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#41
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Interesting cam specs on the Lunati compared to the Ultradyne. The Lunati has more lift (L: .468/.489 vs. U: .454/.454) and a little less duration (L: 219/227 vs. U: 221/230 @ 0.50 and advertised/seat L: 262/268 vs. U: 276/286).
Looks like you had the RARE manifolds installed and O2 sensors to optimize the tune. Gotta love how the EFI does all the tuning/hard work. Wondering if the old 3 tubes used on mine were at all restricting (of course not 22hp)? Similar torque numbers though (480 vs. 482).
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1970 GTO (Granada Gold) - 400 / TH400 Last edited by vertigto; 05-20-2021 at 04:34 PM. |
#42
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Very fun. Is today Christmas? I get to see dyno runs from very similar 400s with the UD276/286 and the Lunati 702 in the same day??
Great numbers on both engines. Past 400 hp and 480 tq with those engines is impressive. I think what may be even more impressive is I think you both have your compressions figure a touch high. If I understand correctly Vertigto is running a icon 14cc piston and roger1 is running a 17 cc dish. Most 62s and 13s run 75-78 cc. Assuming both have had valve jobs, and the heads are trued up (likely close to 75cc head final volume) and both engines have cylinder notches I come up with 9.2-9.3:1 on vertigto and about 8.8-8.9 on Rogers. That is using the diamond racing compression calculator, it adds in ring land volume. That is assuming .042” gaskets and zero deck. I wouldn’t be surprise if both have .045” gaskets and the pistons are down in the deck some. Usually those heads need the head surface down some to be at 72 cc, especially after a valve job. Pontiacs oem rating was well above actual. I posted the compression screen shots of Rogers. For comparing these two cams. They are both quite a bit different in there ratings and the design ramps. Much more going on behind the scene’s there. The UD276/286 is rated at .0045 tappet. And the advertise rating on that Lunati is closer to .007 tappet. Converting them both over to .006 it looks more like this: UD276/286 270/280. @.006” tappet, it runs about a 3* span(longer on closing than opening ramp from .006 to .050. .050” 221/230 .2” 132*,141* The Lunati 702 is advertise at 262/268 At .006” tappet it is close to 267/273 .050” 219/227, .2” 132*/140*, irc, it about 5* span from .006 to .050, and still has some after .050”. That 5* extends the power band some and has a little broader power band, ends up acting like it has a little less overlap. They are almost dead even at .2” lift. Both are great cams in 400 pontiacs. Goes to show you do not need a ton of extra compression on the engines to make good power. At the track those two engines would be a close to a dead even match. Great job on your combo’s! Last edited by Jay S; 05-20-2021 at 06:55 PM. Reason: Add |
#43
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389 .030 over - Voodoo 702 - 230 CFM heads. http://forums.maxperformanceinc.com/...d.php?t=836191 |
#44
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VERY impressed with both of these. Great numbers for 400s/iron heads/very mild cams. I'm also wondering why they didn't go to 5500. Great info here!
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Chris D 69 GTO Liberty Blue/dark blue 467, 850 Holley, T2, Edelbrock Dport 310cfm w Ram Air manifolds, HFT 245/251D .561/.594L, T400, 9" w 3.50s 3905lbs 11.59@ 114, 1.57/ 60' |
#45
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He said he made that decision because of what I told him I wanted the car for (just cruising) and the fact that I had previously asked him if he thought it would make 400HP and it was doing that on a couple previous pulls he did. He figured right. I don't intend to run it over 5K and probably will seldom get to that. He does still think the engine will do better in the car after the computer has more time to learn.
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'69 GTO Convertible - Acquired October 2020. An all original project car. Restomod is underway PROJECT THREAD '83 Chevy Choo Choo SS El Camino - LT1 350/4L60e, Owned for 30 Years, completed 2nd restomod in 2018 PHOTO 2019 BMW 440ix - Twin turbo I6, 8spd auto. PHOTO '55 Chevy Bel Air Sport Coupe - Ram Jet 350 / T56 Magnum 6spd, Restomod Completed Sept. 2012, Sold Sept. 2021 PHOTO |
#46
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“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#47
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#48
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Similarly...once a dyno run made the 400hp goal, I think additional tuning/optimization was deferred by my builder. I believe the curve on my DUI was also set for a max 5500rpm and taking into account the 3.23 gearing (as well as cam specs).
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1970 GTO (Granada Gold) - 400 / TH400 Last edited by vertigto; 05-21-2021 at 11:21 AM. |
#49
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#50
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I took another look at the low resolution video of the second to last dyno run, and it might be that the peak torque is at 3800 instead of 3600. It's so difficulty to see in the video clip to be absolutely sure.
I will post a pic of the best dyno run sheet when I get a copy. Still would be @ 300rpm lower than the Lunati.
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1970 GTO (Granada Gold) - 400 / TH400 Last edited by vertigto; 05-21-2021 at 01:24 PM. |
#51
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Btw, I don't remember what transmission you are going to be running. It seems to me you might be better off with your peak torque lower than mine.
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'69 GTO Convertible - Acquired October 2020. An all original project car. Restomod is underway PROJECT THREAD '83 Chevy Choo Choo SS El Camino - LT1 350/4L60e, Owned for 30 Years, completed 2nd restomod in 2018 PHOTO 2019 BMW 440ix - Twin turbo I6, 8spd auto. PHOTO '55 Chevy Bel Air Sport Coupe - Ram Jet 350 / T56 Magnum 6spd, Restomod Completed Sept. 2012, Sold Sept. 2021 PHOTO |
#52
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1970 GTO (Granada Gold) - 400 / TH400 |
#53
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On those Lunati's, Paul C likes to use those lobes and from what he has said and the many dyno pulls he's been so kind to post, those Voodoo lobes do tend to carry the power up a little further than one would expect, even when he has put them on a 110 LSA, they act like a much wider lobe sep. I think he said it had a little something to do with the asymmetric lobe profile. |
#54
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Either way, not to steer in another direction, But very nicely done with just 400 cubes and what are basically stock factory D-port heads. 400hp with those setups is getting it done pretty good. Good cam choices make a difference
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#55
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I have the dyno sheets (thanks Steve)...it was 3800 for peak torque. I guess there were only 2 runs, so perhaps there may be a little more with tweaking.
Here's the story...
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1970 GTO (Granada Gold) - 400 / TH400 |
#56
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Even though that peaked at 5000, it still carries the HP out pretty well to 5600, only down to 393 from 403.
It'll make a good runner. |
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#57
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Your cam is better for you and mine better for me, I'm pretty sure. Are you going to quarter mile yours? I wont but I agree with the opinion our cars would run neck and neck and be interested to know.
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'69 GTO Convertible - Acquired October 2020. An all original project car. Restomod is underway PROJECT THREAD '83 Chevy Choo Choo SS El Camino - LT1 350/4L60e, Owned for 30 Years, completed 2nd restomod in 2018 PHOTO 2019 BMW 440ix - Twin turbo I6, 8spd auto. PHOTO '55 Chevy Bel Air Sport Coupe - Ram Jet 350 / T56 Magnum 6spd, Restomod Completed Sept. 2012, Sold Sept. 2021 PHOTO |
#58
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Nice, flat torque; good BSFC numbers and fuel burn. This 400 ought to be fun to drive on the street.
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“It takes considerable knowledge just to realize the extent of your own ignorance.” Dr. Thomas Sowell |
#59
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Well now I’m tempted to get my 400 dyno’d too when it’s done in a few weeks. My builder has a dyno so we will see if the budget allows. Spoke to him about it today and he charges $750 to do it.
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#60
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tell you its worth it,find any leaks or issues BEFORE you get it in the car.Tom
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