Can't do a burn out.

[handsomerob]

Originally Posted by Mertz

I have had the truck up to 85 without problems. I was afraid to go any faster on the road I was on but it seemed to be pretty close to all it had at the time of that test run with the carb adjustment I had. My acceloration from 50 and up is great. 50 to 70 seems like seconds but I haven't timed it.

I think it is 2500. It was new when the trans was rebuilt a few years ago. If it is 2500 or 2800 would that mean I would need to have all my timing in at 2500 or 2800 instead of 3000 like I have it now?

Here is a link that sums up the torque converter issue.

http://www.hardtail.com/techtips/sel...converter.html

[breeh]

Originally Posted by handsomerob

Whats the stall on your converter? if your stall speed isn't matched with the torque curve of your engine your truck will be a dog.

It sounds like a converter stall and rear gear ratio mismatch to me. If you bought a converter without considering the rear gears then you are learning a lesson that many of us have had to learn. Cam, stall, rear gears; all must work together.

[Oklahoma]

I had a old tired 350 with 2:73's, that's right 2:73's with a one wheel wonder and I could smoke that tire like no body's business. I think it is the stall, not an expert on then, because I have never had one, but was told by lots of people who like good daily drivers not to put one in mine. I just rebuilt every part of the power train, rebuilt 350, 7000r4, 3:73 posi rear end, electric fan to help the power, and now I can barley spin the tires, a little depressing, but not a big deal to me, but like you said you want to pull a trailer, as do I, so I will be building a stroker motor my self so I know what I have and I guarantee when I'm done it will smoke the tires.
Note: I you just want to smoke the tires for the fun of it, just put a little oil on the tires before you start the power brake and watch the tires light up.

[breeh]

Originally Posted by Oklahoma

Note: I you just want to smoke the tires for the fun of it, just put a little oil on the tires before you start the power brake and watch the tires light up.

Clorox and water makes a nice smoke show too

[Scott Webster]

We used to use Armorall to get my '72 spinning.

[SigX]

You can figure out your ballpark gear ratio pretty easily. Put the rear on jacks and put the transmission in neutral. Put a mark on your drive shaft and rotate your rear wheel exactly once. The number of drive shaft rotations for one wheel rotation is your ratio.

[Blue72slab]

Originally Posted by SigX

You can figure out your ballpark gear ratio pretty easily. Put the rear on jacks and put the transmission in neutral. Put a mark on your drive shaft and rotate your rear wheel exactly once. The number of drive shaft rotations for one wheel rotation is your ratio.

I believe with an open diff you have to rotate the tire twice and make sure the other tire does not move.

[Mertz]

I can do a fine burnout if I start on gravel and then hit the pavement but that is not the point. My attempts have been on dry pavement that isn't even smooth. It is a chip seal road that is pretty rough so it has very good traction especially in our snowy winters. I know if I was on wet smooth pavement I would have a better chance of breaking them loose but that doesn't mean I have the low end torque I want.

Thanks for all the help on this. I will read the article on converters and learn some more. I will also try to find the rear end ratio.

[three80three]

I'm wondering whats the deal with my truck to I have a 84 chevy c10 with a 292 comp cam all new eternal parts a 650 holley double pumper edlebrock intake and a 3200-3600 stall converter, in grass or dirt I'm pulling hole shots like I'm at the track in the water box but when I get on dry ground it won't spin a tire to save my life not even foot braking why is that?

[JonnyC10]

My original 283 2 barrel and Powerglide lights them up no problem. Has original distributer as well.

[trac209]

Something is not right in the off line torque because I've never seen one of these trucks that could not smoke the tires with any v8. My very mild truck will from a 20mph roll fairly easy. I'd say the converter is either too tight for your cam so the powerband is way off.

[Fitz]

Originally Posted by Mertz

Inital is at 12 with total around 50 mechanical and vacuum all in at 3000. Around 34 with mechanical no vacuum. MSD Ready to Run distributor.

50 degrees total? seems like a bit much. GM says mine should be 36 total.

[mechanicalman]

If it's an original style 72 350 then it has extremely low compression like about 7.8:1 or so despite what they claim to be 8.5, trust me it's closer to 7.5. Sounds like you have a good distributor, but it may not be set up for your engine.

I would be surprised if you have a 2500 stall converter, and if you do, what cam did you put in it to need that much stall? Too much cam, too low compression, highway gears and you get exactly what you have described.

IF IT IS STOCK 72 350 COMPRESSION and if the engine is not all full of carbon: Set your initial timing at at least 18 degrees, make your total mechanical timing 38 degrees (vacuum pod dis-connected) all in at 2500-2800. You might have to tweak it later if it pings or cranks slow.

Hook your vacuum pod up to "ported" vacuum.

Try playing with the spring tension on the secondaries of the Q-jet.

With your exhaust system that thing should do pretty good; something is amiss.

[Fitz]

Originally Posted by prostreetC-10

No fun when you can't do a burnout. Time for a BBC.

What is your initial timing set at? That can make a big difference.

The Doctor at GMPP has the cure for your problem! If your truck won't do a burnout with one of these your problem is the loose nut behind the wheel.

[Tzclark]

Plumb your windshield washer sprayers to the back tires and but straight bleach in the reservoir, even with a 6 cylinder you'd be the coolest kid on the block laying patches all over the place.

[three80three]

I have a292 comp extreme cam and I did remove the springs from the weights on my distributor would that have anything to do with it?

[three80three]

I'm not running a quadrajet I have a 650 double pumper and I can't heat the tires up, but one thing is for sure when I'm at a traffic light and I hit the gas man it leaves hard with no problem

[FrankenCub]

Originally Posted by Tzclark

Plumb your windshield washer sprayers to the back tires and but straight bleach in the reservoir, even with a 6 cylinder you'd be the coolest kid on the block laying patches all over the place.

rofl...I was gonna suggest such a thing
My buddy had a washer bottle in his trunk with the sprayers pointing through the wheel wells when we were in high school
My 307 will smoke em pretty good even with a bad cam, tires cost too much money to do it often. Maybe the 3OTT helps lol

[Tzclark]

I am speaking from experience Franken, the stupid crap I did to look cool (in actuality I looked like a moron) but when your 16-17 and want to do burnouts and don't have enough power the situation calls for creativeness.

[FrankenCub]

Originally Posted by Tzclark

I am speaking from experience Franken, the stupid crap I did to look cool (in actuality I looked like a moron) but when your 16-17 and want to do burnouts and don't have enough power the situation calls for creativeness.

I can't agree more, been there too lol. Most of my efforts went into really small and light cars (Pontiac Sunbird) with small blocks and 4spd. Did plenty of stupid things with those cars but they were a dime a dozen.

[davepl]

Secondaries are airflow controlled, so you'll likely never get them open during a brake-torque. That's why brake-torques were so popular with the 2 barrel guys in high school.

But you don't need the secondaries at that kind of RPM.

Run it 0-60 at the track (or similarly safe place) and let us know what you come up with. If you know or can get the weight, that'd help too.

FWIW my Dad's old 68 ran 0-60 in 10 seconds with a 307. I don't think it could turn the tires either :-)

[El Campo]

292 xtreme energy needs more compression than what you have is part of the problem I would guess for one thing

[Tzclark]

Which heads are you running? Valves? Springs? That cam is quite a bit for your motor.

[davepl]

Originally Posted by FrankenCub

I can't agree more, been there too lol. Most of my efforts went into really small and light cars (Pontiac Sunbird) with small blocks and 4spd. Did plenty of stupid things with those cars but they were a dime a dozen.

My then-girlfiend-now-wife had a new 1990 Sunbird GT Turbo. For its day it was a fun car, I didn't even know they had them in the US! I've never seen a Sunbird GT Turbo nor a Cavalier Z/24 down here.

[davepl]

That cam is 244/244 at 0.050. It wants 11:1 compression, a LOT of displacement, a 3000 stall converter, and a light vehicle. It doesn't even wake up until 3000 or so.

The Vette's 427/390 cam, designed for an engine that had WAY more compression and displacement that you are running comes in at 214/218. That appears to be what I'm running in my big block. I think it's actually the same as the 396/325hp cam but don't quote me on it.

If I were you I'd pick up GM part number 3896962. It's made for their 350/290 crate motor, has 222/222 duration (still a lot) and 8.0:1 compression. If it were me I'd even go a little lower, like 210, and look for a wider lobe separation.

This would significantly increase your truck's low end power. Furthermore, it would make it a lot more fun to drive in the city. You'll only miss the old cam over 5800rpm anyway, and if you want a rough idle pull off a plug wire.

Edit: don't just blindly buy that part number, sorry. It could be a roller cam for all I know. Just using it as an example.