Doing a compression test, (both wet and dry) should tell you if there is a
difference between the cylinders and their general condition.
doesn't have to run to do that and it should tell you a little about the
Checking the piston height through the plug holes and relating that
to the rockers/valve positions should let you know if the cam is in correctly
in relation to the crank and valve openings on an individual cylinder basis.
If it is a wrong firing order cam the valve openings should be rather odd
There are the really odd ball things such as plug leads breaking down
and distributor cam (bearings and lobes) being worn way out of spec. Or even
the cam is too wild to work below 3000 rpm. Carbs and Inlet manifold seated
properly on the head?
It is always a worry when someone you don't know has
built an engine and the problem is like this.
Guy R Day
Spridgets list <firstname.lastname@example.org>; email@example.com
Sunday, 20 July 2014, 20:04
Subject: Re: [Spridgets] Bugeye/Frogeye Club.....
Re: Racer guys Engine help
yes, it has run before but never run
well. It is a new engine, built by
someone else. My current thinking is
something along those lines. I am
about to go remove the front cover and see
if it would run I would put a vacuum gauge on it. It
doesn't run well enough
to do that, IIRC, a vacuum gauge won't tell you squat
while you are just
turning it over. And where would I hook it up, no vacuum
ports on the carbs
or intake manifold.
On Jul 20, 2014, at 9:32 AM, Paul
> It REALLY sound like your cam is not installed
correctly. It sounds like
> your engine is in either the compression or
exhaust stroke with the intake
> valves opening thus blowing out fuel / air
(exhaust valve or no valves open
> during these strokes.)
> Has this engine
ever ran or is this a new rebuild/assembly? If it has ran
> before, something
has changed and if not then something was not installed
> correctly. Timing
chain slipped on its sprockets (or installed off a
> or more?)
would take a step back and put a degree wheel on the crank and degree in
cam and see if it is opening the intakes at the correct time.
> And some more info.. with someone else cranking
the engine over there is
> fuel / air blowing out of both carbs.