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2.56, TH400 with custom 2.75 first gear set.. Lots of cubes, 9.1 compression so you can run the timing this engine wants. Zero decked block. Short duration, wide lobe separation, lobes that open and close smoothly and not slammed open and closed. Factory cams are some excellent grinds..
 

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Discussion Starter · #362 · (Edited)
2.56, TH400 with custom 2.75 first gear set.. Lots of cubes, 9.1 compression so you can run the timing this engine wants. Zero decked block. Short duration, wide lobe separation, lobes that open and close smoothly and not slammed open and closed. Factory cams are some excellent grinds..
At least with a 2.75 first gear, you’d have the benefit of getting through the 1800-3800 rpm area much quicker through first gear. When you shift to second, the rpm drops back down somewhere around 3400, right near where my 496 is making 600+ ft*lbs of torque.

The current engine is zero-decked, 1037 head gasket, 10.1:1, with a reasonable cam ground on 111. It idles great and I run the total timing at 35 on 93 octane. I’ll drop in a few gallons of race gas at the track for good measure, but it’s probably OK without it.

If it can hook with the new 225/70-15 Coopers, it’s going 11s in August at Power Tour.
 

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Here you go.

View attachment 716825

The cam is an Isky HR 275/284, 228/238, ground on 111 LSA (to smooth the idle and spread the power to work better with heavy car, 2.56 gear and stock converter). The cam was installed straight up at ICL of 109 (+2 built in).

The low lift flow on the intake valves is better than factory, but not great by Mark’s standards. I’d say this is just one area where his engine will shine compared to mine. His outstanding low lift flow allows a seemingly under-cammed engine make huge power.
View attachment 716830

Still, I feel that I did decent job on this build (especially considering all my crazy ideas), but I’m not a skilled and experienced builder by any stretch of the imagination. Mark’s engine could easily put up 75-100 hp more than mine, using a cam that’s within a couple degrees, if 100 hp is the goal.

Ultimately, improving ET is the goal, as well as looking near stock or retro. With the way I’m running my car, the ET battle will be won in the first 330’. To win this battle, I need torque to overcome the gear and lack of converter, and the ability to apply it to the ground from near idle. The current 116.45 mph (at 4275 lbs) is decent, and sorted out with good air, it might see 119 at 4100 lbs. Do the math with another 50-100 hp, and even more torque, this car might hit mid-11s in the right conditions.

With the long first first gear, my 51 year old car accelerates like a Dodge Viper (the first gear change occurs after 60 mph). Believe me, I’m smiling and enjoying the conversations.
How many rpm you shiftin out of first?
Out of second?
 

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Discussion Starter · #364 ·
How many rpm you shiftin out of first?
Out of second?
Near as I can tell (I don’t have a tach in the car), I start the 1-2 shift at about 5200, it actually shifts about 5600 (70 mph). I shift based on pull in the seat of the pants feel.

It never hits drive (crosses about 5700)…I coast down in second gear (saves on the brakes).

Listen to the video.


E1F9D985-4C33-4545-84FF-F63303458E6D.jpeg
 

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is your fan a thermostatic clutch fan? That can save a lot of power over a solid mounted one. Don't get a HD clutch, just a regular.
 

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Near as I can tell (I don’t have a tach in the car), I start the 1-2 shift at about 5200, it actually shifts about 5600 (70 mph). I shift based on pull in the seat of the pants feel.

It never hits drive (crosses about 5700)…I coast down in second gear (saves on the brakes).

Listen to the video.


View attachment 717054
.
.does this speed and gear and rpm graphic right above here that I'm looking at represent where you shifted?
Are those "after shift rpm's correct ?
I mean
 

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Mike

Tell me your not running a solid fan
 

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Discussion Starter · #369 ·
.
.does this speed and gear and rpm graphic right above here that I'm looking at represent where you shifted?
Are those "after shift rpm's correct ?
I mean
Yes, and rpm after the shift, as best as I can calculate it.
 

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Yes, and rpm after the shift, as best as I can calculate it.
Youd be faster if you shifted later.
You want rpm after shift (drop) to be 4 grand or so because that's where your torque starts coming on .
Wherever you are shifting now is dropping back to 3400 or so where torque Is much lower .
Look at the dyno
 

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I’ll look into Type F. For me to run it, it must be found just about anywhere as I don’t like special order consumables. For example, VR1 is everywhere, and I carry it with me.
I ran an auto parts store brand type f in my car going 8.80’s.
 
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Youd be faster if you shifted later.
You want rpm after shift (drop) to be 4 grand or so because that's where your torque starts coming on .
Wherever you are shifting now is dropping back to 3400 or so where torque Is much lower .
Look at the dyno
Not always true. I shifted my Peanut Port engine at 5200 and leg it out in high gear and the car runs 11 teens, when I shift it at 6100 where I go through the traps the car run high 11.20's. His engine, converter and gearing might only net him more MPH but I don't think it would gain much more ET, to gain more it the car needs to accelerate faster hence more gear and converter, but he is on a quest to see if he can do this with something others would not try. One would need to figure out the difference with the first 660ft. times to be sure.
 

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Not always true. I shifted my Peanut Port engine at 5200 and leg it out in high gear and the car runs 11 teens, when I shift it at 6100 where I go through the traps the car run high 11.20's. His engine, converter and gearing might only net him more MPH but I don't think it would gain much more ET, to gain more it the car needs to accelerate faster hence more gear and converter, but he is on a quest to see if he can do this with something others would not try. One would need to figure out the difference with the first 660ft. times to be sure.
Not sure if know this, you can let me know, but he is driving the car out of the hole with street tires, that 2.0 60 will be much lower with the suspension rebuilt with a drag radial. Things I would like to see:

1. Strait cut turbo 400, quality rebuild
2. Aluminum or carbon fibre driveshaft
3. Fuel system with vent
4. Locked dist
5. 1 inch open spacer same as I run
6. Electric fans
7 Leave the line @ 120 degrees
8. Developed double pumper carb
9. 60 PSI front tire pressure minus all the beauty rings and center caps
10. Drag radials

What do you think it will run then?
 

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What's not allways true ?
That youd want to fall back on a shift into an rpm where you are 3 or 400 rpm below peak torque?
I figured that would be a constant no matter what the combo.
Might be wrong figurin lol that's why I'm askin .
If he is falling back to 3400 on the shift as he estimates then hes about 565 torque at that point according to the dyno.

At 4 grand hes 600 torque and then it hangs prettty good for another 600 rpm or so till torque starts falling BUT at that point the car is moving and hp is still climbing .

Idk I might be wrong but it looks like optimal here would be to wring it out in 1st
Which would let it drop back in bigger torque and then ride it out.
It's a 2 speed run lol
 

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Not sure if know this, you can let me know, but he is driving the car out of the hole with street tires, that 2.0 60 will be much lower with the suspension rebuilt with a drag radial. Things I would like to see:

1. Strait cut turbo 400, quality rebuild
2. Aluminum or carbon fibre driveshaft
3. Fuel system with vent
4. Locked dist
5. 1 inch open spacer same as I run
6. Electric fans
7 Leave the line @ 120 degrees
8. Developed double pumper carb
9. 60 PSI front tire pressure minus all the beauty rings and center caps
10. Drag radials

What do you think it will run then?
11.70
If he ran a stall that flashed to 4 grand and the car hooked then 11.20
But what do I know lol
 

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Discussion Starter · #378 · (Edited)
Youd be faster if you shifted later.
You want rpm after shift (drop) to be 4 grand or so because that's where your torque starts coming on .
Wherever you are shifting now is dropping back to 3400 or so where torque Is much lower .
Look at the dyno
I’m not so sure about that, the torque drops off pretty quick above 5000 rpm, and you really feel the loss in your backside. After the shift, acceleration happens at a rapid pace. The Achilles heel is getting to 3000 rpm the line. You can see this in the race against the 489-powered 1970 MC.


Not always true. I shifted my Peanut Port engine at 5200 and leg it out in high gear and the car runs 11 teens, when I shift it at 6100 where I go through the traps the car run high 11.20's. His engine, converter and gearing might only net him more MPH but I don't think it would gain much more ET, to gain more it the car needs to accelerate faster hence more gear and converter, but he is on a quest to see if he can do this with something others would not try. One would need to figure out the difference with the first 660ft. times to be sure.
I think you’re on the money. Torque is what moves the beast, since I don’t have gears to make the torque, it’s even more important to keep the engine in the bulk of the torque production.

Not sure if know this, you can let me know, but he is driving the car out of the hole with street tires, that 2.0 60 will be much lower with the suspension rebuilt with a drag radial. Things I would like to see:

1. Strait cut turbo 400, quality rebuild
2. Aluminum or carbon fibre driveshaft
3. Fuel system with vent
4. Locked dist
5. 1 inch open spacer same as I run
6. Electric fans
7 Leave the line @ 120 degrees
8. Developed double pumper carb
9. 60 PSI front tire pressure minus all the beauty rings and center caps
10. Drag radials

What do you think it will run then?
1. Yes
2. Yes
3. The cap is vented, but gets me into trouble spitting fuel on starting line
4. I’m curious to try the locked distributor
5. I might need a lower drop base to fit a 1” spacer. You mentioned L88 base, if that’s the case, I’ll find one.
6. I’m curious to know how it’d run with the electric fan, and there’s a great reason to go electric - being able to climb in the engine compartment to work on the engine. I know in my old car, the electric fan was worth about a tenth. That was a higher rpm engine though, I suspect the benefit will be diminished on this low rpm engine.
7. The engine will leave the line at 120 at the next race, if I need to drive down at 5AM.
8. I have no opinion on this? Love the 3310 though - I do want to add a metering block to the secondary though, and read the plugs closely. I hear dual planes like stagger jetting.
9. I run the fronts at 45 psi, and I thought that was pretty brave for 16 year old, 32 psi tires. This weekend, I’ll have new Cooper 225/70-15 tires all around (and 275/60-15 ET Streets on 15x8 4.5” BS rally wheels).
10. If I come up horribly short with the hard tires, I’ll use the drag radials at the track.

11.70s?
 

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That's my point . You need torque.
You got no torque from gear because you got no gear so it's all engine torque and you only have 2 gears .
You need to use every ounce of engine torque you have .

You're saying that torque drops off fast after 5 grand therefore you think shifting sooner is better .

But By doing that and falling back to 3400 on the shift you are coming out of first and starting in second with quite a bit less torque and hp than is available to you. Thats why I'd think youd want to stay in 1st as long as possible because gear is what you lack .
When you are higher up in rpm you have rpm and hp is climbing on your side .

Look at the dyno .
Instead of starting out in second at 3400 and 565 torque and a measly 360 hp why not start out in second at 4 grand with 600 torque and your 450 hp at that point which will pull the big heavy load with no gear out of it's own way and get into the available horsepower versus running 1st gear to 360 hp .That way youd see close to max hp at then end of the show .
Just my 2 cents.
I could be wrong but I'd certainly try it .
Nothing to lose
 

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1971 Chevelle. Carb’d 6.0 LS Th350 3.90 12 Bolt. 1972 Greenbrier Wagon 489, 700r4 3,73 12 bolt
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#7….good luck with that driving to the track. Mine holds heat forever!
 
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