Just bought me a set of Bob Wood tw408-44 cams. It was either the TW-6 or these, after a bit of research I think the 408s will be a little more suited for the future plans I have.

I Cant wait to install them... I can't seem to find a 4 degree advance gear though, are the gains even worth running one? I do plan on head work this winter but will probably install the cams within the next few weeks.

 

Then don't waste money on the advance. Just do the cams, enjoy them then do the heads when you can. You don't HAVE to do the advance.

 

"[A]dvancing a cam advances all valve-timing events, ... most importantly [it] closes the intake valve earlier, which increases low rpm cylinder pressure and usually improves low speed torque at the expense of high-rpm horsepower. As can be expected, retarding a cam closes the intake valve later and improves top-end horsepower at the expense of low-speed torque."

http://www.harley-riders-guide.com/h...dson-cams.html

I always kind of wondered why not just get a cam with a different profile/grind instead of screw around with the advance/retard of the cam sprocket/gear ...? If the cam you have doesn't provide the low end torque you desire, select a different cam ... right?

Just thinking out loud here ....

R/
'Chop

 

When I spoke to Bob Wood last year I asked him about the advance gear. He said it's a cheap supplement to doing the headwork necessary for the cams to function in an optimum situation. It'll mimmick a slightly higher compression. That's all.

I think the same could be said for swapping out different rocker arm ratios to achieve a higher lift. Why swap rockers to achieve a higher lift when you can just buy a cam designed with a higher lift. I've actually been contemplating this mod. 1.725:1 rockers are $140 from HD. For me to buy a new cam and swap it in including new gaskets / o-rings would be more expensive than $140.

Per the bigboyz cam calculator, adding 1.725:1 rockers to the tw6 cams would effectively turn the .510 lift into .541 lift. I've read that the stock 06+ heads can handle up to .600 lift.

 

I really feel these bikes all need mid and top end power improvements. I have never ridden a Harley of any model and said This thing needs more torque down low!
I believe I wll set mine up for the mid top powerband. Maybe if I had a heavier bike I might feel the need for more torque.

 

A 4 degree gear will give you 4lbs extra PSI, it also moves all events to the left. The .030 head gasket will give you 6lbs extra PSI. My 37's were a little soft on the bottom but the 30T pulley made up for that a lot. I would have saved myself a little time and a few gaskets doing the heads the first time when I had the rockers off doing my cams but I thought the cam only would work better than what it did. When I had my heads ported I did the .030 and 1.725's and that did the trick, I'm done with my engine now. I have a T-Max auto tune so tuning wasn't a problem for me but if you figure in that cost also it's better to hold the cams and do the heads at the same time, you can save a few dollars reusing the stock pushrods also. My heads were $375. for porting cc'ing and shipping from FL to ME and back. Signed, been there done that..

 

Thats always been my understanding, Im just going to go ahead and not use the advance gear.

Im going to send the heads off this winter to get ported and the chambers re-sized/milled to bump the compression. I can wait that long for a little more umph. I would do it now but I dont think I could stomach the down time, not while the weathers right for ridin.