L84 Engine rebuild

[Martin T.]

I am about to have a L84 engine rebuilt and want the F.I. unit rebuilt as well. I understand Texas is now selling E85-E95 fuel only at the gas pumps (I am sure the rest of the country will soon follow). I also understand that the seals used in the sixties will not hold up to the alcohol level in the Ethanol based fuels. Does anyone know of seal kits and rebuilding procedures to use when wanting to run a fuelie on the ethanol pump gas without loosing a bunch of horsepower?
I know Aviation fuel is an alternative but the idea of being able to go to the pump seems the better plan.

[Clem Z.]

no parts in your fuel system will stand up to

E85 which is 85% ethanol. i takes all kinds of special parts to run it

[Duke W.]

Re: L84 Engine rebuild

You are misinformed. E85 is a blend of 85 percent ethanol and 15 percent gasoline. It is ONLY suited to certain new "dual-fuel" vehicles, and it is NOT widely marketed.

Current unleaded regular, midgrade, and premium gasolines have some ethanol, but the regulatory limit is 10 percent.

So-called "gasohol", which contains 10 percent ethanol was marketed beginning about 25 years ago, and most fuel system elastomers were upgraded at that time to handle up to 10 percent ethanol.

My recommendation is that you install new rubber hoses at the tank and fuel pump, especially if their age is unknown. As far as the internal gaskets and seals for the FI system are concerned, NOS parts kit elastomers may not be totally suitable to current gasolines, and they are just plain old, so you are taking a small chance, but FI system leak reports are rare. Most the reported problems are hot starting.

Duke

[Robert R.]

Re: L84 Engine rebuild

Duke,
Your response to the previous question gives me a partial answer to a question that I will have to address.
I used to be able to get fuel for my '73 without ethanol, but now it seems that the stations near me all have fuel with 10% ethanol. What other precautions, updates would need to be done for these older cars?
What changes would need to be (or can be) done to carberators along with changing rubber fuel lines to make these fuels work?

Thanks in advance for your response,
Bob Ricchio

[Duke W.]

Re: L84 Engine rebuild

Beginning last year, all commercial gasolines for road use have ethanol. Prior to that it was just CO "non-attainment" areas and sometimes only in winter. Ethanol in gasoline was originally sold to Congress on the basis that it would reduce CO emissions from older pre-O2 sensor cars, and reduce CO from modern O2 sensor cars before they warmed up sufficiently to go into closed loop operation, but these arguments proved to have no technical merit.

So beginning last year the Congrees required that ALL road-use gasoline be partially formulated from "renewable energy" sources, which effectively mandated ethanol, and 10 percent is considered an acceptable concentration for both new and old cars. Depending on your location and time of year ethanol concentration can be anywhere from a few percent to ten percent, maximum.

Most fuel system components manufactured in the last 25 years are compatible with 10 percent ethanol, and this includes such things as rubber fuel hose and carburetor rebuild kits that have been manufactured since the early 1980s.

Any fuel hose that is over 10-15 years is suspect due to plain old age and heat deterioration, especially rubber hoses that are exposed to engine heat. As far as carburetors are concerned, if they continue to perform properly then nothing needs to be done, but when they reach the point where they need to be rebuilt, try to find a recently manufactured rebuild kit, which should include components that are compatible with E10 - 10 percent alcohol and 90 percent gasoline. By "comonents" I refer to organic materials such as gaskets and rubber o-rings. Most metal components will see no harm from E10.

There's no need to panic and rebuild older fuel systems. Just be aware that older cars may experience problems, which would eventually happen anyway, however, current E10 may increase the rate of fuel system component deterioration for old organic components that are over 25 years old.

Duke

[William C.]

Re: L84 Engine rebuild

As I recall the engineering discussions at the time, (70's??) 10% was considerd "acceptable" for the vehicle components in use at the time it was introduced, without modifications or upgrades. More than that and all bets were off...

[John D.]

Re: L84 Engine rebuild

Martin, WE are working on the ethanol fuel situation right now for the old fuel injections. If you use the ethanol mixture-even the 10% added fuel- the high pressure pump seal will end up leaking for sure. Also the rubber grommet around the axle link swells up like a donut. The o'rings for the two supply lines and the spill valve area are readily available in viton. I am not trying to push parts on the DB as it is unethical but we will have a kit shortly that when installed will permit your old '57 to '65's be run on ethanol and not lead. How well they run is another story. My late model GMC hates the crap and gets worse gas mileage than normal-worse than the 9 MPG average (heeeee)
It also doesn't idle as well and sits there and rocks a little bit at stop lights. Put some good fuel in and it straightens out. Anyhow keep in touch as the solution to our nightmare will be resolved in about a month. John