Morris Minor Owners Club

Aw, we need more MM Porn like those photos, Bob. Surely you've got some more stuff to titivate us with???

No sign yet of the collets but I guess the boat has a long way to travel and it is all up-hill from Aus.

Is there a point when you can have too much vac in the crankcase? I assume that a high vac would drain the scroll but not affect the rear mani bearing? The side cover on the Alta is much bigger than the standard engine, is made of alloy and has a suitable stub pipe on it. I might look at copying your plan, if that's OK, and run a later PCV valve into the manifold I've made for the car. Block->catch tank->PCV->manifold ...right? edit..I get it, the catch tank is a restricted air inlet

Is the idea to seal the crankcase or just to restrict the airflow into it? How do you cope with high throttle blow-by which, I guess, will increase pressure? I suppose I need to read up on it.

Got plenty more porn like that – only need a thread to post it on. There is a point where you can have too much vac in the crankcase as I found with my Series E, when I blocked the oil filler and relied only on air getting past the scroll. When the donk was dismantled there was heaps of mayonnaise mainly on alloy parts due to the fact that not enough air was passing through the scroll to purge the crankcase of the combustion by-products. No problems with copying my plans – everything I post is for the benefit of all who wish to use it. The catch tank is only to filter the air being drawn into the motor. The restriction to the air being drawn in is by a restrictor in the hose between the catch tank and the A series oil filler cap. High throttle blow by has not been a problem with any of my installations. I believe this is because even though at high throttle allowing the manifold vacuum to minimise the scroll is much more efficient. This has been demonstrated when taking my car for an extended run (1/2 hour plus) after warming up with varying engine speeds from pottering around to extended runs at 7000 RPM plus. After 4 ruins like this there was no oil dropped on the drip tray.
Bob

Post it on this thread? This is the dedicated porn thread for MM stuff, after all. [Renamed the thread.]

RobThomas wrote:I did wonder...

The original cap is unfiltered and collects dirt and dust inside. Closing it off with a bung would also allow more room to get to the starter motor and dipstick I guess I can leave it off and you can add one later if you want to. With a partially closed-off cap you could run a pipe from the rocker cover to the air filer assembly and make a partial vacuum in the crankcase. Bob might have some useful input on that idea.

Next job is to work out the positioning of the holes for the mounting studs. I placed some M10 nuts roughly where they need to be drilled. Problem is that your head might have holes slightly offset from mine. I may have to shave the bottom off of the cover to get the lid low enough to clear the clips that hold the dissy cap in place. I'd forgotten to factor them in. Doh!

There is one of the Aston Martin DBR9 GT1 main bearing cap studs in the picture with an M10 12.9 HT nut on it. Plenty of length to use on the 6 longest Alta studs. Not yet got anything for the 4 short studs.

Good points regarding the air filter. After reading Bob's comments I wonder if oil leaks are a recurring theme on the side-valve engines? I do wonder if it's worth it though, how does your standard Alta head preform? I'm not planning any other mods on mine and it won't be a daily driver so I don't need to re-invent the wheel.

Regarding the mounting holes is there any measurements you need from my head to confirm the centres? Worst case I could always drill them out myself.

Thanks for the tip off about studs, I guess worst case I could make some up myself or modify them off something else.

Here is a bit more porn you might like to see. I made them with a bit of guidance from 'philthehill'.
Bob

Still not quite sure why I'm being obsessive about the fit when it isn't even for my own car...

Anyway, I measured the positions where I thought the stud holes should be, drilled them out with a small hole and then used very long matches down through the holes and into the stud holes in the head below. If the matches aren't vertical then you know which way to elongate the holes before you drill them out to full size. Tomorrow...brass nuts from brass bar.

Will. What thread do you have on the studs that hold the rockers down and also hold down the cover? Are they BSF or metric? I've drilled these through but haven't cut the thread.

RobThomas wrote:rocker9a.jpg

Will. What thread do you have on the studs that hold the rockers down and also hold down the cover? Are they BSF or metric? I've drilled these through but haven't cut the thread.

Sorry for the delay in replying, I have been without internet access for the last few days. I'm not actually sure what threads I was intending on using for the studs, did you recommend some DB9 ones? Feel free to leave them as they are and I can tap them out as and when I know what threads I'm using.

Thanks!

Ah, it isn't the head studs but the smaller 4 that hold the valve rockers on, something like 5/16 or 8mm. Probably 5/16 BSF (22tpi) but I'll leave them uncut so you can sort your own threads out. The head studs are M10 coarse (1.5mm spacing). On my head the exhaust studs are 5/16 UNF but on Ian's head they are 8mm Metric fine.

Thee valve collets for your engine have finally arrived from Australia, thanks to bob (BlownMM), so he's on our good-guy list.

Thanks Bob!!!

RobThomas wrote:Ah, it isn't the head studs but the smaller 4 that hold the valve rockers on, something like 5/16 or 8mm. Probably 5/16 BSF (22tpi) but I'll leave them uncut so you can sort your own threads out. The head studs are M10 coarse (1.5mm spacing). On my head the exhaust studs are 5/16 UNF but on Ian's head they are 8mm Metric fine.

Thee valve collets for your engine have finally arrived from Australia, thanks to bob (BlownMM), so he's on our good-guy list.

Thanks Bob!!!

Thanks for the info regarding studs, I'll put that to good use in due course.

The head is slowly getting some of the vital missing pieces, your help has been invaluable!!

Waiting for some stuff to arrive so took a bit of time away to get on with my own car. Block cleaned up, stud holes chamfered and new studs put in.

Not too difficult to choose between 'originality' (Rusty Morris studs) and 'practicality' (New Aston Martion DBR9-GT1 main bearing studs) Just need to be trimmed to size once the copper gasket has been trimmed for the +40 bores.

First quick go at chemical engraving of the aluminium rocker cover badge by trying out the process on a sheet of Ali. It needs to be a bit deeper (longer time with the chemicals left on) and the shape of the lettering needs to cut out of the plastic with a bit more care. I might see if I can find someone who makes plastic lettering for the sides of vehicles. Anyone any good at making graphics?? I think it is "Bookman Old Style Bold" and then shrunk across the middle.

Would there be any interest in Alta mugs and T-shirts?

RobThomas wrote:Would there be any interest in Alta mugs and T-shirts?

The fun and games with Acid etching look very difficult!

Yes to mugs and T shirts

Rob
You might try a friendly waterjet cutter. If you have an original they will be able to scan it into their computer and cut from there, either pos or neg. depending on which way you need. I recently had a new plate for a milestone outside our house made and while talking to the waterjet guy he cuts all sorts of things for road signs, letters and arrows etc. They will happily cut plastic which laser does not like. I needed the curve at the top of the sign cut in a laminated plastic with ally in the sandwich, it had already been printed. Best of luck.
Colin

Thanks, Colin. This is more 'shallow etching' than 'deep cutting'. I had tried grinding it all out with a Dremel but this seems to work better. More pics to follow over the weekend, hopefully.

RobThomas wrote:altarock1.jpg

Rob, this is genuinely amazing! Incredible handy work!

How did you manage to do the "Alta" logo in the end?

Rob
Couldn't figure out how to send it from Photobucket via email so have attached it to this post.
Bob