Advantages of using an A+ block?
Turbo Mini Forums

hi after using the search function, i could not find the answer to my question and that being what would be the advantage of using an A+ engine over the normal one? thanks

this is much lamented, but IMO the advantage is pretty much nil.

I thought they had a bit more metal in a few important places???

this is only my opinion, but i belive the older block was made of better metal, in engines i have torn down the bores usually seem less worn in pre A+ blocks. i'm sure people will disagree though

A+ could be better for high rpm due to not having a hole ovwr the cerntre main, but for anything but race lumps i dont think thats an issue.

just use what yoiu can get your hands on

The physical difference is the "hole" over the centre main bearing on most of the "A" blocks - I have two spare ones and both have the hole.

Vizards says avoid them but, as above, only an issue for high revs..... turbos don't generally do high revs.

But there are other "minor" issues like no alternator mounting holes (dynamo instead in a different place), dizzy drive and attachment completely different....

However, it is becoming a case of use what you can get....

Bore wear does seem less in the two spare "A" blocks I have (one is still on standard size) but maybe the engines just got used less in olden days...

Schrödinger's cat - so which one am I ???

The A+ castings have extra webs cast into the outside of the block to stiffen it supposedly.

Own the day

I completely disagree with the material issu,
A+ are definitely the best blocks,
I think that I have above 100s engine dismantling or seen dismantled and A+ bores haven't the same bore wear has preA+,I'm using in my mini a block that does have his first life (about 50 000 miles) in a mg metro, and which is still in std bore with a set of turbo pistons and new rings..
some say that this certainly due to better oil nowadays, but I can say that refreshed preA+ blocks that have never seen dinosaurus oils, and only good oil from nowadays does suffer from bore wear, somes are that bad that a +20 rebore doesn't cover the wear.
I know this will be debate, but older are not always better, and I only keep preA+ blocks to respect originality on innocentis and 1275gt.

There are A blocks without holes as well.

thanks for the answers people.

arrarently a blocks are stronger for longer stroke engines

So where would the MPi blocks fit in this story?
I recall reading these have a different routing of the oil gallaries so that oil always passes through the filter even if the control valve has it running back directly into the sump..?

Han

Dazed and Confused....