John, the AFB in my 60 Electra drys out after 2 days. Bone dry. Same with my 62 Bonneville. Both RAM cars seem to keep fuel longer, carbs not on top of engine.
Now get this! The WCFB in my 56 Fleetwood and 4GC in my Impala do not dry up. They restart immediately a month later...
So there's that.
Danny Plotkin
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: John Grady <jkg@xxxxxxxxxxxxxxxxx>
Date: 6/15/23 9:48 AM (GMT-05:00)
To: dplotkin <dplotkin@xxxxxxxxxxxxxxxxxxx>
Cc: James Douglas <jdd@xxxxxxxxxx>, "Chrysler 300 List Server (chrysler-300-club-international@xxxxxxxxxxxxxxxx)" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Subject: Re: {Chrysler 300} Shutdown fuel perk
this is interesting , but many theories make no sense . I have a 60 buick 401 that has always done this . Hard start especially after sitting , carb was on and off several times . I thought a crack or internal leak , as even after a week it would take a very long crank , distressing to you if far from home . Carb was apparently empty . But you are not sure flooded or empty ? pulling air cleaner is often inconclusive as some gas has come up from first crank . Been there, add in ? closed choke etc
First , even if fuel “ boiled in the bowls” which may happen just after shutdown , ( called “ hot soak” ) especially if you have typical rusted shut exhaust heat valve , — the boiling can’t be so aggressive as to raise bowl gas level enough to run into engine . Remember all paths to venturi involve air vents in their path ( those open brass tubes) and vacuum to lift the fuel up . That vacuum is not there sitting . Gas is below any path to venturi .
I think modern gas has such a high vapor pressure it just rapidly evaporates, a matter of a day (?) leaving a dry carb . But within an hour choked a rich start would happen . If fuel pump is perhaps lower in flow than optimal takes time to refill maybe all this is normal , with 2023 fuel —what I think now ( if exhaust heat is ok) — just shut that heat off permanently unless you live in alaska .
It goes back to 20’s and 30’s when fuel could be like kerosene .
I am rebuilding a packard with stock 37 hot spot intake design like a slant six . I separated the manifolds and machined 1/4” off the exhaust and closed top hole with a bolted steel plate , threw away huge heat riser valve . I expect more hp and no problems with a cooler intake . See also Edelbrock air gap manifolds . They simply outperform heated ones . Right idea . Cool intake flow .
Related , “ vapor lock” as a term is so misunderstood it is unreal . First , the line from pump to carb is under 3 psi pressure , if inlet float valve in carb opens any gas vapor air anything in that line is going to run right through pushed by pump and out that open end . When one sees THIS line insulated etc , it shows a lack of understanding .
But , if suction line near fuel
pump or pump itself gets warm , the suction impact will significantly lower boing point a lot and then you have vapor which the pump cannot move very well , flow stops . This is why electric pumps help real vapor lock by pressurizing what was the warm suction line . But don’t run it through the mechanical pump as a diaphragm rupture means a big fire 🔥 .
This subject could go on , but i have fought random fuel flow stopping in a 50 stude with a 354 hemi for a long time . Finally got into it this week — electric Carter pump , changed it , large 100 micron SS alcohol dragster type stainless mesh filter stead of pump clean as can be no restriction still erratic flow . All lines good no mechanical pump .
After gas tank in and out 2 nd time , we found the line inside the tank (!) was partially full of that same tan/ white residue one finds sometimes in our carbs . It can form a kind of mud deposit . I think ethanol is the culprit when sitting . Some chemical thing goes on with steel or galvanized steel yielding that powder ; also why AFB accell pump check valve sticks .
I am going to try suggestion of marvel oil , i admit to cynicism but why not ? Nothing to
lose .
So insulate suction line near fuel pump , packard had a large thin steel wing between fuel pump mount and block sort of a hot air shield maybe 6 “ projection and heat fin . Jesse Vincent ( Packard Engine designer ) was a genius , we might copy that .
Also stude V8 has fuel pump on top of engine with resulting long suction pipe in hot place . Guess what brand vapor locks all the time ?
thoughts welcome
John
Sent from my iPhone
On Jun 15, 2023, at 8:37 AM, dplotkin <dplotkin@xxxxxxxxxxxxxxxxxxx> wrote:
James, the Corvette folks I deal with use those spacers with good results.
Dan
Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------
From: 'James Douglas' via Chrysler 300 Club International <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Date: 6/15/23 8:34 AM (GMT-05:00)
To: dplotkin@xxxxxxxxxxxxxxxxxxx
Cc: "Chrysler 300 List Server (chrysler-300-club-international@xxxxxxxxxxxxxxxx)" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Subject: RE: {Chrysler 300} Shutdown fuel perk
Hi Danny,
The problem does not happen in my garage in San Francisco. Of course, the temp there is between 60F and 65F 99% of the year. In Winters when it gets over about 85F I notice it.
James
From: dplotkin@xxxxxxxxxxxxxxxxxxx <dplotkin@xxxxxxxxxxxxxxxxxxx>
Sent: Wednesday, June 14, 2023 5:13 PM
To: James Douglas <jdd@xxxxxxxxxx>
Cc: Chrysler 300 List Server (chrysler-300-club-international@xxxxxxxxxxxxxxxx) <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Subject: RE: {Chrysler 300} Shutdown fuel perk
My understanding of percolation is boiling fuel bubbling out into the throttle bores after hot shutdown, flooding the engine and causing a hard hot restart. Is that your experience?
Any pre-emission V8 parked hot in a sealed garage will smell of fuel for several days or as long as it takes for the bowls to dry out.
Danny Plotkin
-----Original Message-----
From: "'James Douglas' via Chrysler 300 Club International" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Sent: Wednesday, June 14, 2023 7:50pm
To: "Chrysler 300 List Server (chrysler-300-club-international@xxxxxxxxxxxxxxxx)" <chrysler-300-club-international@xxxxxxxxxxxxxxxx>
Subject: {Chrysler 300} Shutdown fuel perk
In San Francisco it has never been an issue with fuel perk on shutdown. Too cool 99% of the time. However, at our Winters house, in the Sacramento valley, when I park the car
in the garage and close it up, I can smell the gas for a couple of hours.
Has anyone had any luck using a something like this:
PS, I do plan on sleeving all the steel fuel lines from the frame rail up to the fuel pump and carb at some point. But that will do little for the perk.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit
https://groups.google.com/d/msgid/chrysler-300-club-international/CY5PR19MB617113FB034F0FCFC52DDE2D935AA%40CY5PR19MB6171.namprd19.prod.outlook.com.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit
https://groups.google.com/d/msgid/chrysler-300-club-international/CY5PR19MB617173AAF266D8FEDDCA8AF0935BA%40CY5PR19MB6171.namprd19.prod.outlook.com.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit
https://groups.google.com/d/msgid/chrysler-300-club-international/648b05fc.050a0220.28a46.be65SMTPIN_ADDED_MISSING%40gmr-mx.google.com.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit
https://groups.google.com/d/msgid/chrysler-300-club-international/4047CF7B-6CFC-4B09-8036-AF712480CC51%40gradyresearch.com.
--
For archives go to
http://www.forwardlook.net/300-archive/search.htm#querylang
---
You received this message because you are subscribed to the Google Groups "Chrysler 300 Club International" group.
To unsubscribe from this group and stop receiving emails from it, send an email to
chrysler-300-club-international+unsubscribe@xxxxxxxxxxxxxxxx.
To view this discussion on the web visit
https://groups.google.com/d/msgid/chrysler-300-club-international/648b1af9.050a0220.c86d2.39aaSMTPIN_ADDED_MISSING%40gmr-mx.google.com.
Back to the Home of the Forward Look Network
Archive Sitemap