Bad Timing? |
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Bad Timing? |
landnsea |
Sep 12 2006, 01:57 PM
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#1
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Newbie Group: Members Posts: 3 Joined: 12-September 06 From: Bahrain Member No.: 6,825 |
Hi. I have just finished putting a 1975 2.0 in my 914. I also installed dual new 40 IDF Webers. For a distributor, I installed a modified 009 Bosch centrigugal advance distributor, which I bought from JC Whitney. I adjusted the valves to stock specs, 0.15mm for the intake and 0.2mm for the exhaust. I tuned the carbs with a synchrometer. I set the timing to 27 deg BTDC at 3500RPM, but I know that it is wrong because I am supposed to do this without any advance, which is not possible for this distributor (no vacuum hose to disconnect and plug). As a result, I am getting very sluggish performance from 900 all the way to 2500 rpm. What is the recommended timing for such a setup? Or am I simply using the wrong distributor? Oh, by the way, I live and work in Bahrain, and I brought the 914 with me from LA, just to have something to play with... Bill Nader.
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904svo |
Sep 12 2006, 02:30 PM
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#2
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904SVO Group: Members Posts: 1,118 Joined: 17-November 05 From: Woodstock,Georgia Member No.: 5,146 |
Hi. I have just finished putting a 1975 2.0 in my 914. I also installed dual new 40 IDF Webers. For a distributor, I installed a modified 009 Bosch centrigugal advance distributor, which I bought from JC Whitney. I adjusted the valves to stock specs, 0.15mm for the intake and 0.2mm for the exhaust. I tuned the carbs with a synchrometer. I set the timing to 27 deg BTDC at 3500RPM, but I know that it is wrong because I am supposed to do this without any advance, which is not possible for this distributor (no vacuum hose to disconnect and plug). As a result, I am getting very sluggish performance from 900 all the way to 2500 rpm. What is the recommended timing for such a setup? Or am I simply using the wrong distributor? Oh, by the way, I live and work in Bahrain, and I brought the 914 with me from LA, just to have something to play with... Bill Nader. Sounds like you have the carb's jet set wrong or the venturi is to large should be about 28mm on venturi and main jet 115mm,idle jet .50mm. |
Aaron Cox |
Sep 12 2006, 02:34 PM
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#3
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
i disagree... should be a 30 or 32 vent... but the problem lies in your distributor
the 009, and 050's SUCK. totally wrong advance curve... you may try having all the advance in by 3000 rpm... but then i believe you will be too retarded at idle...... mallory unilite is the only way to fly... 12 intial, 28 final advance by 3000 |
Matt Romanowski |
Sep 12 2006, 02:50 PM
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#4
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Senior Member Group: Members Posts: 878 Joined: 4-January 04 From: Manchester, NH Member No.: 1,507 |
Need more info.
Is it idling ok? How is it above 2500? Sounds like you have an issue with the idle jets. What size are they. You'll be able to get it pretty good with that distributor. Also, what method did you use to get the carbs synced and to best lean idle? Matt |
Cap'n Krusty |
Sep 12 2006, 04:20 PM
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#5
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Cap'n Krusty Group: Members Posts: 10,794 Joined: 24-June 04 From: Santa Maria, CA Member No.: 2,246 Region Association: Central California |
"Modified" 009? Say what? Your technique is fine, but it needs to be 30 degrees at 3K, fully advanced. However, the 009 is junk. 050s work just fine, despite what the previous poster said. Best conventional distributor for you would be a 356/912 cast iron distributor, but they're REALLY hard to come by. The distributors Jake sells are reputed to be the best overall, but they're pricey. I can't address the carb issue, because I have little experience with them, preferring stock EFI. The Cap'n
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Aaron Cox |
Sep 12 2006, 04:28 PM
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#6
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Professional Lawn Dart Group: Retired Admin Posts: 24,541 Joined: 1-February 03 From: OC Member No.: 219 Region Association: Southern California |
"Modified" 009? Say what? Your technique is fine, but it needs to be 30 degrees at 3K, fully advanced. However, the 009 is junk. 050s work just fine, despite what the previous poster said. Best conventional distributor for you would be a 356/912 cast iron distributor, but they're REALLY hard to come by. The distributors Jake sells are reputed to be the best overall, but they're pricey. I can't address the carb issue, because I have little experience with them, preferring stock EFI. The Cap'n krusty.... what is the TOTAL advance of the 050? (something like 23 degrees) so when you set it to 30 btdc at 3k, what is your initial advance? (7 degrees) its too retarded at idle.... BTDT. |
landnsea |
Sep 13 2006, 12:03 PM
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#7
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Newbie Group: Members Posts: 3 Joined: 12-September 06 From: Bahrain Member No.: 6,825 |
Thanks for the respopnses. The engine starts right up and idles fine. I have tuned it a bit today and timed it at 30 BTDC degrees @ 3000 RPM. It is still doing the same, which means it bogs down from idle all the way to a little over 2200 RPM, and then watch out! it takes off like a rocket... There is no powert at low RPM, but plenty over 2500 RPM. What gives? Should I go ahead and replace the distributor or is it a carb jets issue? Bill Nader.
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SGB |
Sep 13 2006, 12:26 PM
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#8
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just visiting Group: Members Posts: 4,086 Joined: 8-March 03 From: Huntsville, AL Member No.: 404 Region Association: South East States |
How tall are the intake manifolds? My car had stubby ones when I got it- they are best for high rpm power b/c flow losses are less, but taller intakes allow the pulses from the valves to generate a wave effect that increases low rpm torque. When I got taller manifolds it effected low rpm opperation the most. The mallory diz helped all across the rpm band- mostly smoother power. Jet issues are usually not subtle and will make the car act up badly.
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landnsea |
Sep 13 2006, 12:52 PM
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#9
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Newbie Group: Members Posts: 3 Joined: 12-September 06 From: Bahrain Member No.: 6,825 |
How tall are the intake manifolds? My car had stubby ones when I got it- they are best for high rpm power b/c flow losses are less, but taller intakes allow the pulses from the valves to generate a wave effect that increases low rpm torque. When I got taller manifolds it effected low rpm opperation the most. The mallory diz helped all across the rpm band- mostly smoother power. Jet issues are usually not subtle and will make the car act up badly. I bought the whole Weber dual carb kit from Empi. The intake manifolds are about 4 inches tall. I first installed them on top of the thick seal that came with the fuel injection system, which made them a bit taller, but then I took the seals out and installed them with just the gaskets. Where did you buy your Mallory diz? |
So.Cal.914 |
Sep 13 2006, 01:50 PM
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#10
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"...And it has a front trunk too." Group: Members Posts: 6,588 Joined: 15-February 04 From: Low Desert, CA./ Hills of N.J. Member No.: 1,658 Region Association: None |
Jake Raby sells them or Google it.
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bd1308 |
Sep 13 2006, 02:03 PM
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#11
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Sir Post-a-lot Group: Members Posts: 8,020 Joined: 24-January 05 From: Louisville,KY Member No.: 3,501 |
AA,
Is 'too retarded' your own judgement or are you getting your sources somewhere else? I found my initial timing to be 7.5 degrees at idle and i found that information on both my 914 engine bay sticker and the engine bay sticker of a bay window bus from 1978, champaigne edition. b |
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