The is an update on my 1982 Empress Class A RV with a Chevrolet 454 CID and Edelbrock 750cfm carburetor that received a "partial" Groove.
After the vehicle sits for awhile I'll turn the engine over and it will try to start, one press of the pedal and turn the key it starts right up everytime.
Took the RV for a ride, 160 miles round trip. I was also towing a 6' X 8' trailer loaded with sound gear.
With the performance I was getting I was sure that there would be an improvement in the MPG but that did not happen ( approximately 6mpg ). What I did get was an engine that idles smoother, responds much quicker and overall feels like a better running machine.
Dissappointed? Not in the least, this is a 1982 Class A RV made the old fashioned way but runs like a much newer model.
My brother is making me an adapter plate to specifically fit this carb so I can enlarge the groove. It will be interesting to see what the results for that will be.
Karl Fortner
GadgetmanTacoma (Youtube)
Original post below....
GadgetmanTacoma
Karl Fortner
Tacoma, Wa.
So, here is what I have,
1982 Empress Class A RV
Chevrolet 454 CID gasoline engine.
Edelbrock 1411 750cfm carburator
So here was my dilemma, the amount of meat from the apex of the butterfly to the bottom edge of the carb base was about 1/16".
I ordered some parts to do a full groove on this but had to put the rig back together to get it fueled up (40 cent discount due to expire).
Then I thought about it and decided to use the small bit to put a partial groove where it could be applied.
Basically it was a full groove from the pivot point of the butterfly with a full cut as far as there was meat to do so. As the meat diminished so did the cut, around the apex of the butterfly was just a minimal cut in that 1/16" space.
Got it all back together with some surprises. Normally, I have to turn over the engine to get fuel to the carb, then pump it twice to get it to fire.
Not this time, cranked it a little extra to fill the floatbowl and it fired up without the extra step. Noticed the engine running smoother, rpms were higher
(had to set the idle down by 400rpm), response to the gas pedal was quicker and sounded better as well.
Took it for fuel and had to lay off the pedal a little, was able to go up a slight incline at 30mph with just a touch more of the pedal.
Each time I had to start the engine, it fired up without touching the pedal.
I will be taking it for a long run in two weeks so I will be ableto get some mpg data at that time.
So... a full groove is a good thing, almost a full groove ain't a bad thing.
I'm liking it!!
Groove on,
Karl
Some additional data
Exhaust header temperature 294F
Exhaust pipe @ muffler input 200F
Exhaust out the tailpipe 108F
Radiator temp 180F
Transcooler 135F
Oilcooler 168F
