Engine

Author
Discussion

minipower

Original Poster:

903 posts

225 months

Monday 7th August 2006
quotequote all
With my limited knowledge of anything mechanical (not for long though as signing up for mechanics course), could someone tell me what the difference is between a 11 stud or 9 stud head?
This question has come about due to a 1300cc engine I've been offered for £100. Does this increased number of studs means its better?

Wildfire

9,821 posts

258 months

Monday 7th August 2006
quotequote all
11 stud head is exactly what it says on the tin. It has 11 studs as opposed to the standard 9. This came on the original Mini Cooper S engines. But some owners have their blocks and head 11 studded for better HG reliability. If the block has been 11 studded then it means it has been modified in some way. Same for the head.

minipower

Original Poster:

903 posts

225 months

Monday 7th August 2006
quotequote all
Cheers for the help.
So this engine should be good as a base for future modifying.
Is 1380 what 1300s are normally over bored to?

kjw

49 posts

236 months

Monday 7th August 2006
quotequote all
1380 is a 60 thou offset rebore, Quite common and very reliable.

Dino42

151 posts

236 months

Monday 7th August 2006
quotequote all
kjw said:
1380 is a 60 thou offset rebore

No it's not!

A '1300' is actually 1275cc when std.
1293cc @ +0.020"
1310cc @ +0.040"
1330cc @ +0.060"
These are the 'normal' service overbore sizes.

1380cc is achieved with 73.5mm pistons offset bored as said to increase reliability.
Most 'A+' blocks can be bored to 73.5mm but I wouldn't say it's totally guarenteed.
Also I would be wary of boring an 'A' series block to 73.5mm and you should bear in mind in either case, that any problems after a 73.5mm bore would render the block scrap unless expensive thick wall liners were fitted.

minipower

Original Poster:

903 posts

225 months

Monday 7th August 2006
quotequote all
So does this mean this engine is ok for overboring or that it would be difficult?
As I want to modify is this a good root or not?

Dino42

151 posts

236 months

Monday 7th August 2006
quotequote all
minipower said:
So does this mean this engine is ok for overboring or that it would be difficult?

Impossible to tell, someone who calls a Mini engine a 1300 is just not giving you enough info to go on.
Any 1275 that's either std. bore or been rebored up to +40 can probably be rebored again, assuming nothing disastrous has happened.

minipower said:
As I want to modify is this a good root or not?

Maybe!
Any secondhand engine is a risk, until you've stripped it down you'll never know for sure.

The fact that it's got 11 studs suggests it's either:
1/ an 'S' engine - in which case you should certainly buy it for £100!!
2/ Been modified already -in which case it could be ideal...or it could be totally knackered!!
3/ It may be from an Austin 1300GT (still 1275cc) - that would account for him calling it a 1300 and for the 11 studs. - This is a nice motor, but very old now ~ late 60's.

Edited by Dino42 on Monday 7th August 23:41

minipower

Original Poster:

903 posts

225 months

Monday 7th August 2006
quotequote all
The man mentioned cooper s but then spoke of the austin 1100 and 1300. He didnt make any suggestions of modifications. Ill phone him on wednesday and ask him these questions.
Cheers for all the help and I now feel slightly more educated.

Also I've been looking on ebay and there seems at times to be some good engines put on the market. A few are already modified, but should this put me off as I could be bidding for just a scrap heap?
Has anyone had experience of buying engines from ebay or am I best to just save up and get a new modified engine?

Edited by minipower on Monday 7th August 23:56

love machine

7,609 posts

241 months

Monday 7th August 2006
quotequote all
Don't buy an S Engine unless you're really sure. Most are 1300GT's 1275GT's. Tappet covers and that platey thing.

Dino42

151 posts

236 months

Tuesday 8th August 2006
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love machine said:
Don't buy an S Engine unless you're really sure

Indeed, buying any so called 's' bits is highly likely to end in you getting ripped off unless you really know your stuff.
minipower said:
am I best to just save up and get a new modified engine

Given you said you were going on a mechanics course I would have thought buying an engine to rebuild - like the one you mentioned - was the best idea.

Dino42

151 posts

236 months

Tuesday 8th August 2006
quotequote all
minipower said:
Ill phone him on wednesday and ask him these questions.

Ask him:
Is it definitly a 1275.
Does/did it run. - If not, why not!
Is it an 'A' or 'A+' block (have a look here to tell the difference A,A+ differences
If it's an 'A' does it have tappet chest covers - if it's a 1275 and has these it's an 's' - bet it won't be! (they're on the back of the engine - the black plates on the yellow A+ engine in the link)
Is it complete with head/gearbox.

At £100 it could well be worthwhile.
I've just noticed you have a '93 1275, this is A+ which might help you. If you replace it with an A you'll need a new distributor and a few other bits - another A+ would be simpler.


Edited by Dino42 on Tuesday 8th August 00:29

minipower

Original Poster:

903 posts

225 months

Tuesday 8th August 2006
quotequote all
I will deffinetly ask all these questions. The person I'm buying it off of rebuilds minis and sells them off, so hopefully he wont try to rip me off or tell lies. Lucky enough my dad will be home at the time so if Im uncertain Ill probably take him a long to have a look.

Again thanks for all the help.

Dino42

151 posts

236 months

Tuesday 8th August 2006
quotequote all
Good luck, let us know how you get on.