Changing Valve Springs

[jakeandlizzy]

I am soon going to swap the springs in a VVC 160 block for Piper springs to allow for the solid cams (1320s).

 

I am not going to remove the head if I can help it, meaning I will just wind some rope (thanks for the advice Simon) into the piston area and turn the crank until all of the valves have pressure against them (so they do not fall into the piston area).

 

From here, how hard is it to remove and swap the springs over? Is there a better way?

[oilyhands]

The VVC springs will handle the lift and RPM from 1320 profiles. I would leave the stock springs in place unless you have overriding reasons not to.

 

If you use the rope method you should constrain the crank from turning. It often requires considerable pressure to break the 'grip' of the collets on the caps, when on the bench I normally tap the cap smartly with a custome mad tool to break this grip, when the head is on the engine it will be a bit more difficult to acccomplish.

 

Oily

[Ivaan]

I changed all my valve caps and collets like this. It works well, but you may need to bodge up a tool to compress the springs. I found a length of steel pipe that was just a bit smaller diameter than the valve cap, into which I cut a couple of access holes either side, to remove / replace the collets. Standing this on top of each valve, I then used a ratchet strap taken right round the engine and pulled the springs down.

To get the collets back in, use a small srewdriver with a small blob of grease to get and hold them in position against the valve stem, until you can release the spring.

Very fiddly, and you'll probably drop the collets a few times. You'll need a magnet on a stick job to retrieve them.

Just take you time, and have a cup of tea between doing each cylinder... and don't swear too much. 😬

 

Clive

[jakeandlizzy]

Oily, OK, I didn 't know you could retain the originals as the Piper blanking kit as, CAM/verniers/etc. came with the piper single springs for this profile of CAM at the time.

 

But I suppose with 10.6mm of lift, which is .4 or so less than 285Hs, it must be OK?

 

If I don't need them, I suppose I will then have a set of Piper single springs for sale as I already have them! --makes the upgrade even cheaper. Now I just need to learn how to get the initial timing done (safe mode so to speak) before I take it down to yours to set the verniers accurately.

 

If I do need them, thank you Ivaan for the instructions -- this makes perfect sense.

 

 

[oilyhands]

It isnt well known that the VVC springs are lighter wire than the standard K series springs and have a lower crush height of 25.4 (installed height of 37.20) so they should take the lift easily.

 

Dave

[millsn]

Jake

You must be able to take them back to the 'shop you got them from?

[Mick Day]

Having helped out on changing valve springs recently it's easier to remove the head completely. At least then one can examine the valves/head interface & know that everything is in good order. The thought of dropping a collet between the valve & seat, & wasting time getting it out, would give me nightmares, especially if I couldn't find it!

[jakeandlizzy]

I got them from someone who already bought the whole kit (from eliseparts).

 

I wonder why they are always still sold with the springs???

[oilyhands]

It isnt well known that the VVC springs are lighter wire

 

That's why and most conversion kits for the VVC do require springs (BP285hs are marginal).

 

Oily

[jakeandlizzy]

Happy days!

 

I will take your advice over eliseparts any day -- that will make my work that much easier.

 

I will start another post to see if I can find some instructions for installing the blanking kit/cams/initial timing as this was one item missing from the kit (and the timing wheel).

[oilyhands]

There are a few simple tips

 

i) the bolts that hold the front blanking plate (the old VVC mech bolts) need to have the heads thinned or they will foul on the back of the verniers, at least 1.5mm needs machining from the tops of the heads.

ii) there is no blanking plate for the cam pos sensor, either leave it in or make your own small plate

iii) the horizontal oilway under the main blank plate that covers the HCU mount needs blocking before the plate is fitted, I normally tap it to M10 and screw in a short piece of M10 studding with loctite

iv) the flanges on the flange bolts holding the forn and rear blank plates need to be reduced in diamter by .5mm or they can bind in the holes.

v) transfer the timing marks from a standard pair of pulleys to the verniers (as per the installation instructions on my website) then fully retard the inlet pulley and fully advance the exhaust pulley that will make them safe WRT to timing

 

There are other places to buy the bits at more favourable rates and with installation instructions.

 

Oily

[jakeandlizzy]

Ah, OK, so mark the belt as fitted to the car in a spot corresponding to timing marks on the original cam belt sprockets and mark the verniers with the marks transferred from original sprockets.

 

I assume then that the sprockets (or pulleys :) ) fit onto the cams in only one way so there cannot be that much confusion.

 

If this is correct, then the job sounds simple (after polishing the followers/greasing everything with cam lube).

 

Thanks again!

[oilyhands]

Dont mark the belt, it can easily skip a tooth.

 

Get the engine to 90BTDC with the lines on ther VVC pulleys lined up.

 

Transpose the timing markings to the verniers as per the instructions on my website for vernier fitting, then fully retard the inlet and fully advance the exhaust. Then fit the pulleys with the timing marks lined up.

 

oily