engine build question
Road Master
Joined: Mar 2008
Posts: 1,209
Likes: 5
From: Michigan
Question when i had the stealer do the se 103 upgrade new heads flat top pistons se 255 cams se hi flo air filter se race tuner rine hart tru duals heavy duty clutch spring dyno tune on my 2007 road king my new numbers were 84 hp and 102 tq are these numbers in the acceptable range for this upgrade and how do i push the hp to the 100 range. thanx to anyone that can help. ps i think the cr is only 9.6 to 9.8
Those numbers look about right from the research I've done. I did a low budget cam swap this spring and when I was searching on here for info I discovered that you really dont gain alot by going to 103 vs 96 with the 255 cams. You need some some head work and increased CR and different cams to get over the 100 HP mark. As a reference, my 96 with 255's makes 78hp/98tq with a similar exhaust/intake as you. For the money I spent, I am very happy with the results.
Road Master
Joined: Nov 2006
Posts: 758
Likes: 0
From: Winston Salen, NC
I did the SE build as well. I did put on the SE high flow heads and used the 258 cams. Very happy and my dyno is near about a flat line from around 2800 rpms to about 5500 rpms at 100 lbs of tq. The builder did an outstanding job. I am adding the EVO 30 tooth next week which will wake up the old but dyno a little more since the 258's do not put out as much tq as the 255's.
Road Master
Joined: Sep 2006
Posts: 1,062
Likes: 4
From: Arizona
OK, First thing. If you go any bigger, just go straight to the 107. Same price as the 103. It is FREE POWER. Cant get that very often.
The Andrews 54 cam choice is a good one. I went with it on my builders advice and am happy I did. The Torque is now above 110ft/lbs from 2500 rpm to 5000rpm. My bike pulls like a train. all at 9.8 compression.
If your on a tight budget, get the 107 pistons and the Andrews 54's. See if you cant sell some stuff around the house and get some head work.
The Andrews 54 cam choice is a good one. I went with it on my builders advice and am happy I did. The Torque is now above 110ft/lbs from 2500 rpm to 5000rpm. My bike pulls like a train. all at 9.8 compression.
If your on a tight budget, get the 107 pistons and the Andrews 54's. See if you cant sell some stuff around the house and get some head work.
Cruiser
Joined: Dec 2008
Posts: 143
Likes: 0
I did the SE build as well. I did put on the SE high flow heads and used the 258 cams. Very happy and my dyno is near about a flat line from around 2800 rpms to about 5500 rpms at 100 lbs of tq. The builder did an outstanding job. I am adding the EVO 30 tooth next week which will wake up the old but dyno a little more since the 258's do not put out as much tq as the 255's.
Ultimate HDF Member
Joined: Feb 2006
Posts: 5,939
Likes: 3
From: TX
Not Monkish... but that's a D&D FatCat.
Thread Starter
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Road Warrior
Joined: Dec 2007
Posts: 1,498
Likes: 213
From: Atoka, TN
Well, I have found a couple places that have low buck 103 kits that are advertised as 10:1 with stock heads.... the 54 cams, I have found for 225, but I will still need springs (don't know what springs I'll need though). And I will need something other than this fuel pak to remedy fuel issues. If I leave the heads alone, I can get what I need for under 1000.... How much power would I be leaving on the table by not porting the heads? My goal is to get the hp above 80 and the torque above 100...
Chris
Chris
Banned
Joined: Sep 2009
Posts: 7,580
Likes: 7
From: The Internet (& Dyer, Indiana)
Well, I have found a couple places that have low buck 103 kits that are advertised as 10:1 with stock heads.... the 54 cams, I have found for 225, but I will still need springs (don't know what springs I'll need though). And I will need something other than this fuel pak to remedy fuel issues. If I leave the heads alone, I can get what I need for under 1000.... How much power would I be leaving on the table by not porting the heads? My goal is to get the hp above 80 and the torque above 100...
Chris
Chris
Good chance you will reach your goal without porting the heads, but for me it would be hard to assemble without doing something with them, even if it's a minimal clean-up & cc.
Road Master
Joined: Sep 2008
Posts: 1,231
Likes: 0
From: FLORIDA
In my opinion, if you are planning on staying with the 96", I wouldn't bother changing the pistons. I would shave the heads and use the Cometic head gaskets.
If you do decide to swap the pistons, you might as well go 103". Won't cost much more at all and you have to do the labor anyway.
10:1 is a safe choice with that cam. It is very well mannered. I run mine at 10.4:1 and it behaves well. The only ping I ever got was in the mountains near Sturgis when it was hot and running on the crappy fuel thay have there. ON decent fuel this thing behaves like a champ! (but I am pushing the limit). 10 - 10.2:1 would put you in a comfortable range for that cam. It is quiete and very well mannered. Lots of low end grunt and still some on the top to play with.
If you do decide to swap the pistons, you might as well go 103". Won't cost much more at all and you have to do the labor anyway.
10:1 is a safe choice with that cam. It is very well mannered. I run mine at 10.4:1 and it behaves well. The only ping I ever got was in the mountains near Sturgis when it was hot and running on the crappy fuel thay have there. ON decent fuel this thing behaves like a champ! (but I am pushing the limit). 10 - 10.2:1 would put you in a comfortable range for that cam. It is quiete and very well mannered. Lots of low end grunt and still some on the top to play with.
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Banned
Joined: Sep 2009
Posts: 7,580
Likes: 7
From: The Internet (& Dyer, Indiana)
Back when they first were coming out with the 54's, I had chatted a lot with a guy who had influence on the creation of that cam. (Jewelen Dewey). He was doing a lot of reputable heads at the time (I had run some of his heads in the past).
Dewey was fortunate enough to get some prototypes to test, before that cam hit the market. He was testing them in stock 96 inchers as a bolt in "cam only" scenario and was having great results. My original plan was cam only!
I wanted to reuse my stock pushrods, so I had the gas tank and rockers off. Figured I might as well throw the thinner head gaskets in. With the heads off I figured it would be hard to put them back on without some headwork. Then I look at the jugs and think "there are no more bolts involved to pull these jugs for 103". LOL
"One-more-itus" got the best of me!!!!!
Many on another board followed my build, for I was truly a guinia pig. I was the first 103 with that cam at the time and many had thought the duration would be too short for a 103. They called it a "baby cam".
Since then it has become more popular and some call it the "underated cam". Best mannered cam I have ever run. Performs in all ranges and still has some ***** at the top. Valvetrain runs quiet as well!
Absolutely no regrets.
I am very familiar with a few cams, but not an expert on all cams (just to set the record straight).
Tourer
Joined: Jul 2009
Posts: 384
Likes: 2
From: Eastern NC
Nice, you still running the stock TB? Also which baffle are you running on the fatcat. Im running the standard baffle on my 98" build and I got a dip right in the same area.
