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I been doing a little research lately on cylinder head porting, after having a conversation with my Dyno shop guy. It's something in definitely interested in doing, maybe over the winter, but it's something I know very little about

My bikes a 15 rgs, stock 103 engine with Andrews 57H cams (exhaust, intake, PV) How do these cams respond to head work? I was just reading up on Fuel Motos C series porting (porting, stainless valves, springs, etc.) I don't have any plans to Big Bore this bike, but I would really like to see it in the 100hp range.
 

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The 57 is a torque-oriented cam.
That said, a torque-oriented head would be our suggestion to amplify the cam.
Our Stage II Torquemaster Head is an example, for that.
That head was used in conjunction with a Cyclerama .575, 110" drop-on cylinder kit, and custom in-house 50mm t/body work.
That combo was tuned at Rossiters HD near the Sarasota, Fla., area.
and at only 10.0 cr, it produced 113 plus hp, and a whopping 131 ft/lbs, sae. (120 ft/lbs. from 2300-to almost 5000 rpms)
STD numbers were 116 plus hp and 135 ft/lbs.
Dyno charts, along with the 20,000 hit thread can be seen on Harley Davidson Motorcycle News & Forums - Harley Davidson Forums.
Just an example. :)
Scott
 

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You have to take into consideration that most shops that promote cylinder head work are there to make money and it is in their best interest to recommend this performance upgrade.
In all reality cylinder head work will only increase the torque on the 103 ci engine around 3 ft lbs +/- so for the cost it isn't a good upgrade when you figure cost vs gain.
In general a good cam along with a good exhaust and stage 1 air intake upgrade is all that you would need to get the performance that you're looking for.
On the 88 inch engines with a big bore kit which took the bike to a 95 inch engine you needed to get around 100 hp to get around 100 ft lbs of torque and you needed to do major performance upgrades to achieve that.
HD added 3/8 of an inch stroked to the 88 inch engine and called it a 96 inch engine and then HD put in the 103 big bore kit in the 96 engine to make the 103 which is the same kit used to take a 88 to a 95.
With the added stroke the 103 engine produced higher torque #'s while having a lower HP #'s so with the stage 1 and cam upgrades you can get 110 +/- ft lbs of torque while still being in the low to mid 90's in HP.
Since torque is where it is all at don't worry about the 100 HP club just get the bike to the 110 torque club and all is good and this can be done with simple stage 1 and a good cam upgrade and a good tune.
 

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Since torque is where it is all at don't worry about the 100 HP club just get the bike to the 110 torque club and all is good and this can be done with simple stage 1 and a good cam upgrade and a good tune.
He should already be there with what he has done to the bike - Hell, a good Stage 1 will get you there sans cams - If he has Cam work, guessing all is good in the Torque Club Hood

Nice Brake down on your post man - Did not know that was the "evolution" for a quick play on words
 

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Yes, is someone goes though a "fluff and puff" in the runners, not much change.
Even without seat changes, and larger valves are used and ports are re-worked very good increases occur. Fact.
When seats are changed to accept larger intake valves, port ID's are port-matched to the t/body's ID, bowls are greatly modified, etc, etc ,etc, and flow number jump by 40-50 cfm or more, the power output of the engine is in fact GREATLY enhanced.
Example;
Our AHDRA 108" engine would consistantly dyno at 165-167 hp/144-146 ft/lbs.
8.88/148.85 mph.
Think that would've occured w/o a good set of heads???
I know it would not have.
Scott
 

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All one has to do is research the hundreds of dyno sheets to see the difference head porting makes. 3 ft lbs is not true. 10-15 more like it.
Depends on the engine size, the bigger engines will get more out of headwork.
But after doing tons of research on headwork on the 103 engine by looking at hundreds of dyno sheets 3 to 5 ft lbs of extra torque is all you're going to get.
Unless you're a person that wants to ride as fast as you can to beat your buddies to the next bar then you may want headwork but for the average rider headwork isn't really needed.
 

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Depends on the engine size, the bigger engines will get more out of headwork.
But after doing tons of research on headwork on the 103 engine by looking at hundreds of dyno sheets 3 to 5 ft lbs of extra torque is all you're going to get.
Unless you're a person that wants to ride as fast as you can to beat your buddies to the next bar then you may want headwork but for the average rider headwork isn't really needed.
Or if you're someone who likes to brag about their dyno sheet.

I looked really hard at doing heads when I put the 57 in my CVO. It would have cost another grand or so, and netted me a little prettier curve and a bit more on the peaks. I opted against it, and I'm glad I did. Would the extra power have been noticeable? Maybe. Probably, even. But would it have been worth an extra grand? Hell no.

FWIW, I'm running a pair of really nice T-Man heads on the Night Train with a 625 cam. It's a pretty fast Harley, but still a slow motorcycle.
 

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We DO NOT up-sell our clients on products that do not perform.
Our business ethics record clearly shows that.
Would not have invested tens of thousands of dollars in machinery, tooling, and R&D in our cylinder head shop area only to squeak out small gains.
Scott
 

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My post was directed at a post on page 1 of this thread where it is stated that

"You have to take into consideration that most shops that promote cylinder head work are there to make money and it is in their best interest to recommend this performance upgrade.
In all reality cylinder head work will only increase the torque on the 103 ci engine around 3 ft lbs +/-"

I'm prayin from the same bible you are Scott, head work plays a significant role in performance/power IME.
 

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The people who put poorly thought out engine combinations together against all advice from knowledgeable builders are always the first to bash quality head work. If done correctly it will produce significant increases in low to mid range power and will not be $1000.
 

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All I know is I have had heads ported and polished in the past with great success. Cleaning up your heads decking them and larger intakes is well worth the time and money. And it does not need to be expensive to be successful.
 

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It looks like some are comparing apples to oranges in that the OP asked if just doing head work to his build was going to get him much. Yet some are posting their experiences with headwork done with a lot of other upgrades. Sticking to what the OP asked, what are the gains he is likely to see with head work alone? One person says 3hp another says 10hp/8tq. My guess is that he may see anything in between depending on how they are worked and how well it is tuned. I would think that 10hp/8tq is very possible but even though you may feel that little of a difference at first it is still not that much of an increase running on the road. It's up to the individual as to weather or not it's money well spent.
 

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To me doing just the heads without doing anything else would be a waste of money. When I did the 107 on mine the second time around everything was planned out to compliment each other, wish I would have paid attention the first time it was done!


Sent from my iPhone using Tapatalk
 

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I been doing a little research lately on cylinder head porting, after having a conversation with my Dyno shop guy. It's something in definitely interested in doing, maybe over the winter, but it's something I know very little about

My bikes a 15 rgs, stock 103 engine with Andrews 57H cams (exhaust, intake, PV) How do these cams respond to head work? I was just reading up on Fuel Motos C series porting (porting, stainless valves, springs, etc.) I don't have any plans to Big Bore this bike, but I would really like to see it in the 100hp range.
Wirh a 2/1, intake, 57H and just the .030 head gasket my bike dyno'd at 98 hp 111 tq at 96 degrees and 55% humidity. On a cooler less humid day its got to putting out 100hp or better. What numbers are you getting with your current setup.
 

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Read post #2!! Scott immediately acknowledged that the Andrews 57 was a torque oriented cam and suggested doing head work to match that cam profile. Heads done correctly for that cam will make a very noticeable difference at a reasonable price. My point is don't get caught up in the hype of the internet, set a plan for how much and at what rpm you want the power and stick to.
 
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