Reving to 6300 and making peak power at 6300 rpm are different all together.

 

This engine has not seen over 3500 RPM. Likely hasn't even opened the secondaries. Likely rolled into the throttle and quick upshifts. A 500 HP engine will feel lazy if you drive it mellow. A dyno tune and drive it hard should put a huge smile on your face. It should pull hard from the bottom up to 6000 RPM if your using your gearing right. That is a solid street build.

 

Bludawg: I was going by this:
So to answer you question....yes because of the AFR's high I/E ratio the duration at .050" is best if the same. The 224 with 1.6 would be best for a 350 wanting peak power around 6300 rpm.

 

I would think a 236* @ .050" to 240* @ .050" in a 355" with with top tier heads, and a good flowing intake that matched the rest of the combination along with the right amount of compression( enough to squeeze all of the low end out with out detonanation, but im not for sure if the dynamic compression being nats *** is nessicery to hit the peak in the same 6300) to make all the low end you can. Cam companies put rpm ranges on their camshafts, the bottom of the range is were the torque just started to move up ward, probably not were you'd want your stall set up at, which is why we either dyno them, drive enough to know or take advice from some folks with experience with that cam and gears who can come up with a decent recomendation for a stall, so when they say it starts to make power at 2500, the cam probably don't come in till 3000 rpm. The same goes for the top end of the rpm range, probably 500 rpm before the very top of the advertised rpm range the cam has hit its zeneth or apex and the remaining rpm in the range is suppose slowly drops or what they refer to hanging in. The end is were hits the wall were it can no longer make power, I'm not for sure if the velocity of the intake charge comes to its peak velocity and the engine has accelerated just past that, but power you expect to hold at what ever thatpower level was, but nope it drops off rapidly. Now were this range hangs in there it might be making enough power to keep acceleration climbing and it might not, but usually well before the end if the advertised rpm range of the camshaft power drops out. Don't know what the advertised rpm range of your cam is, but would figure at 218* and being a roller 5500 rpm with good heads an all, to be close to the rpm were peak horse power occurs. There again the dyno is a fair place to start when figuring were you'd want to shift, and the refining this on the drag strip. Now then a good cam man can alter the events to get peak were you might have bought cam for. Each cam grinder has different styles, traits and similarities in the cams that they spec and looking at there cam is looking at there finger prints all uniquely identifiable to the guy who specs it but completely different and with each one of there cams usually does what the say it will.
l dont think that going from 218* to 224* will raise peak to 6300. When I had the 400" out at the strip I started shifting at 6200 to dodge pesky valve float that can occur with hydraulic rollers around 6300 when your using cheapo street hydraulic roller set, when i say cheap the lifters alone were $450 and with afr 195's and a hydraulic roller and rpm air gap, i could feel were it fell flat on its face, i backed the the rpm down 200 rpm and the et/mph picked up until I hit 5700 rpm on the tattle tail light which ment the shift light came on at 5500 rpm, it stayed the same between 5600 and 5700 rpm. The cam is advertised to 6300 rpm.

 

Headers will be to choke the engine at around 63-6400. Will it rpm higher yes, but power will drop substantially. So my question would be where do you want the max HP to occur in the combo?

 

Also note when you add rocker ration to a lobe designed based on a stock rocker ratio for the engine you gain duration at the valve. Thee 1.6 ratio will add about 1.5 degrees of duration at the valve to this combo.

 

OK....you were right. The world above 3500 RPM is a new world!

Last night I took it out to one of the local out of the way steep hills, and ran it to 5000 plus in every gear but 4th. Did it multiple times going up hill, and did strong engine braking multiple times downhill.

In 4th gear, this engine was still pulling strong, and car accelerating as is approached very high mph (going up hill), and not yet to 5500 RPM. It felt like there was still much more there, but it was as much as I was willing to do......admittedly, I am a chicken, and it was scaring me! I also was running out of straight road and trying to drive an keep an eye on the tach and speedometer, etc....it was fast enough for me to see what this motor can do.

Once I floored it, it was like a rocket boost lit off, and I am assuming that was the secondaries coming in! It was a solid and sudden boost that launched the car, with a slight turning tendency (not sure why or if that is indicative of anything wrong)??? The throttle response, and power, felt smooth without any noticeable hesitation or bog from idle to 5500.

I can see now that while the world below 3500 RPM is actually still strong, as many of you stated, the power really comes in above that. With the four speed, it is available to me when I want it. I like it!

So, thanks to you all. I am happy with the engine. If I was at the beginning again, I might still go 383, just to have more torque down low. Its not in my nature to push an engine to high RPM...I always feel like I am abusing it, and I have never had enough money to abuse my hard earned possessions. But the whole point was just knowing the power is there and I built the right engine. And last night, I found out the power is there to play with when I want to.

I still want to get it on a dyno to get the numbers, and tweak whatever needs tweaked. I have never heard one sign of detonation, so either my timing is right on, or I have more available....!

 

Excellent company to deal with. Anthony has helped me out a bunch over there. Tuned/ upgraded my twin turbo Explorer Sport.

 

Woohoo! It's about time. As for being scared. That's a good thing. My dad told me way back when I was learning to race cars that if most people knew what their cars were capable of, they would sell them because they would be so scared. This applies to most any sports car. I drive particularly nice when I have passengers and sometimes they still get scared. When I have another person like my father with me or I'm solo, look the heck out. And there have been a few times I've tried to teach my son not to be such a scared putz behind the wheel, but he is still learning.


I got my GM 350 crate engine yesterday. I'm going to tear it apart and modify it to make decent power, and you can rest assured I will use it accordingly. Horsepower and torque are equal at 5252 rpm by definition. HP is definitely a function of time, so things don't really begin to happen until the upper rpm range as far as acceleration goes anyway. Some engines have to be really revved in order to do anything. A 350 is a nice mix of mid range torque and HP which is why you car is really coming alive at 3,500 rpm. That sounds about right for a V8. Wait until you get used to it and start shifting hard at the 5,800 to 6,000 rpm range.

 

The slight turning sensation at take off is probably the posi rear end spinning both tires which tends to make your car go to one side. Its fun once you get used to it. I like to drop it from 4rth to 2nd and floor it to get the chirp of the tires breaking loose at 40 and getting to 60 a blink of the eye later.

 

That's good to hear. Glad its working out.

 

Yea! A happy ending!

Adam

 

This confused the hell out of me; then I read this:

http://trust-me-im-an-engineer.kinja...rpm-1650651680


I remember from Physics class how Watt came up with the HP with a horse pulling a weight attached to a rope and a pulley a certain distance in a certain time, but didn't really understand it's application to engine torque and hp relationships and why that cross always happens on the dyno chart where it does.


Mind blown!


Awesome stuff.


Adam

 

Something at or above 6000.

I was thinking back to when my motor was 4.125X4.00 with everything else equal. I can't remember a big drop off. It seemed to power right into 7500 rpm. The local track is 4.3 miles around and I was shifting near the rev limiter in 3 & 4th several times per lap. Then my crankshaft broke so i bored it and reset my rev limiter to 7000 to make it last longer

You are right about header size. A smarter person would buy spread port Gen 1 heads and just have some custom 2.00 inch headers made

 

Now you need a new thread with how proud you are! Geeze, 134 posts and all you needed was to punch that throttle!

Well congrats on your discovery!

 

OP has blown the vette owner stigma lol

Now get yourself an AEM 02 kit from Summit install before hitting the dyno, bet theres more to be found with fine tuning.

now dont you pity all those who only baby their cars they dont know what they are missing. Get your fun in, one day someone will fire sale it not appreciating what youve done to it. Best mindless activity on the planet! When you find you cant look at the tach or speedo its running good.

 

 

Good deal, most new engines scare ya for a while once you get use to it is were you determine if your an addict or not, if once you get use to it if you've gotta have more, unless you've built a turd your an addict. I'm sure there has to be a point that I'd say I'm good, don't need anymore, but haven't found it yet.

 

How bout a video? Any way to show us what she's got??

 

LOL