block off exhaust crossover on B manifold? - Moparts Forums

Register Log In Moparts Forums Moparts Question and Answer block off exhaust crossover on B manifold?

Print Thread

Page 1 of 2

1

2

block off exhaust crossover on B manifold? #104250 08/13/08 12:45 PM 08/13/08 12:45 PM
Joined: Jun 2005 Posts: 2,507 Royersford, PA B bschargerse OP master
bschargerse OP master B Joined: Jun 2005 Posts: 2,507 Royersford, PA	I have a '66 Newport with a 383 and a 2bbl carb. When the engine is hot I can smell gas after it's been sitting for a couple of minutes, it seems the carb is hot and th gas is being boiled out. I have to floor it to restart it. I'm installing a '68-69 383 4bbl cast manifold and either a Carter AVS or a Holley 600, both of which I have laying around. (I also have an Edelbrock 750) I ordered a 1/2" phenolic carb spacer/gasket to act as a heat block. Should I block off the exhaust crossover on the 4bbl manifold, or just let the phenolic spacer do it's job? I'm worried that I may have the same problem with the 4bbl carb. Is there a valley pan available with a blocked crossover or will I have to fabricate something? Thanks guys (and gals) Brian - 1971 Dodge Challenger "The Dodge, which was practically stock, just left the Mustang like you wouldn't believe."

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104251 08/13/08 12:50 PM 08/13/08 12:50 PM
Joined: Jan 2003 Posts: 32,984 Grand Prairie,Texas stumpy I Win
stumpy I Win Joined: Jan 2003 Posts: 32,984 Grand Prairie,Texas	Felpro sells a valley pan with the block off. I think the # is 1214. But you might want to double check that.

Re: block off exhaust crossover on B manifold? [Re: stumpy] #104252 08/13/08 02:54 PM 08/13/08 02:54 PM
Joined: Jan 2007 Posts: 780 Woodinville, WA Viol8r super stock
Viol8r super stock Joined: Jan 2007 Posts: 780 Woodinville, WA	#1215

Re: block off exhaust crossover on B manifold? [Re: Viol8r] #104253 08/13/08 03:00 PM 08/13/08 03:00 PM
Joined: Sep 2004 Posts: 6,906 IL, Aurora A ademon master
ademon master A Joined: Sep 2004 Posts: 6,906 IL, Aurora	If your going to drive in cold weather i would leave it open at least one side open,

Re: block off exhaust crossover on B manifold? [Re: ademon] #104254 08/13/08 03:12 PM 08/13/08 03:12 PM
Joined: Jun 2005 Posts: 2,507 Royersford, PA B bschargerse OP master
bschargerse OP master B Joined: Jun 2005 Posts: 2,507 Royersford, PA	The car will be parked in the winter months, if the weather is mild I might take it out. The carb will have an electric choke. Unless I go with the AVS, in which case I'll have to leave the passage open for the choke coil. Brian - 1971 Dodge Challenger "The Dodge, which was practically stock, just left the Mustang like you wouldn't believe."

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104255 08/14/08 06:15 AM 08/14/08 06:15 AM
Joined: Jul 2008 Posts: 30,490 Florida STAYcation dOc … The village idiot's idiot
dOc … The village idiot's idiot Joined: Jul 2008 Posts: 30,490 Florida STAYcation	If you block the crossover ... your mpg will suffer BIG TIME. The phenolic spacer for the four barrel should work fine. But if you are keeping the 2 barrel on for awhile ...make up a plywood spacer. It works just as well as phenolic.

Re: block off exhaust crossover on B manifold? [Re: dOc …] #104256 08/14/08 07:45 AM 08/14/08 07:45 AM
Joined: Jan 2003 Posts: 3,575 The Netherlands BigBlockMopar master
BigBlockMopar master Joined: Jan 2003 Posts: 3,575 The Netherlands	Block it. BigBlockMopar.com

Re: block off exhaust crossover on B manifold? [Re: dOc …] #104257 08/14/08 11:07 AM 08/14/08 11:07 AM
Joined: Jul 2006 Posts: 4,319 Puyallup, WA S StealthWedge67 master
StealthWedge67 master S Joined: Jul 2006 Posts: 4,319 Puyallup, WA	Quote: If you block the crossover ... your mpg will suffer BIG TIME. Explain how you figure this? a cooler charge will be more effective across the board. I don't see how blocking this will effect gas mileage LemonWedge - Street heavy / Strip ready - 11.07 @ 120

Re: block off exhaust crossover on B manifold? [Re: StealthWedge67] #104258 08/14/08 03:09 PM 08/14/08 03:09 PM
Joined: Jun 2005 Posts: 2,507 Royersford, PA B bschargerse OP master
bschargerse OP master B Joined: Jun 2005 Posts: 2,507 Royersford, PA	I was thinking the same thing, isn't cooler air more dense, allowing for better atomization? Brian - 1971 Dodge Challenger "The Dodge, which was practically stock, just left the Mustang like you wouldn't believe."

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104259 08/14/08 03:19 PM 08/14/08 03:19 PM
Joined: Jan 2003 Posts: 75,094 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,094 A Banana Republic near you.	Quote: I was thinking the same thing, isn't cooler air more dense, allowing for better atomization? times 3 ...

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104260 08/14/08 03:28 PM 08/14/08 03:28 PM
Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska R RapidRobert Circle Track
RapidRobert Circle Track R Joined: Nov 2003 Posts: 36,041 Lincoln Nebraska	Quote: The car will be parked in the winter months, especially with that info My vote is "block it" more heat improves atomization to a point which is real good on warmup but after that crossovers put out way too much heat which reduces density & fuel quality these days cant take the heat without boiling off. live every 24 hour block of time like it's your last day on earth

Re: block off exhaust crossover on B manifold? [Re: RapidRobert] #104261 08/14/08 06:51 PM 08/14/08 06:51 PM
Joined: Sep 2006 Posts: 277 Palmyra, NY 6 63stabamatic enthusiast
63stabamatic enthusiast 6 Joined: Sep 2006 Posts: 277 Palmyra, NY	If you don't need the heat to operate the automatic choke then block it. I couldn't get my stock AVS choke to open all the way with the crossover blocked, even with a new choke control. I took the block out, now I wish I would have just changed carbs, as it's much hotter!

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104262 08/14/08 06:58 PM 08/14/08 06:58 PM
Joined: Jun 2003 Posts: 21,503 It's a dry heat gtx6970 Too Many Posts
gtx6970 Too Many Posts Joined: Jun 2003 Posts: 21,503 It's a dry heat	Quote: Is there a valley pan available with a blocked crossover Yes.

Re: block off exhaust crossover on B manifold? [Re: gtx6970] #104263 08/14/08 08:18 PM 08/14/08 08:18 PM
Joined: Jun 2005 Posts: 2,507 Royersford, PA B bschargerse OP master
bschargerse OP master B Joined: Jun 2005 Posts: 2,507 Royersford, PA	Thanks to all who replied, I hope I can return the favor in the future! Brian - 1971 Dodge Challenger "The Dodge, which was practically stock, just left the Mustang like you wouldn't believe."

Re: block off exhaust crossover on B manifold? [Re: bschargerse] #104264 08/14/08 09:49 PM 08/14/08 09:49 PM
Joined: Jul 2008 Posts: 30,490 Florida STAYcation dOc … The village idiot's idiot
dOc … The village idiot's idiot Joined: Jul 2008 Posts: 30,490 Florida STAYcation	Quote: I was thinking the same thing, isn't cooler air more dense, allowing for better atomization? A warm/hot intake makes for better atomization. Why do you think Ma Mopar puts heat in the intake ? ... and with a blocked crossover ... the mixture has to be fatter to make it more "driveable". That is the purpose of the choke ...correct?

Re: block off exhaust crossover on B manifold? [Re: Viol8r] #104265 08/14/08 09:53 PM 08/14/08 09:53 PM
Joined: Feb 2003 Posts: 2,815 Sobieski Wi B bee1971 master
bee1971 master B Joined: Feb 2003 Posts: 2,815 Sobieski Wi	Quote: #1215 Felpro - Comes with the blocked heat crossover and 4 paper gaskets if needed #1214 - 383/400 #1215 - 440 1971 Dodge Charger Superbee 2011 Ram Sport 1500 Quad Cab Deep Water Blue Loaded Siberian Huskies

Re: block off exhaust crossover on B manifold? [Re: dOc …] #104266 08/14/08 11:49 PM 08/14/08 11:49 PM
Joined: Jan 2003 Posts: 17,862 albany ny 0 05dakota I Live Here
05dakota I Live Here 0 Joined: Jan 2003 Posts: 17,862 albany ny	for sub freezing weather and to help choke fumnction. Quote: Quote: I was thinking the same thing, isn't cooler air more dense, allowing for better atomization? A warm/hot intake makes for better atomization. Why do you think Ma Mopar puts heat in the intake ? ... and with a blocked crossover ... the mixture has to be fatter to make it more "driveable". That is the purpose of the choke ...correct?

Re: block off exhaust crossover on B manifold? [Re: 05dakota] #104267 08/15/08 12:02 AM 08/15/08 12:02 AM
Joined: Jul 2008 Posts: 30,490 Florida STAYcation dOc … The village idiot's idiot
dOc … The village idiot's idiot Joined: Jul 2008 Posts: 30,490 Florida STAYcation	You don't think that the A/F ratio goes rich on a cold-start ..... even when it is 70 degrees outside ?

Re: block off exhaust crossover on B manifold? [Re: 63stabamatic] #104268 08/15/08 07:22 AM 08/15/08 07:22 AM
Joined: Jan 2003 Posts: 75,094 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,094 A Banana Republic near you.	Quote: If you don't need the heat to operate the automatic choke then block it. I couldn't get my stock AVS choke to open all the way with the crossover blocked, even with a new choke control. I took the block out, now I wish I would have just changed carbs, as it's much hotter! or just installed the electric choke off an ebrock on the AVS ....

Re: block off exhaust crossover on B manifold? [Re: dOc …] #104269 08/15/08 07:25 AM 08/15/08 07:25 AM
Joined: Jan 2003 Posts: 75,094 A Banana Republic near you. JohnRR I Win
JohnRR I Win Joined: Jan 2003 Posts: 75,094 A Banana Republic near you.	Quote: You don't think that the A/F ratio goes rich on a cold-start ..... even when it is 70 degrees outside ? it does to a degree by function of the choke flap being closed . keep reaching

Page 1 of 2

1

2

Moderated by Al_Alguire, Hotwheelsjr, moparts, not_a_charger, RangerDan440, tboomer

Hop To

Powered by UBB.threads™ PHP Forum Software 7.7.1