I have always wanted to try Woods TW6 cams and just picked up a set on eBay at a nice price. Current 95" build is set up at 9.8:1 CR. Will the TW6 run good at the compression, or do I need to bump compression to 10.2 - 10.5? Will it be soft on bottom end at 9.8?

 

With an intake valve closing event at 40* ABDC, I'd bump it up to between 10.0 - 10.5:1. Like you said, it will probably feel soft at the bottom staying with what you have now.

How you get from 9.8:1 to 10.25:1 is the trick.

 

Right now, heads are decked .020 with .040 gaskets. Figure I could deck the heads another .030 and use .030 gaskets.

 

What effect does the 4 degree advance gear have on compression? Just curious if it would accomplish same thing with out having to pull heads.

 

u have 204s now ? whats wrong with them?

 

If you go to the Big Boyz Twin-Cam Compression and Engine Displacement Calculator, http://www.bigboyzheadporting.com/TwinCamComp.htm, and input the 4* advance on that cam, you'll notice that the Corrected Compression along with Cold Cranking Compression will increase. You want your Static Compression up around 10.25:1, and Cold Cranking Compression between 190-200 psi. You'll need compression releases installed if you haven't already.

Get with the people who did the work on your heads and discuss it with them. They can develop a plan to get you from point A to point B.

 

I just wanted to try a set of Woods cams based on what I have always heard.

I thought the 204's felt a little soft on the bottom end, but pulled great on top end. Last Friday, I had my heads cc'd to make sure I have the compression set up correctly for the new cams and found my heads were reading 84/84.5 cc's after being decked .020. Guy who did heads originally never cc'd them beforehand and was basing CR on 85cc HD spec. Due to the HD variance on the heads, my static compression was more in the 9.5:1 range rather than the 9.8:1 I was told by builder. This may explain some of the soft bottom end I felt.

 

Thanks - my setup will be almost exactly as you wrote - 10.25:1 static CR, corrected compression of 9.57:1, and cold cranking comp of 198.8. Heads are being reworked right now with releases. Gonna get a good tune and hope I can feel some power gain.