Just bought some used heads heads from ebay - Harley Forum

bundy bruiser · #1 08-14-2009, 03:51 AM

hello
I just bought some 04 twin cam heads from ebay that are used.
This, of course was after reading Donnie Peterson's excellent tech article over the last 2 AIM issues......

I am building up my 05 FXDC 88, and going to use the 04 heads on a build up to port using 570 cams, flat tops, 95" bores and some sort of ignition timing module?? not sure on that.

The question I have is, Donny mentioned about the 05 and up models having smaller valve stems than the 04, thus being lighter etc. I agree totally with this idea and would like to do it on the 04 heads just to keep valve train weight light. I like this idea with a high lift, agressive ramp camshaft. I use this bike everyday to go to work and rack up some miles.

I am guessing the 04 and 05 heads are the same except for smaller valves? Will I have any probs using the rest of my 05 stuff like rocker boxes etc?

Would it just be a matter of inserting smaller valve guides into the 04 heads to allow the 05 and later valves to be run? Is this possible?

I want my porter to do the heads and have them ready before I do the rebuild. The Dyna is my daily rider.
I was going to buy new valves, springs etc to suit the 570 cam and have the heads ready to bolt on when the time comes.

Donnie metioned that evo valves could be used, to increase the valve size on the inlet with a seat recut. but he stated they have the larger size valve stems (the same as the 04 and earlier)

Should I just go with the heavier valves
What other options would there be for bigger valve, and is it worth it in the end?
Cheers
Jason

sinolav · #2 08-14-2009, 01:01 PM

Bundy, I upgraded my 03 ultra with 07 heads after reading Donnies articles, and books. I went with an Andrews 21G cam, and other parts.

There are also subtle differences in the ports and air flow on the new head design casting which make them better that the older heads. So I opted to go with the later heads.

I used my 03 rocker boxes and covers on the 07 heads without any problems.

I have talked to some people that do head work, and they say for about $300, they will port the heads and the older heads will flow just as well. Then you'll have to get new valve stems, seals, springs, valves, valve keepers and shims to get the valve spring height right. Be ready to spend some bucks having this done.

Just keep in mind that if the head part number ends with a -99, even if they have the new valves and beehive springs, they still have the old style ports. You'll find bikes from 05 to early 06 that have the new beehive springs, but the head casting is still the old style, and end in a -99 part number. You'll want a set of heads that end in I believe a -05 or -06 to get the new casting design.

I guess the question to ask yourself is how much you want to spend on head work. If you want all out performance, have the heads ported, and redone as Donnie suggested.

Hope this helps.

bundy bruiser · #3 08-19-2009, 07:18 AM

Thanks for the input Sinolav, much appreciated mate.
I will put new valves etc, so the top end is all new.
I am not chasing huge numbers and my porter is quite talented with all the gear to do it.
I will show him Donnies articles and go from there
Cheers