Lars...Will this really increase mpg
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
Hrm. Well I'm willing to try this to see how it goes since I currently get <10mpg even with my 700R4 w/the 383. I have an Edelbrock 1903 Q-Jet, any links to what spacer I'd need? I have a 2" rise hood so I'm not worried about the height, I just don't know which to get.
Thanks
-Josh
Thanks
-Josh
i see jegs sells a 4 hole qjet 3/4"
350-8726 $35.99
Melting Slicks
Joined: May 2006
Posts: 3,438
Likes: 41
From: Raleigh NC
St. Jude Donor '13-'14
Bingo! velocity also helps the fuel stay suspended in the incoming air (atomized). My thoughts exactly. I went with a XR288 HR to pull up to my max efficient rpm and AFR 195 heads to give me good flow but keep my port velocity up. My VE is 100% between 4500 and 6000, and tripower to help fuel economy and still have the CFM needed to pull at the upper RPM's when needed. My manifold has 6 holes and I put 2 hole spacers on the 2 end carbs. My last tripower manifold was also a 6 hole design and I ran over 20 MPG with a built 327, 3.55 and ST-10. GM discovered this trick for more power and better efficiency in the 50"s and used it until 1969. The only reason they discontinued it was warrantee issues with the later vacumn secondary tripower setups, 1 minor vacumn leak, a bigger cam or any modification that changed your vacumn from stock configuration screwed them up. Back then a lot of guys that ran tripower sucessfully were converting them to mechanical linkages, IE mechanical secondaries. What Matt has done is basiclly 2 2bbls with individual ports for each barrel. He is running on a 2 bbl with 1 - 2 bbl dumper, mechanical secondaries.
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
i'll add what u find to my report.
or, get an 8th grade metal shop student to make a 4 hole plate of sheet metal
i've added popular spacers advertised to improve mpg to my report.
or, get an 8th grade metal shop student to make a 4 hole plate of sheet metal
i've added popular spacers advertised to improve mpg to my report.
Last edited by Matt Gruber; Nov 22, 2007 at 07:23 AM.
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
matt, how would you divide the suction on a carb that has a booster hose and EGR hose on it? would one go to each side of the engine??
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
Looking in a '03 PAW cat
FELPRO 1/4" insulator gasket FEP-1905 $7.49
FITS SPREADBORE! Even YOU can afford to SAVE GAS 
adding more to my report. no need to hire a 13yr. old (unless u insist on metal)
.
andy
if u seal it 100% i'd run PB off one side, everything else off the other.
But, all u have to do is leave ~1/4" of a passage connected and everything will hook up normally
FELPRO 1/4" insulator gasket FEP-1905 $7.49
FITS SPREADBORE! Even YOU can afford to SAVE GAS adding more to my report. no need to hire a 13yr. old
(unless u insist on metal).
andy
if u seal it 100% i'd run PB off one side, everything else off the other.
But, all u have to do is leave ~1/4" of a passage connected and everything will hook up normally
Last edited by Matt Gruber; Nov 22, 2007 at 11:36 AM.
Pro
Joined: Oct 2007
Posts: 587
Likes: 0
From: Overland Park Kansas
The car gets absolutely miserable MPG (<10). I know next to nothing about tuning carbs (just got this car not long ago, first carb car I've ever owned), and I don't know of anywhere around here that tunes them. I ordered that 350-8726 off Jegs, hopefully it helps some
Btw there is a 3/4" or 1" 2 hole spacer on there now, should I hope to see any real improvement with the new one?
Last edited by neuroclast; Nov 22, 2007 at 02:55 PM.
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Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
look closely at that 2 hole spacer. if it matches the bottom of the qjet, it could be ok. The center looks too skinny on the ones i've seen, so i'm not optimistic.
i haven't seen the qjet bottom, so i have no idea if your old 2 hole can work.
That cam u have will need all the help it can get, including epoxy! How many cc's are the trick flow intake ports?.
.
MMMMMMMmmmmm........i smell turkey.....
i haven't seen the qjet bottom, so i have no idea if your old 2 hole can work.
That cam u have will need all the help it can get, including epoxy! How many cc's are the trick flow intake ports?.
.
MMMMMMMmmmmm........i smell turkey.....
Burning Brakes
Joined: Sep 2005
Posts: 832
Likes: 0
From: Sarasota Florida
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
looking at pic #2, once u put a 4 hole plate on it, there appears to be only 1 place of ~1/4" at each butterfly for air to sneak across. Just enough for vacuum acc. like PB etc. That is excellent, must seal up 70-90%.
I would NOT epoxy the last little bit, not at this time, on a qjet.
I would NOT epoxy the last little bit, not at this time, on a qjet.
Pro
Joined: Oct 2007
Posts: 587
Likes: 0
From: Overland Park Kansas
looking at pic #2, once u put a 4 hole plate on it, there appears to be only 1 place of ~1/4" at each butterfly for air to sneak across. Just enough for vacuum acc. like PB etc. That is excellent, must seal up 70-90%.
I would NOT epoxy the last little bit, not at this time, on a qjet.
I would NOT epoxy the last little bit, not at this time, on a qjet.
Melting Slicks
Joined: Sep 2004
Posts: 2,412
Likes: 3
Race Director
Joined: Oct 2000
Posts: 15,110
Likes: 79
From: central FL, near the beach.
will work w/blower, if carb is pressurized.
.
def
be sure to get a qjet tuning book; even if the mod helps, it will need to be leaned out(better atomization needs less gas)
.
report updated again
http://community.webtv.net/MATTGRU/carb
.
def
be sure to get a qjet tuning book; even if the mod helps, it will need to be leaned out(better atomization needs less gas)
.
report updated again
http://community.webtv.net/MATTGRU/carb
