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Title: tuning advice/recommandation Post by: henk on August 31, 2015, 17:19:53 pm this weekend i had the change to put my '67 beetle on a dyno at an open house for a single run.
i must say i hoped that the results where a bit higher,on the other hand the engine is not really tuned in. i never changed the jets,so maybe somebody can give some advice on jets or anything else that i can try to get the horsepower up. i think the compression is maybe a bit low for the cam and it might be a bit to rich on the jetting right now but al the info is welcome. the result was 136hp at the crank and 120hp at the wheels the engine had his peak horsepower on 5800rpm wich is maybe a bit early with that cam as well. i added the print off the run as wel,so maybe you can see something in there. the engine is: - 82x90,50 - 42/37,50 round ported heads - FK-10 with 1.4 ratio rockers - 9,0:1 compression - bosch 010 with points - 1 5/8 header with fatboy - 48 IDA (F11/155/200/55) henk!!! (http://i60.tinypic.com/2en84di.jpg) Title: Re: tuning advice/recommandation Post by: Roman on August 31, 2015, 17:58:57 pm What is your venturi size?
Title: Re: tuning advice/recommandation Post by: Erlend / bug66 on August 31, 2015, 18:30:32 pm Looks like it's dead rich or lean on the transition between idle and main jets.
Title: Re: tuning advice/recommandation Post by: henk on August 31, 2015, 18:31:37 pm What is your venturi size? the venturi's are still the 37mm ones. henk!!! Title: Re: tuning advice/recommandation Post by: Roman on September 01, 2015, 09:06:41 am Looks like it's dead rich or lean on the transition between idle and main jets. It sure looks like it. Do you have the third progresion hole? If not do it. You can go up to 40 venturies and 165 to 170 main jet to get more power at the top, but I think there might be other problems as well. What's your total advance on the ignition? Title: Re: tuning advice/recommandation Post by: Erlend / bug66 on September 01, 2015, 10:43:34 am If the spring in the points is worn, it might not want to rev as high..
Upgrade to pointless ignition. Title: Re: tuning advice/recommandation Post by: henk on September 01, 2015, 11:55:15 am Looks like it's dead rich or lean on the transition between idle and main jets. It sure looks like it. Do you have the third progresion hole? If not do it. You can go up to 40 venturies and 165 to 170 main jet to get more power at the top, but I think there might be other problems as well. What's your total advance on the ignition? no,i don't have the third progression hole. so you think it is running lean now then? advance is now at 28° with the 010. henk!!! Title: Re: tuning advice/recommandation Post by: henk on September 01, 2015, 11:56:56 am If the spring in the points is worn, it might not want to rev as high.. Upgrade to pointless ignition. i use to run MSD,but it cut out all the time. gonna fix it and run it again. with the MSD i was running 30° advance. henk!!! Title: Re: tuning advice/recommandation Post by: Erlend / bug66 on September 01, 2015, 12:22:08 pm Something is happening on the transition..
Fix that. And have a steady spark.. I lost 15hp on the dyno when my MSD digital 6 plus box started to be stupid. With an old AL6 box, the sound is much better, and I can hear that the box is not screwing up the spark.. Title: Re: tuning advice/recommandation Post by: Fiatdude on September 01, 2015, 14:14:26 pm It's a shame that the dyno operator didn't include an AFR reading --- that would of taken all the guess work out of your tuning
Title: Re: tuning advice/recommandation Post by: Flakeyjake on September 01, 2015, 14:46:44 pm Hi Henk, its look like lean about 4500, my suggestion, 40 venturies with F7, 160/190, idle 60 :)
Title: Re: tuning advice/recommandation Post by: henk on September 01, 2015, 20:37:46 pm so it seems everybody thinks it is running lean.
gonna try to run it a bit richer then first and see what it does. @fiatdude:i thinking about buying a AFR-meter so then i'm sure to see what direction i have to go. but gonna try to run it richer first and fix the MSD. henk!!! Title: Re: tuning advice/recommandation Post by: Airspeed on September 01, 2015, 21:05:15 pm 9.0:1 CR? You planning going turbo Henk? ::) :D
Title: Re: tuning advice/recommandation Post by: henk on September 01, 2015, 21:38:51 pm 9.0:1 CR? You planning going turbo Henk? ::) :D haha,i know it should be a bit higher like 9,5 to 10,0,but we build it at the safe side. maybe i look to raise the compression still,but even with the 9,0 i think the hp should be a bit higher. henk!!! |