CarburetorsCarb discussion and questions. Upgrading your Third Gen's carburetor, swapping TBI to carburetor, or TPI to carburetor? Need LG4 or H.O. info? Post it here.
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just a update. I have the carb done, the crane adj vac advance and springs are in. I had to order a throttle lever to get the 700r-4 cable geometry correct. I just learned this. They can't go straight onto the holley linkage.
ok. i started testing WOT launches to 60 MPH. The car was very sluggish with the 37 squirter, i put the 31 back in and it improved greatly. I'll order a tube type 35 and try that. ( does it hurt to use the hollow screw with the smaller than 37 squirter ?) I then had to change from the purple secondary spring to the yellow.
The gears are killing this car and i'm going to change them with in the next 2 weeks. Any suggestions ? I was thinking 355 or 373 ?
I have 72 primaries and 76 secondaries and the plugs look great. I'm also working with the B&M governor shift kit. 1st is at 6200 ( i want 5800 and 2nd is at 4300 ( i want 6000).
Originally posted by MIKE 1985 ok. i started testing WOT launches to 60 MPH. The car was very sluggish with the 37 squirter, i put the 31 back in and it improved greatly. I'll order a tube type 35 and try that. ( does it hurt to use the hollow screw with the smaller than 37 squirter ?) I then had to change from the purple secondary spring to the yellow.
The gears are killing this car and i'm going to change them with in the next 2 weeks. Any suggestions ? I was thinking 355 or 373 ?
I have 72 primaries and 76 secondaries and the plugs look great. I'm also working with the B&M governor shift kit. 1st is at 6200 ( i want 5800 and 2nd is at 4300 ( i want 6000).
I'd definately go with the 3.73's. The 700R-4 has more than enough gear reduction in overdrive to compensate. Your cam is going to need the extra RPM at cruise.
Before I switched to the 5 speed I had a 700R-4 with 3.73's in my car. Very nice combo.
Hollow screw with the smaller shooters not a problem.
alright i have worked on this thing and i'm not making any progress.
i have 68-72 jetting and the plugs are golden brown with either steady highway driving or full throttle passes. I have the hollow screw and the #37 tube type squirter, blue cam in the #2 position. I have the crane adj adv, i've got a curve that reads mechanical 14 intial and 36 total and with vac i have 15 deg of advance with the adjuster set to full block off. But what concernes me is i have the vac pulled on the dist and pinched off, so the car is EASILY starting at 29 deg initial timing ? Plugs show no sign of detonation.
I still have the stumble when slightly accelerating.
I was occasionally ( not everytime) getting a pop through the car when launching from a dead stop.
I read the holley info and tried 8.5 and 6.5 power valves, the 8.5 is a little better, but doesn't cure the problem. I played with acc pump adjustment, 1/2 turn preload works the best.
With vac gauge hooked up i have 12" at idle in P and 8-9" in gear. while cruising at a steady speed on level ground i have 16" of vac.
Then i changed the blue cam pos to the #1 position and it's seems much ,ore responsive off idle, i tried to test, but with the road just slightly wet the car blew the tires off.
One more question, have you ever run a non lockup converter on a 700r-4 ? I'm thinking of purchasing a 10" GER
Originally posted by MIKE 1985 alright i have worked on this thing and i'm not making any progress.
i have 68-72 jetting and the plugs are golden brown with either steady highway driving or full throttle passes. I have the hollow screw and the #37 tube type squirter, blue cam in the #2 position. I have the crane adj adv, i've got a curve that reads mechanical 14 intial and 36 total and with vac i have 15 deg of advance with the adjuster set to full block off. But what concernes me is i have the vac pulled on the dist and pinched off, so the car is EASILY starting at 29 deg initial timing ? Plugs show no sign of detonation.
I still have the stumble when slightly accelerating.
I was occasionally ( not everytime) getting a pop through the car when launching from a dead stop.
I read the holley info and tried 8.5 and 6.5 power valves, the 8.5 is a little better, but doesn't cure the problem. I played with acc pump adjustment, 1/2 turn preload works the best.
With vac gauge hooked up i have 12" at idle in P and 8-9" in gear. while cruising at a steady speed on level ground i have 16" of vac.
Then i changed the blue cam pos to the #1 position and it's seems much ,ore responsive off idle, i tried to test, but with the road just slightly wet the car blew the tires off.
One more question, have you ever run a non lockup converter on a 700r-4 ? I'm thinking of purchasing a 10" GER
Ok...you've got me confused now. Previously you stated that you had: Quote "I have 72 primaries and 76 secondaries and the plugs look great. "
Now you're saying that you have 68 - 72 jets???? Is that 68 Primaries and 72 Secondaries...or am I misunderstanding? That's a huge jump...and 72 Secondaries are far too small to supply enough fuel to that engine.
Please clarify. Transition circuit is controlled by combination of main and idle settings. Too small of a Primary jet will affect transition.
I really do not think you will solve this problem until you have the 3.73's installed.... your cam and gear combination are just too far apart.
One thing to check though. How much of the transition slot is un covered by the throttle butterfly at idle? Should be no more than .040". If too much of the transition slot is uncovered, decrease the Primary idle screw setting and increase Secondary idle stop ( Carb has to be removed to get at setscrew on Secondary side ). Yes...the Secondary side does have an idle circuit. It is preset and the mixture is not adjustable ( Unless you have 4 corner idle as on some HP and Competition series ) but it is there to balance out the Primary butterfly adjustment.
>I have the crane adj adv, i've got a curve that reads mechanical 14 initial and 36 total and with vac i have 15 deg of advance with the adjuster set to full block off. But what concernes me is i have the vac pulled on the dist and pinched off, so the car is EASILY starting at 29 deg initial timing <
I don't understand what you're saying here. When you start the car.. the engine sees only ths static advance that is dialed in. IE: 14 initial. Mehanical advance has not kicked in and you would have 0 deg vacuum advance ( or very close too it ) as the starter motor does not crank the engine over fast enough to create any significant vacuum.
The car is running great now, thanks to a friend of mine helping me out. We just worked off the total mechanical and ran the car then adjusted the carb and timing according to the plugs. So the final is 30 deg total on the balancer ( this produces a 0-60 of 5.25 on the g-tech) and to get the part throttle stumble out i had to go to 76 primary jets and 76 secondary with the long yellow spring, the car runs perfectly now. Increasing the primary jets 6 sizes have the plugs golden brown and the stumble is gone, i was also able to go back to the #31 squirter and the blue cam
the car also now has a turbo 350 and a 10" converter. I'm still looking for a Dana 44 with a 3.45 gear, unfortunatly their costly and hard to come by.
i still question if there's just not something right with this carb, but it runs great, so i'll leave it alone. I plan to test this weekend with the timer to get the best set up and then with the spray. Once dialed in i'll head to the track.
Just wanted to update you, I ordered a new front metering plate and the car is much better.
The current set up is #31 tube type squirter blue cam #2 pos., 74 primary jets, 70 and 72 rear ( the split evens out the plug color. And a stock secondary spring.
With the 3.08 gear and the 2800 stall the G-tech reads 0-60 at 4.87.
I just finished up the nitrous and will be headed to the track within 2 weeks, i'll post results.
It's taken me longer than expected to get it tuned correctly, but it's finally turning out good.
Just wanted to update you, I ordered a new front metering plate and the car is much better.
The current set up is #31 tube type squirter blue cam #2 pos., 74 primary jets, 70 and 72 rear ( the split evens out the plug color. And a stock secondary spring.
With the 3.08 gear and the 2800 stall the G-tech reads 0-60 at 4.87.
I just finished up the nitrous and will be headed to the track within 2 weeks, i'll post results.
It's taken me longer than expected to get it tuned correctly, but it's finally turning out good.
the part throttle stumble was completly gone by switching to the new metering plate., even with a 70 primary jet. I had to go to 74 to get the plug coloring correct.
Originally posted by MIKE 1985 i finally made it out with the 3.08 gear. On motor the car went 12.76 @ 106.91 with 1.85 60' it's going through the traps at 4500 RPM.
i didn't spray it.
Wow...that's pretty impressive. What does the car weigh?
Now you've got me going...I've never run my car at the strip, but my motor combo is pretty close to yours. I was thinking that I should be in the high twelves with MPH around 105.
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