Building a 124 with SE Hurricane heads

[Mother]

11.4 cr and really unsure which cam to run between the S&S 640G's or the Feuling 630's. Motor is going in a '02flht with(for now) 3.37 gearing, chain drive, and a RB Black Hole pipe. Any opinions?
Feuling: 258/263 20/58int 64/19ex .188tdc lift 109cl int 112.5cl ex.630" lift
S&S640:265/270 25/60int 65/25ex .228tdc lift 107.5cl int 110cl ex .640" lift

Appreciate your opinions and insight as always!

[strokerjlk]

Your using hurricane heads , so I assume you want to make the most hp you can.
The 640 is going to make the most hp ,after 5250.

[nw_guy4_fun]

The 640 is going to make the most hp ,after 5250.

I suggest letting the porter decide
5250 will be right where it lays over or is still pulling strong depending on the heads and how well they function.

[Mother]

Don, I did just that this morning. I am going with the S&S 640G's. Feuling 630 cams new in box for sale! the 630's I picked up when the motor was going to be a 117.

[CowboyTutt]

Your using hurricane heads , so I assume you want to make the most hp you can.
The 640 is going to make the most hp ,after 5250.

Ya know, sometimes I surprise myself, but when I looked at the cam numbers this evening, I had to admit, the 640's seemed the better way to go!

Lord help me, I'm starting to think like Stroker!!!! Waugh!

Anyone got any cool-aid?

Just kidding Jim!

-Tutt

[FXDRYDR]

Think you'll be happy with your selection. 640 gets it done.

[strokerjlk]

Originally Posted by nw_guy4_fun

The 640 is going to make the most hp ,after 5250.

I suggest letting the porter decide
5250 will be right where it lays over or is still pulling strong depending on the heads and how well they function.

even stock heads flow to 5250
porter can say what he wants , where the rubber meets the road, it (640) will make more hp after 5250 rpms.
it isnt rocket science, but it is science. I dont care who does the heads.

[C-Cat]

There not as bad down low a some think. I ran them and thought they worked damn good at 11.5 compression on stock castings with 2.02/1.635.

[Thumper49]

I showed both of the builds on the other thread Mother, but i assume you bought just the Hurricane heads by themselfs?

When i installed the 120R i knew after 4 hours of Dyno time that the engine wasnt gonna make a dime over 128 RWHP and soon i bought the 92500004A Pro RX kit from SE with the 12:1 pistons and the RX267 cams i put it back on my Dynojet and worked with a piss poor map software load from SE after making my own adjustments and tweaks i got the bike to run 149 RWHP you are far better off with the 640's .

Not bad mouthing the 120RX but i suppose if you have one and spent the loot for it and it doesnt do much better than what i have witnessed you move over and build another hence the whole reason i went with the S&S 124 with B2 heads from Star my engine was set up with 640 sticks and 660 springs the engine on there dyno run works much better at higher rpm if the sweet spot is 5250 for a 120RX hold on to your ass the 640s love to run up higher something that was missing with the 120rx engine.

Not putting down the RX heads because i own a set on a bike but the B2s now aval are 2800 the cost of the whole kit from SE which included pistons, sticks and heads but if i had to do it all over again i would have used Tmans heads and Cams for that engine , soon ill beable to tell you the diff in the two engines as the 124 came in yesterday from Star but the sheet i seen from Derek on a customers bike with the same engine as the one i just got ran 173 rwhp down in Ga so the 4 cubes, the 640 sticks and B2 heads are bringing this combo into a postion to honeslty run close to if not more than the early 132 i had from Star in a 06 RG we shall see.
Good luck and have fun.

Fred

[FXDRYDR]

That's some big power Fred, keep us posted.

[Thumper49]

Originally Posted by FXDRYDR

That's some big power Fred, keep us posted.

Thanks, Guess when reading these threads on what is out there i know i surly have learned a wealth of info over the years from forums such as this one and i hate to see someone spend there hard earned money to only find out later that the setup isnt what was talked about or advertised by the company.

Owning Thunder Roads Magazine of Michigan after Joe and Pam and while working with them i got to meet alot of great people and i know who is being straight up and who is just selling there wares , To this day honeslty Tman is probley the most knowleagable and friendly person i have spent time with along with Bert Baker and Ron Finch . There is alot of Fourms out there and you learn from everyone and try and help back so someone doesnt end up making the same choice that wasnt ness the right one.

Fred

[nw_guy4_fun]

Mother
OK now that your plan is coming together, the S&S 640 needs compression. Plan for 12:1. Not as easy as it may seem on the surface after all things are laid out in the plan including the protrusions of the big valves needed. Fortunately the TDC lifts are not too crazy.

[BVBOB]

Originally Posted by nw_guy4_fun

Mother
OK now that your plan is coming together, the S&S 640 needs compression. Plan for 12:1. Not as easy as it may seem on the surface after all things are laid out in the plan including the protrusions of the big valves needed. Fortunately the TDC lifts are not too crazy.

Don, you should explain about the valve protrusion and how it relates to valve to valve clearance etc. It would be interesting info to a lot of people here and I don't see much about it on the forums.

[Mother]

Don please elaborate! i got what I think is a clue, but would love to hear your explanation

[nw_guy4_fun]

Sure
There are several factors all working at once here. Once again the modular approach rather than integrated is going to fail . A component like the S&S 640 may seem like a grand cam, I have recommended it many times. But in this case trying to get a proper size valve in these heads to get them to function both sides may force some valve sinking. Not driven by reseating the valves 100% because the seats can be changed but the valves need to have adequate valve to valve clearance at TDC overlap. As the valves sink CCs are added. The heads start at 95cc nominal and move up from there. I would not be surprised if 103 or so is the end point after all the work is done. Now getting back to 85 from there? Now a custom piston comes into play. Mother this is complex and I suggest some expert intervention, Dan Baisley comes to mind. Not as an advisor, give him the job, or pay him for his time. He does not post on the internet. Sachs is another one that would be right at home with this project.