31 replies to this topic

[Jon937]

Stuff used to be over engineered and that is my thinking about how to lighten parts. I could drill through the webs on the A+ block without reducing the overall strength added by having the webs.

I have two 1275 A+ blocks anyway, one has a chunk out of I think one of the main bearing seats (from memory) which is not going to be useful at all. I could try stuff on that block to see what I am able to do with the decent one.

Is there any bits on the A+ block that are over engineered, obviously they cast them with the webs for a reason and does that mean that more material is already missing and thus manufacturer costs would have been less?

I'm trying to think of areas of the block that could be lightened without affecting the workings of the engine.

Obviously lots of people have polished up the inside and installed undercrown cooling jets, or removed a bit by the waterbuck to make that flow more effectively.

[Alex_B]

The polishing inside isnt so much for weight as oil return to the sump in my understanding, and as such wont get much weight out of the block, and I don't imagine you could drill the webs with any sizeable drill, they don't protrude that much. There probably is some material you could remove but I think it would be mostly limited to the outer skin of the block, the internals are about as skinny as is usable I recon, although if you went for a 16v over head cam you could probably remove all the material where the cam followers reside as they are made redundant without pushrods, plus the bmw 16v head and kad 16v head are ally and lighter. 


But if you have a scrap block it might be worth sectioning it in quarters to see where the important bits lie and then machine your other block using the information you gained, it could be an interesting project! 

Also a lighter weight flywheel would help spin the engine up quicker and also loose a lot of mass as the standard is very heavy

[nicklouse]

Sorry have to laugh.

The block as it is not stiff enough. Which is why many engineers bolt it to a 3" bit of steel before boring and honing it.

The actual Wright you could remove safely will have next to no effect on anything. But removing the same weight from the rotating and reciprocating parts will have a big effect. And you would be able to remove more weight and have even greater gains.

There are some 1275 blocks that have voiles above the main bearings. We tend to avoid them as they are weaker.

[Jon937]

I am fitting a lightweight flywheel and backplate. I thought that there maybe some way of reducing weight of the block as it is a large chunk of iron

Would I be able to machine any of the reciprocating parts to reduce the weight of the built engine?

[nicklouse]

Have you got David Vizards book on tuning the A series engine?

Get it an read it before you make a mess of your parts.

But to answer your question. Yes you can and we have been doing so for about 57 years. But the block is one thing that has very little done to it.

[Jon937]

Yes and I have read it cover to cover twice, plus a number of his other books. That is where I get some of the ideas that I have to do to my mini but seak further advice before destroying anything.

[mini13]

Interesting concept,

 

I know of one very successful mini drag racer who has lost quite a bit of weight from the gear casing  with no ill effects, and before anyone says whats the point... this is a car where literally every part is lightend resulting in a sub 500kg car.

 

I could certainly say it is worth a good clean up and "polish" of the casing, as casting marks are stress risers.

[nicklouse]

Sub 500 is not hard. Try 450 without touching the block. Or the gear casing.

[mab01uk]

You might like this......not sure if it was all alloy castings or not.....

 

Pictures of BL's OHC A-Series engine for the Mini in 1975 which featured belt drive to the overhead camshaft, single or twin-SU carbrettors and retained all the familiar A-Series features, such as the starter motor, alternator, distributor and spark plugs on the same forward facing side of the original cylinder block. There were also inline versions developed for BL's rear wheel drive cars. 11 prototypes of all sizes were built and completed 3,200 hours on test beds and 2,200 vehicle miles.
The 1275cc OHC A-Series produced 84bhp @ 6750, torque 80lb/ft @ 4,500 (against 59bhp @ 5300, torque 69lb/ft @ 3000 for the pushrod engine) in standard form.
There were also 970cc and 1097cc versions produced and tested but the project was eventually canceled due to the mounting losses of British Leyland which had become nationalised during the engines development. Lots more info on what could have been in Graham Robson's interesting book.........."A-Series - The First 60 Years"

[mab01uk]

A little birdy told me aluminium heads may be available soon.

 

But I'm probably 15kg overweight. It'd be cheaper for me to lose that before worrying about lightening the car

 

1275 Alloy Cylinder Head

"Alloy head casting with improved water jackets particularly around the exhaust ports and 12mm spark plug. By using the smaller spark plug it has been better positioned for cylinder burn. Out of the box the port gas flows as well as a well modified iron head. The valves are positioned slightly further apart giving the possibility of 38mm and 32mm valves being fitted. The standard head comes with 23cc chambers with plenty of scope of enlarging for turbo applications.The valve inserts give unleaded capability. Deck thickness gives plenty of scope for skimming (increasing C/R). When Fitting an Aluminium head, you MUST run with 100% summer coolant which contains the correct inhibitors to prevent corrosion and electrolytic reaction. If in doubt, please contact your local Moss branch. Torque Settings. Please call your local Moss branch for full specifications."

http://www.moss-euro...ads-1275cc.html

Edited by mab01uk, 03 September 2016 - 07:41 PM.

[morley]

The only mod I can think of is where the water pump bolts too and block and sometimes gets enlarged to improve flow.

As others have said, there's loads of other places you can save weight!

[mini13]

my mistake, that should be circa 400 kg, with a full interior and no fibreglass.

 

 

Sub 500 is not hard. Try 450 without touching the block. Or the gear casing.

Edited by mini13, 03 September 2016 - 08:04 PM.

[Jon937]

Mini13 have you got any photos or info about the lightened box?

Also any other info and photos about any lightened bits of the drag race mini please?

Thank you so much for everything so far everyone

[mini13]

nope, the only info I have in it is this.

 

http://www.turbomini...p=vt&tid=317633

[Jon937]

Thank you.

Does anyone know how much material could be removed from the block, like when fitting a longer stroke crankshaft than 88mm?

Would the gearbox loose to much rigidity removing similar material?

Any ideas for loosing weight from the gearbox?