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Low gears vs 496 RB Stroker??

Frustration

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I recently installed an RB-based 496" engine in my 3800# road runner. It's a 440 Source kit with CNC ported Stealth Heads and a six pack induction. I also run a small solid roller cam with .575 lift and 262 @.050 duration. I have a 3800 RPM 10" converter and 4.30 gears. I drive the car on the street mostly, but do go to the track a couple of times per year. I run the car with M & H street slicks, and it hooks well with no noticeable spin.

I've only had the car to two tracks so far...Maple Grove and Atco. The runs below are the most recent bests.

60'-1.67
1/8-7.352 @93.61 MPH
1/4-11.55 @117.49 MPH

I noticed on my most recent trip that I was turning near 7000 RPM going through the lights. I'm wondering if I should be changing the rear gears, or the converter (or both) in order to find the low 11's I think the car should run. This car has gone 11.17 @ 120.5 MPH with a high compression 440 and the same cam. Has anyone done gear ratio testing with their stroker motors? I have a set of 3.91's that I plan to switch in the spring. Any advise is appreciated. Tommy
 
My 498 (13-1, 5500 flash)was just as quick with 4.10 as 4.56. 10.30's best of 10.17. My 572 (15-1, 6100 flash) has only ever run a 4.10 w/ 10.5x31, 9.02@149. Compression creates torque. My bet is it could less gear and more converter.
Doug
 
My 498 (13-1, 5500 flash)was just as quick with 4.10 as 4.56. 10.30's best of 10.17. My 572 (15-1, 6100 flash) has only ever run a 4.10 w/ 10.5x31, 9.02@149. Compression creates torque. My bet is it could less gear and more converter.
Doug
Thanks Doug. I appreciate the feedback. I wonder if anyone has a similar combination to mine...more of a street car for comparison? Hopefully some will chime in. In the meantime, I have a set of 3.55's that were offered to me to try. I'm going to give them a shot. Tom
 
i think low gears and loose converters defeat the purpose of a big torque engine. whatever i'd do to 440 i wouldn't do to a 500; with all things equal.
 
I'm running a 3600 lb(with driver) Polara street/strip car, 505 stroker , 10.5 to 1, Indy Max Wedge ported heads, solid roller.635 lift, 4500 stall converter, 28"tall M/T drag slicks, and 3.73 gears,
The car runs 10.50's at 129 mph...60 foot is 1.53.
I would suggest that you try those 3.91 gears or even 3.73's because I think your motor is out of breath past 6500 rpm with that small cam...Mine goes thru the traps at about 6400 rpm

John B.
 
I think you'll like the 3.91

I run a 4.10 in my roadrunner 28" tire, it's almost 4000# with me at the wheel. 9 1/2 vert that flashes about 4800. Runs 10.90's through mufflers. Your 60ft looks way slow for the combo, I gotta think the converter is off. My motor is a 511 with a six pack.
 
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The first time I ran the car, I ran it with 30 x 9 x 15 slicks. I made 9 passes at a track rental at Maple Grove. During that day's passes, I ran the best 60' ever at 1.523. The run netted 11.62 @ 115.53 MPH. I didn't mention that 60' above as I was never able to repeat it. In all 8 other passes that day, my best 60' time was 1.698. I thought it was an apparition as I couldn't back it up. Just curious though...wouldn't the current 4.30 gears help my 60' even if the engine is out of breath at the finish line?

I'll get the 3.55's in it in the next couple of weeks. The 3.91's are in my son's convertible. I don't want to pull it apart at this time. Thanks again for the feedback. It is much appreciated. Tom
 
Yea it should 60 real well with the 4.30. Something is off. The 1.52 is what I would expect every pass. Converter out to lunch maybe, what springs do you have in the outboards?
 
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i think low gears and loose converters defeat the purpose of a big torque engine. whatever i'd do to 440 i wouldn't do to a 500; with all things equal.
I would have never in my life bet a cross ram, 15-1, 572 would like a converter as loose as it does. It's had 5 converters from 5600-6400 flash. The loosest have been the quickest.
Doug
 
I recently installed an RB-based 496" engine in my 3800# road runner. It's a 440 Source kit with CNC ported Stealth Heads and a six pack induction. I also run a small solid roller cam with .575 lift and 262 @.050 duration. I have a 3800 RPM 10" converter and 4.30 gears. I drive the car on the street mostly, but do go to the track a couple of times per year. I run the car with M & H street slicks, and it hooks well with no noticeable spin.

I've only had the car to two tracks so far...Maple Grove and Atco. The runs below are the most recent bests.

60'-1.67
1/8-7.352 @93.61 MPH
1/4-11.55 @117.49 MPH

I noticed on my most recent trip that I was turning near 7000 RPM going through the lights. I'm wondering if I should be changing the rear gears, or the converter (or both) in order to find the low 11's I think the car should run. This car has gone 11.17 @ 120.5 MPH with a high compression 440 and the same cam. Has anyone done gear ratio testing with their stroker motors? I have a set of 3.91's that I plan to switch in the spring. Any advise is appreciated. Tommy
something is off . Convertor is too tight - hurts 60' & 330, but rpm is too high for mph . even with 4.30s . A mate last Friday 4.30 gears , 30"tall radial et street ss 6700rpm @ 122 - convertor has 15% slip , was blowing through it .
my 505 went 1.48ish on Friday in poor air and I expect a bit more . I run a 28"radial slick and 4.1 gear . not sure of my rpm as tacho took a dump but went 10.62@125
will know more after Saturday racing
Tex
 
Something definitely not right in the OP's combo. First off, a 493 with cnc heads and a 262 cam running 4:30's should be a 10second car, no question. The stripe RPM does seem pretty high. By comparison, I run 4.10's and a 28" tire (that actually measures 27.5") and I stripe at 6200. I don't find your tire size in your post, but assuming you run a 28" tire, you really shouldn't be any higher than 6500. Also, am I reading correctly a 60 time of 1.67?? That seems WAY off. An 11.50 / 115 time slip should be in the 1.58-1.62 range. These things together suggest to me that youre driving through your converter. There is a difference between a loose converter and a slipping converter. Loose suggests a high stall speed, but a good one will still be firm once you get to that stall speed RPM. Slipping would mean low efficiency at all RPM's (which your 60 time and stripe RPM seems to suggest).

My suggestion is to get the converter looked at by a reputable professional. Pick a company and have them go through it. My own feeling is that I'd do this BEFORE I changed anything else, especially gear. 4.30's would seem perfect for a 262-degree cam with good heads and a 28" tire to me.

My feelings only of course. Good luck finding the potential.
 
I am running M & H 275-60-15's. I will look into a converter change. I'll also check the outboard springs and will get back to you. Thanks again.
 
Is your 496 a 383 strokker ? That is what I want to build for my barracuda 4spd.
 
I am running M & H 275-60-15's. I will look into a converter change. I'll also check the outboard springs and will get back to you. Thanks again.
To clarify: I'd suggest not just "changing the converter"; but sending yours out to be assessed. A good company should be able to tell you what they find inside. Then you'll know more about what's going on. I've used Dynamic with good results, but there are many that would be a good choice.
 
To clarify: I'd suggest not just "changing the converter"; but sending yours out to be assessed. A good company should be able to tell you what they find inside. Then you'll know more about what's going on. I've used Dynamic with good results, but there are many that would be a good choice.
If I were going to send a converter to anybody I would send it to Lenny at ultimate converter in North Carolina. He modified mine and it turned out absolutely perfect
 
Lenny worked last on my tci I have in the roadrunner. Seems to work well!
 
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