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V8 Rockers

daimlersteve
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V8 Rockers

Post by daimlersteve »

v8 rockers
I need a little help here chaps,
what i've seen
inlet-- drilled for oil to valve stem top-- all that i've seen
exhaust-- drilled for oil
exhaust-- undrilled-- more common it seems.
What , when did these changes occur ,? and are ther any other versions out there?

PS, While i have your attention, anyone know the thread on the gear lever ?

steve

Vortex O'Plinth
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Re: V8 Rockers

Post by Vortex O'Plinth »

Can't help you with the rockers, but the thread on the SP250 gear lever is 7/16 - 20 UNF.
Nick

"Don't bother with the Air & Space Museum - there's nothing to see.......".

David S
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Location: Forest of Dean

Re: V8 Rockers

Post by David S »

And re the rocker shafts: you have to be very careful to get them the right way round.
The springs between the rockers make it difficult to be absolutely sure the oil holes correspond with the groove inside the rocker.
I always make a point of laying them down in order when I dismantle the top end.

But I'm sure you know that anyway!

David

daimlersteve
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Re: V8 Rockers

Post by daimlersteve »

Thanks david, now what about the possibility of inlets without oil feed to the valve stems? I had a look at those on one of the SPs and it has oil holes on both inlet and exhaust, so it may be the jag/saloon had the non drilled to the exhaust only.
steve

David S
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Location: Forest of Dean

Re: V8 Rockers

Post by David S »

ooops! nit slow to reply her.

The two rocker shafst look reversible, but they are not.
I think they are the same but must be fitted the right end at the front.

daimlersteve
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Re: V8 Rockers

Post by daimlersteve »

AS i recall the rocker shaft /rocker oiling holes are different centres
steve.
Having set up the new heads correctly fo rocker geometry i should drag an org. head out and check it out.
For those who like a spot of reading , look up --- B3 Racing Engines --- hemi rocker geometry --- 4 sections of interesting stuff. Chrysler got it all wrong way bay in the sixties.

Patrick
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Joined: Mon Feb 15, 2016 6:22 pm

Re: V8 Rockers

Post by Patrick »

My observations on a recent rebuild.
Exhaust rockers have an internal groove (reservoir) opposite both the valve stem top and the tappet adjuster with internal drilling in the rocker going to each side.

Inlet rockers have an internal groove (reservoir) with an internal drilling to the tappet adjuster. On the valve stem pad side there is no groove (reservoir) in the rocker but there is an internal drilling out to the valve stem pad. Note that the rocker shaft has a hole at this point, presumably for lubrication. So in my application the inlet valve stem is being lubricated by oil mist in the rocker box.

Patrick
Original engine, VIN 100078

faeton
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Re: V8 Rockers

Post by faeton »

I have just dragged out some complete spare rocker shafts , I seem for some reason to have three inlet with the groove cut across the end of one shaft . There is also a drilled hole over the valve end of the rocker. The exhaust rockers doesn't have these holes . If I didn't read that this was the correct arrangement it would be easy to assume that the drilled holes would be the exhaust . I have also read somewhere that some valve collets were originally coated , to stop the oil running past into the guides.

Dave

daimlersteve
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Re: V8 Rockers

Post by daimlersteve »

yep, thats what ive found with the saloon rockers.
Org. sp seems to have oiling holes on both.
steve

kent sutton
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Location: Townsville QLD

Re: V8 Rockers

Post by kent sutton »

Dear Steve
Read B3 Racing engines interesting stuff.
But isn't some of this the limitation of using push rods instead o/h cams and bucket tappets?
Ferrari seemed to manage quite well with single cams and rockers for many years but did he design rocker motion "correctly" minimising
lost motion of the cam lobe. Am I correct in interpreting B3 criticism of the Chrysler push rod arrangement as incurring lost power due the valve operating train incurring too much lost motion from the cam profile?
Also have you checked to see how Mr Turner's valve train stacks up?
Yours
Kent

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