Help: Heads for 117" build

[Bagger]

Planning to build up my 107" to 117".   

I have a Tman 625G cam that I'd like to do the build around.  My dilemma is what to do about heads.  My objective is 10.5:1 static  CR and 9.6:1 corrected.   To achieve those CRs I need 92cc combustion chamber in the heads.  My Baisley heads are 87.2cc.  Preference would be to use flat top pistons. If I use a 0.040" head gasket the static compression is too high with 87.2cc heads.

Has anyone used a TMan 625 cam in a 117, if so how did you do your build?
Tman 625G specs:  Intake close 41; Duration 244 /246; Overlap 44

My objective is a tractor build, objective 120 TQ at 2400.  I'm a tourer, not a burn out, wheelie, or bar hopper.  Under 3500 rpm TQ to ride winding back roads, tour mountains and do 5000 mile rides without heat or mechanical issues. 

How would you do heads for a 117"

1.   Can the Baisley head combustion chambers be enlarged to 92cc?
2.   Start from scratch with another set of stock heads?
3.   Should I use 110 heads with dome pistons?
4.    Would 103 heads make for a better starting point with dished pistons.
5.   Should I use dished pistons with the Baisley heads?

Parts in red I intend to use in 117.

Present build:
2002 FLHRCI
107ci / 1746cc
Baisley Superstock Plus Heads (87.2cc  1.940" I / 1.630" E)
S&S 4 3/8" Flywheel
3.937" Axtell cylinders
3.937" CP Flat Top Pistons
0.030" Head Gasket
Wood TW5G cam
HPI 55mm TB
HPI 5.3 gm/sec injectors
Trask A/C
1.4kw starter & 9/66 tooth starter pinion & ring gear
Fuel Moto Jackpot Road & Track 2-1
3.37 Final gear ratio
Barnett Scorpion Clutch
Tuned by Sheffer Performance w/DynoJet Power Vision

[Ohio HD]

If the heads have the meat on them, take them down to 83cc and use S&S dished pistons.

[Bagger]

An 83cc chamber with a -12.0 dished piston and a 0.030 would put CRs where I'd like it.

[Ohio HD]

S&S 4.125" dished pistons are -10.9cc.

[Bagger]

Thanks Ohio, that is very useful information.  Actually that would work with a new head if necessary if I were to use a different head porter.

Here's is what I found Item #: 910-0318

This big bore cylinder and piston kit contains S&S 4-1/8" bore cylinders and forged 10cc dished dome pistons

https://www.sscycle.com/products/117-inch-low-compression-big-bore-kit-for-2007-16-big-twins-wrinkle-black-finish/

[turboprop]

Planning to build up my 107" to 117".   

I have a Tman 625G cam that I'd like to do the build around.  My dilemma is what to do about heads.  My objective is 10.5:1 static  CR and 9.6:1 corrected.   To achieve those CRs I need 92cc combustion chamber in the heads.  My Baisley heads are 87.2cc.  Preference would be to use flat top pistons. If I use a 0.040" head gasket the static compression is too high with 87.2cc heads.

Has anyone used a TMan 625 cam in a 117, if so how did you do your build?
Tman 625G specs:  Intake close 41; Duration 244 /246; Overlap 44

My objective is a tractor build, objective 120 TQ at 2400.  I'm a tourer, not a burn out, wheelie, or bar hopper.  Under 3500 rpm TQ to ride winding back roads, tour mountains and do 5000 mile rides without heat or mechanical issues. 

How would you do heads for a 117"

1.   Can the Baisley head combustion chambers be enlarged to 92cc?
2.   Start from scratch with another set of stock heads?
3.   Should I use 110 heads with dome pistons?
4.   Should I use dished pistons with the Baisley heads?

Parts in red I intend to use in 117.
Present build:
2002 FLHRCI
107ci / 1746cc
Baisley Superstock Plus Heads (87.2cc  1.940" I / 1.630" E)
S&S 4 3/8" Flywheel
3.937" Axtell cylinders
3.937" CP Flat Top Pistons
0.030" Head Gasket
Wood TW5G cam
HPI 55mm TB
HPI 5.3 gm/sec injectors
Trask A/C
1.4kw starter & 9/66 tooth starter pinion & ring gear
Fuel Moto Jackpot Road & Track 2-1
3.37 Final gear ratio
Barnett Scorpion Clutch
Tuned by Sheffer Performance w/DynoJet Power Vision

Have you considered maybe talking with Dan Baisley about his heads and your build plan?

[Bagger]

I intend to call Baisley.  Just want to have knowledge and options to explore. 

Also many good head porters on this site that could be used if I were to use a set of stock unworked 88" heads that I have.  Or would another head like a 103" be better as a starting point.

This will be the last hoo rah for a bike I've owned for 18 years.

[Ohio HD]

Catalog shows -10.9cc. Maybe check with S&S to see that this is correct.


[attach=0]

[Ohio HD]

"If" I were searching for new heads, I'd go after 110 heads with this bore and cubic inch. That of course changes what pistons you need. 

So you need a solid game plan before buying parts....   

[Bagger]

So you need a solid game plan before buying parts....

That's my objective.  And why I put it out on HTT so I can sift through all options. I'm hoping anyone who has used the TMan 625 cam in a 117" will weigh in too.

[kd]

MVA head are 95-96cc out of the box.  A slight trim puts them where you want them.  They won't need any other work and you can set them on .030 gaskets to get the quench you probably want.

[Don D]

Stock heads ported, kb dished pistons, S&S cylinders bored and honed to the pistons, 1.9 x 1.61 ex valves, light weight 7mm valves, conical springs. Economical purposely built for torque, use your cam.
Sell the Baisley heads, they will offset your costs.

[Bagger]

I'd be very satisfied with similar under 3500 TQ like in attached Dyno.

2002 Road Glide Built 09/2012
Don Dorfman's Heads (HD Street Performance)
Stock OEM 1999 head castings
2.00" Intake / 1.610" Exhaust
117 MTC pistons and cylinders
TMan 662-2 cams
Compression 10.8:1 /. CCP 196
Boarzilla
HPI 55mm TB
Tuned by GMR Performance

[Bagger]

Stock heads ported, kb dished pistons, S&S cylinders bored and honed to the pistons, 1.9 x 1.61 ex valves, light weight 7mm valves, conical springs. Economical purposely built for torque, use your cam.
Sell the Baisley heads, they will offset your costs.

Don, wouldn't stock heads ported be the same difference as the stock 2006 heads reworked by Baisley I'm running now in my 107"? In my previous post you reworked the stock 1999 castings and the sum of all parts created a very broad TQ curve.

I'm not committed to the Baisley heads, just want to make sure another head would provide gains over the Baisleys.  Again TQ from 2200 to 3500 rpms is of utmost importance.

[Hillside Motorcycle]

Planning to build up my 107" to 117".   

I have a Tman 625G cam that I'd like to do the build around.  My dilemma is what to do about heads.  My objective is 10.5:1 static  CR and 9.6:1 corrected.   To achieve those CRs I need 92cc combustion chamber in the heads.  My Baisley heads are 87.2cc.  Preference would be to use flat top pistons. If I use a 0.040" head gasket the static compression is too high with 87.2cc heads.

Has anyone used a TMan 625 cam in a 117, if so how did you do your build?
Tman 625G specs:  Intake close 41; Duration 244 /246; Overlap 44

My objective is a tractor build, objective 120 TQ at 2400.  I'm a tourer, not a burn out, wheelie, or bar hopper.  Under 3500 rpm TQ to ride winding back roads, tour mountains and do 5000 mile rides without heat or mechanical issues. 

How would you do heads for a 117"

1.   Can the Baisley head combustion chambers be enlarged to 92cc?
2.   Start from scratch with another set of stock heads?
3.   Should I use 110 heads with dome pistons?
4.   Should I use dished pistons with the Baisley heads?

Parts in red I intend to use in 117.
Present build:
2002 FLHRCI
107ci / 1746cc
Baisley Superstock Plus Heads (87.2cc  1.940" I / 1.630" E)
S&S 4 3/8" Flywheel
3.937" Axtell cylinders
3.937" CP Flat Top Pistons
0.030" Head Gasket
Wood TW5G cam
HPI 55mm TB
HPI 5.3 gm/sec injectors
Trask A/C
1.4kw starter & 9/66 tooth starter pinion & ring gear
Fuel Moto Jackpot Road & Track 2-1
3.37 Final gear ratio
Barnett Scorpion Clutch
Tuned by Sheffer Performance w/DynoJet Power Vision

Have you considered maybe talking with Dan Baisley about his heads and your build plan?

^^^^^^ What he said.

[Deye76]

Baisley heads don't come cheap. Have you considered custom pistons? Usually have to purchase 2 sets, so don't know what the cost comparison looks like. An option, maybe.

[turboprop]

Not speaking for Baisley, but I suspect Dan would prefer to open up those heads a bit by enshrouding the valves. Just a guess, but I would have hoped the OP would have gone to Baisley first instead of a bunch of online experts (including myself). Talk with Dan. Everything else is just peripheral noise.

[Bagger]

Not speaking for Baisley, but I suspect Dan would prefer to open up those heads a bit by enshrouding the valves. Just a guess, but I would have hoped the OP would have gone to Baisley first instead of a bunch of online experts (including myself). Talk with Dan. Everything else is just peripheral noise.

I'm going to call Baisley late this afternoon. 

[kd]

I expect you'll have a good chat and I hope we'll hear his suggestions. 

[Bagger]

I spoke with Dan Baisley this afternoon. Essentially this was the conversation

He pulled my file on my Super stock plus heads.  He asked me how I ride and what rpm range I normally stay within.  I told him what parts I'd be using.  I asked him if I should use my present heads, send another set to be reworked or send a set of 110 heads to achieve my goals.   Dan stated for what I want to achieve, he recommended that my present heads would be best.  That he would refresh the heads and setup for the TMan 625G TDC lifts of .245/.204.  He would keep the valves at 1.94"/1.630.

I asked him about enlarging the chambers.  He says he does not normally remove material from the combustion chamber, but important to make sure valves are unshrouded.  He doesn't want big chambers, tries to keep chambers small for burn efficiency.   I asked him what about using 110" heads.  He said I'd be wasting my money and possibly risk a loss of low to mid rpm torque I'm seeking, that the 110 heads would be better for top end power, higher revving engine.

I expressed a bit of concern about flame travel using a dished piston.  He said although flat top pistons would be ideal for the most efficient flame travel, my present heads, combustion chamber size with a dished piston would make for a fast burning, efficient combustion chamber and a good flame front surface.
 
He said his heads with this TQ cam will provide very good throttle response, acceleration and fuel economy.

[kd]

IMO Mr. Baisley is among the handful of guys out there that will not over sell you and definitely won't offer advice on what he doesn't know to be true.  There probably aren't many that have engineered or built as many powerful engines as he.  No need to mention the quality of work.  It sounds like the direction he is recommending (other than some extra shipping costs) won't break the bank either.

added later:

To be clear, we are very fortunate to have several others with the same high standards available to us here on HTT.

[Don D]

This is the piston I was referring to
KB 918c, early version 1.070 ch 7.2cc dish
4.125 +.005

[Bagger]

This is the piston I was referring to
KB 918c, early version 1.070 ch 7.2cc dish
4.125 +.005

Thank you for taking time to find piston. 

https://uempistons.com/i-30585-kb-forged-piston-twin-cam-96-big-bore-dish-7-2cc-117ci-2007-to-present-rod-7-667-piston-set.html

[Ohio HD]

Those KB pistons have a 1.076" compression height. The S&S 4.125" cylinders for a need a 1.050" compression height.

You'd have to run about a 0.045" to 0050" thick base gasket depending on the rod length, 7.659" or 7.667".

[Don D]

The current versions are 1.086 CH (for stock cylinder stack height) and more difficult to package with S&S cylinders. Their 117" cylinders are for 1.050 CH and a .020 base gasket. I take a 124" cylinder and cut it down to the proper height. No issues. I like to bore and hone them myself then I know they are right.