Having problems starting the engine for the first time…

I have checked that I get a spark at the plugs when cranking the engine over.
I think – will double check later – that all the plugs are connected correctly to the dizzy.

Good news is when cranked for 2-3 seconds the oil pressure light goes out.

When I press the accelerator peddle down I get a LARGE blue flame heading up towards the bedroom above the garage from the carb. ( no filter fitted yet )

Battery is slightly flat so now on charge.

What if any is the significance of the large flame from the carb.

If not a flat battery what is next to check.

Paul

This is the part of the build that I know least about.

[Edited on 26/6/07 by Paul (Notts)]

[Edited on 26/6/07 by Paul (Notts)]
For some strange reason the blue flame coming from the carb was very pleasing.


[Edited on 26/6/07 by Paul (Notts)]

Sounds like you're sparking while the inlet valve is still open. try retarding the ignition a bit???

Plugs could be in the wrong order of course.

[Edited on 26/6/07 by scottc]

That does sound like plug leads crossed - or valve timing way out - you're getting a spark when an inlet valve is open, methinks!

Purely IMHO, of course, as I know three-fifths of sod-all about V8s!

(Damn - Scott beat me by 10 seconds!)

[Edited on 26/6/07 by David Jenkins]

I got some nice big blue falmes from mine when I fitted the dizzy on the wrong cycle... (Still got no hairs on one leg!)

Have you checked that you haven't got it fitted 180º out?

Mark

What do you mean by 180deg out. -how do I check

as I said this is one area I am a bit unsure of ..

Have you got a timing light?

If not, turn the engine over, till its at TDC. then check which terminal of the dizzy cap, the rotor is pointing too. This should be cylinder 1

OK. I am not good at this either, so here is my basic understanding of a 4 stroke engine...

The engine works on 2 rotations of the engine for 1 "bang", each rotation having 2 parts (pistopn down and up). THis makes the 4 strokes.

Stroke 1: fuel and air is sucked into the cylender as the the piston goes down.
Stroke 2: the piston comes up causing compression and as it the top of the storke the spark is added causing an explosion which causes
Stroke 3: the piston down with the explosive gasses created. once the piston hits the bottom of this storke
Stroke 4: pushes all off the gasses out of the exhuast valve and when it gets to the top you go back to 1.

This means that if you add the spark at the top of the exhaust cycle (rather than the compression cycle) you will have forced the fuel into the exhaust manifold and you will cause an explosion in the manifold resluting in a plume of flames from the exhaust. If you had done this you would have the rotor arm in the dizzy pointing the opposite way to which it should, i.e. 180º out.

Does that make sense?

Did I explain that right anyone?

Mark

[Edited on 26/6/07 by Paradoxia0]

Yep spot on.

Easiest way to check that you are timed up on No1 cylinder is to remove the plug from that cylinder, insert a finger tight into hole and turn engine by hand with spanner or ratchet until you can feel the compression on your digit. Then remove digit and turn crank until timing marks line up and then check plug leads fitted in correct order. Refit plug refit lead to plug and start engine.

Oh firing order is usually marked on the inlet manifold and the cylinder no's are usually marked on the adjacent inlet tract. (when using std manifolds)


Edit - motor techs are usually taught the simple 4 stoke cycle, - Suck, Squeeze, Bang, Blow.

[Edited on 26/6/07 by jollygreengiant]

dito the dizzy being 180 deg out, for some reason I have a knack of doing this everytime I refit.

looks like I am 180 deg out s will set up again and try to start in wed.

Firing order is 1,8,4,3,6,5,7,2.

Blue flame is a good sign, petrol and sparks.

Sounds like it is 180 degree's out, have you had the distributor out, bit of a stange statement, to explain the distributor turns once for every two turns of the crank so although the rotor arm may point at the lead the engine could be on a compression or induction stroke.

Regards Mark

Amazing isn't it, I too had my timing 180 degs out on first start. Huge pop and flame out the carb gave me a fright.

Great when it comes right though.

Cheers

Dave