 Does timing affect engine temps?, I swear my engine is running hotter... |
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| pete914 |
 Jan 31 2008, 06:33 AM
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#1
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Member  Group: Members Posts: 178 Joined: 21-August 07 From: east coast Member No.: 8,025  |
So,
I'm running a 1.8L stock Vacuum advance dizzy with single weber (i know...not ideal) and as I've learned the advance curve is wrong for this setup and I have pretty bad lag now before 3000rpm. I swear the engine is running hotter now. Is it because the timing is too retarded in the lower rpm range? does that affect engine temperature? Anyone running a similiar setup with a suggestion as to where to set my timing to get better performance? I don't rev it up much past 4500 Oh, and I just ordered a a centrifugal advance dizzy, if someone is using one of those with a single carb and is having luck, please tell me your settings. Thanks. |
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| SGB |
Jan 31 2008, 07:11 AM
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#2
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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 |
Timing too HIGH for a given RPM range will definitely make hotter running temps in that range. Timing too retarded? IDK, maybe...
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| Jake Raby |
Jan 31 2008, 08:05 AM
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#3
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE Does timing affect engine temps?, I swear my engine is running hotter... ABSOLUTELY!!!!! Timing is EVERYTHING to head and oil temps! TWO degrees can make 50+ degrees of head temp! Retarded timing = higher exhaust gas temps because the burn is slowed and is still occuring while the exhaust valve is open.. High EGT= higher head temps because the port soaks all that head up and spreads it over the heat... Better get this squared away or you'll be a statistic! This post has been edited by Jake Raby: Jan 31 2008, 08:09 AM |
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| pete914 |
Jan 31 2008, 09:00 AM
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#4
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Member Group: Members Posts: 178 Joined: 21-August 07 From: east coast Member No.: 8,025 |
Thabks for the info. Still confused though. Right now my engine is advanced 27 degrees or to whatever the red hatchmark is on the 1.8 fan. However like I said my teener is running pretty bad. Seems like I should still be safe though I haven't advanced the timing that much.
What does EGT mean? Sorry new to this. thanks QUOTE(Jake Raby @ Jan 31 2008, 09:05 AM)  QUOTE Does timing affect engine temps?, I swear my engine is running hotter... ABSOLUTELY!!!!! Timing is EVERYTHING to head and oil temps! TWO degrees can make 50+ degrees of head temp! Retarded timing = higher exhaust gas temps because the burn is slowed and is still occuring while the exhaust valve is open.. High EGT= higher head temps because the port soaks all that head up and spreads it over the heat... Better get this squared away or you'll be a statistic! |
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| Jake Raby |
Jan 31 2008, 09:02 AM
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#5
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
EGT- Exhaust Gas Temperature.
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| toon1 |
Jan 31 2008, 09:49 AM
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#6
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE(Jake Raby @ Jan 31 2008, 06:05 AM) QUOTE Does timing affect engine temps?, I swear my engine is running hotter... ABSOLUTELY!!!!! Timing is EVERYTHING to head and oil temps! TWO degrees can make 50+ degrees of head temp! Retarded timing = higher exhaust gas temps because the burn is slowed and is still occuring while the exhaust valve is open.. High EGT= higher head temps because the port soaks all that head up and spreads it over the heat... Better get this squared away or you'll be a statistic! (IMG:style_emoticons/default/agree.gif) I am doing an engine rebuild bacause of too much timing. These engines seem to like a little more advance on the bottom end, it's definitly snappier. BUT with a mech. dizzy, anything you do on the bottom affects the top. it don't take much on the bottom to go over the top (IMG:style_emoticons/default/biggrin.gif) I can't wait to get my enegine running with the EDIS system to play around with this |
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| Jake Raby |
Jan 31 2008, 09:56 AM
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#7
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE BUT with a mech. dizzy, anything you do on the bottom affects the top. it don't take much on the bottom to go over the top Thats why the Mallory Dizzy is my best selling product hands down :-) It allows more timing down low and limited advance up top.. Adding timing down low will TRICK the driver into thinking they are adding power across the board.. My dyno tuning DVD will show just how bad they screw themselves at peak torque and beyond as well as temps. |
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| toon1 |
Jan 31 2008, 10:13 AM
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#8
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE(Jake Raby @ Jan 31 2008, 07:56 AM) QUOTE BUT with a mech. dizzy, anything you do on the bottom affects the top. it don't take much on the bottom to go over the top Thats why the Mallory Dizzy is my best selling product hands down :-) It allows more timing down low and limited advance up top.. Adding timing down low will TRICK the driver into thinking they are adding power across the board.. My dyno tuning DVD will show just how bad they screw themselves at peak torque and beyond as well as temps. SLight Highjack , Sorry, Jake, since we are on the subject, is there anywhere I can find timing and advance curves for 1.7 running MS with a 36-1 wheel??? Sorry about the highjack |
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| ConeDodger |
Jan 31 2008, 10:16 AM
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#9
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Apex killer! Group: Members Posts: 23,613 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California 
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When I first got my 914 I let a supposedly knowledgeable mechanic work on it. He had the timing set sooooooooooooo advanced the wiring to the starter melted. But it ran well. This masked all the other problems that didn't get fixed. My clue that he didn't know what he was doing was the HEAT coming out of the engine bay.
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| KaptKaos |
Jan 31 2008, 10:42 AM
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#10
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Family Group: Members Posts: 4,009 Joined: 23-April 03 From: Near Wausau Member No.: 607 Region Association: Upper MidWest |
Jake,
I got one of your Mallory setup dizzys second hand. What should I set the timing to at idle and what should it be all in (and at what revs). Please let me know. Thanks, Joe |
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| purple |
Jan 31 2008, 10:50 AM
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#11
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Pigeon feeders attract me Group: Members Posts: 938 Joined: 24-July 07 From: Houston, TX Member No.: 7,942 Region Association: None |
As far as timing a mallory is concerned. I have one from Jake as well. my problem is static timing before firing the engine the first time. as in, the engine was apart and now back together and I can't figure out which way the rotor should point for what cylinder. I know both valves closed on #1 means it's getting close to TDC, but my engine was assembled poorly and i think it's 180* off. so i'm actually timing for #3 TDC i wish someone from houston would help me get this thing running again. i'm at my wit's end. it'll stumble a little when starting trying to get going, but then go back to cranking and never catching. please someone help me (IMG:style_emoticons/default/smile.gif) i'm about to load it onto a trailer and have someone else time it for me. mike callas at rennsport in sealy,tx
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| Spoke |
Jan 31 2008, 10:59 AM
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#12
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Jerry Group: Members Posts: 6,991 Joined: 29-October 04 From: Allentown, PA Member No.: 3,031 Region Association: None
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QUOTE(pete914 @ Jan 31 2008, 07:33 AM) single weber I had the same setup on my 1.7 when I purchased it. Worked ok. Then I got a set of used Weber IDF40's and it transformed the engine into something a lot more fun, more HP, and awesome sounding. It's still a turd but runs much much better now. And it looks a lot cooler with the duals. (IMG:style_emoticons/default/aktion035.gif) |
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| pete914 |
Jan 31 2008, 02:45 PM
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#13
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Member Group: Members Posts: 178 Joined: 21-August 07 From: east coast Member No.: 8,025 |
UPDATE: Wow, got home today and needed to run some errands (I ride my bicycle around town, teener is used for distant errands) and decided to advance the dizzy by ear. Started the car, let it warm up for about 5 minutes. Adjusted the dizzy slightly and the idle smoothed a little. Took it for a test drive and it's pulling in the lower RPM's like it used to now! I'll time it again when I put in the new distributor. Pretty stoked@!
I'm going to try to get dual's next...if anyone has a set, I'm looking. Want to have everything ready to go for the spring (isn't that what everyone says? haha). Very satisfying to start understanding these concepts. Thanks guys. ps- Jake, when I get out of dental school, I'm going to be calling you for a rebuild (IMG:style_emoticons/default/aktion035.gif) |
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| ConeDodger |
Jan 31 2008, 03:13 PM
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#14
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Apex killer! Group: Members Posts: 23,613 Joined: 31-December 04 From: Tahoe Area Member No.: 3,380 Region Association: Northern California
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QUOTE(pete914 @ Jan 31 2008, 12:45 PM) ps- Jake, when I get out of dental school, I'm going to be calling you for a rebuild (IMG:style_emoticons/default/aktion035.gif) Ummmm.... Jake is a little leary around dentists. (IMG:style_emoticons/default/biggrin.gif) |
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| toon1 |
Jan 31 2008, 04:25 PM
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#15
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
QUOTE(pete914 @ Jan 31 2008, 12:45 PM) UPDATE: Wow, got home today and needed to run some errands (I ride my bicycle around town, teener is used for distant errands) and decided to advance the dizzy by ear. Started the car, let it warm up for about 5 minutes. Adjusted the dizzy slightly and the idle smoothed a little. Took it for a test drive and it's pulling in the lower RPM's like it used to now! I'll time it again when I put in the new distributor. Pretty stoked@! I'm going to try to get dual's next...if anyone has a set, I'm looking. Want to have everything ready to go for the spring (isn't that what everyone says? haha). Very satisfying to start understanding these concepts. Thanks guys. ps- Jake, when I get out of dental school, I'm going to be calling you for a rebuild (IMG:style_emoticons/default/aktion035.gif) Make sure you know where that timing really is. It's all good by ear and feel but it needs to be right, or the frying of the motor will begin (IMG:style_emoticons/default/happy11.gif) |
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| EdwardBlume |
Jan 31 2008, 04:35 PM
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#16
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914 Wizard Group: Members Posts: 12,338 Joined: 2-January 03 From: SLO Member No.: 81 Region Association: Central California
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Does advancing the timing add HP too?
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| Jake Raby |
Jan 31 2008, 04:35 PM
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#17
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE the engine was apart and now back together and I can't figure out which way the rotor should point for what cylinder. If you would have followed my rebuild video the dizzy would have been installeed while the casde halves were still apart and you would not be having that issue... Pop off the valve cover, rotate the engine clockwise till the #1 intake valve open fully and closes fully. The next time the TDC mark comes back up that will be true TDC on cylinder #1.. remember the 4 strokes of the engine and the order they occur and then apply common sense :-) |
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| 2-OH! |
Jan 31 2008, 06:26 PM
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#18
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Senior Member Group: Members Posts: 552 Joined: 17-October 03 From: Santa Clarita, Kalifornication Member No.: 1,253 |
I will try not to highjack this thread but I think this question is germaine to the point:
As the motors (cars) get older, parts are exchanged or different mechanics perform creative adjustments, worn internals, new internals, etc... For those of us who have different combinations of cams, or carbs, or FI or distributors, how do you know when the timing is where it needs to be... By that I mean I have a Web Cam 73 and 1.7 heads but everything else inside has been converted to 2.0...Car runs great, pulls good throughout low and high range, idles very well and makes for a very good daily driver...The timing has been a challenge due to the bastardization of the motor...27 degrees will clatter the nuts loose, but at 9 degrees, she runs as described... Yes we would all like to have Jake motors, yes we would all like to have unlimited knowledge, but the facts are, we don't, won't, can't...Plus, Jake (and others in his field) live in search of the perfect motor...Great, we need those kinds of folks but there are those among us who cannot play in that arena... So, is there a sure fire method of determining exactly where the timing should be, so that a level 3 or 5 "do it yourselfer" will know the setting is correct ??? Ok, have your way with me... 2-OH! |
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| Jake Raby |
Jan 31 2008, 07:23 PM
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#19
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
QUOTE Yes we would all like to have Jake motors, yes we would all like to have unlimited knowledge, but the facts are, we don't, won't, can't...Plus, Jake (and others in his field) live in search of the perfect motor...Great, we need those kinds of folks but there are those among us who cannot play in that arena... And thats the reason for my DVD series www.rabyproductions.com LOL |
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| pete914 |
Jan 31 2008, 09:45 PM
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#20
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Member Group: Members Posts: 178 Joined: 21-August 07 From: east coast Member No.: 8,025 |
2-OH,
Co-Sign QUOTE(Jake Raby @ Jan 31 2008, 08:23 PM) QUOTE Yes we would all like to have Jake motors, yes we would all like to have unlimited knowledge, but the facts are, we don't, won't, can't...Plus, Jake (and others in his field) live in search of the perfect motor...Great, we need those kinds of folks but there are those among us who cannot play in that arena... And thats the reason for my DVD series www.rabyproductions.com LOL |
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