I agree that the bonnet can be a high pressure area but I can not see that
this could be 1.5 windscreen height?
Where do you get this data as I am interested air flow over my MG.
I have a front spoiler that is based on the Abingdon Special Tuning one and
it has improved cooling and helps pull the front of the car down at speed. I
guess that by forcing more air in it then has to go some where?
The other thing I have been thinking about is putting an air filter at the
front of the car and have a pipe to the carb. What do you thing?
Simon
-----Original Message-----
From: James Nazarian [mailto:jhn3@uakron.edu]
Sent: 20 August 2003 06:32
To: Telewest (PH); v8
Subject: Re: timing
Paul, I was rereading your post and I have another question for the list.
It occurred to me at some point that I have plenty of air coming into the
engine bay but I don't think that I have much going out. Obviously the
radiator opening is all inflow, and as I understand it the wheelwells are
high pressure areas so the header cutouts should also be contributing to
inflo. With the size and fitment of the V8 it does not leave a lot of space
around the engine and transmission for outflow.
One common solution seems to be to lift the rear of the bonnet, but as you
pointed out, at speed that would be an area of inflow as the high pressure
area in front of the windscreen can reach as far as 1.5 windscreen heights
forward thus causing much of the bonnet to be in a high pressure area. This
seems to be supported by my observations of the bonnet being pushed down and
relieving tension on my hood pins, allowing them to shift.
This would also rule out any form of louvering the bonnet as it will nearly
all be in high pressure air. So I wonder what modifications can be
performed to increase the outflow of air from the engine bay? I have read
that changing to a ST airdam will do this by channeling frontal air around
the car and lowering the pressure under it but because I have already
lowered the car 1" I don't care to do that for this or for aesthetic
reasons.
I have considered the possibility of louvering the front fenders in front of
the doors but I do not care to modify the body in such a way, partially
because of the cost of repainting, but mostly, again, for aesthetic reasons.
This leaves me wanting for another method of increased outflow.
I don't think that it is that big a problem especially since I plan to
reconfigure my airbox to include the carb body, as I detailed earlier, but
it is a curiosity that I would be interested in hearing thoughts about.
James Nazarian
71 MGB Tourer
71 MGBGT V8
85 Dodge Ram
----- Original Message -----
From: "Telewest (PH)" <paul.hunt1@blueyonder.co.uk>
To: "James Nazarian" <jhn3@uakron.edu>; "v8" <mgb-v8@autox.team.net>
Sent: Monday, August 18, 2003 8:34 AM
Subject: Re: timing
> IMHO points bounce will cause the misfire and the high tach reading, but
> they should go above 6k before bouncing. Dunno your engine but the Rover
V8
> is remarkably tolerant to both retarded and advanced ignition, much more
so
> than the 4-cylinder. But with two different distributors it is difficult
to
> believe it is points/timing/advance related. The factory V8 curve should
be
> 26 degrees at 2600 rpm, so your stock dizzie isn't that far out. Doing
some
> warm weather tests the other day I recorded 65C/149F near the carbs with
> 31C/88F ambient. I increased the ambient coming in at the grill to
41C/106F
> and the idle speed did start to drop a little, unfortunately I didn't
record
> the temp near the carbs under those conditions. Are you saying you have
> 180F/82C near the carbs? That is much hotter than I recorded, and
probably
> significantly more than it was during the hotter ambient. Can you run it
> with the bonnet off? Or with the rear jacked up? I know at speed the air
> might be going *in* at the back of the bonnet rather than out but at least
> the carbs might be getting more 'fresh' air that way.
>
> ----- Original Message -----
> From: "James Nazarian" <jhn3@uakron.edu>
> To: "v8" <mgb-v8@autox.team.net>
> Sent: Saturday, August 16, 2003 5:27 AM
> Subject: timing
>
>
> > For the sake of consuming bandwidth here is that 'other' email. I have
> some
> > drivability problems that I just can't shake.
> > ...
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