Re: '79 304 Edelbrock carb problems vs Holley carbs?
Don't foerget the Mazda Wankel rotary:
http://www.rotaryengineillustrated.com/animations.php "Dave Milne" <whoneeds@toknow.com> wrote in message news:SooMg.16060$r61.2875@text.news.blueyonder.co. uk... > Alfa Romeo have been using "twin spark" engines as they call them, since > the > 60's (and still use them today). > I had the 3.0 v6 hemi which was conventional - they only did them on the 4 > cylinder models which ran up to 2 litres. > > Dave Milne, Scotland > > "Lon" <lon.stowell@comcast.net> wrote in message > news:a5CdnXQWXs0PTp3YnZ2dnUVZ_tSdnZ2d@comcast.com. .. > >> Dual points worked, dual plugs worked even better but dunno anyone using >> them since the old straight 8 Nash engines of the late 30's. > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
A 1934 Nash with dual plugs, the other eight are on the carburetor
side: http://www.vapinc.com/1934nashrestor...2/PIC00004.jpg And of course Top Fuel use two: http://www.----------.com/temp/DickLaHaie.jpg God Bless America, Bill O|||||||O mailto:-------------------- Dave Milne wrote: > > Alfa Romeo have been using "twin spark" engines as they call them, since the > 60's (and still use them today). > I had the 3.0 v6 hemi which was conventional - they only did them on the 4 > cylinder models which ran up to 2 litres. > > Dave Milne, Scotland |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
A 1934 Nash with dual plugs, the other eight are on the carburetor
side: http://www.vapinc.com/1934nashrestor...2/PIC00004.jpg And of course Top Fuel use two: http://www.----------.com/temp/DickLaHaie.jpg God Bless America, Bill O|||||||O mailto:-------------------- Dave Milne wrote: > > Alfa Romeo have been using "twin spark" engines as they call them, since the > 60's (and still use them today). > I had the 3.0 v6 hemi which was conventional - they only did them on the 4 > cylinder models which ran up to 2 litres. > > Dave Milne, Scotland |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
A 1934 Nash with dual plugs, the other eight are on the carburetor
side: http://www.vapinc.com/1934nashrestor...2/PIC00004.jpg And of course Top Fuel use two: http://www.----------.com/temp/DickLaHaie.jpg God Bless America, Bill O|||||||O mailto:-------------------- Dave Milne wrote: > > Alfa Romeo have been using "twin spark" engines as they call them, since the > 60's (and still use them today). > I had the 3.0 v6 hemi which was conventional - they only did them on the 4 > cylinder models which ran up to 2 litres. > > Dave Milne, Scotland |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Sounds like a good purchase - will order and wait 3 weeks for it to arrive
(!). Got it fitted at the weekend, relatively painlessly. Well, I mean that metaphorically actually, as I cut the hell out of my thumb as I was putting on the valley pan gasket with blood going everywhere and trying to keep it off the RTV. So now the nastier bits of the emissions control are disconnected (the EGR and the air injection stuff). As it is now not really an emssions controlled vehicle, I attached it to the non-timed part of the carb per the instructions, but that gave me 34 degrees BTDC, so plugged it into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser was playing up a bit, so I'll do the tuning next weekend, but even on the default settings, it is pulling way more strongly than it ever did before - can't be far off. Oh, Edelbrock's instructions in the 2131 manifold state that the Performer 1405 requires a Square bore to ------ bore adapter. Except that both carb and manifold are square bore already, and I hadn't ordered one. Doesn't seem to mention the need for it anywhere else - will drop them a line to check that it is a mistake on their part. Certainly seems to run fine without it. Dave Milne, Scotland "c" <c@me.org> wrote in message news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > yes, they are basically the same carb inside. I believe the jets and rods > interchange, but I'm not positive on that. I do know that the Edelbrock carb > is heavily based on the Carter design. If you understand basic carb > functioning, and what the rods and jets do for the mixture, it will be a > simple process to get it dialed in. If you ruin in to problems, I'm sure we > can get you going in the right direction. Also, there is a book available > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. I > had the book at one time, but loaned it out and never got it back. I do know > that the book is very thorough. > > Chris > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at the > > weekend. > > > > Quite looking forward to it - my carb experience has been mainly with > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > Dave Milne, Scotland > > '91 Grand Wagoneer, '99 TJ > > "c" <c@me.org> wrote in message > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > >> Dave, > >> > >> When the companies that make carb give them their initial settings from > > the > >> factory, they take all kinds of compromised in to consideration. They > > don't > >> know if the carb will be used on a large or small displacement engine, or > > if > >> it will be used in hot or cold climate, high altitude, etc. They also > > don't > >> know what other mods have been done to these engines. The baseline > > settings > >> they give these carbs will allow them to run on most of the applications > >> they will see, but they almost always require tuning to get them to be > >> optimal. My guess would be that this carb would still be a little rich, > > but > >> it is just a guess. I'm not saying it won't run, it will, and it will > >> probably be pretty damn close to right. > >> > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > mixture > >> based on engine vacuum. The rods are controlled by a piston and spring, > >> similar to many other carbs. When the engine vacuum is low, the metering > > rod > >> spring will start to overtake the vacuum pulling the piston down. The > >> rods > >> are tapered, and when they move up in the bore they are in, a smaller > >> diameter of the rod will still be inside the main jet, effectively > >> increasing the total main jet area that fuel can pass thru. If the engine > >> runs too rich at high vacuum conditions, but is ok at low vacuum or wide > >> open throttle, then you simply change the metering rod to on the has a > >> larger diameter on the part of the rod that is in the jet at high vacuum > >> conditions. It really is a simple process, and normally will only require > > 1 > >> or 2 sets of rods to get the carb where you need it to be. > >> > >> Chris > >> > >> > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > manifold > >> > will require a metering or jet change on a stock 360 '91 Grand Wagoneer > > ? > >> > > >> > > >> > Dave Milne, Scotland > >> > '91 Grand Wagoneer, '99 TJ > >> > "c" <c@me.org> wrote in message > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > >> >> Without knowing what size carb, choke or no choke, and which manifold, > > it > >> > is > >> >> hard to tell you what the problem could be. What I can tell you is > >> >> that > >> >> Edelbrock and Holley carbs are both set up from the factory with a > >> >> general > >> >> tune. This mean the carb may or may not need to be set up properly for > >> > your > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > the > >> >> factory set up. Normally they will require a metering rod change, and > >> > maybe > >> >> a jet change as well. You also don't specify the cam specs. > >> > > >> > > >> > > >> > >> > > > > > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Sounds like a good purchase - will order and wait 3 weeks for it to arrive
(!). Got it fitted at the weekend, relatively painlessly. Well, I mean that metaphorically actually, as I cut the hell out of my thumb as I was putting on the valley pan gasket with blood going everywhere and trying to keep it off the RTV. So now the nastier bits of the emissions control are disconnected (the EGR and the air injection stuff). As it is now not really an emssions controlled vehicle, I attached it to the non-timed part of the carb per the instructions, but that gave me 34 degrees BTDC, so plugged it into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser was playing up a bit, so I'll do the tuning next weekend, but even on the default settings, it is pulling way more strongly than it ever did before - can't be far off. Oh, Edelbrock's instructions in the 2131 manifold state that the Performer 1405 requires a Square bore to ------ bore adapter. Except that both carb and manifold are square bore already, and I hadn't ordered one. Doesn't seem to mention the need for it anywhere else - will drop them a line to check that it is a mistake on their part. Certainly seems to run fine without it. Dave Milne, Scotland "c" <c@me.org> wrote in message news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > yes, they are basically the same carb inside. I believe the jets and rods > interchange, but I'm not positive on that. I do know that the Edelbrock carb > is heavily based on the Carter design. If you understand basic carb > functioning, and what the rods and jets do for the mixture, it will be a > simple process to get it dialed in. If you ruin in to problems, I'm sure we > can get you going in the right direction. Also, there is a book available > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. I > had the book at one time, but loaned it out and never got it back. I do know > that the book is very thorough. > > Chris > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at the > > weekend. > > > > Quite looking forward to it - my carb experience has been mainly with > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > Dave Milne, Scotland > > '91 Grand Wagoneer, '99 TJ > > "c" <c@me.org> wrote in message > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > >> Dave, > >> > >> When the companies that make carb give them their initial settings from > > the > >> factory, they take all kinds of compromised in to consideration. They > > don't > >> know if the carb will be used on a large or small displacement engine, or > > if > >> it will be used in hot or cold climate, high altitude, etc. They also > > don't > >> know what other mods have been done to these engines. The baseline > > settings > >> they give these carbs will allow them to run on most of the applications > >> they will see, but they almost always require tuning to get them to be > >> optimal. My guess would be that this carb would still be a little rich, > > but > >> it is just a guess. I'm not saying it won't run, it will, and it will > >> probably be pretty damn close to right. > >> > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > mixture > >> based on engine vacuum. The rods are controlled by a piston and spring, > >> similar to many other carbs. When the engine vacuum is low, the metering > > rod > >> spring will start to overtake the vacuum pulling the piston down. The > >> rods > >> are tapered, and when they move up in the bore they are in, a smaller > >> diameter of the rod will still be inside the main jet, effectively > >> increasing the total main jet area that fuel can pass thru. If the engine > >> runs too rich at high vacuum conditions, but is ok at low vacuum or wide > >> open throttle, then you simply change the metering rod to on the has a > >> larger diameter on the part of the rod that is in the jet at high vacuum > >> conditions. It really is a simple process, and normally will only require > > 1 > >> or 2 sets of rods to get the carb where you need it to be. > >> > >> Chris > >> > >> > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > manifold > >> > will require a metering or jet change on a stock 360 '91 Grand Wagoneer > > ? > >> > > >> > > >> > Dave Milne, Scotland > >> > '91 Grand Wagoneer, '99 TJ > >> > "c" <c@me.org> wrote in message > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > >> >> Without knowing what size carb, choke or no choke, and which manifold, > > it > >> > is > >> >> hard to tell you what the problem could be. What I can tell you is > >> >> that > >> >> Edelbrock and Holley carbs are both set up from the factory with a > >> >> general > >> >> tune. This mean the carb may or may not need to be set up properly for > >> > your > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > the > >> >> factory set up. Normally they will require a metering rod change, and > >> > maybe > >> >> a jet change as well. You also don't specify the cam specs. > >> > > >> > > >> > > >> > >> > > > > > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Sounds like a good purchase - will order and wait 3 weeks for it to arrive
(!). Got it fitted at the weekend, relatively painlessly. Well, I mean that metaphorically actually, as I cut the hell out of my thumb as I was putting on the valley pan gasket with blood going everywhere and trying to keep it off the RTV. So now the nastier bits of the emissions control are disconnected (the EGR and the air injection stuff). As it is now not really an emssions controlled vehicle, I attached it to the non-timed part of the carb per the instructions, but that gave me 34 degrees BTDC, so plugged it into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser was playing up a bit, so I'll do the tuning next weekend, but even on the default settings, it is pulling way more strongly than it ever did before - can't be far off. Oh, Edelbrock's instructions in the 2131 manifold state that the Performer 1405 requires a Square bore to ------ bore adapter. Except that both carb and manifold are square bore already, and I hadn't ordered one. Doesn't seem to mention the need for it anywhere else - will drop them a line to check that it is a mistake on their part. Certainly seems to run fine without it. Dave Milne, Scotland "c" <c@me.org> wrote in message news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > yes, they are basically the same carb inside. I believe the jets and rods > interchange, but I'm not positive on that. I do know that the Edelbrock carb > is heavily based on the Carter design. If you understand basic carb > functioning, and what the rods and jets do for the mixture, it will be a > simple process to get it dialed in. If you ruin in to problems, I'm sure we > can get you going in the right direction. Also, there is a book available > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. I > had the book at one time, but loaned it out and never got it back. I do know > that the book is very thorough. > > Chris > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at the > > weekend. > > > > Quite looking forward to it - my carb experience has been mainly with > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > Dave Milne, Scotland > > '91 Grand Wagoneer, '99 TJ > > "c" <c@me.org> wrote in message > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > >> Dave, > >> > >> When the companies that make carb give them their initial settings from > > the > >> factory, they take all kinds of compromised in to consideration. They > > don't > >> know if the carb will be used on a large or small displacement engine, or > > if > >> it will be used in hot or cold climate, high altitude, etc. They also > > don't > >> know what other mods have been done to these engines. The baseline > > settings > >> they give these carbs will allow them to run on most of the applications > >> they will see, but they almost always require tuning to get them to be > >> optimal. My guess would be that this carb would still be a little rich, > > but > >> it is just a guess. I'm not saying it won't run, it will, and it will > >> probably be pretty damn close to right. > >> > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > mixture > >> based on engine vacuum. The rods are controlled by a piston and spring, > >> similar to many other carbs. When the engine vacuum is low, the metering > > rod > >> spring will start to overtake the vacuum pulling the piston down. The > >> rods > >> are tapered, and when they move up in the bore they are in, a smaller > >> diameter of the rod will still be inside the main jet, effectively > >> increasing the total main jet area that fuel can pass thru. If the engine > >> runs too rich at high vacuum conditions, but is ok at low vacuum or wide > >> open throttle, then you simply change the metering rod to on the has a > >> larger diameter on the part of the rod that is in the jet at high vacuum > >> conditions. It really is a simple process, and normally will only require > > 1 > >> or 2 sets of rods to get the carb where you need it to be. > >> > >> Chris > >> > >> > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > manifold > >> > will require a metering or jet change on a stock 360 '91 Grand Wagoneer > > ? > >> > > >> > > >> > Dave Milne, Scotland > >> > '91 Grand Wagoneer, '99 TJ > >> > "c" <c@me.org> wrote in message > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > >> >> Without knowing what size carb, choke or no choke, and which manifold, > > it > >> > is > >> >> hard to tell you what the problem could be. What I can tell you is > >> >> that > >> >> Edelbrock and Holley carbs are both set up from the factory with a > >> >> general > >> >> tune. This mean the carb may or may not need to be set up properly for > >> > your > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > the > >> >> factory set up. Normally they will require a metering rod change, and > >> > maybe > >> >> a jet change as well. You also don't specify the cam specs. > >> > > >> > > >> > > >> > >> > > > > > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Dave,
It would be a shame to install less restrictive intake components, without similar changes to the exhaust. Earle "Dave Milne" <whoneeds@toknow.com> wrote in message news:D6_Mg.16900$r61.754@text.news.blueyonder.co.u k... > Sounds like a good purchase - will order and wait 3 weeks for it to arrive > (!). > > Got it fitted at the weekend, relatively painlessly. Well, I mean that > metaphorically actually, as I cut the hell out of my thumb as I was putting > on the valley pan gasket with blood going everywhere and trying to keep it > off the RTV. So now the nastier bits of the emissions control are > disconnected (the EGR and the air injection stuff). As it is now not really > an emssions controlled vehicle, I attached it to the non-timed part of the > carb per the instructions, but that gave me 34 degrees BTDC, so plugged it > into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser > was playing up a bit, so I'll do the tuning next weekend, but even on the > default settings, it is pulling way more strongly than it ever did before - > can't be far off. > > Oh, Edelbrock's instructions in the 2131 manifold state that the Performer > 1405 requires a Square bore to ------ bore adapter. Except that both carb > and manifold are square bore already, and I hadn't ordered one. Doesn't > seem to mention the need for it anywhere else - will drop them a line to > check that it is a mistake on their part. Certainly seems to run fine > without it. > > Dave Milne, Scotland > > > "c" <c@me.org> wrote in message > news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > > yes, they are basically the same carb inside. I believe the jets and rods > > interchange, but I'm not positive on that. I do know that the Edelbrock > carb > > is heavily based on the Carter design. If you understand basic carb > > functioning, and what the rods and jets do for the mixture, it will be a > > simple process to get it dialed in. If you ruin in to problems, I'm sure > we > > can get you going in the right direction. Also, there is a book available > > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. > I > > had the book at one time, but loaned it out and never got it back. I do > know > > that the book is very thorough. > > > > Chris > > > > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at > the > > > weekend. > > > > > > Quite looking forward to it - my carb experience has been mainly with > > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > > > Dave Milne, Scotland > > > '91 Grand Wagoneer, '99 TJ > > > "c" <c@me.org> wrote in message > > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > > >> Dave, > > >> > > >> When the companies that make carb give them their initial settings from > > > the > > >> factory, they take all kinds of compromised in to consideration. They > > > don't > > >> know if the carb will be used on a large or small displacement engine, > or > > > if > > >> it will be used in hot or cold climate, high altitude, etc. They also > > > don't > > >> know what other mods have been done to these engines. The baseline > > > settings > > >> they give these carbs will allow them to run on most of the > applications > > >> they will see, but they almost always require tuning to get them to be > > >> optimal. My guess would be that this carb would still be a little rich, > > > but > > >> it is just a guess. I'm not saying it won't run, it will, and it will > > >> probably be pretty damn close to right. > > >> > > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > > mixture > > >> based on engine vacuum. The rods are controlled by a piston and spring, > > >> similar to many other carbs. When the engine vacuum is low, the > metering > > > rod > > >> spring will start to overtake the vacuum pulling the piston down. The > > >> rods > > >> are tapered, and when they move up in the bore they are in, a smaller > > >> diameter of the rod will still be inside the main jet, effectively > > >> increasing the total main jet area that fuel can pass thru. If the > engine > > >> runs too rich at high vacuum conditions, but is ok at low vacuum or > wide > > >> open throttle, then you simply change the metering rod to on the has a > > >> larger diameter on the part of the rod that is in the jet at high > vacuum > > >> conditions. It really is a simple process, and normally will only > require > > > 1 > > >> or 2 sets of rods to get the carb where you need it to be. > > >> > > >> Chris > > >> > > >> > > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > > manifold > > >> > will require a metering or jet change on a stock 360 '91 Grand > Wagoneer > > > ? > > >> > > > >> > > > >> > Dave Milne, Scotland > > >> > '91 Grand Wagoneer, '99 TJ > > >> > "c" <c@me.org> wrote in message > > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > > >> >> Without knowing what size carb, choke or no choke, and which > manifold, > > > it > > >> > is > > >> >> hard to tell you what the problem could be. What I can tell you is > > >> >> that > > >> >> Edelbrock and Holley carbs are both set up from the factory with a > > >> >> general > > >> >> tune. This mean the carb may or may not need to be set up properly > for > > >> > your > > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > > the > > >> >> factory set up. Normally they will require a metering rod change, > and > > >> > maybe > > >> >> a jet change as well. You also don't specify the cam specs. > > >> > > > >> > > > >> > > > >> > > >> > > > > > > > > > > > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Dave,
It would be a shame to install less restrictive intake components, without similar changes to the exhaust. Earle "Dave Milne" <whoneeds@toknow.com> wrote in message news:D6_Mg.16900$r61.754@text.news.blueyonder.co.u k... > Sounds like a good purchase - will order and wait 3 weeks for it to arrive > (!). > > Got it fitted at the weekend, relatively painlessly. Well, I mean that > metaphorically actually, as I cut the hell out of my thumb as I was putting > on the valley pan gasket with blood going everywhere and trying to keep it > off the RTV. So now the nastier bits of the emissions control are > disconnected (the EGR and the air injection stuff). As it is now not really > an emssions controlled vehicle, I attached it to the non-timed part of the > carb per the instructions, but that gave me 34 degrees BTDC, so plugged it > into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser > was playing up a bit, so I'll do the tuning next weekend, but even on the > default settings, it is pulling way more strongly than it ever did before - > can't be far off. > > Oh, Edelbrock's instructions in the 2131 manifold state that the Performer > 1405 requires a Square bore to ------ bore adapter. Except that both carb > and manifold are square bore already, and I hadn't ordered one. Doesn't > seem to mention the need for it anywhere else - will drop them a line to > check that it is a mistake on their part. Certainly seems to run fine > without it. > > Dave Milne, Scotland > > > "c" <c@me.org> wrote in message > news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > > yes, they are basically the same carb inside. I believe the jets and rods > > interchange, but I'm not positive on that. I do know that the Edelbrock > carb > > is heavily based on the Carter design. If you understand basic carb > > functioning, and what the rods and jets do for the mixture, it will be a > > simple process to get it dialed in. If you ruin in to problems, I'm sure > we > > can get you going in the right direction. Also, there is a book available > > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. > I > > had the book at one time, but loaned it out and never got it back. I do > know > > that the book is very thorough. > > > > Chris > > > > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at > the > > > weekend. > > > > > > Quite looking forward to it - my carb experience has been mainly with > > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > > > Dave Milne, Scotland > > > '91 Grand Wagoneer, '99 TJ > > > "c" <c@me.org> wrote in message > > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > > >> Dave, > > >> > > >> When the companies that make carb give them their initial settings from > > > the > > >> factory, they take all kinds of compromised in to consideration. They > > > don't > > >> know if the carb will be used on a large or small displacement engine, > or > > > if > > >> it will be used in hot or cold climate, high altitude, etc. They also > > > don't > > >> know what other mods have been done to these engines. The baseline > > > settings > > >> they give these carbs will allow them to run on most of the > applications > > >> they will see, but they almost always require tuning to get them to be > > >> optimal. My guess would be that this carb would still be a little rich, > > > but > > >> it is just a guess. I'm not saying it won't run, it will, and it will > > >> probably be pretty damn close to right. > > >> > > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > > mixture > > >> based on engine vacuum. The rods are controlled by a piston and spring, > > >> similar to many other carbs. When the engine vacuum is low, the > metering > > > rod > > >> spring will start to overtake the vacuum pulling the piston down. The > > >> rods > > >> are tapered, and when they move up in the bore they are in, a smaller > > >> diameter of the rod will still be inside the main jet, effectively > > >> increasing the total main jet area that fuel can pass thru. If the > engine > > >> runs too rich at high vacuum conditions, but is ok at low vacuum or > wide > > >> open throttle, then you simply change the metering rod to on the has a > > >> larger diameter on the part of the rod that is in the jet at high > vacuum > > >> conditions. It really is a simple process, and normally will only > require > > > 1 > > >> or 2 sets of rods to get the carb where you need it to be. > > >> > > >> Chris > > >> > > >> > > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > > manifold > > >> > will require a metering or jet change on a stock 360 '91 Grand > Wagoneer > > > ? > > >> > > > >> > > > >> > Dave Milne, Scotland > > >> > '91 Grand Wagoneer, '99 TJ > > >> > "c" <c@me.org> wrote in message > > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > > >> >> Without knowing what size carb, choke or no choke, and which > manifold, > > > it > > >> > is > > >> >> hard to tell you what the problem could be. What I can tell you is > > >> >> that > > >> >> Edelbrock and Holley carbs are both set up from the factory with a > > >> >> general > > >> >> tune. This mean the carb may or may not need to be set up properly > for > > >> > your > > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > > the > > >> >> factory set up. Normally they will require a metering rod change, > and > > >> > maybe > > >> >> a jet change as well. You also don't specify the cam specs. > > >> > > > >> > > > >> > > > >> > > >> > > > > > > > > > > > > |
Re: '79 304 Edelbrock carb problems vs Holley carbs?
Dave,
It would be a shame to install less restrictive intake components, without similar changes to the exhaust. Earle "Dave Milne" <whoneeds@toknow.com> wrote in message news:D6_Mg.16900$r61.754@text.news.blueyonder.co.u k... > Sounds like a good purchase - will order and wait 3 weeks for it to arrive > (!). > > Got it fitted at the weekend, relatively painlessly. Well, I mean that > metaphorically actually, as I cut the hell out of my thumb as I was putting > on the valley pan gasket with blood going everywhere and trying to keep it > off the RTV. So now the nastier bits of the emissions control are > disconnected (the EGR and the air injection stuff). As it is now not really > an emssions controlled vehicle, I attached it to the non-timed part of the > carb per the instructions, but that gave me 34 degrees BTDC, so plugged it > into the timed-port and got a more sensible 10 degrees BTDC. Gas analyser > was playing up a bit, so I'll do the tuning next weekend, but even on the > default settings, it is pulling way more strongly than it ever did before - > can't be far off. > > Oh, Edelbrock's instructions in the 2131 manifold state that the Performer > 1405 requires a Square bore to ------ bore adapter. Except that both carb > and manifold are square bore already, and I hadn't ordered one. Doesn't > seem to mention the need for it anywhere else - will drop them a line to > check that it is a mistake on their part. Certainly seems to run fine > without it. > > Dave Milne, Scotland > > > "c" <c@me.org> wrote in message > news:RjPLg.1352$d72.768@tornado.rdc-kc.rr.com... > > Dave, you shouldn't have a problem tuning the Carter/Edelbrock carb, and > > yes, they are basically the same carb inside. I believe the jets and rods > > interchange, but I'm not positive on that. I do know that the Edelbrock > carb > > is heavily based on the Carter design. If you understand basic carb > > functioning, and what the rods and jets do for the mixture, it will be a > > simple process to get it dialed in. If you ruin in to problems, I'm sure > we > > can get you going in the right direction. Also, there is a book available > > called Carter Carb Tuning. Most of it will apply to the Edelbrock as well. > I > > had the book at one time, but loaned it out and never got it back. I do > know > > that the book is very thorough. > > > > Chris > > > > > > "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > news:FiGLg.14805$r61.8273@text.news.blueyonder.co. uk... > > > Thanks. Looks like perhaps I should have ordered the calibration kit in > > > retrospect. Anyhow, after a 2 week wait, it has arrived so I'll fit at > the > > > weekend. > > > > > > Quite looking forward to it - my carb experience has been mainly with > > > multiple SU's (single barrel downdraft) and the odd side draft Weber - > > > never done anything on a 4 barrel like Holley or Edelbrock before. > > > > > > Dave Milne, Scotland > > > '91 Grand Wagoneer, '99 TJ > > > "c" <c@me.org> wrote in message > > > news:1lDLg.1336$d72.134@tornado.rdc-kc.rr.com... > > >> Dave, > > >> > > >> When the companies that make carb give them their initial settings from > > > the > > >> factory, they take all kinds of compromised in to consideration. They > > > don't > > >> know if the carb will be used on a large or small displacement engine, > or > > > if > > >> it will be used in hot or cold climate, high altitude, etc. They also > > > don't > > >> know what other mods have been done to these engines. The baseline > > > settings > > >> they give these carbs will allow them to run on most of the > applications > > >> they will see, but they almost always require tuning to get them to be > > >> optimal. My guess would be that this carb would still be a little rich, > > > but > > >> it is just a guess. I'm not saying it won't run, it will, and it will > > >> probably be pretty damn close to right. > > >> > > >> The metering rod system that Carter/Edelbrock uses will "adjust" the > > > mixture > > >> based on engine vacuum. The rods are controlled by a piston and spring, > > >> similar to many other carbs. When the engine vacuum is low, the > metering > > > rod > > >> spring will start to overtake the vacuum pulling the piston down. The > > >> rods > > >> are tapered, and when they move up in the bore they are in, a smaller > > >> diameter of the rod will still be inside the main jet, effectively > > >> increasing the total main jet area that fuel can pass thru. If the > engine > > >> runs too rich at high vacuum conditions, but is ok at low vacuum or > wide > > >> open throttle, then you simply change the metering rod to on the has a > > >> larger diameter on the part of the rod that is in the jet at high > vacuum > > >> conditions. It really is a simple process, and normally will only > require > > > 1 > > >> or 2 sets of rods to get the carb where you need it to be. > > >> > > >> Chris > > >> > > >> > > >> "Dave Milne" <jeep@_nospam_milne.info> wrote in message > > >> news:OeuLg.14311$r61.1621@text.news.blueyonder.co. uk... > > >> > Any idea if the Edelbrock 600cfm 1405 Performer + Edelbrock 2131 > > > manifold > > >> > will require a metering or jet change on a stock 360 '91 Grand > Wagoneer > > > ? > > >> > > > >> > > > >> > Dave Milne, Scotland > > >> > '91 Grand Wagoneer, '99 TJ > > >> > "c" <c@me.org> wrote in message > > >> > news:cliLg.1294$d72.56@tornado.rdc-kc.rr.com... > > >> >> Without knowing what size carb, choke or no choke, and which > manifold, > > > it > > >> > is > > >> >> hard to tell you what the problem could be. What I can tell you is > > >> >> that > > >> >> Edelbrock and Holley carbs are both set up from the factory with a > > >> >> general > > >> >> tune. This mean the carb may or may not need to be set up properly > for > > >> > your > > >> >> particular engine. In general, the Edelbrock carbs run too rich with > > > the > > >> >> factory set up. Normally they will require a metering rod change, > and > > >> > maybe > > >> >> a jet change as well. You also don't specify the cam specs. > > >> > > > >> > > > >> > > > >> > > >> > > > > > > > > > > > > |
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