one warm, one alot warmer, intake manifords |
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one warm, one alot warmer, intake manifords |
karmanbuilt |
Jun 14 2010, 09:42 PM
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#1
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??? Group: Members Posts: 72 Joined: 7-July 08 From: Emmett, ID. Member No.: 9,262 Region Association: Pacific Northwest |
After installing dual 40's on a '76 2.0, and running the tall manifords. They were set up by Jake, and started up the first time....Semper Fi! Anyway, after a valve adjustment, tweaking the timing, and fine tuning the carbs, took the car out for a fifthteen mile run. Still need to tweak the carbs, but noticed the bank of 1 & 2 were just barely warm. Bank 3 & 4 were almost hot! Searched the oldies posts back to 2003, and found a thread on gaskets. I had installed my manifolds with the gaskets that Jake had sent with the set, but had to remove the manifolds to plug the holes on each side. Reinstalled the manifolds with the FI gaskets. My question...sorry this is so long....was I suppose to add paper gaskets w/the FI ones??
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VaccaRabite |
Jun 15 2010, 06:16 AM
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#2
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
No to the paper gaskets.
The FI gaskets you are talking about are the ones with the plastic spacer? Here is what I did. I took the manifolds, and polished the flange with 400 grit sandpaper on a thick glass window pane until it was totally flat. This took a little time, but as soon as you start you can clearly see all the imperfections in the "flat" of the flange. As to the hot and cold, are you sure that the 1/2 bank of carbs is firing? Did you do any adjustment before you started driving? Sounds to me like you are driving off the 3/4 bank. You have to get them gross adjusted before you start driving. once driving you should only need little tweaks. Zach |
ME733 |
Jun 15 2010, 06:33 AM
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#3
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Senior Member Group: Members Posts: 842 Joined: 25-June 08 From: Atlanta Ga. Member No.: 9,209 Region Association: South East States |
..........AND as the previous post suggested...balancing the carburators may just be the problem....START by disconnecting the carburators from the crossbar/ or linkage....balance the carburators...THEN connect the linkage, ensuring there is NO preload on one or the other carburator...After connecting ensure both carburators are STILL balanced.....this is a good start to solving the problem...AS it could be that the carburator jets ,while marked as a specific size, just might not be the actual size marked., causing one side or the other to run hotter or cooler....What type fan housing you got., could be that the "cooling flappers" are not installed-adjusted properly.(thats why I used to throw them as far as I could, after bending them in half, as I hate the M.F.S.Bitches.).
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karmanbuilt |
Jun 15 2010, 03:07 PM
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#4
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??? Group: Members Posts: 72 Joined: 7-July 08 From: Emmett, ID. Member No.: 9,262 Region Association: Pacific Northwest |
No to the paper gaskets. The FI gaskets you are talking about are the ones with the plastic spacer? Here is what I did. I took the manifolds, and polished the flange with 400 grit sandpaper on a thick glass window pane until it was totally flat. This took a little time, but as soon as you start you can clearly see all the imperfections in the "flat" of the flange. As to the hot and cold, are you sure that the 1/2 bank of carbs is firing? Did you do any adjustment before you started driving? Sounds to me like you are driving off the 3/4 bank. You have to get them gross adjusted before you start driving. once driving you should only need little tweaks. Zach Zach........don't rember if they had plastic spacers....just know they came of a D-Jet system, and rember a post that said to use the stock gaskets to keep car from vapor locking when hot.....Gene |
underthetire |
Jun 15 2010, 03:21 PM
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#5
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914 Guru Group: Members Posts: 5,062 Joined: 7-October 08 From: Brentwood Member No.: 9,623 Region Association: Northern California |
No to the paper gaskets. The FI gaskets you are talking about are the ones with the plastic spacer? Here is what I did. I took the manifolds, and polished the flange with 400 grit sandpaper on a thick glass window pane until it was totally flat. This took a little time, but as soon as you start you can clearly see all the imperfections in the "flat" of the flange. As to the hot and cold, are you sure that the 1/2 bank of carbs is firing? Did you do any adjustment before you started driving? Sounds to me like you are driving off the 3/4 bank. You have to get them gross adjusted before you start driving. once driving you should only need little tweaks. Zach Zach........don't rember if they had plastic spacers....just know they came of a D-Jet system, and rember a post that said to use the stock gaskets to keep car from vapor locking when hot.....Gene Do you mean the phenolic blocks? Those are to eliminate heat from the heads going in to the intake manifolds. |
VaccaRabite |
Jun 15 2010, 03:34 PM
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#6
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
Okay. There are gaskets sold with phenolic plastic between two paper backings. They are about 1/4 inch thick. This is what I like to use, as is stops heat from the head from wicking up the intake manifold and boiling the gas in the carb bowl. Cooler fuel is better then warmer fuel, right?
as to the heat stuff, your 1/2 bank isn't working as expected. Could be for a whole host of reasons. If you just installed the carbs, they are likely not at all balanced or synced, which is important. You also could have dirty jets, fouled spark plugs, or some other reason causing the bank of carbs not to work or to work far less then the other one. You could also have leaks, letting unmetered air in, causing one bank to go really lean. Your carbs might need rebuilding. Are they old? Have they not been run for over 1 year? If they have not been used, the rubber may have dry-rotted and is now leaky. This is just one of those things that carbs do. Do you have a unisyn or a syncrometer? Looks like this: (IMG:http://www.914world.com/bbs2/uploads_offsite/www.duckyimports.com-1435-1276637651.1.jpg) If you don't, get one. You will never get the carbs set right without it. Zach |
karmanbuilt |
Jun 16 2010, 08:24 PM
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#7
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??? Group: Members Posts: 72 Joined: 7-July 08 From: Emmett, ID. Member No.: 9,262 Region Association: Pacific Northwest |
Zach....carbs were installed the end of May, this year. I have had them covered, and plan on getting that sync meter from a friend that helped me set up the idle after a valve adjustment and timing was done. Going to pull the plugs on the 1/2 bank to read them. Do remember one nut not tighting like the other two on that bank. Maybe a leak there??
Gene |
r_towle |
Jun 16 2010, 09:07 PM
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#8
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Custom Member Group: Members Posts: 24,591 Joined: 9-January 03 From: Taxachusetts Member No.: 124 Region Association: North East States |
Gene,
You are chasing all the wrong problems. Get a synchrometer, they are cheap and you will need to OWN one if you have dual carbs....forever. Learn to sync the carbs, there are alot of good suggestions here on how to do it, but its really simple if you think about the engine as an air pump. Get both barrells on each side balanced (assume Jake did this, but check them) then sync up one carb to the other using the linkage. Dont change or fix anything else, you need to balance your carbs first. Rich |
VaccaRabite |
Jun 17 2010, 06:46 AM
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#9
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En Garde! Group: Admin Posts: 13,465 Joined: 15-December 03 From: Dallastown, PA Member No.: 1,435 Region Association: MidAtlantic Region |
(IMG:style_emoticons/default/agree.gif)
your carbs are not synced. That is your issue. All, or at least most, of the work is being done by one side. I would still check the plugs though. the 1/2 bank plugs are probably fouled from driving around and never getting hot enough to burn off the carbon. The will not work right until they are cleaned. Don't drive the car any more until it is balanced. The syncrometer that I pictured is only $30-$40, and you are going to use it more then once. Dual carbs are not a "set and forget" type of deal. You have to maintain them, and that means occasionally checking draw and rebalancing. I carry my syncrometer in the in-car toolbox. Its always with the car, just in case. Zach |
karmanbuilt |
Jun 17 2010, 10:18 AM
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#10
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??? Group: Members Posts: 72 Joined: 7-July 08 From: Emmett, ID. Member No.: 9,262 Region Association: Pacific Northwest |
Zach & Rich...... The last couple of years of being a member of this site, I have come to value your posts that you have written. And also understand that by your trials and errors many of us have learned valuable lessons that we could not have gotten from any manuals. That being said......I will purchase the meter as soon as I can. Car is not being driven now , as I am addressing an ign. sw. problem. Once asked "How do you eat an elephant....one piece at a time" Thanks, Gene
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