8 replies to this topic

[redmini_35]

Hi all, 

 

I've had my 1994 mini 35 for nearly 4 years now and shes been a dream to drive, but now i've started noticing a big drop in oil pressure during hot idle specifically, and an almost stalling sounding knock that's definitely coming from the bottom end... fearing the worst!

 

Its a 1275 on basic parts, nothing done to the internals, just a hif44, lcb, rc40, stub stack filter from MED and had it tuned by AC dodd this year.

 

I do look after the mini, full service every six months and it really doesn't see that many miles as it's not my daily driver. I always check the oil and water levels before taking it for a drive too.  

 

I fitted the oil pressure gauge a while back and never used to see it get quite as low as it does now after just an hour or two of driving. 

 

Now it can be less than 10 when i get home and go to park it up, which is when i hear some bottom end knock sounds....

 

This year i plan to take the engine out and pull it apart. I live in cornwall and would love to have the confidence in it to drive further to bigger shows ect. 

 

I'm also thinking if it's all coming apart then perhaps i should get some internals upgraded too. 

 

Found a 12G940 with bigger valves, bronze guides, ported and polished with double springs which i can't miss, so also wondering what best mods may be good to go with this. Originally i was thinking rebore +20 to a 1293 then maybe sw5 cam and 1.5 rockers, but not sure if this is all necessary to achieve a basic increase of power? 

 

Also worth noting my current block is all A+ series. 

 

Basically i have two questions; what kind of mods would best go with this head in order to achieve a nice increase of power? 

And also is it better to rebuild/rebore my A+ short or to find a 1275 short engine that's already been rebored/rebuilt and then just assemble a completely new engine to just swap over? 

 

Money is a factor but not as big as build quality and reliability. 

 

Many thanks in advance, I think it's obvious i'm a bit green but keen hahah so any advice would be appreciated 

 

 

[nicklouse]

The best bet is to find a reputable builder/machine shop locally and use them. 
 

don’t bother with one that has just been “done”  see to many of those paint jobs to bother with them.

[cal844]

Get your own motor measured and go to next size rebore

[alex-95]

Are you planning on having the machining work done and the rebuild it yourself? I can recommend a shop for block machining and crank grinding etc and another for rebuilding if you aren't planning on doing it yourself.  If you plan on buying the parts yourself then getting TMF+ (£5) would save you quite a bit from minispares. As said above, Keep the current block and get it checked and measured, you may get away with honing the bores rather than re-boring.

 

 

Are you planning on doing anything to the gearbox? I'd be adding a central oil pickup.

[timmy850]

A few reputable companies like Minispares do short blocks on an exchange basis. It might save you a bit of time, and it’s nice getting the crank and pistons installed and all in spec by a pro

http://www.minispare...red/ENG004.aspx

[redmini_35]

Thanks everyone for the helpful replies. I'll go for getting my current short measured and bored up, crank ground etc.

 

Are you planning on having the machining work done and the rebuild it yourself? I can recommend a shop for block machining and crank grinding etc and another for rebuilding if you aren't planning on doing it yourself.  If you plan on buying the parts yourself then getting TMF+ (£5) would save you quite a bit from minispares. As said above, Keep the current block and get it checked and measured, you may get away with honing the bores rather than re-boring.

 

 

Are you planning on doing anything to the gearbox? I'd be adding a central oil pickup.

 

if you've any recomendations that'd be awesome thanks very much! I was going to contact conrwall engine company about the rebore and crank grind to get a quote this week so would be great to have a few options, cheers.

 

I'm alright with engines, although most experience is with marinised diesels, but think i'll be going for the rebuild myself and the help of my Dad. I've ordered the david vizard book too as i've read on other threads that the book is a great help when it comes to deciding on tuning parts and the old man can't find his haha,

 

Will definitely also look into my gearbox, central oil pickup sounds like a great shout too, thanks.

Edited by redmini_35, 29 December 2022 - 05:09 PM.

[alex-95]

Thanks everyone for the helpful replies. I'll go for getting my current short measured and bored up, crank ground etc.

 

Are you planning on having the machining work done and the rebuild it yourself? I can recommend a shop for block machining and crank grinding etc and another for rebuilding if you aren't planning on doing it yourself.  If you plan on buying the parts yourself then getting TMF+ (£5) would save you quite a bit from minispares. As said above, Keep the current block and get it checked and measured, you may get away with honing the bores rather than re-boring.

 

 

Are you planning on doing anything to the gearbox? I'd be adding a central oil pickup.

 

if you've any recomendations that'd be awesome thanks very much! I was going to contact conrwall engine company about the rebore and crank grind to get a quote this week so would be great to have a few options, cheers.

 

I'm alright with engines, although most experience is with marinised diesels, but think i'll be going for the rebuild myself and the help of my Dad. I've ordered the david vizard book too as i've read on other threads that the book is a great help when it comes to deciding on tuning parts and the old man can't find his haha,

 

Will definitely also look into my gearbox, central oil pickup sounds like a great shout too, thanks.

I'll Pm you.

 

Ideal, theres plenty of advice and information around to rebuild them, I followed Mini mag articles and the youtube link below when I did mine.

 

Gearbox's are fairly easy to strip and rebuild, its just knowing what's worn out and what can be used again. You'll probably find the diff is worn out and depending on the power you're planning for your engine may be worth fitting a cross pin diff.

[nicklouse]

Just a reminder. If you go for a machine only you will have to responsible for the removal of all the swarf.

[redmini_35]

Apologies for the late response, hope everyone had a good new year.

 

Thanks Alex, i'll have a look in my inbox now, will also definitely look into a better diff. I'm looking for something around 90hp for now but whilst it's all apart i may aswell upgrade what i can for anything i may do in the future. 

 

 

Just a reminder. If you go for a machine only you will have to responsible for the removal of all the swarf.

Nice one thanks for the heads up

 

Thanks all, i'll mark this closed. 

 

All the best, Jacob