Pinto Ignition Timing

[jimfer01]

I'm redoing the cylinder head (2 litre pinto) because the valve stem seals needed replacing - my MOT man wasn't impressed with the level of exhaust smoke.
Having taken everything apart I have established that I have a Kent FR30 camshaft fitted. Having located the data and instructions on valve timing on the good old internet, setting up that side of things seems straightforward enough.
However, I'm struggling to find any guidance on ignition timing. The Kent data sheet quotes timing figures of 20/60 60/20. Can anyone throw any light on what these mean?

[Ye Ol Ripper]

Re: Pinto Ignition Timing

You maybe interested to know that it is possible to change the valve stem seals on a Ford Pinto without removing the cylinder head. I can divulge how to ,if you haven't already done so but you will also need a second pair of hands to carry out the procedure.

The figures from the Kent literature are valve opening and closing and are nothing to do with the ignition timing.

From the following spec:https://www.kentcams.com/files/kent_...ue_2011_a5.pdf

it is essential to "clock the cam in" using a magnetic stand and dial guage indicator. Ideally using a vernier pulley to adjust the cam timing or you may be able to use an offset key to move the cam pulley around a few degrees.

The figure you need to use from the spec is to time the inlet valve fully open at 110 degrees on the crankshaft. Before doing this check the TDC mark on the bottom pulley is actually TDC. That is done by using the magnetic stand and dial guage indicator to determine where the top of the piston travel is . Check on the front of the engine if the TDC and timing pointer align if not make your correct new mark by painting tipp-ex and a pencil line.
Then remove the bottom pulley and using a protractor mark the 110 deg on your pulley with Tipp-ex and a pencil line and then held in the vice a junior hacksaw to make the marks for TDC and 110 deg.

On the Pinto, provided the cam timing is within 5-8 degrees of spec it won't affect the engines performance.
However if it exceeds this the fuelling and power delivery will be wrong and you can't just pull the distributor around to compensate.
So my point is take your time getting it correct.

That cam profile is for an Automatic and will give you good low end torque.

The ignition timing from memory was somewhere between 5 and 8 degrees for a Pinto, as much more than that the oil down the valve guides used to then cause them to pink(ping) at around 4000rpm.
So you will have to use a timing light and gradually adjust and establish where the engine is happiest.

Can you confirm if this is still fitted with an automatic transmission?

[jimfer01]

Re: Pinto Ignition Timing

It's too late to try changing the stem seals without removing the head - already done. No bad thing as I've taken the opportunity to clean things up. One day I might ask you to explain how it's done with the head on.

It was the ignition timing that was concerning me - I think I have the rest covered. I haven't dialled a cam in before but it seems straightforward enough as long as I follow the guidelines.
Before I took it apart the engine was most comfortable at about 16 degrees BTDC. No way would it idle as low as 8 or 10. This suggest the cam timing was out. I'll start from 10 degrees and see where that gets me.

No automatic transmission. Car came fitted with a 5 speed manual.

Thanks,
Jim

[Ye Ol Ripper]

Re: Pinto Ignition Timing

With regard to the ignition timing, have you in the checked that the distributor is advancing ok with a strobe light?
As if it the engine was unused for some time they can sometimes need freeing up.
What Carb/Carbs are you using the original twin choke downdraught Webber or Twin 45's?