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Retarding a cam?

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Old 05-29-2007, 11:01 PM
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Default Retarding a cam?

I see all the wannabe gurus on here saying "every cam should be degreed", but they fail to mention that it can only be done on our engines if we buy an adjustable timing set. Is this correct? I think so, but I'm not sure. I'm just curious because I may experiment with retarding my cam a little since it has some advance ground in. With my high compression, it may benefit from a couple of degrees of retard.

And yes, I'm ready for the retard jokes.
Old 05-29-2007, 11:23 PM
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For one you can always make your gear set adjustable by elongating the bolt holes and enlarging the dowel hole and using offset bushings or something of that nature, but it would be easier to get an adjustable gear set. Also, it is a good idea to at least check it to make sure you do not have any defective parts grossly throwing off your ICL and also to make sure you actually have a cam that matches what you ordered and what the cam card states you have.
Old 05-29-2007, 11:35 PM
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Oh yeah we checked it with a degree wheel and dial indicator. The grind was AMAZINGLY accurate. All's well. I'm just considering rebuilding soon, and if I do I want to go ahead and fine tune it to death.
Old 05-30-2007, 12:02 AM
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Unless you're getting KR or for some reason you want to move the powerband up, there is no reason to retard the cam. There is advance ground in for a reason.
Old 05-30-2007, 12:23 AM
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Oh, I agree. The reason is that on stock heads, the added advance brings in more down low than it loses up top. But I've seen the "gurus" on here post many times that with higher compression the advance is not needed. And yeah, it falls off a little early. Like I should be shifting around 6400 as it is. I think that with my heads milled at .030" as they are, I could really pick up more up top without losing much down low. I'd much rather spin it a little higher.
Old 05-30-2007, 08:02 AM
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But on stock heads the flow dies up top, so you won't gain that much up top. By all means, if you want to mess around with it go ahead. I like learning things first hand as well.
Old 05-30-2007, 08:18 AM
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Originally Posted by ArcticZ28
But on stock heads the flow dies up top, so you won't gain that much up top. By all means, if you want to mess around with it go ahead. I like learning things first hand as well.
Retarding a cam like his, will generate more power. But instead of getting a cam with some messed up specs and then trying to make it run down low by advancing the ICL...just grind it the way it should be in the first place, straight up and degree it from there. Offset bushings are available for these motors or adjustable timing sets. When the valve events are right, the cars will run. Retarding the cam that has been advanced almost always will generate a better curve.
Old 05-30-2007, 08:26 AM
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Retarding a cam will almost always generate more power, but it won't generate a better power curve at all. It will generate more peak hp later in the powerband while sacrificing down low, which I think he is looking for. A good curve incorporates steady tq through as much of the powerband as possible, which is not what this will do.
Old 05-30-2007, 09:08 AM
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You don't think it'll be more linear? As it is now, it falls off sharply before I'd like it to. And I'm not on stock heads. That's the point.
Old 05-30-2007, 09:19 AM
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All retarding or advancing a cam does is shifts the powerband around in the RPM range. If you have stuff that can flow good up top like aftermarket heads/intake then by all means retard it and see what you can pick up on top, the gain will come at an expense of your low end though.

Anyway yeah ya just want an adjustable timing set, they are very simple to use too plus if you happen to buy one of those cool 2 piece timing covers than changing the cam timing is even easier.
Old 05-30-2007, 09:22 AM
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It'll carry further and peak later, depending how much you retard it. However, 1936Ford could be correct as well and it could produce a better curve for your liking. But, it's all speculation without a graph as each combo will react differently and these terms of more linear and "better curve" are all generalities and quite subjective. It sounds like you're really set on trying it, so go ahead and see what it does.
Old 05-30-2007, 10:55 AM
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Also consider the application and the weight of the car. A DD may have poor day to day manners which may be of no concern if it's primarily a track car. Depends on your application. That said, moving the cam around can produce some fairly dramatic results, depending on you set up.

Andy1
Old 05-30-2007, 01:22 PM
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My cam is installed 4 degrees retarded due to the fact that it's a smaller cam in a big cube motor. It puts down great RWHP and great RWTQ with a great power curve. IMO, it's matched perfectly.




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