Any experienced engine tuners able to assist?

[Ron Sutton]

No.

But just so I'm informed ... I think you had the idle fuel adjustment screw out 2 full turns. Where did you adjust them to?

[Ron Sutton]

i did readjust the idle screws back in the get the desired 900 rpm, would that have anything to do with it

No.

But just so I'm informed ... what did you adjust the idle screw to?

[benno505]

just found a problem as the missus started the car i seen sparks goiung from the number 7 & 5 leads to the headers, ii got a big jump out of it haha, i will replace these i think.

taking the family out for a few hours, wont get back to the car until later, so will probably talk to you tomorrow,

anything else you want me to do in the meantime?

[benno505]

No.

But just so I'm informed ... what did you adjust the idle screw to?

haven't touched them there still at 2 turns out

[Ron Sutton]

just found a problem as the missus started the car i seen sparks goiung from the number 7 & 5 leads to the headers, ii got a big jump out of it haha, i will replace these i think.

taking the family out for a few hours, wont get back to the car until later, so will probably talk to you tomorrow,

anything else you want me to do in the meantime?

HaHa ... I wished I had seen that. If you're going to seriously hurt yourself ... do me a favor ... and ask your wife to video it. We all need a little laugh now & then.

No worries. Let us know when you have that fixed & we'll pick up from there.


Ron Sutton

[benno505]

done running a bit better haha, started it covered both choke horns it shut off, restarted it then turned it off and it didn't overrun

[Ron Sutton]

Cool. I thought you were taking the wife out to dinner?

[benno505]

actually taking the wife and son to the show in about 20 mins.

[Ron Sutton]

Actually ... I guess in your time zone ... lunch?

[benno505]

took her for a big drive today after I attempted tuning the A/F mixtures im I turned them in the vacuum got lower so I turned them out to 2.5 turns it didn't seem to get much higher than 5. and at 5 it was very steady needle on the gauge. went for the big drive and was hard to start had to hold throttle down and everytime I turned it off it overran really bad. but it did drive pretty well through the rpm range,
when putting around you can see fuel smoke coming out the exhaust when it is hot.

[Ron Sutton]

took her for a big drive today after I attempted tuning the A/F mixtures im I turned them in the vacuum got lower so I turned them out to 2.5 turns it didn't seem to get much higher than 5. and at 5 it was very steady needle on the gauge. went for the big drive and was hard to start had to hold throttle down and everytime I turned it off it overran really bad. but it did drive pretty well through the rpm range,
when putting around you can see fuel smoke coming out the exhaust when it is hot.

It's still too rich on the primary sides of the carbs & is most likely very rich on the secondary sides of the carbs. Did you experience any detontation?

[Ron Sutton]

Do a little "process of elimination" test for us, to narrow down the cause of run on. Set the timing at 10° & set the idle at 900rpm ... and shut it off a couple times. Then Set the timing at 20° ... and shut it off a couple times.

This will help me to understand if the run on is caused by the carbs still allowing too much air or preignition.

[benno505]

no detonation what so ever, and I had the rpm upto 5800 it picks up speed very quick with all 8 butterflies open,
I still haven't checked for vacuum leaks, was hoping you had an accurate way to do this.

when I was first driving around for the first 15 mins it was bogging a lot when I took off from the lights etc. I forgot to mention sorry, but after about 30-60 mins this sort of went away.

[benno505]

also Ron I want to put 2 x 2" spacers under the carbs to get the air cleaner in through the hole in my reverse cowl and lift the air cleaner away from the distributor, which type would you recommend and does this affect any tuning?

here is some pics for you.

[Ron Sutton]

Man, Ben, that car looks great. Awesome engine too.

Did you do the little "process of elimination" test for us?

... to narrow down the cause of run on. Set the timing at 10° & set the idle at 900rpm ... and shut it off a couple times. Then Set the timing at 20° ... and shut it off a couple times.

This will help me to understand if the run on is caused by the carbs still allowing too much air or preignition.

[Ron Sutton]

Also Ron I want to put 2 x 2" spacers under the carbs to get the air cleaner in through the hole in my reverse cowl and lift the air cleaner away from the distributor, which type would you recommend and does this affect any tuning?

That would be a good move. I like the "Super Sucker" spacers from HVH best, because they do a lot of testing & have developed units that increase the torque, throttle response, atomize the fuel better & improve the signal to the carb. Part #SS4150-2AL is the 2" tall "solid version" & #SS4150-2ALW is the lightweight version.

Yes, these will definitely affect the final carb tuning. But lets carry on with our tuning steps.

1. We need to confirm the cause of the "run on" ... either to much air past the throttle blades (have a cure for you) ... or vacuum leak (have a method to test for you) ... or there are hot spots in the cylinder causing pre-ignition (which is why I need to do the 10* & 20* timing tests).

2. You leaned the primaries ... but they will need more. This step will depend on the cause of the run-on.

3. We'll want to finalize static timing, timing advance amount & rate & total timing. Can't do this until #1 & #2 are done.

4. The secondaries should also be way too rich. Need 1-3 done to dial this in.

[benno505]

Ron,
Havent been able to do these tests yet and wont be able to get to them until tomorrow,
i will get the outcome to you.

you want me to do the timing test before i hunt for vac leaks?

thanks Ben

[Ron Sutton]

Thanks for the update. No hurry. I'm on your schedule.

Vacuum leak test first. With the engine running, spray carb cleaner (with the little nozzle tube) slowly along the edges of the intake manifold & carb mating surfaces. If the idle picks up anywhere, you have a leak.

Also ... with the engine running ... cap any vacuum hose, 1 at a time. If the idle picks up anywhere, you have a leak.

[benno505]

Okay thanks Ron,

what are you working on a 57 chev? got a build thread?

Ben

[Ron Sutton]

Top secret NASA/CIA spy stuff.

I'm designing a new car for myself ... less Pro Touring ... more Street Warrior for driving & competing in events like AutoX, Road course track day events, all-around street car competitions & Silver State Challenge, which my daughter is going to do with me.

I'll do a thread on it when I get it going.