Hey Jeff, Go punch in the specs from here:http://www.trishieldperf.com/Level 2 engine specs.htm with both the iron heads listed under the fully ported '786 heads here:http://www.trishieldperf.com/competition.htm Those were the actual heads on that motor. and with the aluminum head specs here:http://www.trishieldperf.com/ta_stge_1_aluminum_head_pg_4.htm the good ones.. with the chamber work, down on the bottom.. What you need to know: 1. The actual motor in that dyno sheet was 9.8 to 1 .. I have updated the specs on that buildup, to reflect what we are going to do with the new Alum head. 2. Cam installed at 106* on the intake centerline 3. Valve events are Intake opens 5*BTDC closes 49*ABDC Exhaust opens 54*BTDC closes 10*ATDC. Cam overlap is 19* Cam is 238/248 at .050, rocker ratio 1.65, actual lift in the motor was .538 intake, .534 Exaust. 4. Ignition time set at 34* Then see how close you come out to the actual numbers, that I posted. Then add the aluminum heads, and bump the compression to 10.25.. I am curious how close that sim is to reality.. I have heard that the Engine Analyer Pro sims are pretty good. When those programs first came out, they were wayyyy off, but I hear they are getting better, and prolly will have to invest in one soon. But I always have been a firm beleive in what a motor actually does, on the dyno. Because every engine is a bit different, even built to the same specs. JW
I'll do it when I can Jim. Dyno2000 has no choice for an iron head and a similar head made of aluminum. Can't set the timing either. All we can do really is choose heads from a generic set, change cam specs, CR, exhaust, displacement and fuel type. Anyone know of a better PC dyno? But it can get me in my ballpark. 465HP and 540 lb ft is fine by me with my little 462...:laugh: Should get the Riv hurtlin'!
Try this. 455 +.030 federal mogul pistons 10.5-1 zero deck o-ringed .040 copper gasket stage 2 aluminum head converted to raised port not tall port 315cfm intake at .550 245cfm exhaust at .550 comp cam 260-266 @ .050 .584 intake lift .611exhaust 110 seperation set at 105 intake 2 1/8 TA headers MSD ignition locked at 28 deg adv. TA quadrajet intake converted to dominator converted to raised port to match heads 360cfm balanced Pro systems built 1150 dominator custom built 1 1/2" nitrous plate with NOS big shot spray bar 225hp jets 814HP at 6000 rpm 826 ft lbs. cant remember rpmwas over 700 at 4000 and 800 at 5000 Found worn intake lobe on cam after pull never pulled with fresh cam. Didn't pull past 6000rpm but looked to be leveling off.
Yardley, the dyno 2000 sim that I purchased allows for custom building heads using actual CFM at the standard plotted valve lifts. This is for both intake and exhaust. The testing values (water or mercury) and air correction factors also gets plugged in. Saving the files under distinct names allows for use under different build scenarios. The sim seems to produce some fairly generous numbers for different combos especially in the 5-7000 rpm range which I believe to be bogus. There are several limitations to the program as you stated earlier. However, I am amazed at the technology that can produce software like this even if it is not 100% dead on. I have not used the simulation in several months and need to read the manual again to get a handle on some of the basic functions. When I have a bettor understanding I will try to post some of the combos that have been listed on the board using the given flow curves.
Jeff, I should have mentioned my heads were not really "stock" anymore. Extensive bowl work and port matching may have given me those higher #'s. I found the Summit issue where Holley dynoed "Old Blue" using 5 or 6 different carb combinations. Huge differences in actual #'s. Richard's car liked the 950 Double Pumper the most and I think that it what is on the car now. It made over 400 rear wheel HP. For my situation, I'm looking to get some HP at lower RPMs, and that 750 Holley model 3310 isn't doing that. What do you think of Thermoquad carbs? I have one on a company van I own and I wonder if it would be an improvement over the Holley I have now???? Russ Waters
Yeah George. You can plug in cfm #'s, but you really need to have a lot of the info to be accurate. Aside from that, there are still some limitations. Yet it has been consistant with respect to the 400HP builds I've checked it against. And Russ, I believe both Jims like the Thermoquad. Heck, if I had access to one I'd probably have one of them build it for me. They swear by them. I do know that my Holley was junk before I sent it to Jet. It had sat under a workbench for a decade and was really in need of a gutting, which I tried but had no luck at. And when Jet sent it back it was awesome. Of course, I just had to resend it to them last month to have the shaft bushed, which shocked me they didn't do it when they had it there. But they did it for nothing but the $15 return shipping. Ask 10 people about carbs and you'll get 10 different answers...
