[T2] [VB] Hot engine

[Chris Dreike]

Thanks Dennis,
I am coming to the conclusion that something in my fuel injection settings
needs to be adjusted. I made changes a few weeks ago and I think that
produced the problems. I'm in the process of dialing things back to where
they were. I've taken a couple of test drives and its looking better.
Having a megasquirt fuel injection controller allows me to adjust timing
and fuel delivery precisely at any operating point of the engine. Currently
i'm emulating an SVDA distributor and a Solex 34 carb. 28 degrees at WOT
with AFR in the 12's. At light to medium load I have 40 degrees of advance
and AFR in the high 16's to low 17's. I think this is where I need to be.
There is no detonation even with the large advance as long as I'm running
in the cruise range. On my trip out to Redlands, CA, and all the other
driving around I averaged just over 21 mpg. I think it will be a bit higher
once the dialing is done.

Chris

On Sun, Sep 29, 2019 at 7:33 PM Dennis Gentry <dennis.gentry at gmail.com>
wrote:

> Hi Chris,
>
> If there's nothing blocking the fan intake, it really sounds like your
> timing might be overly advanced if you were able to get it hot in 0 - 50
> mph.  It sounds like you've retarded timing a bit and maybe it got better?
> Of course once you retard too much, you won't get the power you should.
>
> I'd make an effort to get the timing right before looking anywhere else.
> (And until you get things dialed in, better to run a little rich for
> protection from detonation.)
>
> If you said what distributor you have, I missed it, but that will be the
> primary determinant of the correct timing.
>
> Good Luck!
> Dennis
>
>
> On Fri, Sep 27, 2019 at 9:14 PM Robert Mann <robtmann7 at gmail.com> wrote:
>
>>      I hesitate to go sarcastic about digital, but I have no difficulty
>> with the thermocouple acting as spark plug washer, driving the admittedly
>> delicate millivoltmeter made for aircraft in Santa Rosa (they seem to have
>> recovered from the fire which swept thru).
>>
>>      I regret my lack of °F fluency.  My CHT guage is in °C.
>> Half-throttle
>> cruising 110 C {166 F}  Hillclimbing flat-out in 3rd 150 C (c.240 F} and I
>> somehow become nervous about there.
>>
>>      BTW I've never liked that position for the thermocouple.  Doubtless
>> someone has drilled & tapped a suitable part of the head near the plug
>> ...
>>
>> On Sat, Sep 28, 2019 at 10:56 AM Chris Dreike <cdreike at gmail.com> wrote:
>>
>> >  Thanks Jason,
>> > I think I have covered all of the bases you mentioned.
>> > All engine seals are in place. I have the doghouse system.
>> > I have Scat Cool Tins on the bottoms of the cylinders. (Maybe this is a
>> > problem and I should use the stock VW pieces?)
>> > I do not have thermostat flaps installed on the engine. If I pull it, I
>> > will install and wire them in the open position.
>> > I have a wide band sensor from Innovate and have managed to calibrate
>> the
>> > megasquirt reading to the innovate gage to within about .2.
>> > I have an Innovate CHT gage with sensors on sparks 1 and 3. 1 is always
>> > about 15 degrees cooler at around 350F. I checked this with a laser temp
>> > gage and it matches within about 5 degrees F.
>> >
>> > Today I started adjusting the A/F ratio settings and reduced the spark
>> > advance.
>> >
>> > I took a drive up the local "hill" about 700 foot elevation rise and
>> only
>> > saw 380F in 3rd gear at 45mph at WOT. Cooled slightly when I changed to
>> 4th
>> > at WOT however could not quite pull the hill.
>> > I'm going to take a drive down the freeway tonight after traffic dies
>> down
>> > and see what happens. Coming back the other night going slightly
>> downhill
>> > at 50% throttle I was seeing 360-380F. Not good. Should have been about
>> > 310.  At WOT the temp just went up and up.
>> >
>> > Cheers,
>> > Chris
>> >
>> > On Fri, Sep 27, 2019 at 2:48 PM Jason Laster <jason at fasterlaster.com>
>> > wrote:
>> >
>> > > A few thoughts that might help.  First off I ran a 1776 (carb) in my
>> 66
>> > > camper for years.  Totally loaded down with 6 people and a dog with
>> > camping
>> > > gear.  There is enough cooling in the bus with a doghouse for this
>> type
>> > of
>> > > punishment based on my experience.
>> > >
>> > > Double check the engine cooling aspects.
>> > > Engine seal in place.
>> > > All engine tin installed (especially those little pieces on the
>> bottom of
>> > > the cylinder fins).
>> > > Are there thermostat flaps in place and are they indeed operational?
>> > >
>> > > Be sure and double check the AFR with some sort of other
>> calibration.  I
>> > > found on my megasquirt system it reported a little lower than what the
>> > > actual innovative gauge that came with my LC-2 reports.  I bet that
>> isn't
>> > > enough to worry about however.
>> > >
>> > > Another aspect to consider is how you are getting engine head temps?
>> Is
>> > > it a regular CHT gauge that connects under the spark plugs, or is this
>> > the
>> > > MS reading?  Could this just be the normal reading for your engine
>> when
>> > > it's just really hot ambient temp?
>> > >
>> > > --
>> > > Jason
>> > >
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