16 replies to this topic

[booton]

i just installed my new engine i have built.

and it not firing at all. no spluttering nothing.

i have spark on all 4 plugs. ignition timing is set in the middle of the timing teeth.

its a 998 block with a 940 head, the block has been pocked fitted with a piper 270 cam shaft. spacing between the valves and rockers has been done. had good compression when tested dry on the bench.

i also have an adjustable timing chain where i have aligned up the dots perfectly

it has a weber fitted that i had ruining on my older engine so i know it all works

all the ignition system was taken of the other engine as it was all new.


i think the timing might be out.

was i right to set the timing dot to dot with a piper 270

thanks for any help thanks steve

hope to get the engine ruining to go to castle comb on saturday.

[benjy_18]

with an uprated camshaft, theres usually a reccomended timing setting with it, which is where your adjustable timing gears will help you out.

[booton]

aaa ok bought cam shaft second hand didn't come with one.

do u think the difference would stop it from firing.

where could i find this info.

[benjy_18]

might be worth sending a pm to simon (minispares) on here as h might be able to find you the figure.

however i cant say for sure wether it would stop the engine firing

[booton]

http://www.imps4ever...h/camshaft.html
ok i found this site.

it says the cam timing should be 109.

no idea what this means.

[lrostoke]

The timing figures for the 270 are here.

You really need a timing dial and a dial gauge to work out when the correct timing is achieved

http://www.pipercams...t.php?pid=BP270

[sledgehammer]

Once the cam timing is confirmed correct , check dizzi position , once set
check that the plugs smell of fuel & get spark again
if they do , and still no go , then swap the plug leads 1 with 4 , 2 with 3 , or 180 degrees
worth a try

[liirge]

Put a bit of fuel down the carb throat! then try firing her up if it goes you know you have a fuel delivery problem

[jaydee]

Ok so a copule of things before..
First, make sure you have oil pressure or you'll wreck the engine.
Second, Dont run the engine on the starter for more than 30 seconds, or you'll burn it.
Now you said the engine wont fire up..
How did you put the drive shaft in? And how you timed the dizzy in?
Its very easy to mess up things, set cylinder #1 and check dizzy rotor position. Check the timing marks, time it in between 5 and 8 degrees.
Then make sure about fuel delivery, if theres an air leak in the fuel line the carb float will never fill up, hence the wont start.. Remove the fuel feed pipe from the carb, and while a friend is running the engine on the starter, check if fuel is actually pumped out of it.
Make sure the jet in the carb is put in the 'intial setting' two flats under the bridge, and please, tell us what carb you have.
Dont worry that much on camshaft timing on a engine with siamese port head, it will fire up even when timing is out of about 15°.
The cam is used, and you fitted it dot-to-dot. I'd reccomend to measure valve lift at overlap, at TDC you must have equal lift, if so, timing is spot on.
You cant fail with this method when using old camshafts.

Edited by jaydee, 20 September 2011 - 08:52 PM.

[booton]

thanks everyone for the help will be on it till late tonight

[booton]

ok spent y day on the mini engine.
changed the cam timing around 180 degress.

still can not get the thing to fire. i tried changing the plugs around 1-4 2-3 still nothing.

also used a quick start spraynothing.

i think it must be the ignition timing. your thoughts please.

[moss6273]

Unfortunately, you are going to have to start from scratch now that so many things have been changed.
1. Reset your cam timing so that the dots are aligned next to each other and along the centre line between cam and crank (just like the Haynes manual shows). Turn engine over by hand in the normal direction of rotation (clockwise looking from the pulley end) a couple of revolutions and double check the timing marks. If all OK, reassemble timing cover and refit front pulley.
2. With the aid of a friend, place your finger over no.1 spark plug hole and turn engine over on starter. If you get a good push back then you can assume that you have reasonable compression. Alternatively, use a compression tester on all 4 cylinders to be sure.
3. Double check your points gap, rotor arm and cap are as per the Haynes manual or in good condition.
4. Hold your finger over no.1 plug hole and turn the engine over by hand until you can feel the compression building. Remove finger and observe position of piston until it is on TDC. This puts no.1 cylinder in firing position.
5. Slacken distributor and turn clockwise/antickockwise until the points are just about to open in the anticlockwise rotation position. This puts the distributor in the firing position.
6. Replace the rotor arm and note the direction in which the arm is pointing. This will be no.1 cylinder. Nip up clamp on dizzy.
7. Replace distributor cap remembering in which direction rotor arm was pointing. This will be no.1 plug lead position.
8. Refit leads in 1-3-4-2 order ANTICLOCKWISE ROTATION and fit to respective sparkplug. Replace coil/dizzy cap ht lead.
9. If all is well, engine should now start. If not, and you have followed the above steps, the problem lies with the coil, ignition wiring or fuel supply/carburettor. You do not need to worry about the cam timing as it is in the right ball park.
10. If you are sure of a good spark, turn the engine over on full throttle (pumping the accelerator) for approx 15 secs. and stop. If there is a problem with fuelling, you should smell no petrol at the exhaust pipe. If there is a strong smell of petrol here then your problem lies with the ignition.
Hope this helps. Keep us posted.

[booton]

thanks for that, thats brill.

only problem it i have electric ignition and i can not see the gap change for the points

compression test shows 140 psi.
finding it hard to line up dot to dot as there is resistance to put it in the correct place should i remove the rocker assemble to allow me to freely move the cam.

this really doing my head in.

second thing for the oil pressure when you cranking the car over ( not starting) should the oil pressure light ( orage/ yellow) turn off when cranking.

thank again steve

[dklawson]

Please, let's try and be consistent in what we are talking about. There are two timings being discussed above, valve/cam timing and ignition timing. They are very different.

You have put the engine together with a "new" cam. If you aligned the timing gears (crankshaft and cam) dot-to-dot as described in your shop manual... the cam will be close enough to do its job. The optimal cam angle may say it's 109. That's fine. Without offset keys or vernier timing gears you are not likely to be able to set the cam to exactly 109. Again, being off a degree or two isn't going to prevent the engine from starting... you just may not be getting the most out of your cam as you could. Once the engine is assembled, you are not going to be able to change the cam timing without removing the timing chain/gears again.

The second topic is ignition timing and obviously extended from that... the firing order. Set the parking brake, place the gearbox in neutral, take the rocker cover off and remove the spark plugs. Turn the engine over by hand IN ITS NORMAL DIRECTION OF ROTATION. Look into the spark plug hole for cylinder #1 (the water pump end of the engine). When the piston is visible near the top of the bore, grab the rocker arms above cylinder #1. If they are "tight" so you cannot move them, turn the engine over one more complete revolution. When #1 piston is at the top, try the rocker arms again. If they are loose (you can wiggle them) then you are at #1 TDC on the firing stroke (where you want to be). Now take the dizzy cap off and look at where the rotor is pointing. Hold the cap over the distributor like it would be mounted. Note which terminal on the cap the rotor is pointing to. Put the spark plug wire for cylinder #1 on that position. Now put the other wires on in the order 1-3-4-2 going COUNTERCLOCKWISE around the cap. Your plug wires are now on in the correct order.

Move on to ignition timing. Now rotate the engine BACKWARDS through about 1/4 revolution. Stop and then SLOWLY turn the engine forward until your timing marks line up with the pointer. Stop when the pointer is aimed at somewhere around 5 to 8 degrees before top dead center. You said you have electronic ignition. What type? Is it factory or aftermarket. You can static time many of the aftermarket types... I don't know about Lucas. If it is aftermarket ignition, connect a test lamp between coil (-) and earth. Loosen the distributor clamp bolts and turn the key to the run position. SLOWLY turn the distributor body CLOCKWISE until the test lamp goes out. Now turn the distributor VERY slowly CLOCKWISE. STOP immediately when the test light just comes on. That is the point at which the coil would fire and make a spark. Tighten the distributor clamp and refit the spark plugs. If you have fuel, you should now be able to start the engine.

As above, if after all this the engine won't start, tip a thimble of fuel down the carb throat and try starting again. If the engine sputters to life then quickly dies, you have a fuel delivery problem to work on.

[booton]

thats great thanks.

its a brit part eletronic ignition, if that helps.

and i do have a verneer timing chain, which makes it harder. ( i think.)