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ShadowBolt
12-18-2008, 11:01 AM
Since the number eight hole in CMC17's block is fubared I am doing a complete swap over to CMC2. Rebuilt short block, E303 cam and shorty headers. I had a few questions and wonder if anyone here has ideas about those questions. First my machine shop guy that is doing the heads ask about angle milling. Todd does not think that angle milling is within the intent of CMC rules (so I'm not going to do it) but I wonder about how much it would help. The problem with angle milling is you have to modify the coolant holes and head bolt holes so that everything lines up. I was told it would make more power than regular flat milling but from what I read just the cam and headers on a well built short block should make CMC2 power without a problem. The GT40 heads have large combustion chambers and lowers your compression ratio if not milled. The GT40P heads have a smaller chamber but they bring along other issues I don't want to deal with. My plan is to take the GT40's down to the same chamber size as the GT40p's (59 to 61 cc's).

My other question is cam timing. I read where you can change where the engine makes power according to cam timing. If you want to make power at a lower RPM you advance the cam timing and if you want to make power at a higher RPM you retard the cam timing. I have never done anything but line up the dots on the gears and wonder if screwing with this is worth the effort and if it's even legal? I tried to call Tony a few days ago but he has not called me back.

I'm not going to do the angle milling since the guy wants $300.00 to do it and I agree with Todd that it is not within the intent of the rules of CMC but the cam timing I would like to know more about?


JJ

Fbody383
12-18-2008, 12:00 PM
Remember, I'm the new guy but I have read through the rules a couple times.

I agree that angle milling, which is used primarily to increase compression, should be outside the scope of CMC/2.


7.23.3 Any initial timing may be used but no recurving of the distributor or timing map is permitted

That rule is under the ingnition section but I would argue that any initial, and static, advance/retard of the cam is still initial timing. Besides it's fixed and not easily adjustable like moving a distributor.

I hope you get an o.k. to install it the way your engine builder recommends.

Besides, you still have to dyno the thing anyway and this post could get shot down in 10, 9, 8...

ShadowBolt
12-18-2008, 01:41 PM
Remember, I'm the new guy but I have read through the rules a couple times.

I agree that angle milling, which is used primarily to increase compression, should be outside the scope of CMC/2.


7.23.3 Any initial timing may be used but no recurving of the distributor or timing map is permitted

That rule is under the ingnition section but I would argue that any initial, and static, advance/retard of the cam is still initial timing. Besides it's fixed and not easily adjustable like moving a distributor.

I hope you get an o.k. to install it the way your engine builder recommends.

Besides, you still have to dyno the thing anyway and this post could get shot down in 10, 9, 8...


Ignition and valve timing are certainly two different things but I get your point. Rule 7.23.3 has nothing to do with valve timing.

JJ

AI#97
12-18-2008, 02:22 PM
Remember, I'm the new guy but I have read through the rules a couple times.

I agree that angle milling, which is used primarily to increase compression, should be outside the scope of CMC/2.


7.23.3 Any initial timing may be used but no recurving of the distributor or timing map is permitted

That rule is under the ingnition section but I would argue that any initial, and static, advance/retard of the cam is still initial timing. Besides it's fixed and not easily adjustable like moving a distributor.

I hope you get an o.k. to install it the way your engine builder recommends.

Besides, you still have to dyno the thing anyway and this post could get shot down in 10, 9, 8...


Ignition and valve timing are certainly two different things but I get your point. Rule 7.23.3 has nothing to do with valve timing.

JJ

Since the E303 is a specified SPEC cam to meet a power requirement, I would imagine the intent is to install it straight up just like it's cam card indicates using an NON adustable cam gear. Now if you wanted to have a cam ground to E303 specs with retard/advance built into it or even a different LSA...who could check it at the track? ;) Also beware of valve clearance if you do milling and advance/retard. If you are going to get exotic, find some solid lifters and keep your old head gaskets to check clearance.

Angle milling is worthless unless you angle mill the intake and to make it all work so there aren't any "steps" in the runners, the heads and intake have to be gasket matched which isn't legal. Also, your H-pipe won't fit any more. Not worth it.

Al Fernandez
12-18-2008, 04:16 PM
Angle milling isnt ok for CMC cars, as MFW has pointed out. Cam timing is also not ok. We dont specify parts to enable this, and it wouldnt fall into the "stocK" configuration otherwise allowed. Anyway, you wont need it.

I would spend some time measuring compression ratio and ensuring you are getting what you want.

ShadowBolt
12-18-2008, 05:40 PM
Angle milling isnt ok for CMC cars, as MFW has pointed out. Cam timing is also not ok. We dont specify parts to enable this, and it wouldnt fall into the "stocK" configuration otherwise allowed. Anyway, you wont need it.

I would spend some time measuring compression ratio and ensuring you are getting what you want.


Thanks Al! I was hoping the cam timing was not okay so I would not have to do it to compete. I never considered doing the angle milling but I did want to know about it.


JJ

RichardP
12-18-2008, 09:01 PM
Cam timing is also not ok. We dont specify parts to enable this, and it wouldnt fall into the "stocK" configuration otherwise allowed. Anyway, you wont need it.


A 5.0 making CMC2 numbers doesn't fall into the "stock" configuration. Anyway, how do you know he won't need it...


Richard P.

Al Fernandez
12-19-2008, 08:57 AM
It doesnt matter how much power it makes, the rules allow stock engines as they came from the factory, then they allow mixing and matching, then they allow a few specific aftermarket parts. Nowehere in that mix is an allowance for cam timing other than stock. As far as knowing that it wont need it...in the words of Clint Eastwood, I know things about cam timing :wink: :lol:

RichardP
12-19-2008, 10:36 AM
It doesnt matter how much power it makes, the rules allow stock engines as they came from the factory, then they allow mixing and matching, then they allow a few specific aftermarket parts. Nowehere in that mix is an allowance for cam timing other than stock. As far as knowing that it wont need it...in the words of Clint Eastwood, I know things about cam timing :wink: :lol:


It's a good thing there has never been a stock cam that, because of manufacturing tolerances, required adjustments to get it to factory specifications. Anyway, allowing different cam timing sounds like a relatively cheap and easy way to help balance out the numbers. Strangely, people get a little discouraged when they make the legal horsepower number but fall 30 ft lbs short or whatever.

Mostly, I'm interested in what numbers he comes up with. I really don't want to get back to the arena where people find they have to "cheat" to get to legal numbers...


Richard P.

mitchntx
12-19-2008, 11:02 AM
C'Mon Richard.

You should know that it's against the rules to mis-align the dots on the cam and crank gears, not torquing the rockers to factory spec or altering the spring tensions in the oil pump or power steering pump.

Why?

Because it doesn't say you can.

:twisted:

Al Fernandez
12-19-2008, 11:15 AM
I hear you there Richard! lol Personally, I'd love to see the 5.0s having to restrict down slightly. Cam timing is sort of like taking money out of one pocket and putting it into another. You still have the same amount of money, it just might be more or less convenient to get to it.

Jerry, seriously, focus on compression. That will yield power across the entire band, its cheap, and its legal. If I were building a 5.0 I would shoot for 9.7...comfortably under the rule limit but high enough to make a measureable impact.

ShadowBolt
12-19-2008, 11:43 AM
I would have thought cam timing would be okay since it cost nothing. I agree it only moves power around.

9.5 to 9.7 is what I'm shooting for. I'm still not clear on how a 302 can make as much power under the peak as a 350 but it is what it is.


JJ

Rob Liebbe
12-19-2008, 12:59 PM
Unfortunately, peak is the measure.

Don't think of the Ford motor as a handicap, think of it as a challenge and know that success in the face of a challenge is much sweeter than success given to you as a result of a superior platform. :wink:

OK - I know - parity - blah blah blah - but the challenge part still applies. :D

Al Fernandez
12-20-2008, 02:03 PM
Dont feel like you dont have enough firepower with a 5.0. Just remember, your fellow Ford lose...er...colleagues are running 4.6s! 8)