Like the title says, Im doing a cam swap on the LQ9, and thought it would be a good time, to mill the heads to get compression up just a tad or maybe more, but must run 93. I know someone has to have some info about this. My stock compression is like 10.1 right now, so I didnt know if I could get 11.1 and make a significant difference? That full point should yeild what for my tq&hp? I can have the heads milled for cheap.

I was planing a mild cam, with 3k stall, 3.73s, cai, etc. Wanting a more tq and midrange. Truck runs 93 at all times.

 

i think its something like 10-15hp per point in compression. having them ported and polished would be something to look into though, you wil benefit more from that than you will from milling

 

243 heads will also get you to ~11:1 CR...

 

243 would be sweet, if I can swing it. I may just stick with this compression, untill I upgrade the heads then. I was reading since my compression is already, high the 1 point may not show significant changes.

So plans are to just cam the LQ9 for now, I was looking at Trickflow cams,but dont know anything about their profile or ramp rates.

 

It is commonly said that a 1 point increase in compression will correspondingly equal a 3-4% gain in power. That is also assuming that you do not have to pull timing to run the extra compression. With the modern fast-burn chambers and the use of aluminum heads that pull heat out of the cylinders and then finally great engine management systems we now have, we are able to get away with way more than we could on pump gas in years past. Another thing that plays into it is the current tendency to run rather large camshafts that bleed off cylinder pressure, which also has become a lot easier due to wonderfully easy to adapt engine management systems we now have. A lighter weight vehicle that is not under as much load can get away with more as well. Bottom line is I don’t think you would loose or just not gain any thing by trying to get to 11:1, but is pushing things.

 

Well said, and what I have gathered from lots of reading. Thanks, I will not waste my time on that. Focused on a good cam right now.

 

It is my understanding that the ports and runners on the 243's and 317's are the same, only difference is the combustion chamber size...but I could be wrong...

Comp grinds TrickFlow's cams, just not sure which lobes they use (XE, XER, or what). I'm interested in their 220/224 .575/.575 112 for my LQ9