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Couple of ST170 Questions
Barksavon - 31/5/19 at 10:07 PM

We're putting our ST170 engine back together. Put the head back on and next going to put camshafts back in. I've got the crankshaft locked in place with the pin screwed into the block. Should I line up the slots in the end of the cams before I tighten down the bearing journals.
We're using a Focus Haynes manual for reference which covers the Zetec engine but not the ST170. The manual talks about shims when checking / setting valve clearances. Does the ST170 use shims as there were none at all when I took the head to pieces.
Also can anyone tell me whether the cylinder head torque values for the standard 2litre Zetec are the same for the ST engine
Thanks


cliftyhanger - 1/6/19 at 04:46 AM

Not a bad idea to lock the cams, but they turn quite freely (or should) when fitted. But locking will stop anything silly happening. Remember you must not tighten the cam sprocket by locking the cams, you need to use the proper tool. (easy enough to make one, but strugging to remember what I did with the inlet cam. Maybe a spanner on the cam? there is a place for one)
Valve clearances set by the cam buckets. Hope you marked them and get them in the right places.
And I used the std Zetec torque figures when I put my engine back together.


big_wasa - 1/6/19 at 08:32 AM

As above, no shims on an St, if they are out you need new buckets. it’s case of getting the cams in, bearing caps on and measuring the clearances. If you have them out of order it can take an age to check, strip, move, rebuild and re check and again and again until you have the best match.

Do some reading re the vvt pulley From memory you do the timing at rest but if it’s worn it can be out of tolerance. This causes problems with the Oem ecu as the ecu logs it’s out of range. Ie over or under advanced.

I’ve always torqued them the same as a Zetec. They are the same bolts.


Barksavon - 1/6/19 at 09:05 AM

Thanks, everything was kept separately so valves, springs, collets, buckets etc have gone back in the same order....hopefully the clearances will be ok.
Thanks for the advice about the pulley👍👍 we're going to run it on bike carbs megajolt and a separate but controller (unless I succumb to one of the packages offered by danst with ignition and vvt control all in one!!!!)


Barksavon - 1/6/19 at 04:11 PM

Can anyone confirm the correct torque values for the Zetec head bolts. The Haynes gives 1st stage 11 ft lbs, 2nd stage 22 ft lbs, 3rd stage 90 degrees.
We've fitted a Victor Reinz head gasket and the info that came with that states 1st stage 20 - 30 Nm, 2nd 40 - 50m and then 90 - 120 degrees
50 Nm is about 37 ft lbs and then 90deg on top of that is significantly higher than the Haynes figures.
We've worked to the Haynes figures but want to be happy we're right before we go a lot further
Thanks

Got them 20Nm, 40Nm then 90 deg

[Edited on 2/6/19 by Barksavon]