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Discussion Starter · #1 ·
I have a 1971 T2 with an engine I have rebuilt about 6 months ago.. It has 1641 Bs&Ps, standard everything else I think in there to.. I bought a couple of Spanish webber 34 ICT's from JK but haven't managed to start the engine yet and its really frustrating.!!!

On inspection of the distributor drive gear I noticed that it wasn't perfectly perpendicular to the crack in the case but only just out by maybe 5 degrees when the number one piston was at TDC (I found TDC with a pencil down the plug hole)

On adjusting the valves I found that one on each side didn't seem to adjust properly but rather the rocker was always touching the top of the valve stem rather than the adjuster, Although I could just about slide the feeler gauge between really tightly.
I know something isn't right but dont know where ive gone wrong here.. I Recall making sure the cam and crank gear was aligned properly but don't know why it appears my ignition timing is out!

When I try to start it I get a great deal of popping up through the carbs and a bit less from the exhaust but it seems quite a bit of un-burnt vapor..

Its made even more difficult not knowing if these new carbs are contributing to the cause of it not starting, I have changed the jet sizes as described on a walk-through but still no joy.. I think its more so ignition somewhere..
 

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Discussion Starter · #2 ·
Sorry perhaps my Webbers are the copy version, I got them from JK for about 400 for the kit, didn't realize Spain made the genuine ones
 

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On adjusting the valves I found that one on each side didn't seem to adjust properly but rather the rocker was always touching the top of the valve stem rather than the adjuster, Although I could just about slide the feeler gauge between really tightly.
you mean that 2 of your valves you can wind the adjuster screw right out and there's still no clearance? are you definitely checking with the crank/cam at the right orientation?

if the valves aren't closing (or aren't opening) then it won't help your engine to run. i wouldn't be trying to start the engine until i'd worked out why this was happening.

and the orientation of the distributor drive doesn't affect how the engine runs, it's just an aesthetic thing. just orient the dissy so that it sends the sparks to the right plugs at the right time.
 

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post a picture of the rocker to valve.

Are you 100% at TDC before adjustment of that valve? You can check by putting something down the spark plug hole, and turning the engine just a little bit around TDC to find exact TDC. Becarefull as you can jam the screwdriver shaft against the plug threads, but only if you turn the crank something like 30 degrees.

Just for getting an easy start up (in your case, adjust after) set the timing to about 10 BTDC, that wil facilitae starting.

turn the engine through two turns and watch the action of the rocker. Things like deck height, shims under the springs, etc can make a difference, but i would think it would be subtle, more like the cam not quite right, which is why i say turn the engine through and watch the action. Did the cam have a new wheel? Pushrods the correct length? Correct Lifters?

Luke
 

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Discussion Starter · #5 ·
you mean that 2 of your valves you can wind the adjuster screw right out and there's still no clearance? .
yes thats right, ive been around both sides and made sure im on the correct set of valves through the adjustment of each of them.
 

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Remember, there's two TDC's in a four stroke cycle, just making sure the piston is at the top of the stroke is not enough for doing your valve adjustments, you only have a 50:50 chance of getting it right..

No 1 piston at the top of the stroke. AND rotor arm pointing to number 1 plug lead AND both rockers on no1 cylinder should be loose AND the opposite rockers (no.3) should be rocking in opposite directions as you swing the crank backwards & forwards either side of TDC.

When you have number 1 set right turn the engine 1/2 turn anti clockwise, do number 2, 1/2 turn anticlockwise, number 3, 1/2 turn anitclockwise, do number 4.

Your adjuster screws should all have roughly the same amount of adjustment (by eye) If you can't get them right then it would be worth removing the pushrods, one at a time and roll them on a sheet of glass to make sure none are bent.

Dave.
 

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Discussion Starter · #7 ·
Thanks very much once again for your help :) Ive also come across rocker arm shims, I wonder if this could also help.
 

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+1 to my whippy, comparing a good push rod to the one you have with the rocker problem (for bentness and length)

it may or may not be related, but i'll say it. If your dizzy is 180 out, then just rotate the leads 180, dont mess with the shaft inside (which is 180 out), as it has the end play shims which may fall into your gears. On some dizzys you lose the retard on #3, but get it running first, before you worry about sorting that out.
 

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Thanks very much once again for your help :) Ive also come across rocker arm shims, I wonder if this could also help.
If you are running non standard rockers, or a non standard cam then you may need rocker shaft spacers to help correct the geometry. Otherwise, no you don't need them. even if these are fitted, inlet and exhaust should remain pretty much the same.

The intake valve adjuster screw and the exhaust valve adjuster screw on each cylinder should extend roughly the same length when all is well.

Photographs would be handy ;)

Worth a few minutes of your time -

and -

Dave.
 

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Discussion Starter · #10 ·
An update on my van situation.

Over the weekend I had realized that after turning the pulley to tdc and checking the number 1 rocker arms moved they didn't do so I must have adjusted it on the wrong stroke previously. I readjusted them and put some shims under the rocker shaft so I could adjust them correctly. Tried starting it with no joy.. As a last attempt I swapped the ht leads around (1 on 3, etc) and it fired up!

Im wondering what the reason might be as to why its working like this now?

Anybody know?
 

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Discussion Starter · #12 ·
Also does this affect the rocker geometry does anyone know?, I actually cut a pulley shim up to use just to see if it would affect it.. Was about 0.5mm I think
 

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An update on my van situation.

Over the weekend I had realized that after turning the pulley to tdc and checking the number 1 rocker arms moved they didn't do so I must have adjusted it on the wrong stroke previously. I readjusted them and put some shims under the rocker shaft so I could adjust them correctly. Tried starting it with no joy.. As a last attempt I swapped the ht leads around (1 on 3, etc) and it fired up!

Im wondering what the reason might be as to why its working like this now?

Anybody know?
I cant comment on correcting the rocker geomery, but im pleased to hear that you were 180 out on the dizzy, and i helped put you in the right direction =)

Rocker gemetry correction i know nothing about...=( going back to the rebuild, were the heads flycut?, what deck height did you use? both of which can affect the pushrod/rockers. Id be tempted to go backwards and build it back up, but thats only because i dont know if correcting your rocker geometry is either something you should be trying to do or is it just a sticking plaster masking another problem.

LUKE
 

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Rocker pedestal shims are one of the things you can use to help correct the geometry if you are using non- standard parts, such as swivel feet adjusters, high lift cams or higher ratio rockers, or if the heads have been flycut a lot. Sometimes they may be all that is required for minor modifications, but for major mods you will also need to make up your own custom length pushrods.

If all else is standard, fitting shims will make the valve geometry worse.

This might explain a bit more - http://www.volkszone.com/VZi/showthread.php?t=631384

Glad to see you got it running though ;)

Dave.
 
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