Re: Cylinder head

Post by Budbarnsley » Tue Nov 07, 2017 6:34 pm
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
Another thing he's told me (that's if I can explain it properly) is that when he accelerates there is a popping sound as if it's advancing too far (the bob weights are opening too far). Apparently it's sparking before the piston reaches the top. He says that he's going to stop the Bob weights from opening, surely if they are meant to open then the fix is to stop them from opening too far. Thanks Alan

Re: Cylinder head

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Post by Phil Bradshaw » Club admin » Wed Nov 08, 2017 12:33 am
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3587
Ignition timing too far advanced can cause back-fire through the intake but once the engine runs advanced timing usually just makes the engine rattle itself to death.

Restricting the movement of the mechanical advance weights is more likely to make the engine flat-line at well below its normal maximum speed than be a fix for anything.

If the Delco distributor with contact breaker points is fitted then first checks are the points gap and dwell angle.

Points gap should be 0.020 inch.

Dwell angle is 49-51 degree for distributor 9977151 (stamped on body), 35-37 degree for all other D300 distributors.

If the dwell angle cannot be achieved with a small adjustment of the points gap away from 0.020 inch then check for bent distributor mainshaft, worn bushes or excess play in the cam plate or contact breaker base plate.

If the contact points faces are blackened then also try a new condenser; matt grey faces without pips and craters should be fine.
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Cylinder head

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Post by VDUB384 » Club admin » Wed Nov 08, 2017 10:10 am
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1340
If your thinking of going down the electronic route the best one to get is the Aldon system and feed it with a 12 volt positive from fuse 3 it's not a cheap one but better than the Sparkrite it's Aldon MR LS2.
http://www.aldonauto.co.uk/ignition/ign ... plications
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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Re: Cylinder head

Post by Budbarnsley » Wed Nov 08, 2017 10:23 am
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
Thanks for that Phil I'll let you know how we get on.

Re: Cylinder head

Post by Budbarnsley » Wed Nov 08, 2017 11:01 am
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
Thanks Dave I'll see how things go.

Re: Cylinder head

Post by Budbarnsley » Fri Nov 10, 2017 7:37 pm
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
Well got the van back home today and what a difference to what she ran like before. The mechanic did a great job and the price was reasonable, but has he said he was quite happy with it and could do any more. He set the dwell angle to 37 degrees hoping this would cure the problem but on the way home as I asked for that little bit more from the pedal you could here it crackling, it was definitely breaking down and was arcing from the plugs to the aluminium heat shield. I've had new points condenser plugs and even bought new leads off eBay made up from Kevlar material. Stumped, could really do with the last hurdle getting over. Alan

Re: Cylinder head

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Post by VDUB384 » Club admin » Sat Nov 11, 2017 10:34 am
Joined: Wed Sep 12, 2012 9:01 am
Posts: 1340
Hi Alan is it arcing with the new leads if that's the case the leads sound faulty to me.
Dave
Whilst good maintainece is the best prevention"If its not broken don't fix it."
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Re: Cylinder head

Post by Budbarnsley » Sat Nov 11, 2017 3:16 pm
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
This is the third set of leads Dave and all do the samr

Re: Cylinder head

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Post by Phil Bradshaw » Club admin » Sat Nov 11, 2017 11:19 pm
Joined: Sun Sep 02, 2012 7:15 pm
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Copper core leads can flash over to the heat shield; resistive (carbon filament) leads should be used.

Heat shield can be bent away from plugs and leads if it's a bit close: steel type has sharp edges!
  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: Cylinder head

Post by Budbarnsley » Sun Nov 12, 2017 11:01 am
Joined: Fri Sep 08, 2017 8:37 pm
Posts: 17
Cheers Phil

Bought these from spitfire on ebay:
Our ignition cable sets give a superior spark because more of the energy goes to the spark plug to give improved performance, starting and fuel economy.
The construction is a Kevlar centre with a stainless steel winding which carries the electrical pulse to the spark plug. This is encased in a top quality braided outer insulation core to give maximum electrical protection so superior that cables can touch each other or metal on the engine without any electrical impulse or shorting taking place.

Will bend the shield back a bit

Alan

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