I have been reading a lot of threads about guys going to big bore kits. 103 HD, 106ss, 107 fuelmoto etc....
I have also noticed many are doing cams at the same time-good idea.
However, I don't see many doing head work. A few but mostly not.
If it was me and I was going to do a big bore kit and cams I would at least have the heads cleaned up some.
Maybe it's me but doing the heads at the same time would be cost effective I would think. Not to mention a better cam choice for additional power.
Is it me?
Warranty?
Well if it isn't done by a HD dealer with HD parts and installed within 30 days it will not be added to the bike warranty any way.
Why not wait a little longer and do the heads at the same time?
Am I missing something here?
dd

 

I think it all comes down to a cash thing. I think if I had to do it on a budget and couldn't do big bore, cams and heads all at once I would do big bore and heads while the top end was apart then do cams later on. I've read you can gain around 20% by porting a Harley motor but in the same aspect you can also loose that much porting your heads. So you want to send it to someone with a good track record.

 

When I am on a budget I either just do cams or wait and save.
that is how I see it.
I had 30,000 miles on my Ultra before I could do anything to the engine. Then I only did cams. It was still under warranty. I did it when the tensioners needed to be checked. Saved me $150

 

I agree it makes sense to do it all at once, if the budget is there. I did cams last fall, and planned on just doing the heads over the winter, but convinced myself I might as well do the big bore now since I'm this far into it. Found a decent deal on a 103" kit from a forum member, so that's what I'm doing. There's not a ton of labor overlap doing the cams and the heads at the same time if you're using adjustable pushrods.

 

I would only recommend a big bore kit if you do head work and throttle body.
Think about an air pump, now you have bigger pistons but the air flow is restricted, you don't get much out of it. Money is always our main concern, save some and do it right. That's why I added cams and worry about the rest later when I have enough cash lol.

 

I'm doing that very thing as I write this. Going from 96 to 103 with 204 cams stage two. Could have gone stage three and got higher compression heads and porting, but at my age this will be enough for me. Not to mention a lot cheaper.

 

I did forget the throttle body didn't I.
In most cases you can rework the throttle body up to around 115 hp/tq...
Want big hp/tq gotta spend the money on a throttle body.
But that changes it for most riders, big bucks now.
But if you go that far a welded crank and tem... bearings need to be done.
That's me though.

 

My bike I have the big bore, hi comp. pistons, cams and head work. The heads have been ported and bigger valves installed. The motor is at 108/113. The next step will be bigger throttle body and injectors. Might do that next winter though.

 

Check out this website has some good info on porting heads. http://www.floheadworks.com/Articles...ng_secrets.htm

 

Your right head work should be done but it isn't actually necessary to do the whole shebang at once IMO.

By the By did you know HD has put a103" kit on the market with stronger stage II heads which have oversized valves in it? The price here in Canada is just over 2 grand, and I bet it is even cheaper to get in the US. They tell me that this year! Shi! @ years ago I put on the stage II kit without heads for the same price.

If I had it to do over I would buy a fuel moto 107 kit and have the heads done at the same time though, so yup your right!