New heart for the old girl

[allankelly1]

Hi all

Well that was not too bad

Motor all now stripped



And all the parts left in the original oil then bagged tagged and boxed up



Next stage it to arrange for the two cases to be vapour blasted at a local company. Then I can get the cam chain tensioner mod done on the mill at work (new tensioner kit ordered from Dennis via EBay)




And then get that lug welded up) Then I am ready to plan the rebuild.

Catch up soon

Best wishes Al


Sent from my iPhone using Tapatalk

[4wDaz]

 Are you leaving it with the vapour blast finish or painting it ? I do vapour blasting but I decided to paint mine

[allankelly1]

No going to paint the cases in the normal silver


Sent from my iPhone using Tapatalk

[allankelly1]

Well that was fun

First stage of the rebuild done

Decided before I get the cases cleaned I will do the tensioner mod as it would make a bit of a mess with swarf.

Managed to drill out the seized up m8 tensioner bolt and re drill and tap for Dennis’s stainless steel tensioner kit

Also made up a new tensioner bar too as original was damaged after drilling out the m8 section of the tensioner bolt






Planning to now drop top and bottom cases off at the vapour blasters tonight and then on their return I  can start the rebuild starting off with fitting and checking new shell bearings for both mains and big ends

Best wishes Al


Sent from my iPhone using Tapatalk

[allankelly1]

Just a quick update

Vapour blaster have sent a couple of pictures of the cases

Looking good



Will pick them up next week

Best wishes Al


Sent from my iPhone using Tapatalk

[Athame57]

Hi Allan
What sort of money did this cost?

[allankelly1]

The company has quoted 90 -110 plus vat

Think it’s worth  it as cases are then spotlessly clean ready for rebuilding as cases were also painted black and originally looked like this





Sent from my iPhone using Tapatalk

[4wDaz]

4 cylinder crankcases are usually £80 a pair if the customer has degreased them, plus these were black so seems a fair price. It looks like they haven’t gone down to the finest grade glass bead and polished them which is a good thing as the paint will stick better

[allankelly1]

No these cases were first chemically dipped and then vapour blasted and process does not removes original  material from the cases

Had the same done on my rd project and my sons yam MotorX engine






It’s not the same as a grit blasting process

Best wishes Al


Sent from my iPhone using Tapatalk

[McCabe-Thiele (Ted)]

They certainly look like brand new - I've never had vapour blasting done.

I used paint stripper on the outside & mainly petrol on the inside surfaces as I found this removed pretty much everything but it is tedious and messy work - the end product on the inside surfaces isn't as clean as your vapour blasting.

Nice looking job when you look at the before & after pics.

[allankelly1]

Correct me if I'm wrong but there is some abrasive in the vapour blasting?

Yes it does but the process is so gentle on the case that it only remove dirt and surface oxide

If you look carefully you can still see the “shadow” left by the base gasket

It so gentle that it will not remove any paint or powder coat present hence the need to get them chemically dipped first to expose the original surface

I have in the past cleaned wood parts with this process




But still the cases will be thoroughly cleaned again by myself before paint and rebuild


Sent from my iPhone using Tapatalk

[4wDaz]

Correct me if I'm wrong but there is some abrasive in the vapour blasting?

Glass is mainly used for vapour blasting although most media types can be used, fine spherical beads are used for finishing which has a peening affect, not a cutting action. Trouble is some operators add aluminium oxide in with the glass to cut and clean then the glass polishes, it does the job faster but much more abrasive. It’s advisable to tape all bearing surfaces and the glass beads just bounces off. It’s also done at a lot lower pressure compared to dry blasting, normally 30 to 50 psi. The biggest problem is getting rid of all the glass before rebuilding the engine, I pressure wash them, oven dry, blow down then repeat the process again, oilways can be plugged but it still gets in. The safest option is acid clean and soda blast

[allankelly1]

Hi Daz

Like you said you need to ensure the cases are spotless and clean after the process and clean and check all orifices and stud holes then clean again

The company I used was Broomie Racing in Swindon as like you said there are some cowboys out there

Dave’s  main work is vapour cleaning bike engines and he was originally recommended by another bike mate when I was doing the RD350LC as they really specialise in bike engines so know their stuff

Best wishes Al


Sent from my iPhone using Tapatalk

[McCabe-Thiele (Ted)]

Whilst I like the look of an engine casing that is nice and clean inside I asked myself a simple question - how long will it stay clean before normal useage stains the inside again?
Polishing or painting the outside now that's worthwhile as we can see it and maintain the shine.

Back in the 1960's I had Mini 1275 S that had been peviously tuned for stage rallying - it had fully polished gas flowed inlet ports that were a mirror smooth finish - the cylinder head was  also  mirror finish. At that time I was regularly stripping the engine down to fit a better camshaft (Mini Special Tuning 731 was my favourite) change the final drive units etc. In a single year the engine was removed, rebuilt & refitted about every 3 months - it never stayed clean internally!

Every time the engine insides seemed full of brown deposits with carbon in the inlet ports probably due to a ridiculous 649 full race cam having daft valve overlap. When Russian NAFTA petrol was sold in the UK I had to decoke it after 3k miles it was so gummed up due to the crap 5 star leaded petrol they sold over here. The best petrol back then was ICI Petrol it was semi-synthetic made as a by-product from the chemical industry.

The above experience is what  put me off vapour blasting - that said it does look nice if the cost is not an issue - you are starting  from new in terms of the inside cleanliness.

Probably the best way today to keep the inside of an engine clean today is to use fully synthetic engine oil but motorcycle wet clutches and synthetic oils are not a great match so one sticks with mineral oils and hope the modern additatives work.

[McCabe-Thiele (Ted)]

I used to swear by BPVF7 Ted, there were so many detergents in it that you could eat your dinner off the inside of the engine, that’s if you didn’t mind the taste of oil that is.

That reminds me of the early days of Shell Rotella for Diesels - when a customer collected his vehicle they often dipped the oil level and were horified to find it had turned black on the drive home!