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My Cams experience 2010 flhtk pratical this vs that

jdaws said:
You talk about changing the cam timing to get more low end torque. Would it not just (change the torque curve to a lower RPM). In order to have more torque, you have to have more HP. I would think that you would loose HP by retarding the cam.
More HP = More torque.
Im I wrong?
Click to expand...

It seems that a -4* on the SE cam Moves it out from 25* to 29* and if you use the + side of the gear it does Just the opposite....

I put the SE255 specks on the cam comparison by big boyz and it showed to use the -4* to move intake out to 29* closing...

Yes when moving this to 29* you are Loosing a little compression but getting the RPM band move a little out also.. So I guess you are right in thinking LOSS

When you close the intake Earlier, You get More Compression and Compression = Power.
One of the easiest ways to produce More power is add compression....

Then other problems like Octane, spark timing come into play..
Nothing is FREE, it is a Give and Take..

signed....BUBBIE
 
BUBBIE said:
By using the -4* pinion gear by andrews,,,, You can change out the SE 255's and be REAL close to the 48H cams... That takes your intake close from 25* to 29* and it Will move your cam RPM band UP a little.. The 48H is not a cam for me but the timing is. I like the 550 lift and Quiet sound of the SE cam.

I plan to do this when I go to 103" and don't forget to install Pressure Relief Valves as the HIGHER compression is Hard on the Stock Starter and Stock Compensator, giving Kick Backs after a fuel stop and start,,,, giving MOST of the thinking the SE compensator is better and I don't believe that. I'll stick with the STOCK Compensator.

signed....BUBBIE
Click to expand...

Bubbie,

Near the end of last years riding season the dealer changed my 96" to a 103" and the SE255 cam I don't think he mentioned anything about a pressure relief valve. Is this something I should seriously consider? Just how much harder is it on my starter and compensator? It doesn't seem to be having any problem starting that I am aware of. How do I know if it is on there already? Thanks.
 
Trek said:
Bubbie,

Near the end of last years riding season the dealer changed my 96" to a 103" and the SE255 cam I don't think he mentioned anything about a pressure relief valve. Is this something I should seriously consider? Just how much harder is it on my starter and compensator? It doesn't seem to be having any problem starting that I am aware of. How do I know if it is on there already? Thanks.
Click to expand...

On bikes that are stock 96" factory, they will not have Manual(off and on by hand) or electric Compression releases on them.. UN-less put-on when apart,,, Cost is More by a couple hundred $$ at least...

Manual reliefs are "drill and taped" into the heads while heads are Off, Usually by the porter(only if asked to do it).. done at extra cost when you have a bigger engine built..

There are many ways to build an engine going 103" and Keeping the Compression ratios in check where they will work well BUT the reliefs are a good thing to have installed while apart..

The person that does the head work CAN CC the Head valve chambers (larger) to size them UP a little IF NEEDED to lower the compression pressures. Also.

If you have just gone 103" and the SE255's.. A simple compression test showing the numbers of each cyl. That will tell you IF the relief Valves WERE Needed at the time of Your build..

If your static CYL pressures are At or Under 190# (200# is too much without reliefs IMO) and you are NOT having ANY hard starting or Kick-back issues, You might be okay... I would Not tear into the heads to Just do the relief valves,,, Especially when you say Not having starting problems.....

I would always put in the Manual relief valves REGARDLESS of compression pressures when going 103" of Larger.
Having problems with the stock Compensator at 96" is enough to tell me that Opening the pressure when starting the motor Will Be Easier all the way around on the starter and comp. (.)

So Why Not use them EVEN in the stock 96", It Is a Bonus..

IF you are Not having any problems starting Your 103" and If you check your compression to see What the Static Pressure is at Cranking. and fall under the 190 lb. area,,,, Good for you..

Did you also Know that Altitude Makes a very BIG difference in cylinder Pressure..?
SAY IF you are:
At sea level and your pressure is 200 lbs then checked at 800 foot elevation it will change to 195.1 then at 4400 feet where I am when In Az. it drops to 175.3... If you go to 6800 feet in Az. it drops to 161 lbs.

So Where you Live does Make a Big difference in starting Pressures...

Hope that Blaw Blaw Help you and Someone Else Out WHEN they build their Motor...

Knowledge BEFORE the Build is a MUST....

signed....BUBBIE
 
BUBBIE said:
On bikes that are stock 96" factory, they will not have Manual(off and on by hand) or electric Compression releases on them.. UN-less put-on when apart,,, Cost is More by a couple hundred $$ at least...

Manual reliefs are "drill and taped" into the heads while heads are Off, Usually by the porter(only if asked to do it).. done at extra cost when you have a bigger engine built..

There are many ways to build an engine going 103" and Keeping the Compression ratios in check where they will work well BUT the reliefs are a good thing to have installed while apart..

The person that does the head work CAN CC the Head valve chambers (larger) to size them UP a little IF NEEDED to lower the compression pressures. Also.

If you have just gone 103" and the SE255's.. A simple compression test showing the numbers of each cyl. That will tell you IF the relief Valves WERE Needed at the time of Your build..

If your static CYL pressures are At or Under 190# (200# is too much without reliefs IMO) and you are NOT having ANY hard starting or Kick-back issues, You might be okay... I would Not tear into the heads to Just do the relief valves,,, Especially when you say Not having starting problems.....

I would always put in the Manual relief valves REGARDLESS of compression pressures when going 103" of Larger.
Having problems with the stock Compensator at 96" is enough to tell me that Opening the pressure when starting the motor Will Be Easier all the way around on the starter and comp. (.)

So Why Not use them EVEN in the stock 96", It Is a Bonus..

IF you are Not having any problems starting Your 103" and If you check your compression to see What the Static Pressure is at Cranking. and fall under the 190 lb. area,,,, Good for you..

Did you also Know that Altitude Makes a very BIG difference in cylinder Pressure..?
SAY IF you are:
At sea level and your pressure is 200 lbs then checked at 800 foot elevation it will change to 195.1 then at 4400 feet where I am when In Az. it drops to 175.3... If you go to 6800 feet in Az. it drops to 161 lbs.

So Where you Live does Make a Big difference in starting Pressures...

Hope that Blaw Blaw Help you and Someone Else Out WHEN they build their Motor...

Knowledge BEFORE the Build is a MUST....

signed....BUBBIE
Click to expand...

Yes altitude makes a big difference. In Calgary we are at about 3400 feet and my 104 has no problems starting etc. But when I ran down to Oregon coast then she was a little bit more cranky when starting. :)
 
My Screamin Eagle 103" kit with SE255 cams just arrived yesterday (yippeee):D

I live on the west coast pretty close to sea level. According to the Big Boyz calculator, my cold cranking compression with this kit will be in the neighborhood of 199.8 psi... Yikes!

My starter motor has been a little cranky on occasion when trying to start the 96" hot. Needless to say, my heads will be getting machined for manual compression release valves while they are off.

Local cost is $100 per head for machining and another $80 apiece for the valves. Not cheap but considering it should help extend the life of the starter and related components, I think it is money well spent.
 
great post smoke, what type of air cleaner do you have ? i am thinking about putting the 255's with a s/e heavy breather kit on my 103 eg.
 
Hornhonker said:
103 with stock cams is very unimpressive. I think a 96 with 255 would blow away a stock 103.
Click to expand...

I had a stock 103" big bike next to me on day and we were TWISTING on the throttle,,,,, At our Next stop , He wanted to Know What Hop-ups I had?

I said 96" stage one, TFI and se 255's..
He responded to me saying

"WOW, It sure OUT MOVES MINE."

signed....BUBBIE :newsmile01:
 
I've been toying with the idea of upgrading my cams. Not because I need too, I just want too. I'm also looking for another reason to spin a wrench again. Already installed EJK, new slip-ons, and intake. This post has me drooling.
 
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