1973 Vega project Rerun

Tell everyone about the progress of your project! Please respect people's threads.

Moderator: Moderators

Re: 1973 Vega project Rerun

Postby avewhtboy » Fri Feb 26, 2016 11:50 am

6D9 wrote:Dyno results x2


I forgot the print outs, he's supposed to email them to me.

Made 3 pulls, they were all within 2hp at 200hp and 200 ft/lbs of torque, pathetic.

We didn't put the oxygen sensor in because I have a gauge on the dash which showed it lean when
throttle goes wide open then goes real rich and starts puffing black smoke out.

I am trying to tune that out of the carburetor. I should have run the demon carb but I have been
taking parts out of it to test in the quick fuel carb so it was in pieces.

Needless to say I am disappointed, but it's good to know what I am starting with, lots of room for improvement.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia


Re: 1973 Vega project Rerun

Postby zeke » Fri Feb 26, 2016 12:19 pm

What are you shooting for?

avewhtboy wrote:Thanks Zeke nothing near what your ride is looking like but its a driver so I am happy.


At least you're enjoying driving the car, I need to step up the pace and quit messing with extras. :bang:
User avatar
zeke
 
Posts: 2219
Joined: Fri Jul 21, 2006 3:27 am
Location: Southern Ontario, Canada

1979 Chevrolet Monza 2+2

Re: 1973 Vega project Rerun

Postby 6D9 » Fri Feb 26, 2016 12:30 pm

avewhtboy wrote:
6D9 wrote:Dyno results x2


I forgot the print outs, he's supposed to email them to me.

Made 3 pulls, they were all within 2hp at 200hp and 200 ft/lbs of torque, pathetic.

We didn't put the oxygen sensor in because I have a gauge on the dash which showed it lean when
throttle goes wide open then goes real rich and starts puffing black smoke out.

I am trying to tune that out of the carburetor. I should have run the demon carb but I have been
taking parts out of it to test in the quick fuel carb so it was in pieces.

Needless to say I am disappointed, but it's good to know what I am starting with, lots of room for improvement.


You will get it figured out im sure. If its pig rich and belching black smoke im sure thats killing at ton of power.
72 Vega GT...406 sbc..TH700R4...3.42 gear...235/60/15 MT DR's....11.54 at 118.6..Dad's car
72 Vega GT...4cyl..4 speed..all stock
6D9
 
Posts: 184
Joined: Tue Sep 30, 2014 12:48 am

Re: 1973 Vega project Rerun

Postby bugdewde » Fri Feb 26, 2016 12:33 pm

It wouldn't matter if it put out 145 HP. .. .. .. .. side pipes rock! Love it.
Dwight

'73 Vega GT Hatchback, mostly stock....
'72 Vega GT Kammback, 215 V8
'73 Vega Wagon - Currently in Limbo....
My rides: http://www.cardomain.com/id/bugdewde
User avatar
bugdewde
 
Posts: 2063
Joined: Mon Jun 26, 2006 7:08 pm
Location: East Tennessee

1972 Chevrolet Vega Kammback GT

Re: 1973 Vega project Rerun

Postby avewhtboy » Fri Feb 26, 2016 2:21 pm

zeke wrote:What are you shooting for?

avewhtboy wrote:Thanks Zeke nothing near what your ride is looking like but its a driver so I am happy.


At least you're enjoying driving the car, I need to step up the pace and quit messing with extras. :bang:



I don't really have a target since I really don't know anything about the motor except from deciphering the numbers on the block
and heads. It appears to be a standard two bolt main 350 with smog heads. No telling what it came from. They put a high rise
intake and a huge carb to make it look fast I guess. It was idling so high when I bought it couldn't really tell if there was any
sort of performance cam in it. Now it idles fine at 750 rpm with no lope at all so I suspect it's bone stock, performance goals
are minimal. For now I would settle for getting it running correctly.

I have a 400 short block which most likely will make it in the car, performance goals on that motor TBD.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby avewhtboy » Fri Feb 26, 2016 3:03 pm

[/quote]

You will get it figured out im sure. If its pig rich and belching black smoke im sure thats killing at ton of power.[/quote]


I suck at tuning carburetors but I am kind of enjoying the process. My background is with latop and table not jets and power valves.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby avewhtboy » Fri Feb 26, 2016 3:05 pm

bugdewde wrote:It wouldn't matter if it put out 145 HP. .. .. .. .. side pipes rock! Love it.


Ha that's almost true but with 200hp and sidepipes I look, sound and feel like a poser. Good thing these
cars are light weight.

I have to admit it did sound really good except for the spitting from being lean then rich.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby 77nighthawk » Fri Feb 26, 2016 8:24 pm

What carb do you have? I'm guessing a holley, or holley based carb? Vacuum secondaries, or double pumper? CFM? If your going lean upon acceleration, then going rich at high rpm's, I would try lowering the jet sizes, and increasing the size of accelerator pump discharge nozzles.(make sure accelerator pump is working first) Brad
If it don't scare me, I don't want it.

the growing collection
1977 nighthawk
1979 Monza hb
User avatar
77nighthawk
 
Posts: 243
Joined: Thu Feb 24, 2011 1:26 am
Location: Kansas

Re: 1973 Vega project Rerun

Postby avewhtboy » Fri Feb 26, 2016 10:27 pm

77nighthawk wrote:What carb do you have? I'm guessing a holley, or holley based carb? Vacuum secondaries, or double pumper? CFM? If your going lean upon acceleration, then going rich at high rpm's, I would try lowering the jet sizes, and increasing the size of accelerator pump discharge nozzles.(make sure accelerator pump is working first) Brad



Hey Brad it's a quick fuel 750 with vacuum secondaries. I think you are correct on both counts. I purchased a set of accelerator cams and larger accelerator pump and larger squirter nozzles for the off idle stumble but its still there. I am pretty sure the accelerator pump arm needs to be bent, there is some delay between the butterfly opening and the accelerator pump squirt that needs to be corrected. And for sure it needs smaller jets on the primaries as well.

Hopefully I can tune it out and not have to buy another carburetor.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby 77nighthawk » Sat Feb 27, 2016 1:25 am

Have you zero'd the gap between the 2 accelerator pump levers? If not, loosen the nut on top until all of the play is gone. Brad

20160226_235132r25.jpg
20160226_235132r25.jpg (181.02 KiB) Viewed 166 times
If it don't scare me, I don't want it.

the growing collection
1977 nighthawk
1979 Monza hb
User avatar
77nighthawk
 
Posts: 243
Joined: Thu Feb 24, 2011 1:26 am
Location: Kansas

Re: 1973 Vega project Rerun

Postby avewhtboy » Sat Feb 27, 2016 11:44 am

77nighthawk wrote:Have you zero'd the gap between the 2 accelerator pump levers? If not, loosen the nut on top until all of the play is gone. Brad

20160226_235132r25.jpg



I have been working on that. I can see right now that the arm on that carburetor you posted is much stronger than the thin
piece of metal on the quick fuel carb.

Thats where the majority of the problem is I hope. I may have to steal more parts from that other carb.
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby avewhtboy » Mon Feb 29, 2016 11:46 am

Armed with that picture of the accelerator armand lots of google searches, I continued working on my carb tuning over the weekend.
I have it running pretty good now after replacing the poorly made accelerator pump arm that was on the quick fuel carb with the beefier one from the Demon.
That and swapping out to the "brown" accelerator pump cam to take advantage of the 50cc accelerator pump I installed helped quite a bit.

I also bought a jet kit from Summit and ended up replacing the mains with 74 up from 68 that were in it. This fattened up the engine
wear it feels must stronger and responsive. A little more fine tuning and some work on my fuel system to get the pressure stabilized and it
will be ready for another dyno run.

I also installed a Zexel Torsen posi from a fourth gen Camaro. That went in relatively painless and now the axle is really pulling both wheels. WOOT!

Image

Image
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby avewhtboy » Mon Feb 29, 2016 8:37 pm

Dyno results


Image
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

Re: 1973 Vega project Rerun

Postby 6D9 » Tue Mar 01, 2016 1:34 am

With a stock set of smog iron heads the numbers seem about right. Not bad at all.
72 Vega GT...406 sbc..TH700R4...3.42 gear...235/60/15 MT DR's....11.54 at 118.6..Dad's car
72 Vega GT...4cyl..4 speed..all stock
6D9
 
Posts: 184
Joined: Tue Sep 30, 2014 12:48 am

Re: 1973 Vega project Rerun

Postby avewhtboy » Wed Mar 02, 2016 8:58 am

6D9 wrote:With a stock set of smog iron heads the numbers seem about right. Not bad at all.


Yes I suspect this is a bone stock mid 80's motor. It was running extremely lean, which is why I believe power levels were down considerably on the top
end.

I bought a jet kit and have jets 6 sizes bigger currently and it's running much better. I made need to go bigger still, the work continues...

I have signed up for an SCCA autocross event this coming Sunday, March 6th so I need to get it running well before then.

Also, I borrowed a hand winch( aka come a long) to the tow hook on the front of my truck and wrapped the other end around the lower front
control arm and was able to pull my front wheel forward about half of an inch. Took it out and drove it and the scrubbing when turning was
almost all gone. I am going to see if I can get another quarter inch of movement and then maybe I can remove some turn stops to correct the
dump truck turns I have to make now. Though with the new posi and better performing carburetor its much easier to rear steer the car now !
User avatar
avewhtboy
 
Posts: 550
Joined: Thu Sep 24, 2009 11:06 am
Location: Stone Mountain Georgia

PreviousNext

Return to Project Journals

Who is online

Users browsing this forum: No registered users and 1 guest

     
cron