Spacer Gasket & Timing Marks

As some may already know i am Building a "Ghetto" 16VT engine.

I am gonna use Stacked Gaskets or a Spacer... I ve been thinking though??? with the added height between the block and the head the timing marks will no longer allign will they.

I am i right in think that i will just be able to get away with using a Vernier pulley to make sure timing marks are Correct??

Indeed the timing will be slightly out due to the effective increased deck height. A vernier pulley will deal with this fine, AFAIK.

How do you work out how many degrees you need? Or do you just fiddle?

I assume you take the extra height of the head on the spacer gasket and the diameter of the pulley?

Well i plan to allign the Head timing position marks up on the OEM pulley, then fit the Vernier pulley in place with the locking nuts loose so when the cam belt is tensioned, rather than moving the cam round and messing with the timing it stays in the correct position and only moves via the adjustment room available on the vernier rather than moving the cam round..?? if that makes any sense.

Kinda hard to put into words really lol

I did a similar thing when setting up my Shrick Cam on my G60 and that worked wonders. ;-)

Shaggy wrote:Well i plan to allign the Head timing position marks up on the OEM pulley, then fit the Vernier pulley in place with the locking nuts loose so when the cam belt is tensioned, rather than moving the cam round and messing with the timing it stays in the correct position and only moves via the adjustment room available on the vernier rather than moving the cam round..?? if that makes any sense.

Kinda hard to put into words really lol

I did a similar thing when setting up my Shrick Cam on my G60 and that worked wonders. ;-)

sure but how do you know what error is introduced by the different deck height so that you can compensate by offsetting it with the vernier?

Or am I missing something??

^^^^ basically the use of a vernier is to blueprint a cam. Advancing and retarding the cam timing will shift the power band but the reality of it is that the cam will already have advanced timing build into it so the idea is to blue print a cam.

as most of you realise once you've had a head of and skimmed or are using spacer plates/stacked gaskets etc.. the timing marks from pulley to pulley dont line up anymore. So here's how to set up a vernier.

Get yourself a top dead centre tool and degree wheel if you want to do it real acuratelly. Alternativelly miss this part out and judge top dead centre on cyl one with a long chopstick down the spark plug hole.

Fasten the degree wheel centrally to the crank pulley.
Screw the TDC stop tool into spark plug hole number one.
With the cams out rotate the bottom end of the engine all the way clockwise and note the degrees read on the wheel, then rotate all the way anti clockwise and take a reading. Your TDC will be exactly half way between the two degrees readings you've taken.
Remove the TDC tool.

Once the bottom end is at exact tdc make some clear marks to remeber the location incase you accidently jog the crank. Fit the cams to the head at exact TDC. In the case of a 16v the two '0' marks face each other at the level of the rocker cover to head mating face. Also the groove in the back of the exhaust cam for the dizzy will be perfectly parralel to the same surface.

Once the cams are in fit the vernier pulley tightening the central bolt finger tight only so not to shift the cams. Make sure the vernier is set to 0 degrees and the small bolts holding the vernier locked are loosened of so the teeth can rotate freely without the cams turning.

Fit the timing belt and tension it lightly. The vernier should move as you tighten the belt but the cams and crank should remain at exact TDC. Once you got some tension in the timing belt lock of the vernier at whichever degrees setting it's at and tighten up the vernier pulley to the cams.

Turn the engine over two to four times from the crank (2 crank turbs per 1 cam pulley) and double check that the crank and cam TDC's all line up at the same time.

You know have blueprinted your cams to factory spec irrespective of deck height changes.

/\/\/\/\

I think I have a book outlining that procedure but that makes it very clear.Thanks.

Woah, i didnt even think of this when i stacked my gaskets? should i panick?

Flusted wrote:Woah, i didnt even think of this when i stacked my gaskets? should i panick?

no just fix it.

It'd be quite interesting Aid, to get a rolling road of your car as is and them with a vernier fitted to 'fix' it. I'd like to know how much difference it actually makes. So, the extra height should retard the cam timing using the standard pulley?

Yeah i was trying to work out if it would retard. strange cos power comes on very strong at 2.5k with ABF cams and 50mm inlet

I bought a piston stop a while ago but it dosn't work on my car because of the low compression pistons.
Anyone know where to get one for a low comp engine?

Ta.