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Re: Cam timing

To: "WAS" <Waschu2@charter.net>, <healeys@autox.team.net>
Subject: Re: Cam timing
From: "Chris Dimmock" <cd3000@bigpond.net.au>
Date: Wed, 20 Jul 2005 00:06:01 +1000
Wayne,

I think the problem is  "twin Weber DGV carbs on a modified BJ-8 manifold"

Two single choke DGV's are a million miles away from 3 x twin choke 45mm 
webers. And about half a million miles away from 2 x 2inch SUs.

Aren't DGVs a relatively small choke carb - 34 or 36mm? So you've got - what 
2 chokes - each around 34 mm or 36mm - each choke feeding 3 ports (on a BJ8 
mainifold)? and DGVs aren't a performance carb anyway.

So lets get this straight. A STANDARD BJ8 has a pair of 2 inch SU's. Thats 2 
x 2 inch chokes (i.e. each choke is just over 50mm).

This car has 2 x 34mm (I think DGVs are only 34 or 35mm chokes?) - thats 
roughly equivelent to 2 x 1 3/8 in chokes - either way - much less than a 
1.5in (38mm) choke

So the engine has less carburation than it would have with 2 x 1.5in SUs - 
and I used to run 2 x 1.5in SUs on my Bugeye Sprite!

Put on 2 x 2in SUs.

Best

Chris
www.myaustinhealey.com



----- Original Message ----- 
From: "WAS" <Waschu2@charter.net>
To: <healeys@autox.team.net>
Sent: Tuesday, July 19, 2005 4:18 AM
Subject: Cam timing


> Hello,
>
>
>     I need to get another opinion about a friends Healey. Rebuilt 2639 cc 
> .030"  oversize engine, BJ-8 camshaft, Mallery distributor with electronic 
> ignition. The engine is not producing anywhere near the power it should. 
> It idles well, runs smooth, but is way down on power. It has none of the 
> low end torque or high end power that it should.  Another variable is the 
> car has twin Weber DGV carbs on a modified BJ-8 manifold done by Pierce 
> injection. The setup is similar to the goose neck  setup for TR-6's. 
> Measured the  total ignition advance at 3000 rpm and got 35 degrees which 
> seemed close enough. Checked the cam timing per Norman Nock and his Tech 
> Talk, set a wide running clearance, .095" in my case, on valves 11 and 12. 
> Set # 1 cylinder on TDC and measured the clearances on 11 and 12. Should 
> be the same clearance, in my case they are not. # 1 intake had .010" and 
> the exhaust had .057" clearance. I backed up the crank and turned it in 
> the  direction of rotation until #11 and #12 valves had the same clearance 
> and they were the same at 6 degrees BTDC. Total lift at the valves was 
> measured at .360", very close to BJ-8 specs. Measured the opening of the 
> intake and closing of the exhaust and with .012" clearance at the rockers 
> the intake opens at 26 degrees (10 degrees early) and the exhaust closes 
> at 11 degrees (10 degrees early).
>
> I would like to degree the cam but due to an after market crank damper I 
> cannot fit my degree wheel without pulling the radiator and lifting the 
> engine off of the mounts.
>
>     Norms test seems to indicate that the cam is advanced about 6 degrees, 
> my test agrees with the cam being advanced about 10 degrees.
> My guess is the cam being advanced while not good does not explain the 
> lack of power.
>
> When I pulled the spark plugs they look very lean even at idle so I 
> suspect the problem is a very lean mixture across the whole rpm range. Is 
> anyone else out there running two Weber DGV carburetors?
> I told my friend if it were my car I would remove the Webers and put on a 
> pair of HD-8's.




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