Guys do you think we can get the same thing going for 3.7L Headers and Programer?

 

Hey I am looking at 206 cams...but the 212's say you are required to have 70mm TB, intake, exhaust, and a tune. I have all of those except tune. So would it be more beneficial to get 212 or are those more hassle? I have low skills on motor parts installation too. I've only done intake exhaust and my TB, had help with spark plugs.

 

Okay, color me silly, but wouldn't be better to NOT have either valve open at the same time?

Yes, I just went to the 'How engines work' site, and it seems that having both valves open at the same time, however little, is a bad thing. Putting a performance cam in, which increases the amount of time valves are open at the same time, would be worse.

Someone tell me why I am thinking wrong about this. And please use small words.

 

Valve overlap improves performance by using the momentum of the exhaust gases to improve the pumping capacity of the engine. When the exhaust valve opens, the exhaust gas exits the combustion chamber at a high velocity. If the intake starts to open before the exhaust valve closes, the momentum of the exhaust gas leaving helps to pull the intake air into the cylinder. There are trade-offs; unburned fuel can be pulled out with the exhaust gases and and it can cause poor idle in extreme examples. Used in moderation it can improve output without serious side effects. I increased overlap from 3 to 9 degrees on a 145 cu. in. 4 cylinder motor and picked up 10 wheel horsepower and extended the usable power band upward 500 RPM and it still idles like a champ.

http://auto.howstuffworks.com/camshaft.htm

 

Yeah, that's the link I followed earlier to see that. My concern then would be the unburned fuel mixture escaping with the exhaust. The last time I had that issue, it clogged my CAT up as to kill the engine after a few minutes. Not something I would want to relive. Granted, that was a carbed 78 Chev 305, not a injected Dodge 4.7.

Right now, I think I'll just stick to what I have and go for the more air flow and getting a superchip.

 

I found 4.7 H/O cams at http://www.airram.com/product.php?ca...productid=1308. i have the 3.7 so i did not look into them to much i just remember scrolling through them. good luck guys