Power Band Understanding

[Davo]

Tried the wire from battery to coil with the original removed. It ran fine but didnt get me past 3000

 

I suppose there is the possibility that the Rev counter could be wrong could it? It reads 3000 but is actually much higher? Unlikely I would have thought.

[Davo]

If I understand the cam timing set up, something would appear wrong here. This might not be exactly lined up, but it looks like the point is roughly at 6 oclock pointing up. When I look at the timing marks and blades they seem a little out. Would you agree from this video?

 

[Longboarder]

Rev counter sounds OK. That missfire sounds like 3000ish rpm. I believe you have found the problem. Cam timing shown seems way out by about 30 crank degrees advanced!!! I'm surprised it runs at all and has not mangled all the valves if that is a true picture. It looks like the cam belt has jumped two or even three teeth but its also possible that the crank or cam sprockets have slipped on their respective shafts. The cam belt tensioner and the belt must also be in the suspects mix. I would also say you risk the health of the engine if you drive it hard or even if you drive it!

 

Personally I would say get on ebay and get a new 'Gates' brand cambelt and tensioner as a first step. Like this https://www.ebay.co.uk/itm/FORD-PINTO-2-0-OHC-Cam-Belt-Tensioner-Genuine-GATES-INA/162992978179?hash=item25f3237903:g:4DoAAOSwXshWq660 Next have a good look in Haynes and enlist the help of someone who knows this stuff. Probably need the radiator out, hoses off the front of the engine and alternator belt off to help access then strip off both cam sprocket and crank pulley and the toothed sprocket behind it that drives the belt. Reason I would remove the pulleys is they are keyed onto their shafts and should not be able to slip. Indeed it's extremely unlikely that they have slipped but the cam timing is so far out I can hardly believe the engined hasn't lunched on its valves if it's genuinely that far wrong so I would want to confirm the woodruff keys are still properly in place holding the pulleys/sprockets in their correct positions.

Then it's a case of putting it all back together, lining up the cam, crank and dizzy at TDC and putting the belt back on and tensioning it. I would say this is a delicate operation. Not difficult but an experienced helper would be almost essential.

 

Altogether great news but you have a bit of work to do and a new belt should only be £35.

Edited May 6, 2018 by Longboarder

[Davo]

Thanks for the reply. Ive had the radiator off before when changing the fan but the next steps do feel a bit out of my league.

 

Unless I can pursuade my father to join me for a weekend I might have to give in With this one and take it to a friendly garage.

[Longboarder]

There might be a more local Hoodie who can visit to help. Get the new bits and appeal for help on here.

[Guest lotusPaul]

Davo,

 

Just back from being away a while. Where in Fareham are you and when are you there. Im in Gosport when im not on the water.perhaps you could pop over

[Davo]

Thanks paul, very kind but I moved the car from Fareham (where my dad lives) to Bournemouth (where I live) to work on it through the winter. Im often over that way and could do with a chat, but the car is a bit too far away for easy transport unless I hire a trailor.

[Davo]

A bit of a novice question, but if my 2l sohc pinto is a non interference engine, will any damage be done if I get the cam timing wrong?

[IanS]

Quick answer is no damage in the short term.

But risk of burnt valves if run for too long and too far out, but i think that you would notice lack of tick over.

This only applies to standard ford cam, an after market cam with more lift might make it an interference engine.

Edited May 9, 2018 by IanS

[Davo]

Thank you

It was only so I could understand the risk if I mess the procedure up. As far as I know its a standard cam

[Davo]

So it seems off cam timing can indeed cause your engine to not run well or in some cases not at all!

 

Having changed found tdc, aligned the cam pulley markings and fitted a new belt and tensioner the engine not only runs but makes it past 3000 revs!

 

Not a proper test yet but good enough.

 

Just need to tune the carb and the ignition timing now.

 

Thanks to all the online help; and my father and son for pulling it apart this weekend!

[tractor]

good news you will soon be taking the head off and getting it ported and skimmed now you have the knowledge to set cam timing

Edited May 20, 2018 by tractor

[Longboarder]

Well done. Ignition timing to 10 degrees before TDC with the strobe. It will almost certainly have moved when you did the cam belt. Carb's probably OK. And you're in business.

[Davo]

Best timing felt more like 12-14 degrees, or at least thats where idling felt fastest and smoothest. I think I remember reading though that it should be as retarded as possible without causing an issue. Is this correct, and is retard indicated by progression through the marks to the right of tdc?

 

Regardless, performance is much much better now.

[Bob Tucker]

No...the nearer to TDC the strobe flashes, the more retarded the ignition.

The 12-14 degrees will usually suit a tuned engine, but with a standard dizzy,

you end up being too advanced at higher revs. I'd back iit off to 10 degrees for safety

& sacrifice a steady tickover for being safe at high revs.