Irony
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| posted on 13/7/10 at 10:15 AM |
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Rover V8 Lifter Preload
I am building a RV8 and I am just building the heads. They have been steam cleaned and thoroughly washed in parafin. I have lapped the valves in,
cleaned up the springs and keepers which look in good condition. I have new rockers and rocker arms but I am using the same pedestals. I have two
questions for those of you that have built RV8's.
1. Lifter preload. On other V8 it seems possible to set lifter preload for every rocker but this doesn't seem possible on the RV8 due to the
design of the rockers. The only way I have heard of is putting shims under the pedestals. This seems abit crude and awkward as how do you measure
it. Did you guys do this? Is really that important?
2. On the three sets of heads I have, there does not appear to be any sort of little incy wincy boots on the valve stems underneath the springs. I
have seen them for sale. Are little boots vital and my heads just don't have them?
Cheers Fellas
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coozer
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| posted on 13/7/10 at 10:28 AM |
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Well Fella I don't have clue what your talking about, BUT, as I'm just about to go get my first V8 engine this afternoon (which I'm
wetting myself about) I will follow your build very closely.
Its bound to be a very steep learning curve which I'm looking forward to greatly.
Keep me posted!
LG,
Steve
1972 V8 Jago
1980 Z750
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Agriv8
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| posted on 13/7/10 at 10:37 AM |
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I have a document at home about setting pre-load and YES it is important can scan and post up but I will see if I can find an online ver over lunch.
page 14 on here rimmer Bros
to measure i got 3 bits of welding wire the right size for Min Middle and MAx and using these as feeler gages
Edit to add you can get adjustable push rods to set individual pre load
usefull info here realsteel pdf
The boots are valve stem oil seals
Old a rubber waher that often disitegrates over time .
Newer that is pressed onto the valve guide ( you need the later type valve guide for these to work ) as they are machined to fit.
Regards
Agriv8
PS I have some good V8 reading u2u your email address and I will send it through
[Edited on 13/7/10 by Agriv8]
[Edited on 13/7/10 by Agriv8]
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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02GF74
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| posted on 13/7/10 at 10:53 AM |
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tappet preload halfway down the page.
my undersrtanding is that it is necessary if the block or heads have been skimmed ... which is a risky business since there may be problems fitting
the inlet manifiold due to the positon of the inlets moving.
I didn't do the preload bit and not had problems.
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RAYLEE29
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| posted on 13/7/10 at 12:08 PM |
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HI, you only need adjustable pushrods for mechanical tappets most rv8 cams use hydraulic tappets and if you havent heavily modified compressions via
skiiming heads or different pistons you should be able to just bolt it all together.
do fit a rev limiter as new followers will pump up if you over rev the engine breaking valve springs etc
Ray
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Canada EH!
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| posted on 13/7/10 at 05:22 PM |
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I don't know what happened to the Buick engine when Rover got it but most hydraulic lifter engines are adjusted at idle by tightening the
lifter down till it stops clacking then add1/4 to 1/2 a turn tight and lock the adjusting nut and bolt.
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robinj66
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| posted on 13/7/10 at 05:31 PM |
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If you're building the engine to a fairly standard spec then you will probably get away without setting lifter preload (especially if the cam
followers are new) except as previously said, if you have skimmed the heads/block or you are using a really leary cam.
The shims aren't the best way to alter the preload anyway - they alter the rocker geometry - best way is much more expensive - machine the head
where the rocker shaft pedestals sit.
The earlier style valve stem seals are just rubber washers - you could get your valve guides machined to take the later mushroom types but it probably
isn't worth it.
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