Hey guys,
This is my first post on the forum. I have a 65 chevelle with a 327 I run E85 on with a 750 DP carb w/o choke. Rob Mix built it, but I have had to make some mods to get this thing right (and still isn't right), and I am having a terrible time with a lean bog right now. If I could go back, I'd have Mark S build me one but that's neither here nor there.
It's also FLAT/doesn't build power on the upper rpm range.
I have an AFR that I just installed.
My motor is built pretty solid with a cam with a little overlap, decked block, shaved/ported heads, about 12.5-13-1 compression, 4.10 rear th400 with shift kit. If you need more info on any of this let me know.
My initial set up from Rob was:
Air bleeds: 31/68
PVCR: .067
Jets: 89/99 (rear has extensions)
PV:4.5 front (rear is blocked)
IFR: .041
Boosters: 157 ( maybe a little small)
accel pump(s): 30 cc
squirters: 45 (I have tried 42's without luck)
Can't get the thing to idle without the following changes and I have to go in more than 3/4 turn on the 4 corner idle which gives me about .9 lambda and 13 inches of vacuum. I made the following changes, but left everything else the same:
Air bleeds: 31/67
Jets: 83/94
IFR: .035
Any of you guys running a similar combo that have had luck with your settings, or does anyone have any advice. Thanks
Have you considered switching to EFI?
In reply to ebrowntaylor :
In general E85 needs more timing especially at upper RPM
in addition e85 from the pump can have anywhere from 35% to 85% ethanol and it’s impossible to know which. Thus you could be jetted too fat.
Alcohol when you are too rich ( fat ) gets lazy. The lucky thing is the more alcohol you have the more tolerant the engine is to getting too lean. You can tell a lean alcohol engine because it barks like a goose.
So too rich= lazy too lean= barking goose.
Kinzler will sell you a $45 hydrometer along with a $24 measured vial to test the level of alcohol.
If you are buying it from a vender such as VP fuels. Don’t worry if they say it’s E85 then it’s 85% ethanol.
Is this a Holley 650?
Which pump cams?
What does the AFR do when it's going flat on the top end?
Are you verifying the ethanol percentage?
frenchyd said:
In reply to ebrowntaylor :
in addition e85 from the pump can have anywhere from 35% to 85% ethanol and it’s impossible to know which.
It's only supposed to vary from 51 to 83% ethanol per the Department of Energy specification, but that's still a 32% variation that cannot be "set and forget" with a carburetor.
https://www.afdc.energy.gov/uploads/publication/ethanol_handbook.pdf
In reply to CrashBox72 : I’ve bought pump grade E85 with as low as 30% ethanol and as high as 90% ethanol.
The other variable that I don’t have an answer to is what the base stock is. With high ethanol content the base stock can be pretty poor grade and still make decent octane. The advantage of the 114 octane of ethanol.
ebrowntaylor said:
Hey guys,
This is my first post on the forum. I have a 65 chevelle with a 327 I run E85 on with a 750 DP carb w/o choke. Rob Mix built it, but I have had to make some mods to get this thing right (and still isn't right), and I am having a terrible time with a lean bog right now. If I could go back, I'd have Mark S build me one but that's neither here nor there.
It's also FLAT/doesn't build power on the upper rpm range.
I have an AFR that I just installed.
My motor is built pretty solid with a cam with a little overlap, decked block, shaved/ported heads, about 12.5-13-1 compression, 4.10 rear th400 with shift kit. If you need more info on any of this let me know.
My initial set up from Rob was:
Air bleeds: 31/68
PVCR: .067
Jets: 89/99 (rear has extensions)
PV:4.5 front (rear is blocked)
IFR: .041
Boosters: 157 ( maybe a little small)
accel pump(s): 30 cc
squirters: 45 (I have tried 42's without luck)
Can't get the thing to idle without the following changes and I have to go in more than 3/4 turn on the 4 corner idle which gives me about .9 lambda and 13 inches of vacuum. I made the following changes, but left everything else the same:
Air bleeds: 31/67
Jets: 83/94
IFR: .035
Any of you guys running a similar combo that have had luck with your settings, or does anyone have any advice. Thanks
Reading about Holley’s concerted to E85 nearly every one has the 50cc accelerator pumps. Which makes sense because you need to greatly richer up anything to use E85.
