Search found 488 matches
- Thu Oct 22, 2020 2:42 pm
- Forum: Engine Tech
- Topic: Ignition advance at cruise rpm?
- Replies: 60
- Views: 6881
Re: Ignition advance at cruise rpm?
Lots of variables to consider, but probably in the neighborhood of 10-15 degrees more than the mechanical is providing at that RPM. If you are all in at 35 degrees at 2500, then you could prolly be at 50 degrees or so when cruising
- Sat Oct 17, 2020 7:49 pm
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
Great question! Poorly atomized fuel and bad wet flow characteristics have a big impact. But last time I tried to stick my head in the combustion chamber which the engine running ended poorly, so I have to imagine what is going on based off of experience (of my own as well as others). Testing timin...
- Thu Oct 15, 2020 2:25 pm
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
GTR, What intake, carb & spacer are you using? How does it run now compared to when you posted a year or so ago that it was surging at cruise before the new cam? RPM air gap QFT 1050 1 inch 4 hole phenolic spacer Runs best it ever has. Bucking/surging all but eliminated. Very happy with it. The...
- Thu Oct 15, 2020 6:50 am
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
What is your altitude? The higher, the more timing is needed. Is your WOT-AFR maybe a little lean? Dont go leaner than 12.5. Could also contribute to timing hunger of the engine... What pump gas exactly? 93? Burns slower so more timing can be necessary. remember: measured from the perfect amount of...
- Thu Oct 15, 2020 6:50 am
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
GTR, What intake, carb & spacer are you using? How does it run now compared to when you posted a year or so ago that it was surging at cruise before the new cam? RPM air gap QFT 1050 1 inch 4 hole phenolic spacer Runs best it ever has. Bucking/surging all but eliminated. Very happy with it. The...
- Wed Oct 14, 2020 9:27 pm
- Forum: Engine Tech
- Topic: power valve circuit myths
- Replies: 39
- Views: 4542
Re: power valve circuit myths
If the power valve opens at 8.5 and he's idling at 6, the valve will sit there open but not flowing until there's enough depression to draw from the boosters, correct? Yeah I think this is true. I had my main jets fall out once and the car ran fine until the main circuit was activated. AFRs were de...
- Wed Oct 14, 2020 9:05 pm
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
It’s 0.035, plugs are bkr5e
- Wed Oct 14, 2020 7:13 pm
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
Performance engines are spoiled brats. When you give them what you want they are pains in the neck. Give them what THEY want and they are great ( just like my kid). Compression, cam event timing, chamber shape, spark plugs used, measured squish, fuel and afr, intake design and many other variables ...
- Wed Oct 14, 2020 7:07 pm
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Re: Ignition timing questions
The strange thing (to me) is that the optimal timing curve seems fairly advanced compared to almost all the recommendations I see for timing... ...All the recommendations I see out there for an engine like mine are in the range of 14-18 initial, 34-38 all in. If I use those settings the engine feel...
- Wed Oct 14, 2020 10:24 am
- Forum: Engine Tech
- Topic: Ignition timing questions
- Replies: 22
- Views: 2838
Ignition timing questions
Just throwing out some thoughts/questions for discussion. I have a 9.5:1 big block chevy, aluminum heads. It has a Jones HR cam, 110 separation, .600 lift, 240-ish duration at 0.050 makes about 160 psi cranking pressure. The engine runs magnificently, pulling hard from down low to well north of 6000...
- Wed Sep 02, 2020 1:55 pm
- Forum: Show & Tell
- Topic: Show us your Race Car(s)
- Replies: 134
- Views: 103729
Re: Show us your Race Car(s)
Love the color. Very clean.
- Thu Aug 27, 2020 3:30 pm
- Forum: Show & Tell
- Topic: A little outside the norm for this forum (racing karts)
- Replies: 2
- Views: 2647
Re: A little outside the norm for this forum (racing karts)
I'd like to share something that just happened over the last few days. Way back in the early 90's when I was a teenager, we started racing dirt track karts. There was an unlimited class and my dad ended up building 6-7 500cc two stroke powered dirt karts, of which one was mine. We raced as a points ...
- Thu Aug 13, 2020 11:51 am
- Forum: Engine Tech
- Topic: preventing fuel from boiling in the carb
- Replies: 22
- Views: 2680
Re: preventing fuel from boiling in the carb
Are you using a mechanical fuel pump? If so, these pump insulators have shown to be effective. www.summitracing.com/parts/ctr-85-000 https://www.summitracing.com/parts/ctr-85-010 I use this mechanical pump insulator, I have a restricted return line after the fuel log. Also, a 1 inch phenolic spacer...
- Thu Aug 13, 2020 7:00 am
- Forum: Engine Tech
- Topic: preventing fuel from boiling in the carb
- Replies: 22
- Views: 2680
Re: preventing fuel from boiling in the carb
Guys, When running a carb I've seen numerous issues with the carb getting heat soaked after shutting the car down for a short time and then restarting. Not sure what happens, but I assume that the lead free fuel starts to boil in the carb due to it getting heat soaked and the vapours ending up in t...
- Tue Aug 11, 2020 2:17 pm
- Forum: Offtopic Forum
- Topic: All time favorite song.
- Replies: 108
- Views: 70654
Re: All time favorite song.
Super hard question, I will answer with a twist: Favorite Classic Rock Song: https://www.youtube.com/watch?v=-sUXMzkh-jI Favorite soul: https://www.youtube.com/watch?v=ho7796-au8U Favorite Hip Hop: https://www.youtube.com/watch?v=wai13EbZCCM&list=OLAK5uy_l1ZbIBceHVeub4bT3edWQ4ccSoa1-voZc Favorit...