The V8 Owners Forum -

TAFF wrote:Thanks for all the advice chaps.

Yes I did fit the cam and pointers correctly with the piston at TDC.

I have set number 1 firing point by the blowing the finger off the plug hole, and watched the inlet valve close, however I do have to rotate the crank a fair bit to reach the marker ( the scale is just out of view when the valve shuts )

The piston is definitely at TDC, I have used scale to measure the lift in the bore.

The cam is a standard like for like replacement 3.5 carbs.
I think I will remove the front cover next weekend and have another look.
I need to check the oil pump out anyway.

I will keep you informed of my progress.

Thank you all.

IGNORE THE CRANK PULLEY MARKER AT THIS TIME.
The important thing is to be sure that the cam is fitted and aligned correctly with the crankshaft.
And then make sure that the dissy is fitted correctly for the IGN timing.

If the engine ran ok before you changed the parts then you have made a mistake in the re fitting procedure?

TAFF wrote:Thanks for all the advice chaps.

Yes I did fit the cam and pointers correctly with the piston at TDC.

I have set number 1 firing point by the blowing the finger off the plug hole, and watched the inlet valve close, however I do have to rotate the crank a fair bit to reach the marker ( the scale is just out of view when the valve shuts )

The piston is definitely at TDC, I have used scale to measure the lift in the bore.

The cam is a standard like for like replacement 3.5 carbs.
I think I will remove the front cover next weekend and have another look.
I need to check the oil pump out anyway.

I will keep you informed of my progress.

Thank you all.

The piston MAY BE DEFINATELY NEAR TDC.. But is is on a compression stroke??

mgbv8 wrote:

TAFF wrote:Thanks for all the advice chaps.

Yes I did fit the cam and pointers correctly with the piston at TDC.

I have set number 1 firing point by the blowing the finger off the plug hole, and watched the inlet valve close, however I do have to rotate the crank a fair bit to reach the marker ( the scale is just out of view when the valve shuts )

The piston is definitely at TDC, I have used scale to measure the lift in the bore.

The cam is a standard like for like replacement 3.5 carbs.
I think I will remove the front cover next weekend and have another look.
I need to check the oil pump out anyway.

I will keep you informed of my progress.

Thank you all.

The piston MAY BE DEFINATELY NEAR TDC.. But is is on a compression stroke??

so watching the inlet valve open and close, then bringing the piston to TDC, is this not the compression stroke?.
the timing marks were all correct, i have taken a few pictures for reference when i did this, i know i have done something wrong, i just cannot see what at the moment.

The only way to check the timing with electronic ignition is with a timing light. Get someone to crank the engine while you check it. Use some white paint (or Tippex, etc) on the pointer and mark to make them easy to view.
You can buy a new timing light for well under £20 these days.

However, with new tappets an engine can sometimes be hard to start even when everything else is ok. If they weren't left soaking in oil for some time before fitting. Might be worth removing the plugs and spinning it over a few times. But do let the starter motor cool down between doing this.

Piston no 1 is at the front left side looking from the drivers seat.
TAFF, please confirm that you setting the ignition on this piston's TDC firing stroke.

Ok, just to confirm.
it seems that a lot of reply,s are = " are you sure you are on compression stroke" ?
well if you read the previous posts you will find the answer!
if you can't be arsed, then here it is again.

I used the finger over the spark plug hole, rotated the crank by hand, the finger was being forced out from the plug, not in, out.
I also watched the inlet valve open and close ( a little way before TDC on the crank pulley ) i also used a gauge in the plug hole and watched the piston rise to its maximum point ( ON THE COMPRESSION STROKE ! )
NO 1 on the rotor has been set to No1 on the cap and all leads are correct.
I have a spark.
I have fuel
The timing marks have been set correctly.

It will not start, or attempt to start even when rotating the distributor either way, this is at both the TDC and 6deg before points.
Yes something is wrong, i will have to wait until next weekend before i can look at it again.
On top of this i have no oil pressure

Is the dizzy actually turning when you turn the engine over ?

ie...dizzy drive missing = oil pump drive missing

Compression test ?

I assume this engine has never been run ?

If you have a TDC pointer and timing light, you can try and get a few flashes whilst spinning the engine over on the key ( plugs out ) to see if timing is near right to allow starting.

I've rebuilt a RV8 before that wouldn't start untill I moved the distributor a long way from "standard" once it started to warm up though I was able to move the dizzy slowly round until it was back correct and the engine was then timed correctly with a gun. Started just fine after that and I never did discover why it wouldn't start the first time.

TAFF wrote:

mgbv8 wrote:

TAFF wrote:Thanks for all the advice chaps.

Yes I did fit the cam and pointers correctly with the piston at TDC.

I have set number 1 firing point by the blowing the finger off the plug hole, and watched the inlet valve close, however I do have to rotate the crank a fair bit to reach the marker ( the scale is just out of view when the valve shuts )

The piston is definitely at TDC, I have used scale to measure the lift in the bore.

The cam is a standard like for like replacement 3.5 carbs.
I think I will remove the front cover next weekend and have another look.
I need to check the oil pump out anyway.

I will keep you informed of my progress.

Thank you all.

The piston MAY BE DEFINATELY NEAR TDC.. But is is on a compression stroke??

so watching the inlet valve open and close, then bringing the piston to TDC, is this not the compression stroke?.
the timing marks were all correct, i have taken a few pictures for reference when i did this, i know i have done something wrong, i just cannot see what at the moment.

It certainlny is mate. Dont take offence now!! You were rotating the engine clockwise eh ? I know its a numpty question but we need to know.
Pel

TAFF wrote:Ok, just to confirm.
it seems that a lot of reply,s are = " are you sure you are on compression stroke" ?
well if you read the previous posts you will find the answer!
if you can't be arsed, then here it is again.

I used the finger over the spark plug hole, rotated the crank by hand, the finger was being forced out from the plug, not in, out.
I also watched the inlet valve open and close ( a little way before TDC on the crank pulley ) i also used a gauge in the plug hole and watched the piston rise to its maximum point ( ON THE COMPRESSION STROKE ! )
NO 1 on the rotor has been set to No1 on the cap and all leads are correct.
I have a spark.
I have fuel
The timing marks have been set correctly.

It will not start, or attempt to start even when rotating the distributor either way, this is at both the TDC and 6deg before points.
Yes something is wrong, i will have to wait until next weekend before i can look at it again.
On top of this i have no oil pressure

That explains things better Taff. Now thinking along the lines of no oil pressure. You wont see any pressure when cranking to be honest. Why not set the engine to TDC with the dissy in the right place. Then pull the dissy and manually prime the oil system. This will highlight any oil system faults. While its out you can check the dissy drive to make sure its all in good nick and also double check that you havent got badly worn teeth on the cam cog that drives the dissy in case its skipping teeth and sending timing way out with every rotation of the engine. If you are worried aobut oil pressure I would investigate that first I think.
Perry

No such thing as a numpty question, only a numpty answer.

yes clockwise, the crank nut will undo otherwise, i have not torqued it up yet.

this engine has been run up before ( see previous )

it has had partial fire up with dizzy rotated to its limit.

i cannot turn dizzy, give throttle and hold a timing light at the same time.

i will try the timing light on cranking though.

very puzzling, i will get to the bottom of it, keep throwing ideas at me, it all helps, the wife does make a good brew, and she can turn the key, but i don't trust her with the pedals multiple choice is not her strong point.

mgbv8 wrote:

TAFF wrote:Ok, just to confirm.
it seems that a lot of reply,s are = " are you sure you are on compression stroke" ?
well if you read the previous posts you will find the answer!
if you can't be arsed, then here it is again.

I used the finger over the spark plug hole, rotated the crank by hand, the finger was being forced out from the plug, not in, out.
I also watched the inlet valve open and close ( a little way before TDC on the crank pulley ) i also used a gauge in the plug hole and watched the piston rise to its maximum point ( ON THE COMPRESSION STROKE ! )
NO 1 on the rotor has been set to No1 on the cap and all leads are correct.
I have a spark.
I have fuel
The timing marks have been set correctly.

It will not start, or attempt to start even when rotating the distributor either way, this is at both the TDC and 6deg before points.
Yes something is wrong, i will have to wait until next weekend before i can look at it again.
On top of this i have no oil pressure

That explains things better Taff. Now thinking along the lines of no oil pressure. You wont see any pressure when cranking to be honest. Why not set the engine to TDC with the dissy in the right place. Then pull the dissy and manually prime the oil system. This will highlight any oil system faults. While its out you can check the dissy drive to make sure its all in good nick and also double check that you havent got badly worn teeth on the cam cog that drives the dissy in case its skipping teeth and sending timing way out with every rotation of the engine. If you are worried aobut oil pressure I would investigate that first I think.
Perry

tried priming manually, with little resistance, i think the regulator has stuck.
all the gears are in good order as is the drive gear.
will whip the front cover off and start again though.

Long before shafts to allow you to use a drill to prime the pump were thought of, the standard way was to pack the pump with Vaseline and spin the engine on the starter with the plugs removed until the oil pressure light went out. Which is the method I've used lots of times.

It can be tricky to get the dizzy to engage with the oil pump drive as it turns as you insert it due to the skew gears. There is a method given in the BL manual to do this easily - and also align the dizzy and plug leads to the standard positions.

Or add another couple of litres of oil
That means the oil is higher than the pump and the pump will prime a lot more easily
Once the oil is circulated around the galleries etc drain out the excess to get back to correct level

Ian

Re Reading

If the Dizzy arm does not point exactly to the cap electrode your sistributor is not timed correctly

Or you have the incorrect Dizzy arm fitted - I have seen these with a straight arm, one that "tails" and one that goes in advance of the radius of the circle being prescribes
Sure these may be different applications but is yours correct?

Ian