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6 cylinder rocker shaft end caps, removal


daverclasper
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Hi.

Rocker cover off today to sort a noisy tappet (Thanks for feeler tip, with engine running Pete Lewis, worked a treat).

I did notice  that the first 6 rockers did not have oil dribbling out of the top holes (in the past there was none coming from 2,3 and 4 rockers, so this has got worse).

There is oil between the valves and rockers and it pools in the recesses at the top of the push rod holes on the top of the head.

Engine has good oil pressure, according to the gauge so assuming it's sludge in shaft.

Should I be bothered by this as maybe getting worse and clean out the shaft. If so the end caps look like they a held by some sort of pin, that looks like the tops have maybe been peened, though  a bit difficult to see.

I gather engine flush not a great idea (and would it clean the shaft) on an old engine that appears to have some sludge deposits and can disturb and  block passageways ?.

Any help great, thanks,

Dave

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yes its a mills pin   500975 , it should punch out ok.  you  can use a split pin if you wreck it    

a roll pin would work and easier to source   

what gets choked is the hole from the bore scroll to the head of the rocker 

if you strip it down photo or sketch which way each  handed rocker and springs / washers  faces 

if the shaft is stuffed they only seem to sell shafts for  mk2 engines  its too long and needs some careful modifications to fit one,  the end cap for the ils way has to be tapped and a setscrew and washer used to replace the mk2 end caps 

got that tee shirt   mk 1 shaft is  204736  not 214562   ( mk2 )shown by some 

Pete

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you wont remove all the rockers without stripping the shaft down  as the pedestals will be in the way 

if you only want to remove an end rocker , well suppose it will tap out with a hard punch but i would suggest you give it a full overhaul 

and check all the rocker scrolls and feed holes .

pete

 

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I had a similar problem with my GT6, albeit with only one dry rocker - made the decision to change the rocker shaft and didn't regret it as the one I removed was quite heavily scored. The replacement came from Moss, complete with end caps.

Gully

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Thanks.

Think I might attempt this soon, as don't have to use the car for a few days. Only ever worked on OHC heads before, so some questions please.

I understand the pedestal nuts have to be undone a bit at a time, I assume because of valve spring tension. No mention of doing them up like this?.

Also, can those end cap pins be tapped our from either end (of the pin) or are they tapered etc?.

Was thinking, soak the rockers in petrol, then flush with brake cleaner, a bit of firking about with wire if needed?.

Any snags I should prepare for as need to turn it over asap.

Any help great, thanks

Dave 

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Part list calls it a Mills pin  these are a parallel hard pin some have a small groove to let air out in  solid blind holes

It should punch out either way, as I said its ok to use a split pin of the right size if a replacement is needed it does not take a lot of loading

These pins can be quite tight ,   I say split pin as if a refitted  mills  is a bit used /loose it can fall out   and thats trouble 

Pete

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Hi. Probably being over cautious here, though in the factory WS manual for rocker shaft fitment, it says something like. " Screw in the rocker adjuster screws fully before fitting, to avoid possibility of bending pushrods and tighten each pedestal nut a bit at a time". I assume to take load of the shaft?.

Is this necessary?.

Thanks, Dave  

    

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Dave   I would read that to unscrew to increase the tappet gap before fitting  but as you are not replacing rockers just cleaning oilways 

Its not anything to bother about,  just do your tappet gap checks on finishing off.

Yes pull the pedestals down evenly locate all the tappet screws in the push rods as you, go.

Do keep all rockers and pushrods  in their original places they all wear and bed in to each other    so best kept as matched pairs

Pete

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Hi. Have got one end cap off (which I'm assuming is enough to clean shaft) and stripped the shaft. The cap pin is disintegrating a bit and left some swarf behind, so I will not re-use.

I have a split pin that when fitted, is not loose as such, due to the outward tension, though when the split is closed up it will wiggle side to side a bit (I'm guessing about 15 thou. Does it need to be a better fit than this? (going by, quite a bit of oil dribbles out of rocker holes normally, would this drop oil pressure much).

Also, wear on shaft, on all rocker areas, the most is 9 thou. Would this affect efficient valve operation much?. The engine is quiet when running.

Also, eleven of the push rods have a slight flat on the top ball, except one?.

Any help great please.

Cheers, Dave

Ps. On further examination of of shaft/rockers (not cleaned yet), all oil holes appear clear. Could the wear on shaft, also possible wear on the rocker bores cause a loss off oil pressure, causing less oil passage further up the shaft?.

 

 

Edited by daverclasper
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with more ways for the limited supply to escape then yes oil supply to the  front end is going to deteriorate

theres not a lot of pressure as the supply up the rear pedestal is not full flow but limited by a flat on the cam bearing to give a squirt once every cam revolution

if you have 0.009" shaft wear thats nearly as much as the desired clarance  so a new shaft is needed here.

the rockers are probably not worn as much in the bore as the shaft is harder and that takes the wear .

you can stone or emery the pads to remove the ridge which affects the feeler entry , leave the valve contact zone as is.

the flat on the base of the push rod spherical  is normal for oil retention   do keep push rods with their matched follower and tappet screw as theyb are all bedded in to each other 

Pete

Pete

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