As I mentioned in #66, the 210psi cranking compression is not computing for me. I could see 185psi with 86cc heads and .030" head gaskect and flat top pistons. If the are installed advancd, the compression would vary from one cylinder to the other; wouldn't be getting the same readings.

You are talking Andrews stuff; extreme quality control as they grind most of the cams for the aftermarket. I do know that they ground a batch of cams for a popular builder a year or so back and the ramps were off just at few thousandths which made the ramps noisy but did not affect performance.

Those 67Gs are a little long for your application, IMHO. Why not pick up a set of TMan's new 600S series and see what happens? Cheaper than buying another bike.

Send the 67s back to Andrews to check if they are within spec or not. I got a set of cam gears from Andrews two years or so ago that I couldn't make work; when I got the inner lase right the outer lash was off and visa versa. I called Andrews and sent the gears back. They did find something wrong with one of the gears and sent me a new set.

 

Another silly question: Would a 2002 crank be keyed in exactly the same spot for the cam gear as my 2003? My crank was used and came from a 2002 model.

@djl- Does andrews make there own gears? My cams are andrews, but my gear drive kit is S&S. He did have to change one of the gears because it was too tight, but that was discovered during the original build. As far as throughing different cams at it, I think I need to find out more specifics about my heads first. All I really know is valve sizes, and that's it. 2" in, 1.65" out. The shop I talked to yesterday said they are making the big numbers all the time with smaller valves then that, but they grind there own cams.

 

Yes to your crank question; not an issue.

Andrews makes the geas for S&S and, like I said, grinds most of the cams for the aftermarket, like S&S, etc. The cam profiles are created by a vendor, say S&S, and Andrewus grinds to their specs.

Where did you get your heads? You do need to know the details, like chamber volume, springs and how much lift the springs can handle. However, trying another set of cams wit the same or less TDC lift is not an issue.

 

The heads came from Axtell. It was a complete kit. They supplied: cylinders, pistons, cams, DTT ignition, intake manifold, Mikuni 45 Carb with air filter, gaskets, and spark plugs. And a "free" t-shirt.

The heads have 2" intake, 1.65" exhaust, 89cc chamber volume, and chamfored exhaust ports. The guides are cut down to accomadate up to .700 of lift, not that I would go there. He says the comp ratio should be about 10.6:1.

 

OK. Using a CR calculator, 89cc chambers, .030" head gasket, 0.00" deck height and flat top pistons, the calculator shows static CR should be 10.07. Assuming all the above data is accurate, the only two unknowns are deck height and piston dome volume. Deck height won't change the numbers much at all. So, the pistons must have a dome. Working backwards to get the 10.6 that Axtell says you should be getting, indicates a dome of 4cc to 6cc. You need to find out the dome volume to back check actual CR against calculated.

 

They are definitely domed, I will find out how much as soon as I can catch Chaz on the phone again.

 

A carbed, 107" over-square, with a good set of heads,, and a 2", or 2.020" intake valve, rolling off around 172 cfm, @ 10", at .700 lift, and with a Wood 8 will absolutely, without a single shadow of doubt, rip, with either a 45 Mik, or S&S G, and with either a Supertrapp, Thunderheader, D&D Fatcat, or a set of Cycle Shack pipes.
120-125 hp, and 125 or so, ft/lbs.
No brag, but it is just what they make.
Scott

 

Scott, .700 lift sounds a little crazy for a street motor that I am hoping to run for a long time. I don't know anything about CFM... Any thought on a reasonable expectation from the Andrews 67G, .570 of lift?

 

What Scott is refering to is the CFM the heads flow at a particular lift. See this chart from Tman. This is just a reference to his stage 3 heads. I strongly believe your problem is minor. All things considered Axtell makes some pretty steller products and packages. When I talked them, I ordered their cylinders and pistons. The pistons I recieved were their flatops made by JE. They were flat tops displacing -3ccs. Combined with my builders headwork and .040 head gasket, I'm at 10.3:1, 185ish CCP, haven't personally measured it. Both Axtell and Andrews steered me to the 67s. They used to offer their "Mountain Motor" with Andrews 60s, they told me now that they like the 67s. And for some reason Axtell loves cycle shack M pipes, they are LOUD! and I didn't want that much noise. They tried to get me to go for them. Mine flat out rips, now you're making me want to get on a dyno to see how it does. With the CCP you mentioned I don't see how the heads are to blame, but I also don't know what they do to them. I'm sure it'll get figured out, any chance the dyno was run in 4th gear?

 

Matt, all of my runs have been 4th gear roll ons, from both tuners. What kind of difference might 5th make? See the chart I posted in post #38, that was the first guy, but it matches the second. We had a friends Yamaha tuned by the second guy last night. He said he always dynos in 4th. All this being said, I have ridden a lot of bikes, and mine does not feel like the numbers are off on the machine. By the seat of the pants, it FEELS like it is only making about 100.

Edit to add: My friends 110 inch Yamaha made only 90 HP, and 125 torque. I think the torque may be so much higher because he changed a pulley, but in any case his bike walks away from mine easy, just not as easy as it used too.