Flex fuel E85 conversion?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

85raiderburban · 05-21-2018, 05:58 AM

The '80 is under construction as of now. I've got many plans for her this summer (GMT HVAC swap, air bags, paint job, etc) but we'll focus on this issue first. So because the octane prices continue to rise and show no mercy of dropping in the near future and because I have access to the flex fuel at a lovely buck 90 per gallon, i figured i should look into this before i plan for my next road trip (sept, oct ish). Another factor besides saving $$ is the current engine swap I'm doing MAY REQUIRE it. I came up on a first year, 1968 cadillac 472. Yes, the 380 HP/550 lb footer 10.5:1 compression version designed for lead gasoline. Converted to HEI and upgraded timing gears. I heard this engine idle for 4 min before i handed over the $300 the seller and I agreed on, and sounded good, so i'm unaware if she will ping (detonate) under a load once I get her bolted down to the chassis.

I've heard quite a bit are of different opinions and claims from those who are all for it and those who say steer clear from it. What do you all think. Has anyone on here done a successful conversion to their square?

The list of course, feel free to let me know if I missed anything and ill make a note of it.
FUEL TANK - go plastic or keep original (anodized)?
FUEL LINES - stainless or alky resistant rubber?
FUEL PUMP - mechanical ok? or is electric a must?
CARBURETOR - of course one rated for alky is needed
ENGINE - anything internally that would corrode from e85 use?
OIL - any specific or special oil to use??

68longhorn · 05-21-2018, 08:48 AM

If mechanical fuel pump buy an alcohol pump. Also it takes more quantity to make the same power with e85. So make sure your fuel system can deliver enough volume

Ziegelsteinfaust · 05-21-2018, 06:07 PM

10.5 to 1 compression is to low for E85 to provide any benefits.

Get her to around 13-1 and you have power for days. Plus near gasoline mpg.

E85 has a lower btu content, but also a higher effective octane rating. So in my opinion to use it effectively you have to build a engine for it.

68longhorn · 05-21-2018, 08:56 PM

Just add boost!

Ziegelsteinfaust · 05-21-2018, 09:21 PM

Quote:

Originally Posted by 68longhorn

Just add boost!

Or this

05-21-2018, 05:58 AM	#1
85raiderburban Registered User Join Date: Nov 2014 Location: between AZ & NV Posts: 67	Flex fuel E85 conversion?? The '80 is under construction as of now. I've got many plans for her this summer (GMT HVAC swap, air bags, paint job, etc) but we'll focus on this issue first. So because the octane prices continue to rise and show no mercy of dropping in the near future and because I have access to the flex fuel at a lovely buck 90 per gallon, i figured i should look into this before i plan for my next road trip (sept, oct ish). Another factor besides saving $$ is the current engine swap I'm doing MAY REQUIRE it. I came up on a first year, 1968 cadillac 472. Yes, the 380 HP/550 lb footer 10.5:1 compression version designed for lead gasoline. Converted to HEI and upgraded timing gears. I heard this engine idle for 4 min before i handed over the $300 the seller and I agreed on, and sounded good, so i'm unaware if she will ping (detonate) under a load once I get her bolted down to the chassis. I've heard quite a bit are of different opinions and claims from those who are all for it and those who say steer clear from it. What do you all think. Has anyone on here done a successful conversion to their square? The list of course, feel free to let me know if I missed anything and ill make a note of it. FUEL TANK - go plastic or keep original (anodized)? FUEL LINES - stainless or alky resistant rubber? FUEL PUMP - mechanical ok? or is electric a must? CARBURETOR - of course one rated for alky is needed ENGINE - anything internally that would corrode from e85 use? OIL - any specific or special oil to use?? __________________ UNDER CONSTRUCTION '80 Suburban C20 (C6P) (Silverado) - '68 472 (Edelbrock 1813, PH8026 LT's, H pipe) / '91 4L80 (manual shift,vac modulator, 350 converter) / 14B FF 3.21 G80 34' s/ '96 GMT400 interior

05-21-2018, 08:48 AM	#2
68longhorn Registered User Join Date: Jun 2007 Location: Cape Coral, Florida Posts: 1,123	Re: Flex fuel E85 conversion?? If mechanical fuel pump buy an alcohol pump. Also it takes more quantity to make the same power with e85. So make sure your fuel system can deliver enough volume __________________ 1986 Custom Deluxe 10 1978 Caprice 2 door - sold 1937 Chevrolet 2 door sedan - project

05-21-2018, 06:07 PM	#3
Ziegelsteinfaust Registered User Join Date: Dec 2012 Location: Temple City Posts: 3,628	Re: Flex fuel E85 conversion?? 10.5 to 1 compression is to low for E85 to provide any benefits. Get her to around 13-1 and you have power for days. Plus near gasoline mpg. E85 has a lower btu content, but also a higher effective octane rating. So in my opinion to use it effectively you have to build a engine for it.

05-21-2018, 08:56 PM	#4
68longhorn Registered User Join Date: Jun 2007 Location: Cape Coral, Florida Posts: 1,123	Re: Flex fuel E85 conversion?? Just add boost! __________________ 1986 Custom Deluxe 10 1978 Caprice 2 door - sold 1937 Chevrolet 2 door sedan - project

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