Dizzy firing order

[MetaJacko]

Hi,

My mechanic is just fitting the dizzy and sorting out
the timing but he is having problems working out where number 1 is on the dizzy, where he expects it to be dosn't relate to TDC as he would expect it to. (He is more used to V6s)
I sssume the correct firing order is 1-5-4-2-6-3-7-8 so once no 1
is defined the others should be simple I'm also assuming the cylinders are

Front of Car
5 1
6 2
7 3
8 4

If i'm wrong please tell me
What point is TDC?

I'm not that mechanical myself so I may have asked the questions in a daft way

Thanks

Paul

[trularin]

The cylinder closes to the front of the engine is # 1.

[MetaJacko]

Hi,

Do you mean the point on the dizzy nearest the front goes to 1

Paul

[Ron61]

Paul,

The order that you show is correct for your 390. On my FE the #1 on ther distributor is almost directly in the rear of the cap as you look at it from the front. This can be located in a different position as long as you make sure that you have the firing order correct. I ran it for years with the #1 Distributor Cap location on the right side, before I pulled the distributor and corrected it back to the way it came.

TDC is when you have the #1 piston at the top of it's travel. I use a simple way to determing this. Take the plugs out, turn the motor over with a small wire gauge in the plug hole resting on top of the piston. When it starts back down you have passed TDC. Once you have that set, then put your distributor in with the rotor pointing to the terminal that will go to #1 piston and then make sure to wire all the rest in the correct firing order. The older caps had the #1 marked on them but they don't seem to do that any more.

Ron

[MetaJacko]

Thanks,

That all makes sense.

Paul

[MetaJacko]

Just had a chat with my mechanic again.
He is apparently getting confused with the TDC mark on the pully. It dosn't match up with the top of the compression stroke of #1 but he is sure you couldn't put the pully on the wrong way round. It seems to be 70 - 80deg out.

Is this something that is possible

If so, can you get an accurate enough reading for TDC just off measuring the top of #1 compression stroke?


Thanks

Paul

[blykins]

Make sure he knows which cylinder is #1 cylinder....and make sure he knows that 1,2,3,4 are on the same side.....5,6,7,8 on the other. With that being said, yes, you can get an accurate reading measuring off the top of #1 compression stroke. You can use a dial indicator down the spark plug hole....when you find the apex of the stroke....that would be TDC. Then you can see how close your timing mark is.

[MetaJacko]

Hi,

Yep, the cyl nos are written on the inlet manifold along with the firing order (Its an alu PI manifold).

I guess the answer is to ignore the TDC mark on the pully and measure out a new one?

The current one seems to 70 - 80deg out

Paul

[B. SMITH]

EASY MISTAKE DEPT.

MAKE SURE YOU ARE LOCATING TDC ON THE COMPRESSION STROKE, "BOTH VALVES CLOSED" WHICH IS EVERY OTHER TDC IN A 4 CYCLE ENGINE.

B. SMITH

[MetaJacko]

Yep, doing that,

TDC on the pully is still 70deg out

Thanks for the point though, It is one of those obvious things that you can easily miss.

Paul

[Ron61]

B.

Good advise as we forgot to mention that.

Paul,

If you are on the compression stroke, then the easy way would be to remark your pulley. I did that once and it worked ok for me.

Ron

[MetaJacko]

Originally posted by Ron61


B.

Good advise as we forgot to mention that.

Paul,

If you are on the compression stroke, then the easy way would be to remark your pulley. I did that once and it worked ok for me.

Ron

I think that's the way we will go.
Just suprised that the existing TDC mark did not point to TDC

Thanks

Paul

[Michael C Henry]

If the elastomer is sliping between the inner and outer ring it will probably slip some more.If it's an old original harmonic balancer ,they do go bad. I'm using an oem harmonic balancer but it is in good shape.. The key can also shear. Have you checked that?George at Gueeesford said the key was just for locating ,the press fit and the torque on the bolt are actually keeping the harmonic balancer in place . The torque on the ARP bolt I installed is quite a bit more than oem.If the harmonic balancer isn't timed correct, keeps changing referense marks what good is it anyway? sounds like it is just keeping the oil in the timing cover.

[Naumoff]

Paul, Are you just messing with everyone? If your Mechanic can't figure it out then I would get another Mechanic. Get a new harmonic balancer. I spun one off under acceleration. Not fun.
pull spark plug on #1 cylinder and seal it with your finger. Turn engine crank shaft with a wrench from the front. when it blows your finger out it is coming up on compression stroke and that is when and where you want the #1 spark plug to fire. use the wire method if you don't trust your existing balancer (which you should replace anyway) to determine when the piston is at the top of the cylinder. Drop distributor in with the rotor button on so you can set the #1 position in theproper location. Follow the firing order and the numbers on your intake manifold. It should fire up and then you can set the timing.

Tony

[MetaJacko]

Hi Mike,

Ok that now makes sense. After the crank was re-balanced
all the turning gear (fly wheel, crank, balancer, pully)
was sent off to be balanced. I guess maybe the way it all fits
together now is how it was balanced to.

Hi Tony,

Thanks for your helpful reply,
You will know when I'm messing with everyone becouse I will say 'I am messing with everyone'

Please remember, FEs are not common outside of America.
Maybe I could get a different mechanic but this one is local, and I've already seen the damage done by mechanics that think they know what they are doing and don't ask. (My engine was re-built about 92 by a 'respected' company and they set all the valve lash too tight which may have resulted in my rocker shaft braking)

I thought the whole point of this forum was so people could ask quiestions that may seem simple to others and get honist answers not sarcastic comments!

Thank you for your advice anyway. The basic problem we were having is that TDC on the pully didn't match TDC determined by #1 compression but I can now see why that would be and therefore we should be able to get it sorted

Paul

[Naumoff]

Sorry Paul,

Didn't see that you are from UK til after I posted. Guess I should of looked before I typed. Mechanics that can work on V8 are a dime a dozon here. My Uncle lives in Croughton near Bambury.

Tony

[MetaJacko]

No worries Tony,

Thanks for the help, should be able to get everything working soon.

The mechanic I'm using is more used to moding BMWs (His own car looks like something out of 'The Fast and the Furious' with the lights and everything )

Paul

[Naumoff]

He is going to love the rumble of a Big Block V8 when you guys fire that thing up. Good luck and don't pass on the left!

Tony

[MetaJacko]

Yep!
He got complaints last time when he was 'testing' it after re-setting my rockers.

(That was before the rod bearing went resulting in the re-build )

Paul