please give feedback on cams

Alright this question is to anybody running a big single. I personally run a 478/87/.90 on my 6.7 and can be fully lit to 50+psi by 2350. Drive pressure can be held at 1:1ish, but egts on heavy tuning with my fueling can be a little toasty (sw6 maxs@ 1450, sw8 maxs@1700+). Roughly how well will a 181/210 vs. 188/220 cam increase spool rpm wise and how would egts be since more air volume is be pushed into the motor. Truck currently has stock cam and head. Not sure where the truck sits power wise, but know that I can bust my drw loose at 50mph so any thoughts?
 
Here is the video of my last race of the season, this is with a 25psi transbrake in 4x4 high launch in some nasty thick mud. Placed 3rd this race and finished 2nd in points for the season in Modified Street.

Thanks for a great cam Zach.

http://youtu.be/l_Mub77j4dk
 
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blackmega3500 said:
Alright this question is to anybody running a big single. I personally run a 478/87/.90 on my 6.7 and can be fully lit to 50+psi by 2350. Drive pressure can be held at 1:1ish, but egts on heavy tuning with my fueling can be a little toasty (sw6 maxs@ 1450, sw8 maxs@1700+). Roughly how well will a 181/210 vs. 188/220 cam increase spool rpm wise and how would egts be since more air volume is be pushed into the motor. Truck currently has stock cam and head. Not sure where the truck sits power wise, but know that I can bust my drw loose at 50mph so any thoughts?
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The 478 will spool much better with the 188-220. It runs a very aggressive intake that moves more air through the engine at almost any rpm from just off idle to over 4,000rpm than any other cam we sell.

One thing you will see is less overall boost but it will coome on quicker. The reason for the less boost is that the air is entering the cylinder quicker and easier from the higher lift and longer duration at .200" and over. One thing you will see is a larger imbalance in drive pressure to boost pressure. Since you are moving more air into the engine, you will be able to burn more fuel and have much more exhaust pressure. This is not because of a poor design in cam but from all of the added volume that is going through your engine.

The turbo will spool better, you will have less smoke, more power, if you had a lot of smoke previously, you might even make a bit more egt as you are burning more fuel making more heat.

Even though the boost will drop, if you had a turbo speed gauge, you would see an increase in speed which means you are moving a lot more air.

Also at the higher rpm you might see much higher drive presssure which means an external gate if you do not have one.

Thanks,

Zach
 
Appreciate the info Zach. Now I've had my head decked once, will I need to have the pistons flycut for the 188/220? Side note on Sw6 with dual pumps and 150's I can completely clean them up. So what your saying is its expected to have greater egts the more efficiently you burn the fuel?
 
Since they are clean already, the extra air should lower egt a decent amount. Typically when you over-fuel excessively it actually cools the cylinder because there is not enough oxygen to burn the fuel so the fuel droplets turning into vapor absorb the heat in the cylinder. Now introduce a lot more oxygen, and you will have a lot more combustion and heat.

In a cylinder that is clean already, the added oxygen cannot burn any more of the fuel, but will start to cool things down a bit.

Zach
 
Since they are clean already, the extra air should lower egt a decent amount. Typically when you over-fuel excessively it actually cools the cylinder because there is not enough oxygen to burn the fuel so the fuel droplets turning into vapor absorb the heat in the cylinder. Now introduce a lot more oxygen, and you will have a lot more combustion and heat.

In a cylinder that is clean already, the added oxygen cannot burn any more of the fuel, but will start to cool things down a bit.

Zach
 
Do you have all the testers you need, Zach?
I have access to a dyno. 100% no doubt. It belongs to a friend and I have the record for person with the most pulls on it. 7 different cars/trucks I've owned have played on that drum. LOL!

Interested in much earlier spooling primarily, and of course prefer that to occur while adding power. While not dropping fuel economy.
 
I assume pretty snappy. I will know when testing is done very shortly.

Adam, I will let you know if we need any others.

Zach
 
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...can't wait for the results. Been researching lash settings. Let us know what you are recommending for these bad boys. :D
 
got my 188 in yesterday, really impressed. Overall ive noticed a big improvement it spool and a HUGE reduction in smoke, what was a large black cloud and a dark soot trail at WOT is now a puff of black then a barely noticible haze at wot. Boost comes on instantaneously, building 5psi at any point where the truck is driving down the road maintaining speed.

few concerns I had, after the install, when re-installing the rockers and lashing the valves, I had about 3 full screws of play on each rocker before they came back to lash (meaning something in the system is smaller than stock), Is it the base circle of the cam?

really happy with how the whole job went, my 320,000mile stock cam was very worn, and the 188 really wakes the truck up, think my stoich is off, need some more fuel now:rockwoot:
 
ahale2772 said:
got my 188 in yesterday, really impressed. Overall ive noticed a big improvement it spool and a HUGE reduction in smoke, what was a large black cloud and a dark soot trail at WOT is now a puff of black then a barely noticible haze at wot. Boost comes on instantaneously, building 5psi at any point where the truck is driving down the road maintaining speed.

few concerns I had, after the install, when re-installing the rockers and lashing the valves, I had about 3 full screws of play on each rocker before they came back to lash (meaning something in the system is smaller than stock), Is it the base circle of the cam?

really happy with how the whole job went, my 320,000mile stock cam was very worn, and the 188 really wakes the truck up, think my stoich is off, need some more fuel now:rockwoot:
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Glad you like it, and thanks for the feedback. Yes the basecircle is smaller which is the reason for the adjustment. If you get our pushrods, they are .020" longer to help take up some of the slack and put the rocker arm geometry back to where it needs to be.

Thanks,

Zach
 
good to know, glad its not an issue, ill get pushrods sooner than later

thanks again for all your help
 
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