Gas gobbler?

Mikkels · Post by **Mikkels** » Wed Mar 03, 2004 8:16 am

Well I took the car to Torque Performance in Avondale. Robin there
confirmed my fears that we were way rich. A/F around 11:1. Robin was
able to adjust the AFM to get a spot on mixture. Nice guy and great
service. Car makes 84 KW at the rear wheels. I have no idea whether
that is good for an 1800 or not? Timings at 14 degrees, K&N filter in
std box extractors and lightened std flywheel. It feels good to drive
and is much smoother.

Don

Rex Johnston · Post by **Rex Johnston** » Wed Mar 03, 2004 8:49 am

On Wed, 2004-03-03 at 08:16, mikkels wrote:

Well I took the car to Torque Performance in Avondale. Robin there
confirmed my fears that we were way rich. A/F around 11:1. Robin was

11:1 at WOT? Still too rich anyway. No wonder it chewed through the
gas. Good thing you got onto this, running that rich has a tendency to
wash oil off the bore, which then acts wear stuff out rather faster than
normal.

able to adjust the AFM to get a spot on mixture. Nice guy and great
service. Car makes 84 KW at the rear wheels. I have no idea whether

Sounds about right. Probably around 110kW at the flywheel.

that is good for an 1800 or not? Timings at 14 degrees, K&N filter in
std box extractors and lightened std flywheel. It feels good to drive
and is much smoother.

Great!

Cheers, Rex

Lou Girardin · Post by **Lou Girardin** » Wed Mar 03, 2004 11:58 am

I'd make it more like 100KW at the crank. MX's lose about 20% between crank
and wheels. Still good though, and more than stock.
Lou

Rex Johnston · Post by **Rex Johnston** » Wed Mar 03, 2004 4:19 pm

mikkels wrote:

Just read the full report and he says that the mixture dropped to 11:1
at any load regardless of throttle setting but was OK at cruise.
Average A/F now 13:1 which drops slightly at WOT but the curve is very
flat across the rev range other than at idle where things are a lot
leaner.

This is with the O2 sensor disconnected, right? Otherwise closed loop
would force it
to run around 14.7:1. If that is the case, then it sounds just fine.

Ajax into the intake? I'd have thought that would make it worse.

Cheers, Rex

Mikkels · Post by **Mikkels** » Wed Mar 03, 2004 4:57 pm

Yes Robin talked about the effect of the mixture on the bores. I will
keep an eye on the oil consumption which was negligible over the last
couple of months however the oil has got dirty rather quick and smelt
like petrol when I changed it. This helped to point me at the mixture as
a problem.

He reckoned that if there is a problem you can sometimes re seat the
rings by allowing the engine to inhale a very small amount of Ajax
powder!!!

I guess if you are facing a ring job it would be worth a try before
doing that. I take it the principle is that the powder does a kind of
"hone on the fly"

I am skeptical. Anybody heard of this?

Don

Mikkels · Post by **Mikkels** » Wed Mar 03, 2004 5:06 pm

Just read the full report and he says that the mixture dropped to 11:1
at any load regardless of throttle setting but was OK at cruise.
Average A/F now 13:1 which drops slightly at WOT but the curve is very
flat across the rev range other than at idle where things are a lot
leaner.

Don

Lou Girardin · Post by **Lou Girardin** » Wed Mar 03, 2004 7:48 pm

Do NOT put ajax or anything similar in the bores. Unless you really want to
do a full rebuild.
Lou

jeff · Post by **jeff** » Wed Mar 03, 2004 7:56 pm

just curious - how did he adjust the mixture? I'm
assuming there's no aftermarket computer?

BTW - 11:1 at WOT is normal apparently... Norm Garrett
had an article about it in one of the old Miata
magazines.

Jeff

--- mikkels <mikkels@ihug.co.nz> wrote:
[...]

Wayne · Post by **Wayne** » Wed Mar 03, 2004 9:28 pm

This character Robin that recommends using Ajax to give the bore a hone,
does he do motor overhauls? If so he probably drives a Porsche and can well
afford to do so, giving advice like that. Ask him to show you how to do it
on HIS car. No Ajax hones for this Kid.

I would suggest that a modern motor with excess 'bore wash' would take
several thousand Kms to do any significant damage, but still excess fuel
that contaminates the oil is not good and will be wearing the bore at a
faster rate than normal. Lets face it 50's and 60's cars consumed more fuel
than they burnt and some of them reached in excess of 100,000 miles and only
needed two or three valve grinds, 10 or so exhaust systems and then only
probably needed a re-ring for another 100.

Wayne Sinclair
sinclan@xtra.co.nz

Eric West · Post by **Eric West** » Thu Mar 04, 2004 10:33 am

Surely, thinking about it logically, if the powder is drawn into the cylinder on the induction stroke, it will then either get puffed out on the exhaust stroke, if the engine is not firing, or incinerated during the power stroke. In either event it is hard to see it remaining in the cylinder for a long enough period or in sufficient quantity to do any good. Given the effort that Mazda goes to (with deleterious effects on performance) to keep abrasives out of the engine, I cant see why anyone would want to do this

Eric

Mikkels · Post by **Mikkels** » Thu Mar 04, 2004 1:00 pm

Not sure Rex

I was not there at the time. This is what was given to me when I picked
up the car. It was on the dyno report.

Don

Mikkels · Post by **Mikkels** » Thu Mar 04, 2004 1:02 pm

Adjusted the spring tension on the AFM after removing the plastic cover.

Mikkels · Post by **Mikkels** » Thu Mar 04, 2004 1:02 pm

It was not high on my list of things I want to do to the car.

Mikkels · Post by **Mikkels** » Thu Mar 04, 2004 1:05 pm

No Robin did not recommend me doing this. He said that he had seen it
done and seen it work (sometimes). One of those urban myths I think. I
just wondered if others had heard of it.

Don

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