35 replies to this topic

[mattyglover16]

Morning, I'm fairly new to this so sorry in advance if this has already been mentioned in the past,

 

I'm looking to change my 1275 to a 1330cc. I want it to drive smooth on the road as that is where it will be used the most. Don't want to be revving to 3000rpm before the car moves haha. I've been looking and I just need to know exactly what is needed to achieve this build, such as what carbs people use and are they any other modifications you have to make such as  brakes, driveshaft, gear ratios, oil coolers, cams, pistons, cylinder head valves, crankshafts etc etc? Just need a list really of what I need and what is needed to do.

 

I'm guessing an HIF44 would be the best carb to power this. I have also been looking at kent 500 mild road cams are these suitable in a 1330 build ?

 

Thanks  

[JetBlackEreg]

I cant comment on everything but some of the following might be helpful - 

 

Kent 266 is a good road cam and very smooth.

kent 276 or piper 270 are slightly lumpy but I have one in my road car and it performs well low down and all the way up to 6k according to spec.

 

A HIF 44 is sufficient power for your use, there are companies that will 'vizard' the carb which take any rough edges out of the carb and ensures maximum potential from the carb.

 

A balanced crankshaft would make the engine run smoother. 

 

When increasing the bore size you will need new pistons so working out the desired compression ratio will need to be taken into consideration, I believe there's a guide on here or a machine shop would be able to help. In terms of the cylinder head someone such as turbo phil I believe does machining work on standard heads and would be able to help with the CR as well as the porting and polishing of the head.

 

Larger 8.4" brakes could be used if your're on 7.5 or drums however you need 12" wheels for these. 

 

You could consider changing your final drive which would aid acceleration but would be screaming on the motorway. 

Upon rebuilding my engine I had the differential rebuilt which cost around £80 and was well worth it.

 

I'm not the most experienced person on here but I hope this helps.

[Luke.c123]

 

A HIF 44 is sufficient power for your use, there are companies that will 'vizard' the carb which take any rough edges out of the carb and ensures maximum potential from the carb.

 

 

do you know the companies name by any chance? :)

[JetBlackEreg]

 

 

A HIF 44 is sufficient power for your use, there are companies that will 'vizard' the carb which take any rough edges out of the carb and ensures maximum potential from the carb.

 

 

do you know the companies name by any chance? :)

 

http://www.retromini...roducts_id=1055

 

Here we be! There is a list of what they do.

[mattyglover16]

Will a Mechanical fuel pump be enough to power a HIF44 running 1330?

[Luke.c123]

Will a Mechanical fuel pump be enough to power a HIF44 running 1330?

should be, my mate has a a series bored to 1400 and then stroked to 1600 runnning on a mechanical pump, with a thirsty webber carb  

[Cooperman]

When re-boring it is always best to go to the next size up. The difference between 1275 & 1330 is negligible and depends so much on the build quality rather than the increased cc's.

So the increments are 1275, 1293, 1310 then finally 1330. After that it's best to sleeve back to 1275 to prolong block life - after all there will never be any new ones, or at least new ones which are affordable.

Best road cam is an MG Metro or Kent 266 (or similar).#

With regard to the head an MG Metro head with 35.6 mm inlet valves, all moderately gas-flowed and with around 10:1 C.R. is also ideal.

Use 21253 pistons and slightly lighten the flywheel using a pre-verto clutch/flywheel.

Run an Aldon 'Yellow' distributor.

An HIF44 carb will be excellent, especially if it is slightly improved. A 1275 Cooper alloy inlet manifold works well, but needs a bit of cleaning up inside.

Standard drive shafts are OK unless the car is for competition.

A cross-pin diff will last well. Ideal final drive ratio is 3.1:1 or 3.44:1 for optimum acceleration with standard gear ratios.

An oil cooler is only necessary if you run with a sump guard. Always use a top quality 20w50 mineral oil and change it every 3000 miles.

 

Just noticed this is my 17000th post!

Edited by Cooperman, 18 August 2015 - 02:34 PM.

[phil hill]

Just noticed this is my 17000th post!

Congratulations Cooperman !!

 

17,000 posts of infinite Mini wisdom !!

 

Phil.

[Guess-Works.com]

To increase the engine size from 1275 to 1330 ( a massive increase of 55cc ) you need change nothing on your car apart from the size of the holes in the engine block and the pistons...

 

But while you're there, if you actually want to make use of those extra 55cc's then you'll need to do a few other things.... an by the sounds of it you're after an engine which will cruise, rather than one which will make your ears bleed.

 

So change the cam for something with a good torque curve, eg SW5, Piper 255 or similar

 

When boreing get the machine shop to offset the bore which will maintain the gap between cylinders 2 and 3 and help keep the strength in the block, also means you have two more bores before its liner time.

 

Put a decent head on the to, nothing too big, get something with bigger exhaust valves...

 

HIF44 will be fine, as will the mechanical pump

 

balancing is not too necessary as you'll not be revving the engine anywhere near the limits where it becomes an issue..

 

drop a long final drive in the gearbox strapped to an x-pin...

[Guess-Works.com]

 

Just noticed this is my 17000th post!

Congratulations Cooperman !!

 

17,000 posts of infinite Mini wisdom !!

 

Phil.

 

 

blimey... he's catching up...

[phil hill]

 

blimey... he's catching up...

 

Lol, yep I guess he is !!

 

Phil.

[mattyglover16]

When re-boring it is always best to go to the next size up. The difference between 1275 & 1330 is negligible and depends so much on the build quality rather than the increased cc's.
So the increments are 1275, 1293, 1310 then finally 1330. After that it's best to sleeve back to 1275 to prolong block life - after all there will never be any new ones, or at least new ones which are affordable.
Best road cam is an MG Metro or Kent 266 (or similar).#
With regard to the head an MG Metro head with 35.6 mm inlet valves, all moderately gas-flowed and with around 10:1 C.R. is also ideal.
Use 21253 pistons and slightly lighten the flywheel using a pre-verto clutch/flywheel.
Run an Aldon 'Yellow' distributor.
An HIF44 carb will be excellent, especially if it is slightly improved. A 1275 Cooper alloy inlet manifold works well, but needs a bit of cleaning up inside.
Standard drive shafts are OK unless the car is for competition.
A cross-pin diff will last well. Ideal final drive ratio is 3.1:1 or 3.44:1 for optimum acceleration with standard gear ratios.
An oil cooler is only necessary if you run with a sump guard. Always use a top quality 20w50 mineral oil and change it every 3000 miles.
 
Just noticed this is my 17000th post!

 
 
 
 
 
Congrats on your 17k post
 
Thanks very much for your help, least now I can start looking pricing bits up and purchasing them. What valves and springs do you recommend in the head and are the standard rockers fine or do you have to change those too? Do the conrods have to be changed aswell ? Sorry for spamming you with questions

Edited by mattyglover16, 18 August 2015 - 03:08 PM.

[KernowCooper]

Standard rockers will be fine on your build as will the conrods

[mattyglover16]

Standard rockers will be fine on your build as will the conrods

 

 

Thank you, would you suggest changing the conrods to new standard ones or keep the orgianls ?

[carbon]

Matty,

 

If you're currently at 1275, and the bores are worn, then I would only take it out to 1293. Good blocks are getting rarer, and you won't gain as much from the extra few ccs as you can from other improvements.

 

If the bores are good then use the money saved by not reboring and would suggest following:

- MD266 cam

- set of Keith Calver's 1.4 ratio rockers

- head flowed (36mm inlet, 29 or 30mm exhaust)

- CR about 9.5 with 95 octane, or 9.75 with 99 octane

- Maniflow freeflow with twin box RC40

- stick with HIF44, on a well ported inlet manifold