[Fot] Engine Problem

[MadMarx]

Ignition problems are sometimes hidden and misleading to a fuel problem.
>From this point I always start from ignition to fuel and then deeper to the
engine.

>From what I suppose is that your double ignition distributor did work well
on one corner and failed at the opposite corner. You replaced the
distributor and I could imagine that maybe the ignition advance wasn't set
correctly and so the ignition was too late at high revs which caused
overheating of the engine and a lack of power.
I could also imagine a shrunk piston #3 with some piston slap now caused by
overheating. I suppose the # 3 had the best compression and did overheat
most and died first.

Chris

-----Urspr|ngliche Nachricht-----
Von: fot-bounces at autox.team.net [mailto:fot-bounces at autox.team.net] Im
Auftrag von Gary Horstkorta
Gesendet: Mittwoch, 8. April 2009 02:45
An: Fot at autox.team.net
Betreff: [Fot] Engine Problem

Hello:



OK, here's a TR4 engine situation I'd like to receive some feedback on.
During the winter layoff, no major engine changes just routine maintenance.
Engine always started quickly and ran smoothly up and down rpm range while
in the garage.  However, at this past weekend's vintage race at Infineon
Raceway, I encountered the following:



1.       Saturday's first practice session, the car began hesitating at
4,000rpm and reluctantly would edge its way up to 5,000.  Engine oil
pressure and water temp normal

2.       In paddock, checked fuel pressure with a gauge, it was high at 3.0
lbs for my 1.75" stock SU carbs.  Reset to 2.0.

3.       Saturday's race, same problems.  Checked fuel level in carb at the
needle jet orifice without the "dome" on and fuel pump running.  Level was
uneven, one carb flooding the other low.  Reset floats so even fuel level
just below the orifice opening.

4.       Sunday morning practice the problem was worse and now the engine
would almost die around left hand turns but run strong around right hand
turns.  Checked everything from fuel pickup in fuel cell all the way up
through the carbs, all seemed OK.  However, the car would barely start, run
badly then die.

5.       Out of desperation we turned to the ignition system which is
Mallory dual point dizzy and coil.  Replaced coil - no change; replaced
plugs - no change; checked timing - OK; replaced distributor with stock
Lucas, engine started and ran fine.  Huh??

6.       Road test up a steep hill at full throttle and down a road, no
problem except acceleration was not crisp.

7.       Ran race and engine was steady around all corners but car was down
on power and after three laps, water temp was higher than it normally runs
but stable at 200 degrees.  Four laps later sudden fluctuation of water temp
gauge meant I'd lost water.  Shut the engine off

8.       Towed pack to pit, able to start the car and put it into the
trailer, running OK but with a "rattling" sound from the engine.



Back in the garage, inspection of the valve train showed nothing obvious.
Removed plugs which were all black and sooty, turned engine over by hand
then by the starter, no obvious problems or sounds.  Ran a compression test
with the following numbers:  cylinder #1  160; #2  155;  #3   210;   #4
170.  Also noticed a different mechanical sound from down in the engine when
cranking for #3 compression test, not present when testing other cylinders.




OK, so that is where I am right now.  We (myself and two friends - one a
long-time Triumph racer/builder and a the other a British car mechanic)
initially felt this was a fuel problem, however, after the problem
disappeared by changing the distributor, we're all a bit baffled.  Next step
is to remove the head and pan for inspection.  Anyone experience a similar
set of problems, ie, seemingly a fuel problem but turns out to be
electrical?  What would cause a dizzy to work around some turns and not the
other?  What would cause such a high number on cylinder #3?  Thanks.



Gary

1962 TR4
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