Which cam????

[roadglide08]

I have a 08' RoadGlide with 103 BB, forged 10:5.1 comp piston, 211 cams, SERT, SE stage 1 AC and 2 into1 Thunderheader (full exhaust).  With the 211s don't come in quick enough for me, so talked with local harley mech.  I thought about putting in 255s for the low end tq.  He said with the 10:5.1 comp piston I would need comp releases (hot starts) and then he didn't know how it would act (pinging, noises).  He recommended I install the 251s, and said that I would get decent low end tq with the higher comp piston (better than the 211 anyway).  Any thoughts??

[pddredduece]

If you go with the SE251 cams, you will need to go with roller rockers. The lift on the cam is 550 or more, with out roller rockers you will wear out your valve guides and valve guide seals quickly. I know my 95" build with 251 cams wore out the valve seals in 1000 miles. The motor was using oil. Look in the Harley twin cam performance book under the performance cam section. Good luck!

[mscoolone]

If you are able to post your cold Cranking com presion will be able to better help.

A couple of cam that may work are the Woods 6-6, Andrews TW54, with a good tune. These cams should slightly raise the cranking compression and provide better low/mid end torque.

[roadglide08]

I appreciate the help, but I contacted the HD mech. about the about the stock rocker issue.  He said it was not an issue with the newer TCs he said it was with the older ones.  He said all I needed was stronger springs and .30” longer push rods.  I checked out the SE hi po catalog and I essentially have the SE Pro Stage 3 kit but with 211 cams, installing the 251s would be the same as the Stage 3.  I have thought about other cams yet I have 2 years left under warranty so I want to stay with MoCo parts, sorry forgot to mention that in first post.

[05FLHTC]

What pistons comes with that stage 111 kit that gives you 10.5 CR?

[truckerdave10]

I'm running SE 204's in a 07 Roadglide, got them for $100 so in they went. 10:1 cast pistons and no pinging whatsoever. No problems cranking. Bike has plenty of low end torque and will pull front wheel off the ground, still runs out through the gears real good. They worked a lot better than i thought they would.
      I have basically the Andrews equivalent of SE 211's in a 95" Dyna(TW55G) and i can imagine they wouldn't work too well in a big heavy touring bike. Above 3000 rpm though you feel like you've been shot from a cannon.

[05FLHTC]

SE 204  Many happy campers running them in stock 96" motors, good bottom end & with a good tune should give the 103 255 builds a run for the money.

204 is a very underrated cam IMO, they never have made the flavor on the month here on this site

[Don D]

Pistons flat top in that 103" the 204 is OK
Got domes think again and the 251 will be close to the same feel as the 211s with just a tad bit more down low not much.
I assume you want to stay with SE camshafts

[Admiral Akbar]

I'd bet that 204s might require a pretty good tuner.. I'd try playing with the exhaust first.. Dump the TH or try pounding the baffles in.. Max

[05FLHTC]

Yep I'm struggling with how this 103 with a SE head gasket gets 10.5 CR???

[Don D]

SE domed piston would have to be in there not flatops.

[05FLHTC]

Man sure would think that domes would put the CR well into the 11's...unless the heads are like 90+cc? I'm scratching my head...

[Admiral Akbar]

All you got to do is get the heads down to 81 ccs and flattops fill the bill.. And you can used the cheaper flattoped pistons. Max

[roadglide08]

RE: What pistons comes with that stage 111 kit that gives you 10.5 CR?

They are Scream'n Eagle Pro Twin Cam High Compression Forged Pistons For Stock Cylinder Heads; part# 22144-08

[mapboy]

I've got an '08 Street Glide, 103" with the 10.5:1 HIGH COMP forged pistons, stock heads too.  (Guys, it's in the book).  Also have the 251's.  Love the thing, although the power DOES come on a little late for a bagger.  My other ride is a 95"  '03 FXD with SE Perf heads and 211's.  It DOES come on strong around 3000 RPM's.  Someone above nailed it.  The 251's will give you a little more low end than the 211's, but I'm not sure how much.  Those also come on really strong around 3000-3200 RPM's.  Not sure what you can do (cam-wise) with the 10.5:1 pistons, though, without possible detonation issues.  Me, I'm considering some minor head work.  (Yeah, I know.  Won't help the bottom end at all).

JMO, based on seat 'o pants dyno, you understand.  Take it for what it's worth.

Mapboy

P.S.  --  The 251's aren't in any of the "Stage" kits. . . . .but the chart in the book shows that the high comp pistons and stock heads give ya 10.5:1. . . .

[Mopar]

2008 street Glide with 103 stage IV with 251 cams. 104 hp 106 torque SAE corrected. I like the 251 cams. Mine are noisey. could be the big valves and springs.

[roadglide08]

Actually if you look in the new SE catalog the 103 stage III has the high comp pistons, new springs, longer push rods, 251 cams and SE race tuner.  I thank you for letting me know what you think of the cams in the same set up as I'll have.  When I asked the mech about the 211s in a bagger he said he'd do his very best to talk the person out of them because they are worthless in a big bike. He also said he had been building that set up before it became a kit and he loved it for a streetable and reliable build.

[mapboy]

Cool.  Just went and looked.  That wasn't in the '08 catalog (pretty sure. . .).  Anyway, I was under the impression that only the dealer that put it together would honor the warranty.  Now maybe any of the dealers will, 'cause that's exactly what they threw in.  Rush slips, by the way.  Don't know what baffle.  Runs great.

Good luck with yours!

Mapboy

[Don D]

That's a lot of gear and cost to get those numbers and even with the 251 cams the heads are very big for a 103" motor and I can think of a lot better ways to get one of these new bikes down the road for less $$ and a big grin. The SE Stg. IV kit is considered for "off road" use and carries no warrenty (motor) technically and the only qualified 103 "street legal" build is the SE stage II with the SE255 cams.
No put down but just for the others that are considering upgrades and haven't jumped in the water yet. Considering the gearing they have, the payload, and parasitic losses like the bigger rear tires. These new bikes are a lot more fun to ride with big torque on early IMHO.
This can be done with mild headwork and a cam, stock TB, a good tune and pipe as always are very important.

[roadglide08]

Dewey:                         I hear ya about the 255s, that's what I wanted first.  But that's where the problem lyes, I already have the high comp piston installed and the 255s don't work well with the high comp. The next best thing I can go to (staying with MoCo) is the 251s

[tomp]

Dump the TH 2:1 exhaust. They are good up top but bad down low. You would have had beter low end with stock header and slip-ons or Go Supertrap or D&D fat cat 2:1.

Dump the 10.5:1 pistons and go with flat tops

Now you are ready for a good low end set of cams like the 255s or other

[rigidthumper]

IF the heads are stock, (Most of the 08 heads I checked were ~86ccs) & pistons are typical (.010 down) and you used a stock HG, you're closer to 10:1  than 10.5:1. About a 40° close should get you near what you want.
You could try the HQ 525, Woods 6, S&S 570, TW44.
What is your cranking compression?

[Don D]

Dewey:                         I hear ya about the 255s, that's what I wanted first.  But that's where the problem lyes, I already have the high comp piston installed and the 255s don't work well with the high comp. The next best thing I can go to (staying with MoCo) is the 251s

There are many cams that will work as mentioned by Robin. I would stay with the roller chain and not use gear drive. The MOCO does not offer anything that is about 240° and about a 40 close but those are good numbers to reach your goal, as stated above. I would not exceed 9.1-9.2/1 corrected for cam compression. The heads can be opened up if need be.