Correct valve clearances?
Correct valve clearances?
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Discussion

haircutmike

Original Poster:

22,511 posts

234 months

Friday 17th February 2012
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Does anyone knoww the correct valve clearances when using adjustable pushrods?

I have been told many variations but what is correct?

haircutmike

Original Poster:

22,511 posts

234 months

Friday 17th February 2012
quotequote all
Bunpski

haircutmike

Original Poster:

22,511 posts

234 months

Saturday 18th February 2012
quotequote all
I know what you mean, it's a compromise.

I need the clearances for solid lifters and adjustable pushrods.

carsy

3,019 posts

195 months

Saturday 18th February 2012
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Sorry Peter cant help with clearances, just interested as to why you have gone to solid lifters.

haircutmike

Original Poster:

22,511 posts

234 months

Saturday 18th February 2012
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Track days, very hot engine, higher constant engine speeds, thin oil, (even with oil cooler) which leads to occasional bleed down of the lifters.

Thought I'd give the solids a go and see if there is an improvement!

black and green

669 posts

221 months

Saturday 18th February 2012
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Can you get the clearance spec off the cam manufacturer or the installation paperwork?

haircutmike

Original Poster:

22,511 posts

234 months

Saturday 18th February 2012
quotequote all
They actually stated, 16 inlet and 19 exhaust but some people state otherwise, hence my confusion and asking!

haircutmike

Original Poster:

22,511 posts

234 months

Saturday 18th February 2012
quotequote all
Update.

Cam supplier said, 16 inlet, 19 exhaust.
JE stated 7 for both when measured at TBC.

I set at the former on the heal of the cam today then measured at TBC and low and behold, it wasn't far off 7 thou!

Goaty Bill

1,779 posts

181 months

Sunday 19th February 2012
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B-Reight said:
Just trying to set mine at the moment using shims, one bank was was easy with all between 20 & 40 thou, the other bank ranges from 15 to 95 thou! Bugger.
yikes

I knew the RV8 rocker gear was appalling, I didn't realise it was that appalling!

When running BBCs, I always considered anything more than 5 thou off spec to be reason to have the valve covers off. TBH I have never asked what the clearances are on mine. It's just one of those jobs I always left to the expert.

The road to mediocre performance is a short and easy one it seems.

Brummmie

5,284 posts

251 months

Sunday 19th February 2012
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Goaty Bill said:
B-Reight said:
Just trying to set mine at the moment using shims, one bank was was easy with all between 20 & 40 thou, the other bank ranges from 15 to 95 thou! Bugger.
yikes

I knew the RV8 rocker gear was appalling, I didn't realise it was that appalling!

When running BBCs, I always considered anything more than 5 thou off spec to be reason to have the valve covers off. TBH I have never asked what the clearances are on mine. It's just one of those jobs I always left to the expert.

The road to mediocre performance is a short and easy one it seems.
Its probably the valves further through the head?
You would have the measure with a tool, you could have the ones that are the shortest through cut in a little, 80 thou difference is a bit on the large side to compromise.
I have just had a 5 angle valve job done on my LS heads, the spring heights are at the shortest 1.850 and the longest 1.880 (0.030" compromise), so i am shimming under the springs to give even open valve spring pressures.

ETA you could grind the required amount of the tallest valves, but this would be a bodge as your spring pressures would be uneven, but better than that big compromise in lifter pre load.
I heard it somewhere that Range Rover used to set them at up to 120 thou to keep em quiet, but they are not revving them that hard, i think at 0.020" it will sound like a bag o nails, i think i set mine at 60-80 back in the day, i tried less but sitting at the traffic lights with it sounding like a well worn sewing machine p!ssed me off.
This is when i had HCM chimeara BTW! (Dereks engine)

Edited by Brummmie on Sunday 19th February 12:08

v8 racing

2,064 posts

281 months

Thursday 23rd February 2012
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haircutmike said:
Update.

Cam supplier said, 16 inlet, 19 exhaust.
JE stated 7 for both when measured at TBC.

I set at the former on the heal of the cam today then measured at TBC and low and behold, it wasn't far off 7 thou!
Changing cams again pete!, out of interest that does not make sense, if you set the valve clearance on the base circle, it should be the same at tdc, if its not then you have a major run out issue with the cam.