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Re: Losing power at high rpms...

To: MG List <mgs@autox.team.net>
Subject: Re: Losing power at high rpms...
From: Max Heim <max_heim@sbcglobal.net>
Date: Thu, 07 Sep 2006 20:35:07 -0700
I bet the orange deposits are from the octane booster.

How high is your compression ratio?

My 67 Barracuda with 10.5:1 compression runs on 91, retarded 2 or 3 degrees
from spec. I found octane booster to be expensive, and inconvenient, as in
unavailable at many service stations where you had to fill up, and had used
your last bottle. If you read the label, you will see it is full of some
really noxious substances, like toluene.

As for your symptoms, I would check the float bowls for debris (assuming you
have SUs).


--

Max Heim
'66 MGB GHN3L76149
If you're near Mountain View, CA,
it's the primer red one with chrome wires


on 9/7/06 12:26 PM, craigw@sonic.net at craigw@sonic.net wrote:

> Hi folks. I've got a very high compression MGB. Therefore, I've been using
> premium California fuel (91 octane) & using an NOS octane booster to keep
> my B from pinging under load. It's been working pretty well for the most
> part.
> 
> This weekend I was on the freeway in 5th gear doing around 65mph, and
> found that when I increased the throttle, the car actually felt like it
> was losing power. This was the first I've noticed this. The MGB usually
> increases speed etc., at this level.
> 
> I got to my destination. Upon leaving, the B started fine and drove fine
> (it seemed) until I put it under load going up a slight grade at around
> 40mph. It felt like maybe a cylinder was 'missing' but not as starkly as
> if a plug wire had been removed. Anyway, I drove it home through town and
> tried not to load it down; kept the revs higher than usual. I parked it
> and just got around to looking at it yesterday.
> 
> I removed the plugs and found that they all had a nice, even 'bright
> orange' deposit on them; almost like rust. They smelled normal. I cleaned
> them off & re-installed them. I also removed the fuel filter (which looked
> like it had some orange gunk in it as well) and replaced it too. I took
> the B around the neighborhood and found it still didn't like it when I
> stepped on the throttle upwards of 4000 to 4500 rpms. After around 10
> minutes or so, the car seemed like it was starting to perform normally
> again.
> 
> I checked the coolant and it seemed fine. I checked the exhaust and saw
> nothing whatsoever coming out of the tailpipe. The engine is a Glenn
> Towery rebuild which I've had in the car now for 5 years or so, with not
> too many miles on it.
> 
> Anyone have a clue what the 'orange' deposits might be?
> 
> Thanks, and best regards,
> Craig Wiper
> Santa Rosa, CA




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