48H and compression

[Big Dave]

Question for the builders and Dyno Guys

I have a 09 FLHTCU 96 inch Bagger

Running 48 cams otherwise basic stk , with air cleaner and slip ons

CCC 192 front 194 rear , I think stock compression was advertised as 9.2-1

I have new 103 pistons from a wethead 2015 advertised as 10.1-1

I was just going to get my cylinders bored to match the pistons but wondered if 48s would handle a bump in Compression

Riding style is heavy touring 25-3500 rpm so low end torque is what I need

cams were great in a stk 96 , only doing this as i have to pull the heads for seals and breathers

Thanks

Dave

[838]

I ran a 95" at 10:1 with the 48. It was great. Needs an ace tune. 103" will rip 👍👍👍

[Barrett]

There's one listed here in a 103"
https://university.fuelmotousa.com/article/h-d-twin-cam-103-camshaft-shootout/

[Big Dave]

I have looked at those my only concern was the wet heads had more compression versus the air cooled 103

Im doing it but was wondering what to expect - lived my life - no replacement for displacement

Dave

[harpwrench]

Wet heads higher compression is from smaller cc heads, same pistons either way

[Big Dave]

Thanks i'm good to go

Dave

[PoorUB]

Use a .030" head gasket, not the stock .045". You will end up with 10.15 to 1 static compression.

[Big Dave]

Thank you

Dave

[rigidthumper]

What is your tuning plan?

[Big Dave]

Powervision canned map then the Dyno

Dave

[PBSTN]

I don't know if they're needed. But you might install mcr's while the heads are off.

[Big Dave]

Would be a bone head move not to I think , dont want to go 

Dave

[rigidthumper]

I think you'll really like that combo. If you can, measure/trim the cylinders to zero the deck height- helps with detonation.

[838]

0 deck and .030" will put you at close to 205ccp. That'll be one snappy ride!!! Can the 48 be tuned at this compression?

To the OP... I notice every time there'sa new thread on the Andrews 48 it gets lots of (good) attention 👍.

[838]

It tuned real easy at 10:1. Which would be the .030" head gasket and no zero deck (assuming pistons down a few thousandths in the hole). But (as ridged said) the tighter quench helps detonation so might even do better at 10.15... but that's a question for an expert. I'm just a dude that ran the 48 successfully at 10:1 👍.

[Big Dave]

Real experience is worth a lot

Thanks

[PoorUB]

As much as guys like the 48, I ran them in a stock 103 and they felt pretty soft. A slight compression bump would help. Also, im my opinion Andrews compression recommendations are on the conservative side.

The .030" head gasket with raise cold cranking compression from 197 PSI to 204. If the guy doing the tuning can't tune it at 204 he probably can't tune it at 197 either.


Similar to Andrews 57's. They are supposed to be a drop in but they are kinda flat with stock compression, but haul real nice when you get close to 10.5 to 1 compression.

[Big Dave]

Thanks I like what your saying , waiting on the pistons in the mail then its time to start pulling parts 

Dave

[sfmichael]

depending on the miles of the bike I would recommend a valve job especially if you have access to a performance machine shop that can perform a good multi angle valve job

a performance valve job will add some very inexpensive horsepower and new valve stem seals are a plus

[Adam76]

depending on the miles of the bike I would recommend a valve job especially if you have access to a performance machine shop that can perform a good multi angle valve job

a performance valve job will add some very inexpensive horsepower and new valve stem seals are a plus

Hey sfmichael, I'm still learning. Can you please explain what a 3- angle valve job actually
does to increase performers.. does it increase chamber volume?  How exactly does it help?
Thanks

[Don D]

Harleys stock valve job is 3 angles. Performance shops such as mine have seat angle combinations that enhance flow and are more concentric than a stock valve job, that is the goal.
Short story
When I was 21 working flat rate for a Mercedes dealer doing heavy line I told the boss I was doing a "competition valve job" on the MB heads. He looked and laughed, the valve job was 3 angles and the same as stock. Back then we used stones. that was a long time ago and some of the other terms being coined were "3/4 race cam"   

[Adam76]

Harleys stock valve job is 3 angles. Performance shops such as mine have seat angle combinations that enhance flow and are more concentric than a stock valve job, that is the goal.
Short story
When I was 21 working flat rate for a Mercedes dealer doing heavy line I told the boss I was doing a "competition valve job" on the MB heads. He looked and laughed, the valve job was 3 angles and the same as stock. Back then we used stones. that was a long time ago and some of the other terms being coined were "3/4 race cam"   

OK thanks,  that's really good to know. So if a 3 amble job is not much better than stock....  what exactly is a competition valve job?  And if you could only do one thing to improve a set of heads, what would it be? Thanks

[Don D]

And if you could only do one thing to improve a set of heads, what would it be?

My point was about the advertising being attached to what is just good machine shop practices.

One thing OK, Our Blueprint Package includes a Serdi valve job that includes 5 seat angles intake and 3 exhaust plus a radius, two angles on the valves. A little port clean up and heads CCd, $275, if guides replaced add $100, plus shipping.

[Adam76]

And if you could only do one thing to improve a set of heads, what would it be?

My point was about the advertising being attached to what is just good machine shop practices.

One thing OK, Our Blueprint Package includes a Serdi valve job that includes 5 seat angles intake and 3 exhaust plus a radius, two angles on the valves. A little port clean up and heads CCd, $275, if guides replaced add $100, plus shipping.

👍👍

[Arseclown]

Depending on where you are and ride (climate and fuel), at round 10.1-10.2:1 cr I'd consider the s&s570 cam which also comes with the ezy start feature.

[sfmichael]

depending on the miles of the bike I would recommend a valve job especially if you have access to a performance machine shop that can perform a good multi angle valve job

a performance valve job will add some very inexpensive horsepower and new valve stem seals are a plus

Hey sfmichael, I'm still learning. Can you please explain what a 3- angle valve job actually
does to increase performers.. does it increase chamber volume?  How exactly does it help?
Thanks

As Don already stated a good valve job done by in a controlled machine shop environment will almost always be better than what a factory can produce. Think quality vs. quantity.
Also while a good 3 angle job is fine, a 5 angle along with back cutting the valves will typically enhance flow a measurable amount.
In a machine shop environment much more attention to detail is typically afforded and the end result in the hands of a good machinist will always be superior. No knock against the factory, their stuff works fine...but a hand-tailored suit will usually fit better than off the rack 

[838]

And Don did this exact job for me on a 95" at 10:1 with an Andrews 48. At the same time I had a stage 2 bike 96" with an Andrews 48... the 95" with the blueprint won in every aspect.

[Hossamania]

Horsepower is in the heads.

[Adam76]

And Don did this exact job for me on a 95" at 10:1 with an Andrews 48. At the same time I had a stage 2 bike 96" with an Andrews 48... the 95" with the blueprint won in every aspect.

Nice, never seen a 95" with 48s... what numbers did you end up with?
Thanks

[838]

It never saw a dyno. It was tuned using twin scan. It ran great though. There's something about that 4" stroke motor. Smoothest roll on power delivery of any Harley I've ridden. Roll on it at 70 and it was instantly at 90. even 2 up and loaded full dresser.

Run it at 10:1 and get the heads cleaned up... ran great and no detonation, even in 100+ weather and CA pump gas.

A standard bolt in A48 with a 96" goes 105/95... I'd say this one was close to 120tq but nosed off completely by 5k.

[Adam76]

It never saw a dyno. It was tuned using twin scan. It ran great though. There's something about that 4" stroke motor. Smoothest roll on power delivery of any Harley I've ridden. Roll on it at 70 and it was instantly at 90. even 2 up and loaded full dresser.

Run it at 10:1 and get the heads cleaned up... ran great and no detonation, even in 100+ weather and CA pump gas.

A standard bolt in A48 with a 96" goes 105/95... I'd say this one was close to 120tq but nosed off completely by 5k.

Wow, that's impressive.   

[Big Dave]

I'll close this off for those interested

Cylinders bored to 103 , mild port on heads , Stk valves with new grind, heads milled .010 ,Big boyz calculator shows me at 10.01 and 196.5 CCP with the 48 cams

Canned tune from fuel Motto -- Dyno set for mid April

I have a very strong running bike with the pull right where i ride , I haven't push it yet due to brake in

So Far So Good 

Dave

[838]

You'll have lots of fun with that 👍. Looking forward to the dyno sheet. Post it when you get it done!

[sfmichael]

should be fun - who did the heads?

[Big Dave]

All the work was done by Outlaw V Twin in Kelowna BC Canada

Jem of a shop that dosnt advertise much , I found them through A racer in Calgary that ships all there bikes and work to him

Full machine shop , restorations and dyno tuning , Fellows name is Josh and is by recommendation only

Super nice guy that answered all my questions and just made me comfortable

Dave

[sfmichael]

 

[Big Dave]

Set to ride the drum Friday April 16 th

Running really well ---- Had to replace the clutch though 

Dave

[838]

Set to ride the drum Friday April 16 th

Running really well ---- Had to replace the clutch though 

Dave

Did you get it on a dyno yet?

[Big Dave]

Sorry -- The drum is my slang for the Dyno  --- Next Friday

Dave

[kd]

Are you actually riding this bike without a tune or AFR check?   

[Adam76]

Set to ride the drum Friday April 16 th

Running really well ---- Had to replace the clutch though 

Dave

Nice Dave, what clutch set up did you go with?

[Big Dave]

Are you actually riding this bike without a tune or AFR check? 

Of course not as per prier post tune with power vision canned maps plus auto tune runs untill I can get on the drum ( Dyno )

Dave

[Big Dave]

Set to ride the drum Friday April 16 th

Running really well ---- Had to replace the clutch though 

Dave

Nice Dave, what clutch set up did you go with?

Stock clutch with newer SE pressure spring , When it started slipping i pulled it apart and found it was just plain worn out

Dave

90,000 nothing lasts any more

[Adam76]

Set to ride the drum Friday April 16 th

Running really well ---- Had to replace the clutch though 

Dave

Nice Dave, what clutch set up did you go with?

Stock clutch with newer SE pressure spring , When it started slipping i pulled it apart and found it was just plain worn out

Dave

90,000 nothing lasts any more

Thanks Dave, I'm also replacing my clutch spring with a new one, the trike one that's rated just under the SE one - and possibly a new set of Barnett Kevlar clutch plates or something similar while I'm in there

At 90,000kns you're not still in your stock clutch plates are you? 🤔
Cheers. 👍

[Big Dave]

Original clutch

I Replaced the steels and fibers , the were still in spec , just barely , with the SE spring I'm sure I'll be fine its a touring bike and thats what we do

Dave

[Adam76]

Original clutch

I Replaced the steels and fibers , the were still in spec , just barely , with the SE spring I'm sure I'll be fine its a touring bike and thats what we do

Dave

👍 thanks. I'll check my steels and fibres for spec before replacing.

[838]

👍. How you liking that  roll on power at highway speeds?  That's where my 48 build was the most fun for sure.

Great  power delivery everywhere in the touring rpm range, Have fun with it now!

[Big Dave]

The smoothness when you roll on is unbelievable , Im really happy with the bike

Thanks

Dave

I guess this is done they pull any reference to the dyno sheet

[kd]

Dave, there are rules on posting dyno results (sheet) and the format they are printed in.  This is to standardize the picture they paint for some readers that are not familiar with correction factors in the dyno numbers and graph.  Read the posting rules in the dyno section and see if you can meet the test before posting it.  I don't remember what your graph was standardized to but I expect it missed the mark.

[Ohio HD]

  @KD   

The sheet was in STD and not SAE. They should also be posted in the dyno section and format the post title appropriately.

[Big Dave]

The sheet I posted was not for bragging rights it was asked for

That was what I received from the tuner and Im happy with the ride

Im out

Dave

[Ohio HD]

You're not being picked on, these posting rules for dyno sheets applies to everyone.


https://harleytechtalk.com/htt/index.php/topic,79401.0.html

[kd]

   I will add that it is my observation that properly posted sheets and specs in the dyno section tends to garner more and very valuable conversation that benefits all members with a record in the dyno section.  That's where we all go to determine the value of various combinations.  It's not about bragging rights, It's about building an information bank that is useable.  I remember how I used the section to build my engine and was grateful for all of the help from members that posted and commented there.  Consequently, I returned the favor by posting my results and rideability comments there too.  Recalling your searches for info here when you were making build decisions, I suspect you already understand.   

[Adam76]

I'll close this off for those interested

Cylinders bored to 103 , mild port on heads , Stk valves with new grind, heads milled .010 ,Big boyz calculator shows me at 10.01 and 196.5 CCP with the 48 cams

Canned tune from fuel Motto -- Dyno set for mid April

I have a very strong running bike with the pull right where i ride , I haven't push it yet due to brake in

So Far So Good 

Dave

Dave, thanks for sharing your info.

Curious to know at 196ccp - did you install compression releases? Do you have any trouble with hot starts?
Thanks

[Big Dave]

I had manual comp releases installed and have forgotten to use them , on a hot start it is a bit slow but starts every time 

Dave

[Adam76]

I had manual comp releases installed and have forgotten to use them , on a hot start it is a bit slow but starts every time 

Dave

Thanks👍