I thought you guys might be interested in this info. I copied it off 1320techtalk. Bill went the extra mile to get some good data.
I have some results regarding the AIRWOLF cylinder heads. I have been very impressed with the results and workmanship of these cylinders heads. The only changes made in the dyno testing was the cylinder heads. The cylinder heads combustion chamber was a tad smaller then my current heads. So this netted an increase of approximately .25 in compression.
This is the engine combo
JE 13 CC dome pistons
Super vic intake modified by speier racing heads
Race demon Carb
Jones cam 262/266 at .050 680/640 lift on a 110
AFR heads were previously reworked by speier racing heads. This work netted a gain of .2 in the 1/8 mile with no other changes.
Also the headers used on the dyno were a set of sprint car headers. They were two inch primaries with 3.5 collectors. The primary tubes were in the 35-40 inch range. Unfortunitly I was unable to use my headers for these test because they would not clear the dyno stand. Per Pipemax, the headers used were not the optimal heads and I feel that some power was not realized on the dyno. The headers I have in the car are right what pipe max calls for.
I made a couple passes last saturday. Car ran 6.70 at 102.5 in 2500 corrected altitude. I then pulled the motor and conducted the following:
First the engine was dyno in its current configuration. We tried different timing settings and it showed to like 35 degrees. We did not change anything on the carb as egts and o2 showed that it was on.
Then the head swap was conducted. I had to get shorter pushrods to correct the rocker arm geometry
We made the first few pulls and the engine was down on power. My dyno operator felt is was the powervalves and wanted to square up/richen the jetting and remove the powervalves. We did this with no improvement. Well it turned out that we hadn't properly adjusted the throttle linkage and we were not getting WOT. Once we corrected that, the Airwolf heads started to shine.
Immediately we noticed that the peak power had move from 6700 to 7000. Furthermore, engine was now making 40 more uncorrect hp at 7000. We tried different timing, and jetting. Ended up with the best results at 80 squared, with 33 degrees of timing before I ran out of fuel to continue testing. I still think it is on the rich side, and will want the original jetting that I had in there.
Below are the dyno results.
I took the car out friday night, Car went email@example.com
with a 1.44 sixty off the footbrake leaving at 2600 rpms. Air was at 2600 corrected altitude. This was the best et to date at the track at about 1600 higher CA. Best et to date was in San Antonio with mineshaft air of -300 feet. It ran a 6.42@106.
I also feel there is more in it, I forgot to bring the cable to reprogram my ignition box to change the shift point. There for these new best ets are shifting at 7000. Shifting at 7400-7500 would further take advantage of the heads. I believe there is probably another .05 in it. I will find out next weekend. I could really feel it start pulling about 6500.
I calculate the heads were go for a solid 40-50 hp over the worked AFR heads.
As Chad and I discussed before, my previous limitation was the on power was the cylinder head.
I am working on getting the electronic data for the dyno stuff.
Please let me know what you think or if you have any questions.
As I stated before, the workmanship on these heads is awesome, and the customer service is second to none. As I expected no less from chad, these heads have surpassed my expectation of them.
Empty Pockets Racing
74 Chevy Nova