Hello,
Newer member to the forum. I have a winter project, converting an 2005 88" Fatboy to 98". Doing the newer cam plate oil pump etcetera. Looking at Andrews 37N low lift or Woods 555 high lift cams. Will have ported but stock 2005 valves which i believe had the newer bee hive springs. Undecided on pistons either -1.6cc or +3cc. -1.6 being 9.5-1 &+3cc being 10.1-1 I believe. I know compression and cylinder pressure are also important. I ride mostly in town. Although do several highway trips a year.
second question. I have the 5 speed transmission. If I produce enough torque can I change a drive gear somewhere to run at lower rpm on highway?

Thanks,

 

You better address the Valve seal issue while you have the heads off. 005 had issues with their valve seals. also from what I have read the 2005 heads are the worst flowing twincam heads

 

Agree with Scudda but assume guide seals will be replaced as part of the porting. I would further add that porting without increasing valve size is a mistake and counter productive to the plan. Why plan a build to increase performance but pass on one of the key performance enhancing modifications; not smart IMHO.

Forget about lower compression and consider the Andrews 57 cams at about 10.2 static; same profile as the 37 but with more lift; not OTT on compression but will produce a nice balanced curve with a good tune.
Complete the build and ride a while before considering a drive change to lower cruise rpms; lowering cruise rpms lowers rpms in all other gears as well.

 

Was thinking of finding a set of newer 103 take off heads. They would have larger valves I believe and also ACR. Then send them out for porting.

 

88"/96"/103" heads are all the same casting but there was a redesign in '06 and the later heads do flow better. Valves are not bigger in the later heads but stem diameter was reduced from 5/16" to to 7mm and beehive springs were introduced in '05 along with POS valve guide seals. It doesn't make any sense to buy another set of heads and then spend the same amount to have them ported that you will spend to have your '05 heads ported. Do the smart thing and have your '05 heads ported but not until you select a cam set and build around the cam.

 

Reaper's heads (2005 model year) came with the crappy seals, which I had replaced, but the older double springs and 5/16" valves. When I did the rebuild this summer, I mistakenly ordered a set of beehive springs from Wood, only to find out I needed the double springs instead. Transition years are a PITA!

I agree with djl. Have your stock heads worked. That's what I did.

Cheers!

 

We use that 37 often in our 98" kits.
Very strong, broad power.
Very straightforward combination.
Scott