Fanalone restoration

[ncundy]

David,

Lapping the cams (or any hardened surface you can get at) was done with these:

http://www.ezelap.com/honestone.htm

Starting at medium to get the mark out (don't use it like a file - just mild pressure away from you following the shape), then fine followed by super-fine. Finish with 1500 grade paper. It takes a while so get a chair and a beer ! Keep the stones clean by dipping in thinners occassionally and don't worry about altering the shape of the cams or putting flats on the journals, with the hardened surface you're only taking 10ths of thou off.

Honing the inside of the rockers was done using the tool in the photos. A piece of hard steel bar turned to just under size (about 15.95mm on the calipers), cut a slot top and bottom and thread with a #3 tap to give it a tapered thread. Screw a bolt (loosely) in then put some grinding paste mixed with oil on the bar (photo 1), turn at low speed with the rocker on moving the rocker around (no real pressure), turn the rocker around and repeat to make sure there is no taper in the rocker. Then take rocker off, tighten bolt a few turns to spread the bar and repeat until you have the correct dimension on the rocker.

This cleans the insides of the rockers up nicely leaving a nice finish without turning the whole thing into a machine shop visit.

Neil

[DavidLaver]

I really like that honing tool.   The EXTERIOR of that rocker looks rather good as well.

David

[ncundy]

Thanks David, I'm very pleased with how they all turned out. It's a bit tedious doing it all but worth it I think

[DavidLaver]

I'm reminded of someone who scratch built a model aircraft engine - a whopping great multi cylinder thing.   He was asked by someone in the crowd why he built something so complex. He replied that he liked an engine to take him some time to build as all he ever did when they were finished was start another one.

Would I be right in saying "you won't know what to do with yourself" when its finished?

David

[ncundy]

lol  . I hope to be driving it, but we'll cross that bridge when we get there 

Anyway, voila: a finished cylinder head. Two pictures; a before and after taken about a year apart.

[ColinMarr]

Very nice! Definitely a work of art - both the original and the refurbishment.

[ncundy]

Well, not feeling too pleased this morning 

I spent ages checking all bolt lengths, cleaning the threads, trial fitting etc. Torqued the bolts down to 50% yesterday and went back to finish the job today and three of the helicoils are jiggered. But the plot thickens as I have taken the first out and low and behold there is the remains of a previous helicoil underneath it 

Now as I have said in other posts there have been several strange things about this head: the cam bearings had been fitted incorrectly, one of the rocker shafts was badly worn and bent and it had the incorrect valve caps on. Someone has been here before me with a "bodge it and scarper" job.

Anyhow - now I can hone my helicoil skills 

[angelorange]

Hmmm... sorry to hear..

I have been there myself twice too often and that was paying someone else to build the engine. First time was wrong cam caps, poor camshaft, stuck helicoils holding cam caps  that had been helicoiled once too often, mashed head bolt heads etc etc ....  However, Peter Gerrish (timecerts?) and SEP Engineering saved the day.

She now sings beautifully - just rolling road tested and successfully raced at Cadwell with no major issues.

[ncundy]

Well, the job starts. Today I have taken the hollow cap dowels out and the remaining helicoils. The dowels are a tight fit so I took them out by hydraulics. I filled each hole with thick oil (steering box oil), gently heated the head locally with a blow torch and put in a aluminium punch. With a couple of sharp taps the dowel pops out. Then I could get the helicoils out.

The plan is to take the holes out and thread to take a bull end stud, then put the dowels back. We'll see how it goes.

[fay66]

Hi Neil,
Neat job, good luck with the rest

I take it the heat was to expand the head to make it easier to get the dowels out?

Brian
8227

[ColinMarr]

Very clever! I am full of admiration.

Colin

[DavidLaver]

You fox!!

David

[ncundy]

Easy tiger,easy. People will start talking !

[ncundy]

Brian, yes they are too tight to feel comfortable giving them a good whack so a bit of heat seemed like a wise thing to do.
The punch has to be almost an interference fit to work (otherwise all you've made is an oil filled water pistol !).
My dad turned a couple up as they lasted about 6 dowels before getting too loose.

[fay66]

Hi Neil,
I have memories from my younger days of trying to hydraulic out a flywheel spigot bush with a not tight enough drift, once experienced, remembered for evermore

Brian
8227