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[98fxstc]

I am being told that CVO heads are not a very good canvas to start from, if given a choice.  Two builders have told me now that the valves are actually a little bigger than preferred for max flow on a 117ci.  Of course there are work around tricks to make them perform, if you already have the castings, but one reputable builder said if I am buying new HD castings they'd rather start with 103 castings than CVO castings for my 117ci project.

dnlpnd

Two builders
only one of them reputable ?

I see quite often guys are having 110 heads ported for use on 120R's and 124's

Your builders are out of step with everybody else in the game

[Ridgerunr]

That Dewey guy knows his onions . I wondered if he was still around.

Rocktop117 you going to keep the .570 cams in the 117"?

[KC2GIW]

x2.

GMR Performance says one of the big reasons his 113" runs so well is b/c the stock 110 intake valve is a little too large for 110.

Could be one of the reasons the preliminary results from the 117 kits are so impressive.  [And I use that term through the lens of "Screamin' Eagle branded bolt on parts"]

[rockytop117]

That Dewey guy knows his onions . I wondered if he was still around.

Rocktop117 you going to keep the .570 cams in the 117"?

yes they have been a very useable cam for touring & my riding style. I'm having the heads prepped in the event we make a cam change down the road but I feel it will be a 125-130 square when it's all tuned & done! 

[HunterJ]

Interested in seeing the results of the 570. I have GMR 577 in now with a set of Dave Mackie 598 on the shelf. One of them will go in the 117.

[HD Street Performance]

From another thread on this forum, if this bloke told me the sun wasn't gunna come up I would go buy batteries.......

I have been porting H-D heads since 1978 {sold biz last year} anyway , I always liked to use 89-90 %  valve to seat ratio . The H-D 110" heads have a 93 % ratio on the intake !!!!!!! YOU WANT POWER ,CHEAP ?   Put in a 2.125 intake valve { H-D #  18190-08}  $15.50 ea. } that will get you a 90.5 % ratio and do a 4 angle seat cut ,  'mill' the heads .030-.040  and use a Cometic .030 head gasket and a cam.

let me 'spain' a little.  When you have 93% seat to valve {1.930 dia.} with a 2.080 valve ,you need to look HARD to see the 45 degree cut and forget about the 60 degree ! You have nothin but a big hole. Nothing to cut your angles on ,right ? By going with a bigger valve {.045 bigger}  you can do a 30-45-60-70 cuts. YES ?  THE STOCK VALVES ARE 'BACK CUT'  30 DEGREE. its all about making the Y , with the back cut on the valve and the cuts on the seat. Look at a Y , bigger on the top and then narrows down ,yes. Just remember 1 thing , 80% of your air flow is controlled by the valve and the seat. The only other way is to weld up the ports. The stock 110"  heads flow BAD. once you 'fix' the valve and the seat {cuts} they do fine. Whatever ,been doing this stuff for over 30 years,not trying to sell ANYTHING. Dewey 

Had the same conversation word for word...
Right on the money.
Got to play the hand we are dealt and none of the heads are great to begin with but knowing how to get there is the deal and the treatment varies case by case.
The CVO head can work very well after those fixes.

[dnlpnd]

From another thread on this forum, if this bloke told me the sun wasn't gunna come up I would go buy batteries.......

I have been porting H-D heads since 1978 {sold biz last year} anyway , I always liked to use 89-90 %  valve to seat ratio . The H-D 110" heads have a 93 % ratio on the intake !!!!!!! YOU WANT POWER ,CHEAP ?   Put in a 2.125 intake valve { H-D #  18190-08}  $15.50 ea. } that will get you a 90.5 % ratio and do a 4 angle seat cut ,  'mill' the heads .030-.040  and use a Cometic .030 head gasket and a cam.

let me 'spain' a little.  When you have 93% seat to valve {1.930 dia.} with a 2.080 valve ,you need to look HARD to see the 45 degree cut and forget about the 60 degree ! You have nothin but a big hole. Nothing to cut your angles on ,right ? By going with a bigger valve {.045 bigger}  you can do a 30-45-60-70 cuts. YES ?  THE STOCK VALVES ARE 'BACK CUT'  30 DEGREE. its all about making the Y , with the back cut on the valve and the cuts on the seat. Look at a Y , bigger on the top and then narrows down ,yes. Just remember 1 thing , 80% of your air flow is controlled by the valve and the seat. The only other way is to weld up the ports. The stock 110"  heads flow BAD. once you 'fix' the valve and the seat {cuts} they do fine. Whatever ,been doing this stuff for over 30 years,not trying to sell ANYTHING. Dewey

Had the same conversation word for word...
Right on the money.
Got to play the hand we are dealt and none of the heads are great to begin with but knowing how to get there is the deal and the treatment varies case by case.
The CVO head can work very well after those fixes.

"Of course there are work around tricks to make them perform, if you already have the castings, ...".

dnlpnd

[rockytop117]

(2) sets for sale on amother "V-Twin Forum" (1) used (1) NIP

[Ridgerunr]

Rockytop, have seen the .570 work very well in motors 88"-110". Bet it will still shine in your 117" . Don't skimp on the tune.

[FLSTFI Dave]

Had my 110 CVO heads and jugs done by dewey's.  Seem to work well on my mild build.  I'm running the 259E cam, the HPI 55 Throttle body, 5.3 injectors, compression was set at 10.8 to 1.  Bike runs super smooth and makes very good power.  124 HP and 125 torque.

Wonder how it would do with the 117 Kit, just the pistons and jugs.  I know I would loose some compression.

[Ridgerunr]

" I know I would loose some compression."
Dave, check the paperwork that came with your heads.....combustion chamber size. With a .030" hg you might be close.

[KC2GIW]

Is there such a thing as an .030 4.125" HG?  And is that NOT what comes in the 117 kit?

[rockytop117]

Rockytop, have seen the .570 work very well in motors 88"-110". Bet it will still shine in your 117" . Don't skimp on the tune.

I'll be taking it to Matoon IL to "Stroker".. He's tuned my last 3 bikes direct link & wouldn't go anywhere else! 

[Lever]

Stroker is good

Sent from my SCH-I535 using Tapatalk

[cvosjoe]

" I know I would loose some compression."
Dave, check the paperwork that came with your heads.....combustion chamber size. With a .030" hg you might be close.

John,
Dave and I have the same engine parts but our exhaust system is different. Our builds are identical on the HP but my TQ is 129 (could be from the exhaust). 

Our heads have been milled 0.052 and the chamber adjusted to 96cc. Currently with a 0.30 head gasket the build has a Calculated CR (cold) of 10.78, Corrected CR of 9.6 that gives a Cranking Compression of 201. Using the 117 cylinders and pistons the numbers change to Calculated CR (cold) of 10.1, Corrected CR of 9.0 that gives a Cranking Compression of 185.

There would still be gains by increasing the cubic inches but compared to the current build the lower compression would effect the overall outcome. As for myself I would like to keep the Calculated CR around 10.5 to 11 with the Cranking Compression at 200 or a little above. I don't mind using a little fuel additive to compensate for the higher cranking compression.