I have 08 FLHT with 103", SE 10.5:1 pistons, Woods 408-44 cam, PCV and propipe. I am happy with my build and I want to add automatic compression releases to my heads. As far as I will take the heads off I started to think about headporting. I don't want to increase cr anymore. The cost is up to 1500$ so I am curious about what can I gain after spending that money. My options are porting the heads at bigboyz or hillside or buying R&R twincam cast iron heads. Please help me to decide first to port or not then if the answer is yes which one to choose.Thanks in advance
Reha

 

There are some things to think about.

You have 10.5 pistons. Your improvements have to have this in the picture.

What is your CCP (Cold Cranking Pressure) now? Do a pressure test to find out.
This will determind weather you mill the heads or not. May be a big,-Not. Or not too much.
Because this will increase the CR too high quick, considering a 103 already.
Need to figure this cause big valves and head work can increase Combustion Chamber voluum so may need to take off a little. Important consideration.

I haven't run Cast Iron on anything fro 25 years. The main advantage to Aluminum and why every manufacture uses this is," heat transfer". Except for exotic coatings to keep heat in the combustion chamber, keeping things cooler is the way to performance. And on the street where it is most important.

The main thing about head work is --All The Power-- or lack of it is in the heads. The heart of performance. Everything else is to assis that.
There is a lot of imorovement to be gain with head work on the stock HD heads. And they are perfectly good for this.

In 1920 airplane engines had---Twin Overhead Cams---Duel sparkplugs--- 4 Valves per cilender--- Supercharging. Working on Fuel injection.
All in the heads. It is not new knowledge.

 

You are not getting the full benefit of the cams without porting the heads. Let that puppy breath!

 

Headporting will get the engine working properly. I understand from articles I've read etc that the stock heads are going to be the limiting factor on any tuned Harley without porting because regardless of other mods - big bore, cams etc - the stock heads can't flow enough to realise any meaningful performance gain over 4000 rpm. Also I think you'll find the R&R cast heads are aluminium not iron (and the better for it).

 

as stated above there is alot just waiting to get out with porting.

I have never used Hillside, but they do have alot of experience with Woods products which would put them up front the job. Getting the port work tailored to the cam profiles will be money well spent.

 

everything happens in the heads...........air and fuel in and exhaust gas out. also its velocity that you want, bigger isn't always better.

 

That is the main reason I wanted to ask you guys. In some topics I read that the 96" heads have enough flow and in some topics people say you shouldn't go to bigger valves if your engine isn't too big. How big should I go in the valves? Do better flow means more power everytime? If yes the R&R heads is one of the best. I also want to learn that how porting the heads will change the feeling while riding. The main power increase comes from increasing compression which is already done. Will I have 10 more hp or torque or will it just rev faster? I live in Turkey and I have to decide and do it at the first time. Everytime costs me around 1000$

 

1.940" White Diamond(Kibblewhite) intake valves, along with 1.630", Blach Diamond, 40* high-tulip exhausts.
275 cfm @ 28" will run that 103".
Scott

 

anytime you can get more air/fuel in your motor you will make more HP/TQ,at what rpm this takes place is the problem with alot of head porters as the ports are enlarged too much,and air volicity is lost,thus having air stagnation at lower rpms.use a reputable porter (if thinking of scott(hillside) or badboyz,scott would be my choice hands down)

 

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