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My new stock stroke 400 build

What are you looking at for horse power? Considering low compression, I am guessing around 375.
 
Yes, the shop breaks everything in using their 650 Holley DP. The plan is to have them optimize the tune with the dyno carb, and the switch to the Demon, and then try the AFB. They are both 625's so it should be a pretty fair comparison. The AFB was on the car when I bought it, but the manifold setup was terrible, so it never really had a chance. I bought the Demon for the small primaries, to try and balance economy and power. We'll see.
That is very cool... there isn't a lot of info/testing of those carbs and i wanted small primaries also.. Plus how could i hate a Gogglevalve :)
 
What are you looking at for horse power? Considering low compression, I am guessing around 375.
You're probably about right Dave. The old 400 was only 9:1 but it had 10 degrees more camshaft and it made just over 400 HP. Lower than 375 would be disappointing , but anything higher would be a bonus. I am almost more interested in the torque curve, that is what this heavy car needs.
 
I talked to the shop this morning, and they are going to glass bead the runners and run the heads through the washer again, to clean up some of the areas I couldn't reach with my short carbide. I know it won't increase the flow, but I will feel better that everything is clean.

They are also ordering the KB 240 pistons today .030 over, so we are starting to make progress. Not sure if I mentioned it before, but we will be running it on the dyno to break in the cam, and get some numbers. They have dynoed the last two engines I built, so looking forward to it.

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what brand Dyno are they using ?
 
I picked up the transmission today. It turned out there was more work needed than I at first thought. The drum had a failed thrust washer, so it scored the thrust surface. The pump was also scored, and the gears were loose on the shafts in one of the planetaries. Fortunately he had lots of good used parts available, so it wasn't a problem.

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I stopped by the shop today and dyno day is set for next Wednesday, fingers crossed.
 
My friend had a machine shop for a while. He had a SIM test machine which would heat the oil and spin the engine. You could somewhat break it in without running it.
He also had a Dyno with all his own instrumentation.
Smart guy.
 
Break in is my biggest concern Don, and making sure there are no oil or water leaks. After that I can enjoy watching the numbers roll by, and see how all my planning worked out.
 
Well after a tiring day I am home relaxing. The good news is there were no oil leaks or water leaks, and the cam broke in just fine. We made 7 pulls in total after break in. The best pull was with the 650 DP dyno carb, no surprise there. It made 420 lb/ft of torque at 3900 with over 400 lb/ ft from 3000 to 4300. Horsepower was a little disappointing with only 340 at 4800 rpm. I guess I needed more cam, but I did say low end torque was the goal.

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After the Holley, we tested the AFB. It made 400 lb/ft at 4100 and 325 horsepower at 4900. The air fuel ratio was pretty good, and I didn't have a strip kit to change it anyway, so we switched to the Street Demon.
 
When we first put the Street Demon on it made 400 lb/ft at 3900 and 317 horsepower at 4800 rpm, but the air fuel ratio was pretty lean . We switched from 80 to 82 jets and it picked up to 405 lb/ ft and 332 horsepower. We then swapped out to richer metering rods and ended up with 497 lb/ ft at 3800 and 335 horsepower. A slightly smaller metering rod picked up low end torque a little, but peak torque and horsepower went down to 404/329.

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Well after a tiring day I am home relaxing. The good news is there were no oil leaks or water leaks, and the cam broke in just fine. We made 7 pulls in total after break in. The best pull was with the 650 DP dyno carb, no surprise there. It made 420 lb/ft of torque at 3900 with over 400 lb/ ft from 3000 to 4300. Horsepower was a little disappointing with only 340 at 4800 rpm. I guess I needed more cam, but I did say low end torque was the goal.

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View attachment 1674739
What were the other carbs?
Sounds like a good day.
 
Well after a tiring day I am home relaxing. The good news is there were no oil leaks or water leaks, and the cam broke in just fine. We made 7 pulls in total after break in. The best pull was with the 650 DP dyno carb, no surprise there. It made 420 lb/ft of torque at 3900 with over 400 lb/ ft from 3000 to 4300. Horsepower was a little disappointing with only 340 at 4800 rpm. I guess I needed more cam, but I did say low end torque was the goal.

View attachment 1674738

View attachment 1674739
What were the other carbs?
Sounds like a good day

Oops, got it
 
The bottom line was less horsepower than expected, but pretty much exactly what I expected for torque. The Holley was the winner in the carb derby, with the SD second and the AFB bringing up the rear. My goal was to run on regular gas and make as much low end torque as possible, so I think I met the goals. But then again, with better heads and a bigger cam.......
 
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I have a pretty good video of one dyno run with the SD, but I don't know how to upload it.
 
Congratulations on your dyno runs, Dave. They look like the numbers that Chrysler put on the 383 HP, with more compression.
 
Congratulations on your dyno runs, Dave. They look like the numbers that Chrysler put on the 383 HP, with more compression.
Can't compare, Chrysler did not put headers on the 383.
 
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