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CVO Technical => Twin Cam => Topic started by: PigRiderCVO on January 30, 2019, 11:10:05 AM
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Hello CVO family. My bike was bone stock so last year I installed S&S 585 cams, SE adjustable pushrods, SE Heavy Breather, D&D FatCat 2into1, tuned with a TTS tuner. That yielded 105hp/110tq.
I want to get all I can without going into my bottom end or sacrificing longevity.
I'm thinking more compression by thinner head gasket or milling heads. I'd like some feedback from you guys. Folks aren't very knowledgeable about these SE103s around here. Any suggestions are welcome and appreciated
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You are short on compression. The true compression for those models is about 8.3:1. That cam comes on real well at 10.5. That is a piston change. No reason not to bump it to 107 when doing that with a mahle domed piston. The chambers on your heads are huge ~98cc iirc.
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What's the part number on those pistons? Could I get that compression by taking something off the head or changing the gasket and not doing the pistons?
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Pistons are the proper way. Milling etc is a fine tuning aid.
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I'm asking my tech if he's familiar with those pistons. I looked but I can't find em for my bikeb
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You will need to use a dome meant for a bath tub chamber. Will work better than the arias alternative.
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May want to try Keith Black too. They have some nice stuff.
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That's a very respectable graph for what it is now, nice :2vrolijk_21:
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Yea she hauls ass. Anyone have a part number for any pistons that'll fit my Hemi heads? I'm having trouble finding anything. My Tech is doing a cc pour test on my heads now and I think he wants to mill them after. Like bro said above, I'd like to go with pistons and mill later if need be
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Have you thought of a set of take off heads to work?
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Originally Arias made the pistons for HD. Those were also supplied for the HTCC SE catalog items. The builds did not last. Rings wore out prematurely. Many reasons, no need to get too deep in the grass. A standard bathtub dome designed for the OEM head will work in most cases. My recommendation, Mahle. It can then be bored to 107" and pick up a few hp and torque just by virtue of the added cubes. Set it to 10.5:1 with a .030 head gasket.
The heads can benefit greatly with porting. The ports are too small for the combination of parts. The origin of the ports was from and for an 80" EVO SE head. Port the heads. Use a decent pipe and if you have to use duals consider the S&S over under 2 into 1 into 2 duals and Cobra 909 mufflers. Other 2 into 1 pipes work great, many of those.
After all of that if you want more another $500 spent on a larger TB will get you another ~5 horsepower over 4K. The S&S 585 at 107" 10.5:1 set up as I am describing can potentially make in the mid 120s for horsepower and torque and will come on right after idle.
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Adding 4 cubes by making the cylinders paper thin is not really worth the trouble in the grand scheme of things. (especially if longevity is important). Getting the heads worked on along with a better TB would go a long way. A first over 103 (dome) would be damn near as good and would simply last longer. (Performance vs. longevity) Will 4 cubes make more power? Of course, but I'd trade a few FT/lbs for added longevity, but that's just me. You'll have to make
that call. (That D&D pipe is very good BTW.)
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the CVO 103 heads are going to take a lot of milling to get to 10.5-1,find pistons or use a set of late regular 96/103 heads.
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the CVO 103 heads are going to take a lot of milling to get to 10.5-1,find pistons or use a set of late regular 96/103 heads.
+1 Good advice.
The 96/103 ACR are pretty damn good, with a minor amount of work. Milling the $hit out of the heads
is not a good idea, for several reasons. (Using a dome piston is the way to do it, milling should be done
to fine tune the CR or bump it slightly)
Milling them too far can cause manifold fitment problems, piston to valve clearance changes and things like
that.
I'd think about some ported 103 heads with small dome pistons, who cares about "logos"? I prefer the
stealth look personally. But 'different strokes' as they say..
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The cvo heads are fine and then you retain the logos, some care about that. I have milled them and it has a desired affect, a perimeter squish band. Some milling and a dome work very well.