Head Temps with U85 Gas..

RLA · Oct 17, 2012

Does anyone know or has anyone checked the
difference in head temps using either types
of gasoline??

I am just wondering, since on older air cooled
engine's the head temps are much higher using
U85.. Also since I now have 2 tractors a 620 &
630 with cracked heads? Would this be true in
water cooled engines as well? Both have working
thermostats & neither have been overheated. But
Both get worked. & Both have A5621R heads.
Since spark plugs are at least 2 heat ranges
hotter, just don't know whether I'm am thinking
right or wrong.. Maybe I'm just Lucky? LOL

DONMYEIL · Oct 17, 2012

Cracked heads wasnt unusual on those tractors .

BushogPapa · Oct 17, 2012

Do you mean "E-85" ???

Head temps should be lower with it as it takes more per given amount of air..

The 620, etc seldom crack a head if cool water is NEVER added to a warm engine...

Ron..

gtx1967jewison · Oct 17, 2012

E85 at the proper tune will give a LOWER head temp. Alcohol Burns cooler. The reason your seeing high head temps is a LEAN mixture. You must richen the mixture ALOT to use E85. Like 20%+

jd b puller · Oct 17, 2012

You need to use about 50% more E-85 than regular fuel. These old tractors were pretty forgiving on fuel, but as stated before, you're way lean. You need to change or drill out the jets in the carb. I haven't messed with E-85 in a duplex, but in a single, I basically had the load jet all the way open and it was a tick lean. (A little lean is good, you are a lot lean).

Also, colder plugs would be a better direction than "hotter" plugs. E-85 is a little unusual in that it stutters when it's lean and also when it's rich. I never got mine rich enough to make it black smoke, but if real lean, it would white smoke (not sure if it was so hot it was burning up the oil residue in the cylinder or trying to cook the pistons. When I pulled the head, the pistons looked good though.

E-85 is great if you're looking for HP. If you're looking to save money over 87 octane, you are barking up the wrong tree.

Hittin' Hard · Oct 20, 2012

I'm running it in a b puller and I've got both jets opened up just about double from what I was running them at with pump gas.

buickanddeere · Oct 20, 2012

Thermal shock cracks the heads. Thermal shock is caused by careless operators.

Head Temps with U85 Gas..

RLA

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DONMYEIL

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BushogPapa

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gtx1967jewison

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jd b puller

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Hittin' Hard

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buickanddeere

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