Valve Springs

XRLNT-8 · 27-12-2008, 09:03 PM

Hi all,

Today the xr8 spat the chewie, no.6 valve spring broke leaving me stranded (not far from home so very lucky!).

Q1: The left bank is easy to get to, how much work is involved in getting the rhs rocker cover off to do the rest of the springs?

Q2: What brand springs should I get?

Any advice would be appreciated.

Cheers,

Simon

b2tf · 27-12-2008, 09:58 PM

Bugger eh, when you do redo the springs check the valves and make sure there's no damage.

To do the RHS rocker cover you're going to need to remove the upper manifold/TB setup, bit of a quick guide from memory;

* Undo the screws that hold the '5 Litre V8' manifold plaque on, 2 bolts under there, undo them. Another 2 of the same sort, one is at the front of the upper manifold (same head size) and there is one in a real bugger of a spot at the rear of it near the firewall. I'm doing this from memory and it's been a while since I've taken mine off but I think this is all of them to get the upper off, if not someone will correct me no doubt.

* When I took mine off I removed the Throttle Body from the manifold and left it connected to the cable and just worked around it. The cable spring mechanism is a bit fiddly to put back together if you do decide to remove the TB entirely but it will depend on if you have enough room to get the rocker cover off and work on the springs with it being there.

* Be careful when you lift the manifold off, it may be a bit sticky but they do chip/crack easily on the edges so lift it off and put it in a box/on a bench somewhere to keep it safe. Perhaps a good time to give it a go over with autosol if you're that way inclined.

* From memory 5 bolts for each rocker cover, undo them and keep the gasket clean as it is re-usable. From there you should be able to do the job.

Now as for springs I wont be much help as I used Edelbrock Valve Springs that came pre-assembled with my heads, however Crow make a replacement P/N 7738 that a lot of guys seem to use. You can also get springs from Comp Cams and these get good reports also.

Hope that helps

XRLNT-8 · 28-12-2008, 10:48 AM

Thanks for the reply B2tf, it helps a lot. I had a suspicion the bolts were hiding under the plate!

The broken spring hadn't collapsed fully just cracked so the valve has been closing, just not enough for compression. I guess the only way to check the valve is to take the head off?

5.0 ED · 28-12-2008, 11:44 AM

yeah i'd recommend you just go with the crow 7738 unless you planning a very large lift camshaft installation in the future.

As for checking to see if it bent the valve, you should be pretty right, you will tell by the install height if somethings not right, as in with no rocker gear on and all new valve springs installed, if you get a straight steel ruler, and place it across the top of valves, they should all be the same height (all exhaust same, all intake same), if u bent one it'd be lower cause it won't sit in seat properly.

**Whoosha** · 28-12-2008, 12:03 PM

Quote:

Originally Posted by XRLNT-8

Thanks for the reply B2tf, it helps a lot. I had a suspicion the bolts were hiding under the plate!

The broken spring hadn't collapsed fully just cracked so the valve has been closing, just not enough for compression. I guess the only way to check the valve is to take the head off?

Sounds the same as what happen to mine, I went the qwik fix just replaced the one $5.75 just filled the cylnder with air first to make sure it was sealing still and replaced the spring. 3 trips to Heathcote since and all is well

:

XRLNT-8 · 28-12-2008, 09:12 PM

Hey Whoosha, how many kays has your engine done? I am in two minds right now, do I change them all or just the busted one!! My engine has done 159,000. The other springs might go another 10 years then again they might start popping one by one from now on...

b2tf · 28-12-2008, 09:25 PM

Not taking anything away from Whoosha but if it were me I would most definitely be doing all of them. Far better to do them all now than have another one let go and possibly end up needing head work to fix it.

CRAIGAU3220 · 29-12-2008, 12:30 AM

My au has done 58k, Lots of drags and lots of high rpm (cant help my self) 212rwkw and pulls to 6000rpm quite easily.

should i start to worry about valve springs yet.

5.0 ED · 29-12-2008, 09:54 AM

it may pull 6000rpm easily but u may also find yourself a couple extra kw's by doing them all with a slightly stiffer spring, although you may not hear or notice it, you start to get valve float and spring wobble well before the engine misses.

according to crane cams, a heavier spring does not lose hp due to having to open each spring, cause of the kenetic energy in each spring helping to push the next open. So heavier springs should always be a win win scenario in terms of power.

I can only base what i have seen of a couple motors we have changed and then put on dyno and they have all made more power in the rev's, but we were also changing them cause there was an issue too.

CRAIGAU3220 · 29-12-2008, 11:26 AM

Thanks for the advice 5.0whiteaughia, Will get it done.

Cheers.

honer · 29-12-2008, 12:23 PM

Good advice, I think I may do mine before the cars get reguarly driven

Seems the 220's have a nasty habit of breaking springs

**Whoosha** · 29-12-2008, 03:29 PM

Quote:

Originally Posted by XRLNT-8

Hey Whoosha, how many kays has your engine done? I am in two minds right now, do I change them all or just the busted one!! My engine has done 159,000. The other springs might go another 10 years then again they might start popping one by one from now on...

With those sort of Ks as B2tf said I would be thinking of doing the lot. mine only had 50000k on it at that stage and still only has 79000ks on it .. and has retired from the track ......... maybe

:

crakrz · 29-12-2008, 09:13 PM

Are the valve springs in the 220kw motor just standard windsor springs or are they a bit heavier, due to the slightly improved cam?

XRLNT-8 · 29-12-2008, 09:30 PM

Well all done and dusted, mechanic mate came over with his super dooper valve spring tool and a set of crow springs and was all done in 4 hours. Nothing really difficult with the job, but the spring tool he brought along was a little gem, kinda like a bearing puller with a star wheel at the top for screwing it closed. I did notice however that the original springs have different lengths (inlet and outlet) but the crow set were all the same. Anyhow all good now. (touch wood!)

Cheers for all advice.

Simon