Spacer Rama - The dual plane spacer test
#1
Spacer Rama - The dual plane spacer test
I needed a heat insulator for my carb to stop fuel bubbling and bowl overflow on the hot Florida days. So, the question became, which one. Four hole? Open? Divider style? After a bit of reading, it turns out that opinions and experiences vary. This just means one thing. Spacer test!
Here are the 3 test spacers. Predictions welcome!
Here are the 3 test spacers. Predictions welcome!
#4
On The Tree
open
The open gets my bid too. Seen it on our dyno. You will see a gain in mph. We have milled the divider out of rpm intakes when a spacer won't fit under the hood. If the carb is too small it allows the cylinders to pull from both sides of the carb.Usually a dual-plane intake can use a bigger carb.
Aleck
Aleck
#10
On The Tree
This spacer has shown 8 rwhp on some cars on our dyno. I'm going to try it on our car this week. Of course it would need trimming to fit over the plenum divider on the RPM manifold.
Aleck
Aleck
#13
I put the dual plane divider spacer in today for driving around until I could do the test because I need some insulation for the carb. As you may have suspected, there was no seat of the pants difference, but I did notice the my WOT AFR leaned out about .3. I thought this was interesting.
#14
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Whats the theory behind how those HVH tapered spacers work ? is it the shaping of the airflow as it makes the 90deg turn under the carb or just gettting the carb higher off the manifold floor ?
#16
8 Second Club
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I put the dual plane divider spacer in today for driving around until I could do the test because I need some insulation for the carb. As you may have suspected, there was no seat of the pants difference, but I did notice the my WOT AFR leaned out about .3. I thought this was interesting.
#17
On The Tree
The spacer gives more plenum volume, and like others have said less carb signal, so you need more jet. Same reason a Victor needs more jet and pump shot than an RPM.
I wish I had an RPM to do back/back dyno.
Aleck
I wish I had an RPM to do back/back dyno.
Aleck
#19
http://4secondsflat.com/carburetor_spacers.htm
I am also interested in what spacer would give best gains. I have only 3/4 on an inch under my hood and came across this warhead cone spacer and may have to give it a go see if I see any gains.
I am also interested in what spacer would give best gains. I have only 3/4 on an inch under my hood and came across this warhead cone spacer and may have to give it a go see if I see any gains.