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Re: V8 rocker shaft bronze bushes
Posted: Thu Feb 11, 2021 9:36 am
by freddynav
Update.
So I have reamed all of the rockers to 22.98mm. The one on the left is original (approx 20.4mm), and the one on the right is reamed
Re: V8 rocker shaft bronze bushes
Posted: Sat Mar 06, 2021 7:03 am
by Mc Tool
This is good work freddynav and is in line with my thoughts on retaining oil pressure to the rockers . A plain bearing needs a bit of pressure to operate , more than it needs high flow. The thing is most of us probly dont have either the nouse or the access to the nessesary machinery , and paying to get it done would probly cost more than a flash set of rollers and post /shaft assy . I do totally see the fun in it and if I had the gear Id be right in there too
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 12, 2021 6:23 pm
by freddynav
Hi everyone.
Sorry for the gap since last posting. Progress however has been made. First up was finishing the 16 bronze bushes. Oh and yes I know there are only 15 here. 16 just messed up the symmetry of the photo of the lovely shiny bits.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 12, 2021 6:25 pm
by freddynav
Next was to press them in to the reamed out rockers. There is 10 microns interference which proved to be exactly the amount required. Had to be careful to align the oil hole which is slightly oversize in the bush to allow for a little misalignment.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 12, 2021 6:25 pm
by freddynav
First test fit revealed that when pressing the bushes in to the rockers they narrowed by about 6 microns so a few minutes on the honing machine brought them back to having 10 microns clearance. Next time with will be compensated for in the machining stage. Now they fit over the shafts beautifully.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 12, 2021 9:21 pm
by ChrisJC
Very nice.
Chris.
Re: V8 rocker shaft bronze bushes
Posted: Wed Mar 24, 2021 9:32 am
by GDCobra
That's a neat looking job, got me tempted now!
Just looking at the side of the rocker, there is a small slot cast in, presumably for oil reliefe at ends, will you be extending that into the bush?
Re: V8 rocker shaft bronze bushes
Posted: Wed Mar 24, 2021 12:05 pm
by GDCobra
Just looking at some photo's of my rocker assembely, one thing I'd like to do if/when I can get some machine access is to make up some billet pedastels, those case items look awfully spindly, I'd also extend the outer ones to support the end of the shaft which looks like a weakness to me.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 26, 2021 3:05 pm
by freddynav
Hi GDCobra.
I have been contemplating the potential ‘oil relief’ cutouts. At the moment I have decided not to extend them into the bush. Mainly because I do not see the utility for there is plenty of opportunity for oil to escape and perhaps even encourage oil to feed through the rocker onto the pushrod.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 26, 2021 3:06 pm
by freddynav
And talking of pedestals.........
Hopefully this weekend will see the shafts completed and fitted.
Re: V8 rocker shaft bronze bushes
Posted: Fri Mar 26, 2021 4:03 pm
by GDCobra
freddynav wrote: ↑Fri Mar 26, 2021 3:06 pm
And talking of pedestals.........
Hopefully this weekend will see the shafts completed and fitted.
Nice!
Did you consider extending the outer ones to support the ends of the shafts?
What you need now is some clear rocker covers so you can see the fruits of your labour, would be a shame to hide it all away!
Re: V8 rocker shaft bronze bushes
Posted: Sat Mar 27, 2021 8:58 am
by freddynav
GDCobra wrote: ↑Fri Mar 26, 2021 4:03 pm
freddynav wrote: ↑Fri Mar 26, 2021 3:06 pm
And talking of pedestals.........
Hopefully this weekend will see the shafts completed and fitted.
Nice!
Did you consider extending the outer ones to support the ends of the shafts?
What you need now is some clear rocker covers so you can see the fruits of your labour, would be a shame to hide it all away!
I have not considered extending the outer pedestals but simply because the thought had not occurred to me. I shall look at this when I fit these rockers for this may well be an easy modification for future iterations.
Re: V8 rocker shaft bronze bushes
Posted: Sat Mar 27, 2021 1:09 pm
by GDCobra
freddynav wrote: ↑Sat Mar 27, 2021 8:58 am
GDCobra wrote: ↑Fri Mar 26, 2021 4:03 pm
freddynav wrote: ↑Fri Mar 26, 2021 3:06 pm
And talking of pedestals.........
Hopefully this weekend will see the shafts completed and fitted.
Nice!
Did you consider extending the outer ones to support the ends of the shafts?
What you need now is some clear rocker covers so you can see the fruits of your labour, would be a shame to hide it all away!
I have not considered extending the outer pedestals but simply because the thought had not occurred to me. I shall look at this when I fit these rockers for this may well be an easy modification for future iterations.
Given what you've done so far I don't think it would be any problem for you, something I'm sure I've seen done before but may have been on different engine.
BTW, I'm just trying to remember, isn't there an oil feed through those rocker posts? Have you included that?
Sorry got to go, granny's due for her egg sucking lesson!
Re: V8 rocker shaft bronze bushes
Posted: Sat Mar 27, 2021 8:55 pm
by freddynav
Yes there is an oil way through the pedestals. I should have taken a picture of the underside and you will see the design is similar to the original. Basically the mounting hole through the bottom of the pedestal is larger than the hole through the top part and oil flows around the mounting bolt. There is therefore a milled recess on the bottom surface to join the oil feed hole on the cylinder head to the main mounting hole on the pedestal. In essence, my ones work exactly as the original ones.
Re: V8 rocker shaft bronze bushes
Posted: Sat Mar 27, 2021 11:15 pm
by GDCobra
freddynav wrote: ↑Sat Mar 27, 2021 8:55 pm
Yes there is an oil way through the pedestals. I should have taken a picture of the underside and you will see the design is similar to the original. Basically the mounting hole through the bottom of the pedestal is larger than the hole through the top part and oil flows around the mounting bolt. There is therefore a milled recess on the bottom surface to join the oil feed hole on the cylinder head to the main mounting hole on the pedestal. In essence, my ones work exactly as the original ones.
I knew you'd be on top of that but thought better mention just in case, would hate to see your good work go to waste due to a small oversight.
