Stoffregen Motorsports Posted September 10, 2019 Report Share Posted September 10, 2019 We used JE and Wiseco mostly. I think at some point we used Cosworth pistons too. The problem for you is that these were custom domed pistons built for lots of compression and long rods. Custom forged pistons in a street engine are not always a good idea though. A modern OEM cast piston can usually run tighter piston to wall clearance, which keeps piston knock down. If you must use forged pistons, the secret to long life is in the ring pack. When you call, ask the sales person what they would recommend for street use. Quote Link to comment
alexg89 Posted September 10, 2019 Author Report Share Posted September 10, 2019 On 5/24/2019 at 12:55 AM, scooter said: so after reading this whole thing, I think you need to go to a 70f8 jet and turn your needles in. the idle jets do both the progression and idle. to fix your idle, turn your idle needles in till max rpm and back them out 1/4-1/2 turn ish. you need to get rich enough on 15-20% throttle that its not popping back through the carbs... it would be nice to get close to stoch in light throttle but you can pretty much forget about that. the best luck with my side drafts has been running 12.5:1-13:1 afrs throughout the range, including idle. if slow press to 15% throttle results in surging or popping you need to go up on the idles. you can try changing F numbers as well. if it doesnt sound crisp and its blubbery and has black plugs then go down, but you shouldnt get carb backfires from being too rich. i think it needs bigger mains as well. how is it WFO from lowish rpm (2500) to redline? i could see a 160 main and 190 air corrector being very close... depending on your altitude. there could be a whole thing started with emulsion tubes as well. considering the size of it and the ve% of a ka vs an L it may be beneficial to go to F2 emulsion tubes. I wonder what it would it be like if you locked the dizzy too (peak timing all the time) your second video sounds great. keep it up. buy the big kit from redline. be the butt dyno, you should be able to tell a difference in a single size jet change. Scooter also im at sea level.. im in Cocoa beach as close to the water as it gets lol im gonna mess with these jets again since ive put the cam in and try to get it to cooperate a little more Quote Link to comment
alexg89 Posted September 10, 2019 Author Report Share Posted September 10, 2019 5 hours ago, Stoffregen Motorsports said: We used JE and Wiseco mostly. I think at some point we used Cosworth pistons too. The problem for you is that these were custom domed pistons built for lots of compression and long rods. Custom forged pistons in a street engine are not always a good idea though. A modern OEM cast piston can usually run tighter piston to wall clearance, which keeps piston knock down. If you must use forged pistons, the secret to long life is in the ring pack. When you call, ask the sales person what they would recommend for street use. Awesome .. when i call them ill ask ..Thank you sir Quote Link to comment
alexg89 Posted October 14, 2019 Author Report Share Posted October 14, 2019 well guy that did my head has been taking his time .. so i may get it back this week.. As for jets ive been fooling around with them but ill be damned if i cant figure this thing out still lol i have 160 main and 185 air corrector now.. took the idle down to a 60f8 and it seems to have helped with low end performance but im back to a shitty transition and its leaning out again. Im guessing i was able to make the lean transition with more fuel but it was blubbery and sluggish with the 70f8s in it I have the idle screw just cracked so the butterflys arnt resting on the carb housing and i have the air adjusters opened i think 2 turns so it will at least idle at like 600rpm Ive been searing high and low in my area and noone deals with webers .. anyone live in the central fl area with some more jets and has a weekend to come give a guy a hand lol Quote Link to comment
Crashtd420 Posted October 14, 2019 Report Share Posted October 14, 2019 I just recently ran my truck across a dyno and did some playing with the jets air correctors and emulsion tubes..... While I could move the fuel numbers around with the main and air corrector I could never get rid of my transition stumble..... I ended up going with f7 emulsion tubes and my transition is so much better..... I think I posted an explanation from distributorguy and I can say he was spot on describing the circuits..... I'll look back and see , if not I'll post again... Right now what emulsion tube are you running? Quote Link to comment
Crashtd420 Posted October 14, 2019 Report Share Posted October 14, 2019 Yup go back one page and read that post.... 1 Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 14 hours ago, Crashtd420 said: Right now what emulsion tube are you running? I have the f2 tubes right now Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 15 hours ago, Crashtd420 said: Yup go back one page and read that post.... Read and noted Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 This is what gets confusing.i found this .. and what the carbs came with was an F16 .. and i have F2s in it now.. which way do i go lol "For each size of idle jet there are a range of air bleed alternatives available. The ones in normal use are F2, F8, F9 and F6. Generally speaking start your selection with an F9 air bleed. A full list of the various ‘f’ numbers as it relates the rich to lean running is shown in Figure. The most commonly used air size designations, running from weak to rich. Those in most normal use are shown in bold. Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 This page has good info but for what i have the information isnt there .. i have a 2.4l and everything kinda stops around 2000ccs so it leaves me guesssing https://cnx.org/contents/oKbaEWQ3@2/Selection-and-Tuning-of-Weber-DCOE-Carburetors Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 1 hour ago, alexg89 said: This is what gets confusing.i found this .. and what the carbs came with was an F16 .. and i have F2s in it now.. which way do i go lol "For each size of idle jet there are a range of air bleed alternatives available. The ones in normal use are F2, F8, F9 and F6. Generally speaking start your selection with an F9 air bleed. A full list of the various ‘f’ numbers as it relates the rich to lean running is shown in Figure. The most commonly used air size designations, running from weak to rich. Those in most normal use are shown in bold. Now that's weird I have a chart that says the f7 is richer than the f8.... I went from F11 to F8 then F7.... Every time it closed the transition gap ... I'll post the 2 charts I was looking at on my morning break .... Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 Wait we are talking emulsion tubes right.... I hate how idle jets also have f #s... Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 1 minute ago, Crashtd420 said: Wait we are talking emulsion tubes right.... I hate how idle jets also have f #s... That is correct Emulsion tubes Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 I'll look at my weber book later... I feel like the f# chart you posted is the idle jets but I could be wrong... By the chart I have I believe you need f8 tubes..... Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 3 minutes ago, Crashtd420 said: I'll look at my weber book later... I feel like the f# chart you posted is the idle jets but I could be wrong... By the chart I have I believe you need f8 tubes..... I believe you are correct now that i went back and read through that link again i posted.. my bad Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 So at 597 cc per cylinder i should bump up to f8s instead of the f2s i have Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 1 hour ago, alexg89 said: So at 597 cc per cylinder i should bump up to f8s instead of the f2s i have I think so..... since I have a single side draft on an l16 ( i combined 2 cylinders for 800cc) I went with the f7 and that worked good for me.... My take on it is the emulsion tube moves around where the mains kind of start working.... Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 23 minutes ago, Crashtd420 said: I think so..... since I have a single side draft on an l16 ( i combined 2 cylinders for 800cc) I went with the f7 and that worked good for me.... My take on it is the emulsion tube moves around where the mains kind of start working.... This may be my key to success lol cause like i said with the smaller idles in it, its not so sluggish.. so f8s then i could come down on my mains maybe and get it a little leaner up top .. afr is just pig rich all the time lol now granted its only on cylinder 2 and im basing the rest of the mixtures off of that but it puts me in the ball park.. Recently got a Vband for the exhaust so im not using a band clamp and once thats on ill get an 02 bung down stream Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 Basically yes.... Remember if you go leaner on your main watch the top end.... you may have to go richer with your air corrector..... That's what I need to do.... The emulsion tube will move the curve not neccessary make it running richer but will make things richer sooner.. the main and air corrector with adjust the air/fuel at that point..... ... The top end is actually pretty easy once you get the transition right..... I hate spending other peoples money if I'm wrong but I do believe the f8 tube will get you closer to your goal.... I know some people say those are the last thing to change but in my honest opinion they need to be correct before you can choose the right idle, main and air correctors.... Quote Link to comment
alexg89 Posted October 15, 2019 Author Report Share Posted October 15, 2019 I wholeheartedly believe that its gonna help .. when i went from the f16s to the f2s it made a huge difference .. and if the f2s cant keep up because of CC's then it only makes sense I have to mask the transition with to much fuel which in turn makes it sluggish and non responsive 1 Quote Link to comment
Crashtd420 Posted October 15, 2019 Report Share Posted October 15, 2019 I would have to agree with you..... You last statement is basically what was happening to me.... I could put fuel in everywhere except where I needed it.... Hopefully the f8 is enough.... Quote Link to comment
alexg89 Posted October 16, 2019 Author Report Share Posted October 16, 2019 16 hours ago, Crashtd420 said: Hopefully the f8 is enough.... Thats what im hoping for.. time will soon tell and i shall report back ! Quote Link to comment
alexg89 Posted October 18, 2019 Author Report Share Posted October 18, 2019 Well stuck them in and it seemed to help out up top alot but i still have this transition bullshit.. and i stuck the fat idles back in and its still an issue.. And to add to it i think i had mains and acs to big on both.. it would bog under load and miss real bad up top .. went down on both 1 size and it helped alot.. but this transition thing is absolutely unreal Quote Link to comment
alexg89 Posted November 6, 2019 Author Report Share Posted November 6, 2019 found some interesting info out there may be helpfull in my case Hey... I just did the TWM DCOE 45 152 conversion.... I ended up with smaller chokes... I started with 36mm, moved to 30mm, then tried 32mm, and lastly 34mm...L24/E88 mild cam engine....best was 34mm... 145HP at 7k RPM30mm GREAT STREET chokes... smooth transistion to mains at <2kRPM32mm better performance... slight increase in peak HP smooth transition at 2.2k RPM34mm Track performance... slight increase again in peak HP@>RPM.. poor transistion at 2.8kRPM36mm POOR PERFORMANCE... huge hole in my HP graph... no change in peak HP.==============================================as you increase choke ID.. the entire system becomes less predictable...bigger chokes need bigger fuel jets... they also need larger air bleeds at high RPM... the bigger you go... the harder it is to get a good transition from low speed circuits to high speed circuits... and the transistion off idle becomes leaner and leaner...The 152, made in Spain versions of these carbys seem to be set up for larger displacment/higher vacuum engines than the early Italian versions. The DCOE 152 transition holes ahead of the idle port are quite different than in the earlier models. This may be why so many people report having a flat spot just off idle...in addition... the drilling of these holes was performed AFTER the installation of the throttle plates... if your carbys have had the plates removed then the holes may not all line up properly any more....Also.... the proper way to set idle speed is NOT with the "idle speed" screw... I know you are thinking... WTF.. that is why they put that screw there.... well... it is something that can be used to set idle speed... but there is another way to ensure that the transition holes are opening at the proper times.=======Set the throttle plates to just cover the first transition holes... then choose idle jets to control both fuel AND air flow into the idle circuit.... the air balance screws can then be used to set low-flowing throttle bores to match the higher flow bores... these air balance screws are unique to the DCOE152 series.. and they are very useful.... REMEMBER.. these screws should all initially be closed.. get the engine running well and then FINE tune the flow through a UNISYN meter using the airbleed balance screws on the low flow throats ONLY...if you are having trouble synchronizing the idle flow from carb to carb then check the linkages for binding.. .if you cant get a particular carb to flow the same on both bores... then check that the air bleeds are clean and unobstructed... or check compression on that cylinders involved... Quote Link to comment
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