Project Money Pit !

The cylinder head is bought and paid for and the seller is in Louth in Lincolnshire.

However, I think we have a plan.

A work colleague is going to collect it for me, on one of his trips.

Just have to be patient
I’m near Louth and happy to help if your collection plan doesn’t work out.
 
Good to see the spirit of ukgser alive and well…… looking after each other with no thought of financial gain, just good karma.
 
The right side monolever cylinder head has finally landed - all the way from Lincolnshire.

Just needs a quick strip and clean.

IMG_2642.jpeg

This is now a complete monolever spec R65 engine.

Got a bit of an issue with the inlet valve gear so can’t be fitted just yet - but getting closer
 
Correction to my earlier post.

I have just realised, this is now a complete R65 monolever spec engine - save the valve gear.

I’ll put something up in the ‘wanted’ section but does anyone have a full set of 1985 on monolever / paralever valve gear they’re willing to part with ?

 
I've got boxes of rocker gear; the odd valve, too. Which specific bits are you after? Rockers, shafts, valves (sizes?), collets, springs, bearings, shims?
 
Got the right side piston / cylinder and head fitted.

No rockers - just the holders so I can torque everything up.

Fitted carburettors and some choke / throttle cables.

IMG_2650.jpeg

Only got one old style rocker cover at the moment but the engine is otherwise looking pretty complete.

We have spark, confirmed by switching the bike on and flipping the kill switch on and off.

And after a tidy up for the weekend - we’re here

IMG_2651.jpeg

Next weekend - fluids and see if we can build up some oil pressure.
 
@Gelandestrasse

The rocker assemblies themselves Tim.

2 inlet & 2 exhaust if you have them 🤞

I could likely reuse the adjuster screws and locknut, but all the remainder
I’ve had a look and I’ve only 3 rocker assemblies, 2x No2 and 1 x No1. But there’s pitting on at least one of them. Looking at picture of the head posted earlier, are you sure it’s a Mono? My rocker posts have locating bosses on the bottom and a spacer washer (thick)?
 
I’ve had a look and I’ve only 3 rocker assemblies, 2x No2 and 1 x No1. But there’s pitting on at least one of them. Looking at picture of the head posted earlier, are you sure it’s a Mono? My rocker posts have locating bosses on the bottom and a spacer washer (thick)?

It’s definitely got R65 mono heads with 35mm exhaust outlet (unique to R65’s) with 40mm inlet valves and 36mm exhaust.

Earlier R65 twin shock heads have 38mm inlet and 34mm exhaust valves.

Found this photo of mono rocker with black plastic spacer and shim

IMG_2652.jpeg

The 3 sets of rockers I have don’t have the black collar or shims and I think are pre 85 twin shock type 🤔
 
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From MAX BMW's website https://shop.maxbmw.com/fiche/DiagramsMain.aspx?vid=51626&rnd=10232024.

These are the pictures. But your photo above shows the correct rocker but not the same posts as MAX...

View attachment 391467View attachment 391468

I looked up the part number for item 9, the support and it says it’s fitted to a range of other airheads

IMG_2653.jpeg
My older /5 BMW and the G/S definitely dont have posts that have a protrusion on the base like that.

In fact, I’ve never seen one like that 🤔

Wonder if it’s a generic diagram ?
 
I find the parts list misleading as the rockers will fit many models, across models, and up down the age range. Inevitably, Snowbum has a web page on them, but I think it goes along the lines of you can upgrade to a later version but not necessarily the latest, depending on the year of your heads. If your heads are like those in post #143, I have lots of rocker posts for those, which may fit more than one width of rocker arm (ie the length along between the posts) but I only have the 3 rocker arms that suit the plastic shim. This picture is from MAX BMW for the pre-85 bikes. Look familiar?

Screenshot 2025-03-10 at 19.24.34.png
 
I find the parts list misleading as the rockers will fit many models, across models, and up down the age range. Inevitably, Snowbum has a web page on them, but I think it goes along the lines of you can upgrade to a later version but not necessarily the latest, depending on the year of your heads. If your heads are like those in post #143, I have lots of rocker posts for those, which may fit more than one width of rocker arm (ie the length along between the posts) but I only have the 3 rocker arms that suit the plastic shim. This picture is from MAX BMW for the pre-85 bikes. Look familiar?

View attachment 391696

Thanks again Tim.

Will message you.

I have since found this which reinforces what you say about compatibility.

It appears those support buttons are a push fit and in theory at least, removable

 
Thanks again Tim.

Will message you.

I have since found this which reinforces what you say about compatibility.

It appears those support buttons are a push fit and in theory at least, removable

Largiader is very good but not perfect. He states in the linked article that all rocker shafts are 14.5mm in diameter. In fact, they are 15.5mm in diameter. A small mistake, but enough to mean you have to check all his other figures (in my book). He does a good job of summarising the rocker story for Airhead engines. Good not excellent because I've a stack of rocker posts that he doesn't refer to. It's all a learning curve!
 
I filled the gearbox and engine with oil this afternoon.

Spun it over for a few seconds on the starter and the oil pressure warning light is not going out.

I pulled the oil pressure switch / sensor and had another quick spin - no oil coming out of where it threads into the crankcase and no oil at the valve gear.

I suspect the oil pump hasn’t primed and the engine isn’t spinning fast enough on the starter to draw oil up from the sump.

Should I be worried ?

Will it prime and pump if I start the engine ?

Thoughts welcome
 
What read before - A good oil pump/engine will generate around 80psi when cold and will see the oil pressure relief valve opening straight away.
 
What read before - A good oil pump/engine will generate around 80psi when cold and will see the oil pressure relief valve opening straight away.

This isn’t a running bike - yet.

Still got some work to do before I attempt to fire it.

I have only spun it over on the starter.

The R80 engine I built last year built oil pressure really quickly - just on the starter - but this one hasn’t.

I was considering removing the oil pressure switch (again) and pumping fresh oil in there to kind of ‘back bleed’ it to give the oil pump a chance to lift some oil from the sump.
 


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