .105 on exhaust and .095 on Intake after that measurment. I asked him to email me everything saves trying to remember .

fikmik
4 years ago

I have identical setup and bike is a weapon. Engine need much more maintenance then others. Tappets every 15000km if you choose JIMS otherwise 10000km. Dont change for adjustable push-rods as you asking for trouble. I have this bike from 2 years daily ride. Key to is with tune so find some one who understand how everything works and will tune as should. Many people complaining about 266 cams but i love it. Bike is very Lumpy and pulling like a truck.

fikmik
4 years ago

Quoting FONTANA302 on 11 Dec 2019 10:31 AM
Bandit Sportsman holds my 148hp/144 tq no problems - 120R motor:

Standard box & belt no problem.

Look in following thread.

https://www.hdforums.com.au/Thread/204981/78/

I saw 120R with full rebuild including Hurricane set compression 12:1 and was pulling almost 160HP.

tussuck
4 years ago

So why a SE120R and not say a S&S 120? Is it cost?

Krash Kinkade
4 years ago

Quoting FONTANA302 on 11 Dec 2019 10:31 AM
Bandit Sportsman holds my 148hp/144 tq no problems - 120R motor:

Standard box & belt no problem.

Look in following thread.

https://www.hdforums.com.au/Thread/204981/78/

Quoting fikmik on 17 Jan 2020 10:29 PM
I saw 120R with full rebuild including Hurricane set compression 12:1 and was pulling almost 160HP.

I think if you used a less aggressive cam, lifters would last a lot longer, only reason I say this is, the Twin cam have the lifters in the alloy cases, so if they fail they take the cases with them.

FONTANA302
4 years ago

Cost no issue. I just like doing scratch builds & picking what I think works best. Wasn't one thing untouched on my 120R, I just started with new bare screaming eagle cases, new bare MVA heads & new screaming eagle barrels (all modified). Nothing else Harley in mine... Only reason I call it a 120R is because of S&S 120R stroke crank & rod length. Bore size is larger than 120R & cases have custom timken conversion & lefty bearing in RHS amongst other mods.

If I bought an S&S motor I'd pull it apart & not use half the parts (just the way I am).

fikmik
4 years ago

Quoting FONTANA302 on 11 Dec 2019 10:31 AM
Bandit Sportsman holds my 148hp/144 tq no problems - 120R motor:

Standard box & belt no problem.

Look in following thread.

https://www.hdforums.com.au/Thread/204981/78/

Quoting fikmik on 17 Jan 2020 10:29 PM
I saw 120R with full rebuild including Hurricane set compression 12:1 and was pulling almost 160HP.

Quoting Krash Kinkade on 17 Jan 2020 11:40 PM
I think if you used a less aggressive cam, lifters would last a lot longer, only reason I say this is, the Twin cam have the lifters in the alloy cases, so if they fail they take the cases with them.

Correct that why you need to change Lifters every 15K. If you can afford to have 120R you also should do proper maintenance. If you don't do you will destroy engine and you can blame only you self

Deputy Dog
4 years ago

Quoting speedzter on 02 Jan 2020 01:29 AM
The numbers are a little bit strange (Pistons down the hole @ .028 front and .0275 rear) ?

Also it will take a fair chunk of milling to get to 11.5:1 , it will likely upset TDC valve to piston clearance depending on Cam choice.
What Cam ? 11.5:1 would be spot on for the S&S 640, around 9.5:1 corrected @ 200psi CCP .

Quoting Phatty on 02 Jan 2020 01:52 AMedited: 02 Jan 2020 01:55 AM
.028 and .0275 is how low the piston is from TDC in the barrel at it's highest point. The rear is only 1/2 a thou difference from the front.
I was asked by Krash to see where they sat. Cams are the S&S 640 Gear Drive. I have no idea what is involved in milling and all the other maching to get the compression.
The maching wont happen till next week after he checks it all out. I'll be talking to him Saturday to get info before it all goes ahead.

Phatty, I too have a 120R in my streetglide. its been in since 2015. Changed the lifter to S&S and install S&S roller rockers even before i installed it. Not one ounce of problems since, running standard clutch with heavy duty diaphragm and centrifugal pressure plates. Just make sure you have it tuned by someone that knows what the fuck there doing.

Phatty
4 years ago

A little bit more info from the mate, The head gaskets that came of were .050" and he has special ordered the .025" gaskets ( I asked him to order 2 extra sets as spare )
Heads have been milled 10 thou and with the .025" less head gasket we should be good for compression. I will be using Adjustable pushrods that came with the Gear Drive Cam Set from S&S. I'll have a chat with him again on the weekend.

Deputy Dog, Mate says the same as you. Once I get it I'll have to look around and see who's the tuner Guru.

A bit more of what's going into her.
AV&V beehive springs
Roller Rockers
Offset rocker support plate
Cometic .025" head gaskets ( Special Order )
+1.5 quart oil pan

KiwiRob
4 years ago

Those head gaskets are a bit thin Phatty if you are indeed running 0 deck clearance. Most people run 0.030" as a minimum to allow for carbon build-up. - Rob

Krash Kinkade
4 years ago

Quoting KiwiRob on 04 Feb 2020 09:18 PM
Those head gaskets are a bit thin Phatty if you are indeed running 0 deck clearance. Most people run 0.030" as a minimum to allow for carbon build-up. - Rob

I agree with KiwiRob, too tight swish & at different stages ( like start up & until motor warmed ) things are kissing. happens on all out race motors but they don't ride that far before rebuilds. a street bike you want to be able to ride with out worrying.

Phatty
4 years ago

Mates just installed the gaskets and heads and has done clearance checks with clay, 0.060" on the Intake - 0.080" on the Exhaust - .050" of eyebrow clearance.
He says theres a workshop downtown that has a stand where they hookup the motor and give it a run.
He asked if the bike was going to be cable or TBW, The one that came with the motor is cable. I want to do a Fatboy S 2017 last of the Twincam so TBW.
Couple of options we have are CVO SE 58mm or one of the Horsepower Inc 58mm.

I asked him about the gasket being too thin, He said All good and it's getting setup spot on . we'll see how it goes.

Topics

2/2

New Build 120R

New Build 120R

paulybronco

Phatty

speedzter

FONTANA302

Phatty

fikmik

fikmik

tussuck

Krash Kinkade

FONTANA302

fikmik

Deputy Dog

Phatty

KiwiRob

Krash Kinkade

Phatty