Made changes! No Faster! Me Confused ???
#1638034
06/24/14 09:02 PM
06/24/14 09:02 PM
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Joined: Feb 2006
Posts: 476 Alberta, Canada
451Guy
OP
mopar
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OP
mopar
Joined: Feb 2006
Posts: 476
Alberta, Canada
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Sorry this is long but here we go. I have been at the track the last few weekends racing Hot Rod/Super Street. Unfortunately, I was eliminated a little earlier than I would have liked on Sunday and was able to made a couple of wide open test hits. I have done quite a bit to my car and I was fully expecting it to pick up. I will describe my previous combo and what has changed and you guys can offer advice.
Original Engine Combo 512 cubic inch 400 based engine 3.380 Bore - 4.250 Stroke 13.5 Compression Max Wedge ported Indy SR ported by Jeff at Modern 1.5 Ratio Harland Sharpe Rockers 1050 Chuck Nytten Gas dominator Indy 4500 Intake with approximately 3/4 of spacer Hooker Fender well headers (44 Primary Tubes) with 3.5 inch exhaust exciting before the rear tires Scott Brown Roller Cam 630 lift with 1.5 rocker, 278 Duration@ 50, 112 centerline
Transmission Powerglide with 1.80 Straight cut gear set 5600 PTI 8 Converter
Rear End Mark Williams Sheet metal 9 with aluminum center section and rifle drilled 40 spline axles. 456 Gears
Chassis 1971 Demon all steel except fiberglass hood, deck lid front and rear bumpers Full cage with round tube back half Factory Glass 6 pack hood scoop carb not sealed. Stock engine compartment with inner fenders except where headers go through Factory dash 4 Link rear suspension Custom built rack and pinion Front suspension. QA 1 Double adjustable Front Shocks QA 1 Double adjustable Rear Coil Overs Anti Sway bar Goodyear 24 front tire Goodyear 32 x 15.5 x 15 Car weighs 3040 pounds with my big butt in it.
Best ET with this combo is 9.58 @ 139 with a 1.36 60. That took placing the fall in 2007 and I dont have a corrected altitude.
1st set of changes I made.
Changed Heads from Ported SRs to INDY -1s CNC 325 Replaced the 1.5 Rockers with 1.6 Rockers Went from Hooker Fenderwell Headers (44 primary) to shorter Headman Hustlers (36 primary) both 2 Removed the exhaust Removed non sealed 6 pack hood scoop and added a sealed pro stock scoop. Replaced the PTC converter with an A1 that stalled at 6200 Replaced Goodyears with Hoosiers. 26on front, 32x15.5 x 15 Slicks
September 2013 Corrected Altitude - 3409 60 1.401 330 3.973 660 6.145 Mph 113.20 1000 8.029 1/4 9.625 Mph 140.75
2nd Set of Changes
Lowered the Stall to 5600 to try to get the pig to leave Added a Star Machine Vacuum pump and puke can
June 2014 Corrected Altitude - 3971 60 1.386 330 3.958 660 6.139 Mph 112.78 1000 8.029 1/4 9.636 Mph 140.14
To be honest I thought that it would pick up a bit. In the past removing the exhaust was a tenth. The shorter headers were a 15 17 horsepower better on the dyno. I thought the heads would be a wash. I thought that the rockers would help a tiny bit too. Also sealing the scoop to the carb is supposed to be the best thing since nitros.
Any Input would be appreciated and any suggestions. I would really like to get this thing to leave.
Thanx 451 Guy
512 cu in 71 Demon Super Street Car - NO LONGER - Broke Crank Best ET 9.57 @ 139.96
451 cu in Pump Gas - 71 Demon Super Street Car Best ET 9.99 @ 136.80
512 cu in 69 Charger R/T Best ET 11.39 @ 118.11
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Re: Made changes! No Faster! Me Confused ???
[Re: 451Guy]
#1638035
06/24/14 09:14 PM
06/24/14 09:14 PM
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Joined: Sep 2004
Posts: 1,499 San Antonio,TX
440W8 Duster
pro stock
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pro stock
Joined: Sep 2004
Posts: 1,499
San Antonio,TX
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Did you try to shift it higher or lower? did you dyno it? What do you shift it at? What does the converter fall back to when you shift it? http://youtu.be/RTDkU8WCjLo
70 Duster W8 motor. 1.29 60ft 5.79 1/8 at 120 mph glide with 1.80 gear @3170 lbs.
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Re: Made changes! No Faster! Me Confused ???
[Re: 451Guy]
#1638036
06/24/14 09:15 PM
06/24/14 09:15 PM
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Joined: Jan 2003
Posts: 4,616 Kissimmee Fl.
dusturbd340W5
master
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master
Joined: Jan 2003
Posts: 4,616
Kissimmee Fl.
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I say you are leaving a lot on the table with that small of a cam.
70 duster full chassis super pro 416 CNC Indybrock heads 727 w/brake
best so far 1.212 60 6.219 in 1/8 at 110.88 9.768 at 137.81 1/4
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Re: Made changes! No Faster! Me Confused ???
[Re: MR_P_BODY]
#1638038
06/24/14 10:22 PM
06/24/14 10:22 PM
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Joined: Dec 2005
Posts: 1,495 Shelby mi.
JAKE68
pro stock
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pro stock
Joined: Dec 2005
Posts: 1,495
Shelby mi.
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See im looking at it alittle different. Those old no. were your best. what was your average. did the compression stay they same from the different heads,did you have it back on the dyno and retune your new combo,it may be out to lunch. also Im thinking that is a lot of converter for that thing hardly any mph for that et even thou it picked up 1.5 mph from your old Best!!
JAKES AUTOMOTIVE
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Re: Made changes! No Faster! Me Confused ???
[Re: dusturbd340W5]
#1638039
06/24/14 10:24 PM
06/24/14 10:24 PM
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Joined: Jan 2003
Posts: 11,786 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,786
Portage,michigan
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Quote:
I say you are leaving a lot on the table with that small of a cam.
Not a fan at all of Scott Brown cams. Ran one he did for me few years back and it was a dog, compared to what it replaced.
Your car should be fairly light, should 60 well better than 1.36. That wide LSA cam I bet isn't helping that at all.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car Best so far, 10.32 1/4 1.41 best 60 foot 6.56 at 104.17
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Re: Made changes! No Faster! Me Confused ???
[Re: B3422W5]
#1638040
06/24/14 11:13 PM
06/24/14 11:13 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Quote:
Quote:
I say you are leaving a lot on the table with that small of a cam.
Not a fan at all of Scott Brown cams. Ran one he did for me few years back and it was a dog, compared to what it replaced.
Your car should be fairly light, should 60 well better than 1.36. That wide LSA cam I bet isn't helping that at all.
I didnt care for my Scott Brown cam either.. he liked the 112 LSA but mine was short on lift and a bit too much duration
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Re: Made changes! No Faster! Me Confused ???
[Re: B3422W5]
#1638041
06/24/14 11:16 PM
06/24/14 11:16 PM
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Joined: Feb 2006
Posts: 698 Alberta Canada
Edge
mopar
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mopar
Joined: Feb 2006
Posts: 698
Alberta Canada
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1.5 MPH over your previous best is good news so you are making more power. 60 foot is still pretty soft with lots of opportunity for improvement.
76 Duster
work in progress
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Re: Made changes! No Faster! Me Confused ???
[Re: Edge]
#1638042
06/24/14 11:21 PM
06/24/14 11:21 PM
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Joined: Jan 2003
Posts: 11,786 Portage,michigan
B3422W5
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 11,786
Portage,michigan
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If I were the OP, I would give Dwayne Porter a call with all your combination, and have him spec out the correct cam for you. I would bet good money doing that one thing would show solid gains across the map.
69 Dart GTS A4 Silver All steel, flat factory hood, 3360race weight 418 BPE factory replacement headed stroker, 565 lift solid cam, footbrake street/strip car Best so far, 10.32 1/4 1.41 best 60 foot 6.56 at 104.17
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Re: Made changes! No Faster! Me Confused ???
[Re: dusturbd340W5]
#1638043
06/24/14 11:49 PM
06/24/14 11:49 PM
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Joined: Mar 2007
Posts: 3,300 Northern Indiana
Dunnuck Racing
master
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master
Joined: Mar 2007
Posts: 3,300
Northern Indiana
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Quote:
I say you are leaving a lot on the table with that small of a cam.
Nowhere near optimum camshaft for the application.. Those heads really wake up with some lift, and getting valve timing correct will help everywhere. Keith
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Re: Made changes! No Faster! Me Confused ???
[Re: Monte_Smith]
#1638045
06/25/14 09:10 AM
06/25/14 09:10 AM
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Joined: Jan 2003
Posts: 10,081 Frostbitefalls MN (Rocky&Bullw...
gregsdart
I Live Here
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I Live Here
Joined: Jan 2003
Posts: 10,081
Frostbitefalls MN (Rocky&Bullw...
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Look at the head flow at your current net valve lift(.600) versus what you will have with about .725 lift (.750 lift gross). A decent roller for your combo IMHO would be about 280 to 282 at .050 intake, 288 at .050 exhaust, on a 110 LSA probably in at 108. The 110 LSA is that wide to accommodate the long 288 exhaust duration and keep the overlap about right. Less exhaust duration might dictate a cam of 108 LSA. These numbers are coming from all the recommendations I have gotten for my 528 with 440-1 heads. I am not that much bigger than your motor, so the cams ought to be similar. Also, the smaller the intake valve to cubes, the narrower the LSA needs to be. The reason is the poorer the heads flow for the size motor, the more overlap is needed to get the intake flow moving. The first cam I had in the 528 was an Isky RR735. It had 280/288/110 specs, .735 intake lift with 1.5 rockers. I had 1.55 ratio rockers on then for .761 gross lift. That cam made 847 hp on the dyno, and the car went 8.77 at 153 on radial slicks at 3,000 lbs. That would be about 8.85 on bias tires. You have a lot of power there, it just needs to be unlocked with a cam and compression. I run 15/1 with alky, and wouldn't run less than 13.5 or 14/1 with gas. I am also a fan of very loose converters. They flat work for me. I got a $1500 lesson on that this spring. I tried another converter, set for about 500 rpm over peak torque. The car slowed over 2 tenths!. My current converter flashes to 6600 and I shift at 7100, which I know is very loose, but it is at least .05 faster than it was flashing to 6,000. You run a glide, so being loose enough would be even more important to you, IMO. I run a three speed.
Last edited by gregsdart; 06/25/14 09:18 AM.
8.582, 160.18 mph best, 2905 lbs 549, indy 572-13, alky
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Re: Made changes! No Faster! Me Confused ???
[Re: gregsdart]
#1638046
06/26/14 06:34 PM
06/26/14 06:34 PM
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Joined: Feb 2006
Posts: 476 Alberta, Canada
451Guy
OP
mopar
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OP
mopar
Joined: Feb 2006
Posts: 476
Alberta, Canada
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Thanks guys for the responses. I had a chance to read them but I have been crazy busy so I could not respond till now. The cam was designed for the 451 I had in the car previously. It worked well in that motor. It was easy on parts and I had not had issues with it. We had dynoed a friends motor that had a way bigger cam in it and the results were similar so I went with it. I must admit I was a little hurt when the dyno operator asked me what year motorhome the engine was going in once he had heard it run. With regards to the 4 link I think this is the area I need to concentrate on. I have a set of scales and I am going to scale it. I will also plot the bars once that is done and I know where we are at I can make some adjustments. The issue at our track is we don't get any runs so it could take a full season to get the four link set up. I realize that if I want it to work right I need to do it but I also want race. I am still not sure that the converter is right. I have attached a copy of the dyno sheet. I am confused by the torque curve on this sheet. Almost like the operator should have lowered the start rpm for the pulls to get the torque peak. In my opinion (which is more than likely completely wrong) I think that a 5600 to 6200 stall is too high. I am tempted to try a lower stall just for kicks but the eight (that's right Eight perfectly good converters) that I currently own are stopping me from buying another one. There are a lot of guys on this site that have forgotten more about this stuff than I will ever know so your input and expertise are greatly appreciated.
Thanx 451 Guy
512 cu in 71 Demon Super Street Car - NO LONGER - Broke Crank Best ET 9.57 @ 139.96
451 cu in Pump Gas - 71 Demon Super Street Car Best ET 9.99 @ 136.80
512 cu in 69 Charger R/T Best ET 11.39 @ 118.11
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Re: Made changes! No Faster! Me Confused ???
[Re: 451Guy]
#1638047
06/26/14 06:44 PM
06/26/14 06:44 PM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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Based on the dyno sheet your peak torque is either right at the 4600 or before it.. so thats hard to say.. but its falling from that point
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Re: Made changes! No Faster! Me Confused ???
[Re: 451Guy]
#1638048
06/26/14 07:01 PM
06/26/14 07:01 PM
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Joined: Oct 2010
Posts: 582 Dayton, OH
1980volare
My man card has just been revoked.
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My man card has just been revoked.
Joined: Oct 2010
Posts: 582
Dayton, OH
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Re: Made changes! No Faster! Me Confused ???
[Re: 451Guy]
#1638049
06/26/14 09:15 PM
06/26/14 09:15 PM
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Joined: Nov 2004
Posts: 6,890 North Alabama
Monte_Smith
master
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master
Joined: Nov 2004
Posts: 6,890
North Alabama
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Quote:
Thanks guys for the responses. I had a chance to read them but I have been crazy busy so I could not respond till now.
The cam was designed for the 451 I had in the car previously. It worked well in that motor. It was easy on parts and I had not had issues with it. We had dynoed a friends motor that had a way bigger cam in it and the results were similar so I went with it. I must admit I was a little hurt when the dyno operator asked me what year motorhome the engine was going in once he had heard it run.
With regards to the 4 link I think this is the area I need to concentrate on. I have a set of scales and I am going to scale it. I will also plot the bars once that is done and I know where we are at I can make some adjustments. The issue at our track is we don't get any runs so it could take a full season to get the four link set up. I realize that if I want it to work right I need to do it but I also want race.
I am still not sure that the converter is right. I have attached a copy of the dyno sheet. I am confused by the torque curve on this sheet. Almost like the operator should have lowered the start rpm for the pulls to get the torque peak. In my opinion (which is more than likely completely wrong) I think that a 5600 to 6200 stall is too high. I am tempted to try a lower stall just for kicks but the eight (that's right Eight perfectly good converters) that I currently own are stopping me from buying another one.
There are a lot of guys on this site that have forgotten more about this stuff than I will ever know so your input and expertise are greatly appreciated.
The cam was designed for the 451............. Well there you go.........LOL!!!
Monte
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Re: Made changes! No Faster! Me Confused ???
[Re: Monte_Smith]
#1638050
06/26/14 09:41 PM
06/26/14 09:41 PM
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Joined: Jan 2003
Posts: 4,616 Kissimmee Fl.
dusturbd340W5
master
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master
Joined: Jan 2003
Posts: 4,616
Kissimmee Fl.
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motors never going to give what it should with that cam. I ran a cam larger than that in a sb 416
70 duster full chassis super pro 416 CNC Indybrock heads 727 w/brake
best so far 1.212 60 6.219 in 1/8 at 110.88 9.768 at 137.81 1/4
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Re: Made changes! No Faster! Me Confused ???
[Re: dusturbd340W5]
#1638051
06/26/14 10:25 PM
06/26/14 10:25 PM
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Joined: Feb 2006
Posts: 476 Alberta, Canada
451Guy
OP
mopar
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OP
mopar
Joined: Feb 2006
Posts: 476
Alberta, Canada
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thanks again for the responses but I the questions I asked was not "please critique my cam choice". The cam has been a constant and I am aware that it,s not optimum for the new combination but my question is based on the changes that I made with no improvement in ET. Changing the heads, increasing the rocker ratio to 1.6 from 1.5, adding a pro stock hood scoop that is sealed to the carb rather than the old school six pac scoop, lowering the stall by 500 rpm. Last time I did that the car picked up 4 tenths! Putting on a shorter tube header which was worth 20 hp on the dyno. Lastly adding a vacuum pump. I thought that this stuff would make a a bit of a difference. But maybe not.
Thanx 451 Guy
512 cu in 71 Demon Super Street Car - NO LONGER - Broke Crank Best ET 9.57 @ 139.96
451 cu in Pump Gas - 71 Demon Super Street Car Best ET 9.99 @ 136.80
512 cu in 69 Charger R/T Best ET 11.39 @ 118.11
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