Here is a graph of both the 212/218 114 LSA cam and the 200/206 109 cam.

Most of the magic (off idle and through 2,000) is off the graph. I'll guarantee that if you really want to use the truck as a truck, the smaller cam is better (look at the left end of the red line). The gas milage/fuel economy for this cam is about 10 - 15% better than the 212/218 for daily driving. However, I miss the passing performance of the 212/218 cam on the road. Both of these cams were tuned for 87 Octane. Here is a very similar Crane Cam on eBay http://cgi.ebay.com/ebaymotors/ws/eB...%3ASS%3AUS%3A1. Crane claims the same thing that I am claiming.

I'm in the process of building a 408 Stroker to run on 87 Octane. I plan to use the 212/218 cam again, but I will have lots more low end torque due to displacement and the displacement shifts the performance band downward in the the RPM range.

Steve

 

All good stuff Steve!!

From where did you get your custom grind 200/206 109 cam?
Vould you like to chare the detailed cam spec?
Any changes neccecary on valve train components?

Br//

 

I used DynoSim Pro Tools to come up with the basic design and discussed the specifications with personnel at Comp and they recommended a couple of minor changes. I do some free-lance technical writing on the side (from my day job as an aircraft electronics engineer) and I did some research and wrote an article on the DynoSim Series for Comp in their Power & Performance News publication (see p. 22 for the article http://www.powerandperformancenews.c...ormance04.pdf).

I'll be glad to post the exact specs from the cam card soon (I'll have to do a little searching in computer files or in paper files for my truck).

All my best,

Steve

 

When I put the 205/212 cam in my 5.3L (with the stock converter) I was very pleased with the results. No loss of low end. Not saying a 200/206 isn't good, but I think you're leaving a lot on the table over the stock 191/190.

 

I think that the 205/212 would be an excellent cam too. The Comp 54-408-11 which has been out for years is a 206/212 cam. If you have a pickup (especially a short cab) and you tow only infrequently, the 206/212 cam is probably better because you have a lower mass that you are trying to get moving. When I'm towing my trailer, the gross combination weight is over 15,000 pounds. With this kind of mass, you want a cam that is really strong on the bottom end.

Steve

 

That low-lift 206/212 from Comp you can likely get away with installing and using the stock valvetrain components (springs, pushrods, etc.). I chose the Cam Motion cam with higher lift, but needed to put in better valve springs.

 

Ok Thanks for the feed back, i realy apriciate it.

When we are talking Tq increase over stock below 2000 rpm, are there any gains to be had from a better flowing cyl head?
I am asking because it could make sense to get what ever heads you guys recomend rather than spending money to have my stock heads skimed for increase of CR.
(figuring that the CR increase could be had almost for free with a after market cyl head.)

Br//

 

Tahoe,
What is the lowest octane you can buy in Sweden?

I ported my heads just for the learning experience and I did experience some seat of the pants gains and about 15 HP on the Dyno at about 5,000 RPM's when I was running the 212/218 cam. With heads that have really good efficiencies "as cast" like the LS1 series (including the 4.8/5.3/6.0 L truck heads) you won't really gain much in my opinion to port the heads for the RPM range you are interested in. As you exceed 4,000 RPM's, good porting will really start to shine. Also, I don't believe that you will gain much for your application by raising the compression ratio if you would ordinarily burn something equivalent to 87 Octane fuel. For vehicles driven in an ordinary fashion (non-race or high performance upper RPM register), higher compression ratios requiring higher octane won't buy you much. In fact, it will just make the vehicle more expensive to operate. If you want to gain more power and use higher octane fuel, get your powertrain control module programmed for higher octane by advancing the high octane spark table.

Steve

 

Hi
Ok, I by in to the cyl head flow line of thought.

I am running om E85 witch is 105 octane. Good stuff, and 45% cheaper than gas in Sweden.

I have already optimized the high octane timing table for E85.
I am running, minimum, the timing from the max Tq table, and some more in places.
Never a KR.

The E85 fuel would let me run around 13-1 compression, remember 105 octane.
Have to redo the timing!

The CR icrease may be the most cost efficient thing I could do.
I have read elsewere that for evry 0,5 increase in CR there is a 5% Tq gain.

Any thoughts on that? Does trhis apply to the LSx engines?

Br//

 

In North America we rate fuel using the r+m/2 method, I think in Europe it slightly different, take this into account when comparing NA and European fuel octane.

peace
Hog