Hesitation on acceleration. The best check for oil level is to unscrew and
lift the plastic damper cap, then press it back down. As long as you feel
the damping effect of the oil *before* the cap reaches the cover you have
enough oil, how much before shows you how much of a 'reserve' you have. To
top up just poor engine oil in to fill up the damper cylinder. The level
isn't critical - as long as you have enough any excess will soon be drawn
off and burnt. Whereas on HS carbs you can usually remove the damper piston
completely and pour oil into the empty damper cylinder HIFs often have a
spring retaining clip. They should not need topping up in thousands of
miles - if my present four and those on the myriad of BL cars I have had in
the past are anything to go by. I think HSs have a blind damper cylinder
meaning it cannot leak from below whereas the HIFs are bored right through
and have a seal. If this seal is lost or poorly fitting then it will need
topping-up much more frequently. Some of the official diagrams showing the
oil level are incorrect in that it is shown 1/2" *above* the top of the
damper cylinder. If you try and maintain it at this level you will be
topping up every few days. the correct level is about 1/2" *below* the top
of the cylinder, but as I say as long as you can feel the damping action
before the plastic cap reaches the cover you have enough.
PaulH.
----- Original Message -----
From: "Richard Lang" <rhlang@mindspring.com>
To: <mgs@autox.team.net>
Sent: Sunday, October 12, 2003 11:37 PM
Subject: SU Carb Oil Level
> I have a 1978 MGB with a 1972 engine with HS4 Carbs. What are the
> symptoms/effects on engine performance when the oil level in the piston
> chamber is low? How often should you expect to add oil?
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