|
|
![]() |
#1 |
Junior Member
Join Date: Jul 2007
Location: Indianapolis,IN
Posts: 63
Likes: 0
Liked 0 Times in 0 Posts
|
![]()
I put a new scoop on the roadster over the winter and went racing this weekend and had a lot of problems with the air pulling the fuel out of the vent tubes on the carberatour. The carberatour sits about 2 inches from the top of the new scoop and the front vent tube sits about 3/4 of an inch from the top and the rear vent tube sits about 1/4 of and inch from the top. the first run the car surged in and out from about half track on and only went 9.67 @ 157mph in super gas trim. Then i made some changes and no improvement. I run a under the carb dedenbear stop and took it off and that gave the carb about 1 inch to 1 1/2 inches of more clearance. the first pass ALL OUT it went 7.84 @ 167 then i used a piece of rubber hose and put it on the vent tubes with a small notch in the middle and the car went 7.77 @ 171.40. Im trying to figure a way to use my under the carb stop for super gas without having to cut the new scoop out and installing another one. Any ideas would be greatly appreciated.
__________________
Ryan Dillman 316K S/G |
![]() |
![]() |
![]() |
#2 |
Senior Member
Join Date: Sep 2002
Posts: 502
Likes: 5
Liked 10 Times in 7 Posts
|
![]()
is the back of the scoop open in any way ? seems to me there would have to be a inlet and a outlet for it to draft. the hood/scoop could actually be dropping down on the run and closing off the vents....... if so, make a stand and install it in the center stud of the carb. (air cleaner stud )
And are you useing a tray to seal carb to the hood/scoop..... this is a must too ! hope this helps ... let us know Rick
__________________
Rick Bailey 3439 SC Last edited by Rick Bailey; 04-23-2012 at 12:21 PM. |
![]() |
![]() |
![]() |
#3 |
Senior Member
Join Date: Apr 2006
Location: Wadsworth, Ohio
Posts: 510
Likes: 0
Liked 0 Times in 0 Posts
|
![]()
Ryan, I have seen people put 90* spark plug boots over the vent tubes to fix that problem.
BB |
![]() |
![]() |
![]() |
#4 |
VIP Member
Join Date: Feb 2006
Location: Dela-where?
Posts: 2,193
Likes: 1,160
Liked 1,877 Times in 577 Posts
|
![]()
X 2, i think it would clear without cutting, worth a shot, and as for your other post, under carb t-stop the only way to go, IMO
__________________
KEITH MAYERS 2-1/2 X somebody Still many X nobody |
![]() |
![]() |
![]() |
#5 |
Senior Member
Join Date: Jul 2007
Posts: 557
Likes: 6
Liked 13 Times in 3 Posts
|
![]()
If you are running this set up without any kind of pan to seal it off, I have seen where the air going around the carb into the engine bay will pull fuel out of the carb. Had a friend with a simular problem years ago, I had him put a scoop plug in and he picked up 6 mph. The next week he had an air pan installed.
Chuck |
![]() |
![]() |
![]() |
#6 |
VIP Member
Join Date: Oct 2002
Location: Commerce, Mi
Posts: 1,387
Likes: 1
Liked 4 Times in 2 Posts
|
![]()
Ryan..... I think the dimension is 6 or 7 inches from the throttle plates....but they all act a little different.....mine is very close and seems to work fine sealed or not....but put something on the vent tubes....I have a hose on ours....and a plate stop is a better choice....7.77 seemed stout but the speed seemed slow....something is not as happy as it could be...probably got to try a few things....use tape and test a little....unfortunately you probably want to race next weekend....better test on Thursday and have a backup plan.....can you run it without the scoop for the weekend....just a suggestion....
Rock.... |
![]() |
![]() |
![]() |
#7 |
VIP Member
Join Date: Jan 2003
Location: Allentown,PA
Posts: 2,476
Likes: 889
Liked 882 Times in 236 Posts
|
![]()
Had a similar problem several years ago.
Venting the bowls outside the scoop had a result similar to what you saw. A friend who is involved with Pro Stock carbs suggested a couple of 1" holes in the scoop tray,adding or removing plugs untill the pressure sweet spot was found. 2 1" holes made a huge difference, but eventually raising the scoop to allow 4" over the carb was far more effective.
__________________
Tom Goldman 1500 SG , 1506 STK |
![]() |
![]() |
![]() |
#8 |
Junior Member
Join Date: Jul 2007
Location: Indianapolis,IN
Posts: 63
Likes: 0
Liked 0 Times in 0 Posts
|
![]()
Rick Greg risk is coming tonight to measure to make a pan for the scoop but he doesn't seem to think it will cure the problem.
__________________
Ryan Dillman 316K S/G |
![]() |
![]() |
![]() |
|
|