looses power - Page 2

D. Hake 4459 · 10-27-2014, 11:38 PM

I'm with Paul in post #2. Jim Hale could be a big help on that combination. His '64 Sport Fury can run those times in G/SA at about the same weight. I wouldn't expect him to give away all his secrets but he might point you in the right direction. I don't know how tall of a tire you have on there but that seems like a lot of rpm for 122 mph. Converter slippage?

Paul Precht · 10-27-2014, 11:40 PM

Approx 15 HP per tenth in this range and weight. Four tenth's quicker with the present gearing would put this car through the traps around 8,000 RPM with a motor that makes peak HP below 7,000, not good for ET or the life of the motor. Without knowing the cam specs, head casting and flow specs it's hard to know what the potential is and that's assuming the short block is up to snuff. The carb should be set up on a flow bench because just a couple of degree's on the secondaries with an AFB can make a huge difference in flow, and when you're running a carb that's the equivalent of a 2BRL carb on a motor this size that is very important.

69Cobra · 10-28-2014, 09:50 AM

Based on some MPH, RPM, Gear ratio calculations assuming he's using a 30" tire with very little % slip. He's either running 136MPH, a 5.49 gear or only really turning it about 6,681RPM's. Obviously we know what his real MPH and gear ratio is, so that only leave a couple things. Either its only running about 6700 out the back or the converter is flat gone and slipping over 10%.

10-27-2014, 11:38 PM	#1
D. Hake 4459 Junior Member Join Date: Sep 2013 Location: Muskogee, Oklahoma Posts: 83 Likes: 56 Liked 2 Times in 1 Post	Re: looses power I'm with Paul in post #2. Jim Hale could be a big help on that combination. His '64 Sport Fury can run those times in G/SA at about the same weight. I wouldn't expect him to give away all his secrets but he might point you in the right direction. I don't know how tall of a tire you have on there but that seems like a lot of rpm for 122 mph. Converter slippage? __________________ Derek Hake 4459 H/SA 69' Roadrunner

10-28-2014, 09:50 AM	#3
69Cobra Senior Member Join Date: Aug 2007 Location: California, Ky Posts: 669 Likes: 62 Liked 2 Times in 2 Posts	Re: looses power Based on some MPH, RPM, Gear ratio calculations assuming he's using a 30" tire with very little % slip. He's either running 136MPH, a 5.49 gear or only really turning it about 6,681RPM's. Obviously we know what his real MPH and gear ratio is, so that only leave a couple things. Either its only running about 6700 out the back or the converter is flat gone and slipping over 10%. __________________ Kris Rachford 69 Cobra 428CJ 4 Speed C/S 3032 Last edited by 69Cobra; 10-28-2014 at 09:53 AM.

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10-27-2014, 11:40 PM	#2
Paul Precht Senior Member Join Date: Dec 2001 Location: Elysburg, Pa Posts: 733 Likes: 362 Liked 327 Times in 121 Posts	Re: looses power Approx 15 HP per tenth in this range and weight. Four tenth's quicker with the present gearing would put this car through the traps around 8,000 RPM with a motor that makes peak HP below 7,000, not good for ET or the life of the motor. Without knowing the cam specs, head casting and flow specs it's hard to know what the potential is and that's assuming the short block is up to snuff. The carb should be set up on a flow bench because just a couple of degree's on the secondaries with an AFB can make a huge difference in flow, and when you're running a carb that's the equivalent of a 2BRL carb on a motor this size that is very important.