Tdc # 1 ?!!?

[svandamme]

Guys ,

i'm a bit of a pickle here

been messing with the car all day , at one point did i get a 2 cyllinder puff, but now the beast is flooded ( including muffler which is now the mixture chamber for my tailpipe rocket engine >>> VERY flooded 1.5 meter torchflame when i held a match to it)

i'll leave the beast to rest till saturday, but progress has been made
i now have fuel AND MSD-spark ( only had spark this morning , turns out my MFI in hose , was connected to my gas tank return connection )



all that remains is getting the timing of it all


can somebody tell me the best way to find TDC #1 on my engine
but i need to be absolutely sure

tried : looking into the intake stack ( not very visible, didn't work )
tried : looking at the valves , removed upper valve cover
but i'm not sure on that one either... the car didn't fire on that , only fired on couple of cyllinders after if i switched the ignition wires around so 1 started where 4 should be

does anybody have any good tips on this? to much gasoline fumes today ... i'm inbetween high and major headache, not sure which way it's going to go yet...

[Paulporsche]

I feel your pain. Unfortunately, I don't think I can be of much help right now.

Hang in there. There are lots of smart guys here who have BTDT.

[Porsche_monkey]

Does your car have the Z1 mark on the pulley?

[svandamme]

Originally posted by PBH
Does your car have the Z1 mark on the pulley?

yep , but the engine was out of the car, distributor was removed mfi belt removed... and now the shiznit doesn't fizzle anymore


i tried figuring it out , but i'm not a flat six expert... on a 4 banger it's easy ... Z1 is always TDC#1

on the flat six , it's either 1 or 4 and i keep confusing myself..
looking at the upper valves wasn't to clear either since the difference between 0 or a 360 rotation is negligable when looking at the intake valve ( or i'm not experienced enough to interprete it )

[Porsche_monkey]

Should be dowelled. Can be wrong if it is.

[svandamme]

what does dowelled mean?? not familiar with that term...

[Wil Ferch]

Go to the archives there are many post on this ( "TDC", number 1, etc)

Basically, first make sure that the wires on the cap are in this firing order 1-6-2-4-3-5.

Number one should fire when number one valves are closed...and distributor pointer is on "notch". When on "notch", either 1 or 4 are at TDC, but only one of these will have valves closed. If you can "rock" the rocker arm of the valve...that one is closed.

If you have a MFI / belt...that may introduce other timing issues I can't comment upon.

Others can be more clear on this ......

--Wil

EDIT:
The graph in this post might help:
Valve adjustment question again

[Matt77Euro27]

Turn the crankshaft pulley until the #1 intake valve actuates. The next time the Z1 comes around again after the intake valve #1 has opened and closed and lines up with the notch is TDC#1. Good luck.

[svandamme]

Will ,

my firing order is right, tripple checked that several times,
it's the either 1 or 4 that is bugging me

do i need to look at both upper and lower valves for this?
or can i just look at the lower ones ( since the engine is in the car, those are easier to access?

you mention rock the arm
in Waynes book , i noticed the 4 stroke cycle over a 720 degrees

on that diagram , i could see that the valves are closed at 0
but at 360 ( TDC for 4 ) they are nearly closed... wouldn't the valve be "rockable" too?

[B D]

Do you have a compression check gauge?

[svandamme]

yep , have that, but don't see how it can tell me if my valves are closed or not, since the gauge just works by cranking the engine, unlike a leak down tester that can be pressurised... ( no leak would be pretty decent indication of closed valves )

is there a way a compression tester can tell me something?

[304065]

You can order, from the eastwood company, a whistle that screws into the spark plug hole. You take out the plugs, screw in the whistle, and rotate the engine. When the whistling stops on #1, that piston is at TDC. Whether it's intake or exhaust, well, you can look at the valves, or look at the Z1 mark, or the notch in the distributor should line up with the rotor. The Z in Z1 stands for "Zundung" which means "spark."

And stop holding a match to the tailpipe or you are going to need some Hollandaise sauce to go with your barbecued self!

[aigel]

Okay, now, take the hose off that tester, make sure you take the valve out too, if it has one and thread it into cylider #1. Then put your thumb on the hose and turn the engine over. As you approach TDC compression on that cylinder, it will pressurize the chamber to the point where you won't be able to hold your thumb on there. There you have it, TDC Compression on 1. If you are off, being the exhaust stroke, you will never feel or get any pressure coming up to the mark, because the exhaust valve is open.

HTH, George

[aigel]

John:

That whislte will only whistle on the COMPRESSION stroke. On the exhaust stroke it will not whistle, becaues the pressure is going right out of the exhaust valve. It does the same thing than your thumb on that hose. On engines with shorter ways to the spark plug hole, you can even put your index finger in there - straight...

Cheers, George

[B D]

Thanks aigel you're quick. If you can't remove the hose then at least you will know you're on #1.

[svandamme]

George, that whistle thing .. sounds good , but i doubt ill find a supplier that sells those in holland

the hose of the compression tester... sounds good too , but i'm not sure if i can take the hose off the gauge, will need to check that ( it's not my tester, it's from the DYI shop where i work on my car)

ill give that a try

suppose i can't get the hose of the tester

would manually turning over the engine to 1 , register on a compression gauge if attached??

Originally posted by B D
Thanks aigel you're quick. If you can't remove the hose then at least you will know you're on #1.

BD , you mean just attached it to #1, then crank the engine , stop it at the z1 mark and i will not be able to remove the gauge because of compression??

Originally posted by john_cramer

And stop holding a match to the tailpipe or you are going to need some Hollandaise sauce to go with your barbecued self!

John,
i seemed a decent way of measuring the amount of flooding in my engine... and reminded me of back when i was 16 ... hotrodding 40 CC 2strokes..... buy new muffler. then fill it with fuel... stand clear ... ignite... then install on the 2stroker....instant hp gain and nice sound

[B D]

BD , you mean just attached it to #1, then crank the engine , stop it at the z1 mark and i will not be able to remove the gauge because of compression??

Basically if you're at Z1 and the gauge just moved and gave you a reading you know you're at TDC. Just like the whistle but no sound.

[svandamme]

why didn't i think of that while i was at the car

i blame vapor lock on my mind...
first i was battling to get fuel ... fearing bad mfi pump.. then to much fuell... a good night sleep, and wait till saturday(gottowork tomorrow) and everybody's great advice....
saturday... i'll find me a chicken and voodoo sacrifice it on friday for good measure...

thanks guys, for bearing with me on this one

[banjomike]

Even easier than using the compression guage. Pull the spark plug in cylinder 1. Turn the motor to the Z1 mark. Stick a screwdriver into the sparkplug hole. If you hit nothing, turn it around again to Z1 and stick the screwdriver in. When you feel the top of the cylinder you know you're at TDC.

[svandamme]

Banjo,

screwdriver doesn't go in the hole with engine in the car ( enough trouble getting the spark plugs in or out )..

i actually tried this with a welding rod last week... but all that happened, was something jamming the welding rod... it actually scraped some of the stuff off the rod... as if the rod was beeing clamped inside the engine...( valves?!? i can't visualize the inside of the cylliner enough to imagine how it could be getting stuck) so i quickly cancelled that idea cause i didn't like the idea of chunks falling in my cyllinder... or actually forcing the engine with some of the components having a welding rod wedged in between em...