New engine combo, what will it run?

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71Demon540

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Something John (Pittsburghracer) and others really enjoyed on this site was taking a guess at what a new combo would run. I remember when @-Boosted- was making changes to Fred, there were a lot of posts on what the car would run with the changes he would make. So here it goes,

1971 Demon
2825lbs race ready (With driver)
4 link rear suspension w/anti roll bar
Coil over front suspension with upper and lower a-arms
Viking double adjustable shocks front and rear
Dana 60 w/ 4.56 gears
32x13.5W Hoosier slicks
727 w/2.28 first gear and trans brake
8" turbo action converter 6500 stall

New engine combo is 540" low deck Indy block
4.500 bore
4.250 stroke
Indy 440-1 heads
Indy single plane intake
1" HVH 4 hole tapered spacer
APD 1175 dominator
14.8:1 compression
.776/.752 111 LSA 285/296@.050
Kromer kraft headers 2"-2 1/8"-2 1/4" double stepped primary tubed with 4" collector

Old engine combo was a 528" low deck Indy block
4.500 bore
4.150 stroke
Same heads and intake
14.5:1 compression
AED 1150 dominator
Same camshaft
Same headers

Old engine ran a best of 5.43 @ 125mph and typically ran low to mid 5.50s in normal hot summer air. In any decent air it would go into the high 40s. When it spit out the 5.43, we were in very good conditions at a good track. It did it back to back so it wasn't a fluke.

I probably won't get to the track til mid-end of May to give results. But that is right around the corner.

So lets hear the predictions for the new combo and what guys think it will run...



Video of the initial fire up of the engine
 
Low 5.40's good track and good weather high 5.20's
 
5.38 @ 127mph and damnit I miss phone calls from John! Heck, I miss our conversations too! We had some doozies.... lol
 
Something John (Pittsburghracer) and others really enjoyed on this site was taking a guess at what a new combo would run. I remember when @-Boosted- was making changes to Fred, there were a lot of posts on what the car would run with the changes he would make. So here it goes,

1971 Demon
2825lbs race ready (With driver)
4 link rear suspension w/anti roll bar
Coil over front suspension with upper and lower a-arms
Viking double adjustable shocks front and rear
Dana 60 w/ 4.56 gears
32x13.5W Hoosier slicks
727 w/2.28 first gear and trans brake
8" turbo action converter 6500 stall

New engine combo is 540" low deck Indy block
4.500 bore
4.250 stroke
Indy 440-1 heads
Indy single plane intake
1" HVH 4 hole tapered spacer
APD 1175 dominator
14.8:1 compression
.776/.752 111 LSA 285/296@.050
Kromer kraft headers 2"-2 1/8"-2 1/4" double stepped primary tubed with 4" collector

Old engine combo was a 528" low deck Indy block
4.500 bore
4.150 stroke
Same heads and intake
14.5:1 compression
AED 1150 dominator
Same camshaft
Same headers

Old engine ran a best of 5.43 @ 125mph and typically ran low to mid 5.50s in normal hot summer air. In any decent air it would go into the high 40s. When it spit out the 5.43, we were in very good conditions at a good track. It did it back to back so it wasn't a fluke.

I probably won't get to the track til mid-end of May to give results. But that is right around the corner.

So lets hear the predictions for the new combo and what guys think it will run...



Video of the initial fire up of the engine

Damn RJ, that sounds great. I'll have to go do a 1/4 to 1/8 th conversion to see what that is.
Throw a guess though 5.15-5.25 just because I see you drive on YouTube
 
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Something John (Pittsburghracer) and others really enjoyed on this site was taking a guess at what a new combo would run. I remember when @-Boosted- was making changes to Fred, there were a lot of posts on what the car would run with the changes he would make. So here it goes,

1971 Demon
2825lbs race ready (With driver)
4 link rear suspension w/anti roll bar
Coil over front suspension with upper and lower a-arms
Viking double adjustable shocks front and rear
Dana 60 w/ 4.56 gears
32x13.5W Hoosier slicks
727 w/2.28 first gear and trans brake
8" turbo action converter 6500 stall

New engine combo is 540" low deck Indy block
4.500 bore
4.250 stroke
Indy 440-1 heads
Indy single plane intake
1" HVH 4 hole tapered spacer
APD 1175 dominator
14.8:1 compression
.776/.752 111 LSA 285/296@.050
Kromer kraft headers 2"-2 1/8"-2 1/4" double stepped primary tubed with 4" collector

Old engine combo was a 528" low deck Indy block
4.500 bore
4.150 stroke
Same heads and intake
14.5:1 compression
AED 1150 dominator
Same camshaft
Same headers

Old engine ran a best of 5.43 @ 125mph and typically ran low to mid 5.50s in normal hot summer air. In any decent air it would go into the high 40s. When it spit out the 5.43, we were in very good conditions at a good track. It did it back to back so it wasn't a fluke.

I probably won't get to the track til mid-end of May to give results. But that is right around the corner.

So lets hear the predictions for the new combo and what guys think it will run...



Video of the initial fire up of the engine

So main changes are 12 more cubes, .3 compression, and carb setup w/ carb spacer?
Did the rotating assembly change much? Bob, rod or piston weights up or down significantly?
Same fuel?
 
If that doesn’t go 5-teens on a 13.5w at that weight I’d be disappointed. That’s a killer combo.
 
What fuel do you use?
Oh and BTW your new screen name needs to change to 71demon540
 
Low 5.40's good track and good weather high 5.20's
That would be awesome! Honestly if it runs 5.40s all season long and doesn’t go into the 50s, I will be happy. I think that’s a realistic goal.
So main changes are 12 more cubes, .3 compression, and carb setup w/ carb spacer?
Did the rotating assembly change much? Bob, rod or piston weights up or down significantly?
Same fuel?

Yes 12 more cubic inch, little more compression, new carburetor. Same spacer used with my AED. The rotating assembly is little bit shorter rod. The 528 had 6.76 rod this has 6.700 rod. The piston has a much more flat dome with 0cc effective. Piston weighs about the same. (Can’t remember exact weight). We went with a thicker wrist pin so gained little weight there.
Yes same fuel. 112 Sunoco is what I run. Yes I’ll change my name now lol.

I’ll be honest if this thing runs as good as people on here are predicting I will be very happy. Usually takes a good bit of power to pick up that much, but sure would be cool.

Thanks everyone for the predictions.

@-Boosted-
We all miss John for sure and I sure miss our convos as well. I think your prediction is very close to what I am guessing.
 
your car is in the zone where small changes don't have as much affect as a 12 sec car would. you didn't make any real big change so it will be interesting to see what happens.

i think 5.38-5.40
 
your car is in the zone where small changes don't have as much affect as a 12 sec car would. you didn't make any real big change so it will be interesting to see what happens.

i think 5.38-5.40
That’s what I’m thinking as well. Hoping to run 30s in decent air and 40s primarily.
 
Based on your previous runs and taking into accountant how much more power it takes to go faster when you are already at 5:40.

At 2825 pounds it will take a lot of power to make it faster, so I am going to say you might see 5.35 out of it.

If you cold lose some weight you could get it to really go.

Tom
 
Based on your previous runs and taking into accountant how much more power it takes to go faster when you are already at 5:40.

At 2825 pounds it will take a lot of power to make it faster, so I am going to say you might see 5.35 out of it.

If you cold lose some weight you could get it to really go.

Tom
Thanks Tom. Pretty much my thought process as well. I try to be realistic in my expectations when it comes to gaining ET.
 
I'm sure it'll pick-up from the last combo despite the minor changes because it's fresh. What were the incrementals to the 1/8? 60/330 It's always been a great running package. You just don't see too many bracket cars this quick, especially mopars.
 
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