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| jet for a 1920 on a 82 d150 https://www.slantsix.org/forum/viewtopic.php?t=50308 |
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| Author: | enrique lopez [ Mon Nov 12, 2012 12:23 pm ] |
| Post subject: | jet for a 1920 on a 82 d150 |
hi, I am running a holley 1920 on my stock 82 d150. It has 3.5 gears in the rear end and tires are 235/75 r15. I do a lot of city driving and once in a month I take a long 3 1/2 hour highway trip. My truck is my toy, I tinker with it constantly. I would like to know what jet I should have on my slant 6 for best fuel economy. I have a 62 jet on it now, I had a 58 on it for a while (loved the economy), but the truck hesitated for a bit when taking off. I would greatly appreciate any info on the subject. thanks a lot... |
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| Author: | Reed [ Mon Nov 12, 2012 12:36 pm ] |
| Post subject: | |
Try a 60. |
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| Author: | enrique lopez [ Mon Nov 12, 2012 12:41 pm ] |
| Post subject: | |
i have considered a 60. I just was wondering if there was a better way to calculate the proper jet size? Or does everyone go trial and error on this subject? |
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| Author: | SlantSixDan [ Mon Nov 12, 2012 1:02 pm ] |
| Post subject: | |
Try it, read the spark plugs, try it again. There's no calculation to be done. If the truck ran well with the 58 except for acceleration stumble, why not put the 58 back in and increase the accelerator pump shot by adjusting the accelerator pump linkage? Carburetor operation and repair manuals and links to training movies and carb repair/modification threads are posted here for free download. |
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| Author: | enrique lopez [ Mon Nov 12, 2012 1:05 pm ] |
| Post subject: | |
The reason for my question is mainly because I read the posts on this forum a lot.... This is were I get my ideas on what I would like to do to my truck... Not all the ideas turn out great,, but I have fun learning and doing... I have read threads were people have gone UP in jet size to improve fuel economy,,I want to make sure I'm moving in the right direction with jets and not the opposite. I will try the 58 jet and adjust the accelerator linkage as you suggest,, thanks again for the info and a bigggg thanks for all the time you invest (all of you) helping us with our problems,, My truck runs a lot better thanks to this forum. You have done more for my truck than any mechanic has. |
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| Author: | Aggressive Ted [ Mon Nov 12, 2012 1:39 pm ] |
| Post subject: | |
Quote: I will try the 58 jet and adjust the accelerator linkage as you suggest,,
This advice from SL6Dan is really important. It can make a real big difference. He suggested this to me years ago and it really, really made a big difference! Take the slop out of the linkage and make sure the accelerator pump arm moves freely on the shaft. Sometimes folks don't oil that pivot shaft for the cam and it can build up rust making the accelerator pump bind and sluggish....Mine is lightening fast and will break both P215-70R tires loose. As you see, I run a #57. |
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| Author: | SlantSixDan [ Mon Nov 12, 2012 2:25 pm ] |
| Post subject: | |
The linkage is never supposed to be oiled. Oil collects dust and grit—no good. If you feel you must lubricate the linkages, use a good brand of spray silicone, which is non-greasy and won't attract dust or grit. There are three holes in the throttle lever where the accelerator pump linkage connects: outer, middle, and inner. The inner hole gives the shortest pump stroke. The outer hole gives the longest pump stroke. Before you try bending or otherwise tweaking any parts, try moving the pump link to the next-outer hole from where it is now to get a longer pump stroke. Also, while you have the carb apart to change the jet, grasp the accelerator pump drive spring between two pairs of needle-nose pliers and carefully stretch it so it's a little longer. Do it carefully so you don't spoil the spring tension. This will drive the pump diaphragm more briskly. Also make sure your distributor vacuum advance is in good shape, hooked up to the correct port, and timing is set correctly. That all has a large effect on acceleration. And the thermostatic air cleaner assembly should also be intact, hooked up correctly, and working. |
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| Author: | DusterIdiot [ Mon Nov 12, 2012 8:39 pm ] |
| Post subject: | x2 |
Quote: If the truck ran well with the 58 except for acceleration stumble, why not put the 58 back in and increase the accelerator pump shot by adjusting the accelerator pump linkage?
Off idle stumble indicates a lean out from the idle through the transition circuit which is 'covered' by the acc. pump shot...Dan's hit it on the head either change the linkage to increase the shot or bring the timing of the shot on sooner...The only other cause could be a vacc leak somewhere.If you're running a stock motor the #58 should be enough for the smaller CFM of the Holley 1920... -D.Idiot |
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| Author: | enrique lopez [ Tue Nov 13, 2012 12:33 pm ] |
| Post subject: | |
ok. I will make the adjustments. Thanks for the info.. I have enough info on the subject, I'll take it from here. Keep on slanting!!! |
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