damn... i may be worse off than I thought... the only thing i have better than your motor is that its a four bolt main... that does seem oddly low though...
First dyno run...yesss....could it be my cam....oh noes....
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SeeMy355 said:
Do you mean the CR is 10.9:1? That may be a little high for that cam and those heads.
Correct me if I'm wrong, but since its a chassis dyno, wont the gears affect how much horsepower is going to the rear tires. Its more efficient to have a steeper gear if he's looking at having more hp at the rear tire. If he had a high gear then the motor would be loaded up and probably wouldn't be the correct gear for the camshaft. But since he has 373 gears than he should be set.
patmckinneyracing said:
It does and doesn't. The numbers given are usually taken at the point where the transmission is in 1:1, and thus it is accurate. If you saw the figures for the lower gears they would look way higher than they actually are. I think the chassis dyno compensates for the rotation of the driveshaft by comparing engine RPM and wheel RPM. As for those numbers, I would have hoped to see at least 300whp. Is your timing stable, or does it jump around a bit when you check it with a timing light? As for the rest of the combo, Vortec heads have a very specific valve job from the factory that is better than most machine shops can duplicate. A valve job many times winds up hurting flow. They are also sensitive to porting and can get worse with the wrong work ( like any other head). Finally, what kind of exhaust setup are you running? It may be the big cork in the whole combination.
My timing is stable...
Since it was set during this dyno run, this has been the best the car has performed since I got it...
I just know that I'm still not reaching the full potential of this engine...
As far as my exhaust is concerned, I have Hedman headers to 2.5 all the way back to 40 series Flowmasters, 2.5 outlets on the Flowmasters...
Since it was set during this dyno run, this has been the best the car has performed since I got it...
I just know that I'm still not reaching the full potential of this engine...
As far as my exhaust is concerned, I have Hedman headers to 2.5 all the way back to 40 series Flowmasters, 2.5 outlets on the Flowmasters...
Did you degree in the camshaft? The duration on that cam to me seems to be right on the borderline for an 11.1:1 engine with vortech heads. If it wasn't degreed in this could hurt the power.
What is your timing at? Any pinging?
There are a lot of good write-ups on the internet about high compression ratio and cylinder pressure.
What is your timing at? Any pinging?
There are a lot of good write-ups on the internet about high compression ratio and cylinder pressure.
I'm interested to know what the machine shop did to your heads to run with that cam. The cam lifts are .488 and .510. The valve guide seal will be pinched between the retainer and guide if valve lift exceeds 0.470 inches and it's not suggested to run anything with more than a .460 lift. Also what valve springs are you running?
I did not degree the cam...
It was installed dot to dot...
When I went in for the dyno run the technician performed a fuel/air mixture test at my request and it was determined that I was running really lean. We swapped out the jets on my carburetor, but the mechanic that was there suggested that I get a bigger carburetor because the Holley 670 was starving the engine...
It was installed dot to dot...
When I went in for the dyno run the technician performed a fuel/air mixture test at my request and it was determined that I was running really lean. We swapped out the jets on my carburetor, but the mechanic that was there suggested that I get a bigger carburetor because the Holley 670 was starving the engine...
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