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Post Info TOPIC: Spring Liberation


A Poncho Legend!

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RE: Spring Liberation


Well I always kinda joke with folks who ask me about fuel mileage in my 454 LeMans, I usualy say its 9 mpg, idling, city, highway, pulling 3000 pounds. makes no difference, in one word B A D. 



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Ray White, Toronto ON

Formerly - The one and only 1973 LeMans 454 "Astro-Jet"

Built March 9, 1973 - Oshawa ON

1993 Corvette Convertible LT 1

Built January 10, 1993 - Bowling Green Kentucky 

 




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73SC wrote:

Well I always kinda joke with folks who ask me about fuel mileage in my 454 LeMans, I usualy say its 9 mpg, idling, city, highway, pulling 3000 pounds. makes no difference, in one word B A D. 


 The 454 in my motorhome gets better than that.



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norontcan wrote:
73SC wrote:

Well I always kinda joke with folks who ask me about fuel mileage in my 454 LeMans, I usualy say its 9 mpg, idling, city, highway, pulling 3000 pounds. makes no difference, in one word B A D. 


 The 454 in my motorhome gets better than that.


I am thinking perhaps I might step my cam back down from a Comp 270H Magnam to a stock GM L34 / L36 cam grind of 3883986.  The engine runs nice with the 270 but it is right on the upper cusp of using stock drive components in terms of converters and rear ends.  With a 2.56 in the back end and my stock converter and the TH400, I think  I missed the mark a tiny bit with my cam selection at rebuild.

The 3883986 grind came with 390 hp 427 and the 360 hp 396 and since my car is a cruiser and will continue that way, I am thinking a 3883986 will be finding its way into this 396.  At 84 cents for premium and oil at negative margins, gas price is not problem (I can't drive it around anyway at this time of covid) but I don't like the low end perfromance of the cam and its appetitie for fuel.  If I was going to go for a long distance cruise, (which is nice to think about but the old girl is not leaving the driveway during covid) I would have to retro fit a 100 gallon auxillary tank in the trunk to get me to the next gas station, lol.

If I was doing all over again, I would have stuck a 3883986 grind in it at the time of rebuild.  Howards cam and Crane continue to make 3883986 grinds today.  

 



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Liberated the 67 yesterday, and it felt good to get it out. Not many classics on the road, so I'm sure, right or wrong it stood out. 

Jake, I'll bet I even get significantly better than 9 with my 496/3.55's even with a 850 dbl pumper. I've never calculated it, but really, I feel my economy isn't less than 9. For the most part, the engine is sitting at 2300 when cruising out in the country. It's a sweet spot for this motor. It Just purrs. And it doesn't have to do any work getting up with the 3.55's. Highway, it's a pig as it simply revs too high, but keep it under 90 kph and she's happy. 

Maybe I'm way off, but it seems strange a 396 would be so poor with that gear. Perhaps such a high gear is part of the problem? The engine with that cam isn't sitting in it's most efficient spot most of the time..unless your doing 70 mph. I think I'd look at changing the gear. Unless you actually planed on doing a lot of long distance travel, a lower gear might actually be more efficient. Cheers.

 



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cdnpont wrote:

Liberated the 67 yesterday, and it felt good to get it out. Not many classics on the road, so I'm sure, right or wrong it stood out. 

Jake, I'll bet I even get significantly better than 9 with my 496/3.55's even with a 850 dbl pumper. I've never calculated it, but really, I feel my economy isn't less than 9. For the most part, the engine is sitting at 2300 when cruising out in the country. It's a sweet spot for this motor. It Just purrs. And it doesn't have to do any work getting up with the 3.55's. Highway, it's a pig as it simply revs too high, but keep it under 90 kph and she's happy. 

Maybe I'm way off, but it seems strange a 396 would be so poor with that gear. Perhaps such a high gear is part of the problem? The engine with that cam isn't sitting in it's most efficient spot most of the time..unless your doing 70 mph. I think I'd look at changing the gear. Unless you actually planed on doing a lot of long distance travel, a lower gear might actually be more efficient. Cheers.


Now that you have picked the 67 from winter hibernation, you can admire it while it sits on your driveway,......like me!  Maybe we should start a new thread, "Show us your CP or Classic sitting on your Driveway" I might start that thread later today when I get home.

Anyways about RPM's and highway driving, I calculated on a RPM / Gear ratio / tire size that with a 2.56, 27.2 diameter wheel and at 65 mph that my revolution is 2,111.  So, I have to add back what, 300 RPM's for converter slippage?  So, I am 2400 - 2450 at 65 mph, I think?  The motor is just purring like you say.  The motor is in a complete sweet spot and if I need to pass, no problem, the tranny doesn't even want to kick down, it just torques and accelerates, smooth as silk. 

I have not done a scientific gas consumption calculation either so I might do that this summer once this covid situation subsides.  I do want to keep it as a highway cruiser as I will run back and forth about a 120 km from Morden area to Wpg.  It's fun to play around with it tho, it gives great satisfaction to tinker around with it.   



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Spring ?

April 21st ?

Yep, right now at my place.

002a.jpg



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Hopefully sitting in my Garage photos will be ok.

I actually had my detent disable for some time while I sourced a new cable. All you need to do to pass with a big block is wiggle your toes. biggrin

With passing gear enabled it feels like the engine is going to suck in the hood. Mine kicks out at 83 mph and "if my calculations are correct when this baby hits 88 miles per hour you're gonna see some serious S**t." (Dr. Emmett Brown)

 

 



-- Edited by 73SC on Tuesday 21st of April 2020 01:52:33 PM

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Ray White, Toronto ON

Formerly - The one and only 1973 LeMans 454 "Astro-Jet"

Built March 9, 1973 - Oshawa ON

1993 Corvette Convertible LT 1

Built January 10, 1993 - Bowling Green Kentucky 

 


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With these gas prices and no classics on the road, it feels like we gone back in time and forward.EABE53E1-FD23-4189-BE97-9BB629B84AD9.jpeg



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pontiax- (canadian pontiac X frame)1964 Parisienne 2dr. Hardtop ,lagoon aqua metallic (Q) ,421 cid Dart Industries block and heads. 550 hp. 575 ft lb  of torque.

 



A Poncho Legend!

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pontiax wrote:

With these gas prices and no classics on the road, it feels like we gone back in time and forward.EABE53E1-FD23-4189-BE97-9BB629B84AD9.jpeg


 Wow, thought that was my car for a second....

 

 

LeMans rear rq.jpg



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Ray White, Toronto ON

Formerly - The one and only 1973 LeMans 454 "Astro-Jet"

Built March 9, 1973 - Oshawa ON

1993 Corvette Convertible LT 1

Built January 10, 1993 - Bowling Green Kentucky 

 


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