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[smkymtnboy]

  I know the hd specs states compression is 9.2:1 on a 110 c.i.  on three separate occasions at two different dealerships they are telling me the water cooled versions are running closer to 10:1. just wandering bs or not. oh, yes they are referring to the 2015 models.

[Para Bellum]

I wondered about that too.  Thought I saw somewhere HD said they had boosted compression, and later noticed specs still said 9.2:1

[GMR-PERFORMANCE]

CVO engines are still running the same compression as non water cooled. This information is directly from pulling the heads CC'ing the chamber..  HG is approx the same thickness .048 crushed and still in the range of 95 cc chambers.

Now the 103 twin cooled was said to have increased compression. again based on real world measuring still 84-85 cc chambers HG is .045/.048 crushed same old flat top piston.


Where HD came up with the increase thing I cannot guess on that nor do I care.

9.8 on 103 engines and 9.3 avg on CVO. 

[smkymtnboy]

CVO engines are still running the same compression as non water cooled. This information is directly from pulling the heads CC'ing the chamber..  HG is approx the same thickness .048 crushed and still in the range of 95 cc chambers.

Now the 103 twin cooled was said to have increased compression. again based on real world measuring still 84-85 cc chambers HG is .045/.048 crushed same old flat top piston.


Where HD came up with the increase thing I cannot guess on that nor do I care.

9.8 on 103 engines and 9.3 avg on CVO.

thanks for responding!

[GMR-PERFORMANCE]

Just an FYI you can buy a Cometic .030 for the twin cooled, it has been out for some time.. If you decide to increase the compression. Make sure you have the correct gasket. 

[Mr D]

Just an FYI you can buy a Cometic .030 for the twin cooled, it has been out for some time.. If you decide to increase the compression. Make sure you have the correct gasket. 

Using a .030 on a 103 wethead, what kind of a bump in compression?

[GMR-PERFORMANCE]

2 tenths approx so the twin cooled comp ratio checke's @ 9.9 heavy in stock form on avg and you would end up 10.2.. again this is based on avg numbers. I have seen chambers on both stock 103 and CVO 110 range +/- 2.5 cc either way.

[Mr D]

2 tenths approx so the twin cooled comp ratio checke's @ 9.9 heavy in stock form on avg and you would end up 10.2.. again this is based on avg numbers. I have seen chambers on both stock 103 and CVO 110 range +/- 2.5 cc either way.

Thanks, Steve 

IYHO, worth adding on a 103 TK with a CR 575 bolt in

[GMR-PERFORMANCE]

Not really , I mean if you are doing the work yourself , doing the cam swap at that time and have not tuned it then its your deal. But really the gains are not going to be massive. and the added compression would alter the tune. Not sure if its going to be enough to largre offset the tune but I would bet its 6% change.

[Mr D]

Not really , I mean if you are doing the work yourself , doing the cam swap at that time and have not tuned it then its your deal. But really the gains are not going to be massive. and the added compression would alter the tune. Not sure if its going to be enough to largre offset the tune but I would bet its 6% change.

N'uff said

Bike already has the cam & has been tuned

I'll Ride On

[bakon]

thanks for info

local dealer talking buddy into new 585 Harley cam on 2014 CVO Limited.  Told him I think he would need valve springs and bump up compression.

Maybe better off just Andrews 57H and a Cometic .030 gasket? Don't know where these 110 heads flow but I thought they were same as stock 103 heads with lift properties, about .560 lift max? Right or Wrong?

[HD Street Performance]

Told him I think he would need valve springs and bump up compression.

Not needed on either the 110 or 103.
The 110 heads have adequate flow for the bolt-in variety cams and then some to feed that motor below 6k rpm.
The stock OEM head on the 103 works ok too but can see 7-10% more hp with appropriate porting using the smaller cams.

[bakon]

stock 103 and 110 heads take .585 lift?

thought .560 was max?

[GMR-PERFORMANCE]

UPDATE

I have a 2015 limited here and these chambers are smaller  F 80.5 CC R 80.1 CC . I may have gotten a fluke or the first  several off the line as they where all 2014 bikes ??  SO

I checked stock head gasket compressed thickness  .045  Piston is .006 down in the hole  so 10.1.1 for this build.. 

SO please use this new info , as I just completed 3 more of theses twin cooled builds, and wanted to make sure that the numbers are all matching..  Makes sense as to the reason the tq numbers are so good on the new builds in combo with the better than older stock cam.

[timo482]

I'm confused - does it appear that the wet heads have smaller chambers - or only that *some* wet heads have smaller chambers.

if they all have smaller chambers and thus all have higher or potentially higher compression - that would be news

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