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timing belt stuff

Post by teh » Subscribing Member » Tue Feb 05, 2019 6:36 pm
Joined: Mon Jul 16, 2018 9:10 am
Posts: 50
I'm getting to the end of my tether with this van, I think the auxiliary pully has been fitted backwards because I can only see a circle on it instead of the V I was expecting, I can't get the pulley off because it seems to have been glued on with something, I can't find the V on the back side because it's too messy.....

can someone either show me a picture of the V mark to help me spot what I'm looking for, or tell me where it is in relation to the circle on the front so I can position this pully properly

I'm also struggling with the tensioner, there is a funny bolt at the bottom which looks like the inverse of a torx, can anybody tell me if this is standard and if so what size bit I need for it?

Re: timing belt stuff

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Post by Phil Bradshaw » Club admin » Tue Feb 05, 2019 8:44 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3827
V mark usually is just a nick on the inside of the pulley rim (ignore balance holes which can be drilled anywhere).

Image

Unfortunately I can't find a better photo at present, or put my hand on a pulley to have a look at.

Quick and dirty fix for when the auxiliary pulley won't budge from its shaft (risk of breaking thrust washer if hammer too large...) -

Set up camshaft pulley mark to align with bolt head centres when crankshaft is at TDC (top dead centre).

Install distributor so that the three securing screws land in the centres of their slots.

Adjust contact breaker points gap to 0.020 inch (0.5 mm).

Rotate auxiliary shaft clockwise until rotor points to No. 1 ignition HT lead and points have opened to about 0.010 inch (0.2 mm) or thereabouts (a bit past just opening for static ignition timing).

Select the best pulley position to slip on the cambelt; nearest tooth will do. Fit belt then temporarily mark tooth which aligns with the camshaft pulley mark.

Adjust belt tension, rotate crankshaft two full turns, at the end checking for points opening and pulley mark back where it started at TDC; adjust belt position as necessary (can be a tooth out with slack taken out - why this check is to be skipped at your own risk!).

Also re-adjust tension as necessary: should be possible to just twist the belt through 90 degree in the run between the camshaft and auxiliary shaft pulleys when the belt is tight between the camshaft and crankshaft pulleys.

Image

Tensioner screw with flanged external Torx (hexalobular) head I think is T8. Usual tool is a 1/2-inch cold chisel: Torx head screw is the only one of its kind on a CF.

Mangled Torx screw can be replaced by 5/16-inch UNC high tensile screw long enough to use with a thick flat washer (M8 form G is ideal) and rectangular section spring lock washer (i.e. Torx screw thread length + washers thickness).
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: timing belt stuff

Post by teh » Subscribing Member » Fri Feb 08, 2019 2:15 pm
Joined: Mon Jul 16, 2018 9:10 am
Posts: 50
Thanks, it was E10 "external" or "female" torx needed, the head is pretty mashed though so I'll replace with your suggestion

the tensioner does not look serviceable to me but it spins smoothly at the moment, while it's off is there anything you would suggest I could do to prolong it's life?

I will also time it based on your suggestions, looking at the pulley I think it might have been glued on because it's missing the key :?

while the belt is off do you think it's a good idea to spin up the auxilliary pully with a drill to get some oil flowing round the engine before I try to start it?

Re: timing belt stuff

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Post by Phil Bradshaw » Club admin » Fri Feb 08, 2019 3:44 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3827
If the tensioner pulley spins smoothly then all it may need is a scrub of the belt face with a rotary wire brush.

Pulley with no key probably is held on with Loctite Bearing Fit or similar. More can be added if desired: capillary action will draw fluid into gaps and crevices where it will cure in absence of air.

Trick for releasing cured adhesive is to cook the parts until engine oil on the surface starts to smoke then use a puller to remove the pulley. Leave until shaft has to be removed though - auxiliary shaft seal probably will suffer.

For priming the oil pump I've found that a cup wire brush pressed against the pulley bolt does the job well enough without breaking anything; pulley can try to stall once the pump starts working. Don't forget that the distributor has to be installed to drive the pump... :)
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: timing belt stuff

Post by teh » Subscribing Member » Sun Feb 17, 2019 8:11 pm
Joined: Mon Jul 16, 2018 9:10 am
Posts: 50
thanks for the advice, I tried spinning up the pulley but the fuel pump is not sucking anything and the oil pump doesn't seem to be doing anything either, the distributor rotor is turning though

also no timing belt cover so I'm not sure how to find TDC at the mo, if there's another mark on the block I can't see it through all the mess

Re: timing belt stuff

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Post by Phil Bradshaw » Club admin » Sun Feb 17, 2019 9:48 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3827
Auxiliary pulley may have to spin quite fast for a pump to prime. If you have been using a cup brush in a cordless drill then try a mains powered drill for higher speed and torque (and much more care in applying it to the pulley!).

If that doesn't work then the pump may have to be removed in order to prime it via the two ports in the bottom of the pump. Once a pump has been primed a cordless drill should be ample.

TDC mark is on the front of the crankcase, clockwise from vertical along a line between the crankshaft and camshaft (lower image is tilted anti-clockwise from horizontal) -

Image

9° BTDC for static ignition timing with cover removed is half a tooth on the crankshaft pulley clockwise from TDC (rotate crankshaft clockwise to this point).
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

Re: timing belt stuff

Post by teh » Subscribing Member » Tue Feb 19, 2019 7:18 pm
Joined: Mon Jul 16, 2018 9:10 am
Posts: 50
thanks, I'll try again tomorrow

am I safe to mess this up or is the slant 2.3 an interference engine?

Re: timing belt stuff

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Post by Phil Bradshaw » Club admin » Tue Feb 19, 2019 7:51 pm
Joined: Sun Sep 02, 2012 7:15 pm
Posts: 3827
On low compression engines it's quite hard to clout valves with pistons unless the head has been skimmed past specifications; best to be safe though.

With the crankshaft at about 90° BTDC it will be safe to turn the camshaft without any on the inlet valves touching pistons (exhaust valve heads don't protrude as much).

Once the camshaft pulley mark is more or less aligned with the pulley centres the crankshaft can be brought to TDC.
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  • What is real is not the external form but the idea, the essence of things. Constantin Brâncuși

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