Engine Spec Help
Discussion
Hello
I currently own a classic mini 1000 and wanted to give it a bit more pace
Basically it is currently running a 998cc engine standard apart from a bigger HS4 Carb from a 1275 on a minisport inlet that I had properly jetted and then a straight through 2.5" system that is probably sapping a lot of power...
Anyway I just want it to be a bit nippier and wondered the best way to go about this was!
The engine itself seems a bit tired it is on about 75,000 miles and doesn't really pull the car along that well at all (probably due to an exhaust) so think it would be better to get a new engine either way.
I already have a 12g295 head with double vale springs in good condition sat in the garage and believe this is the basis of a decent 998? It would be nice to see 60bhp as should be around 40bhp stock?
My budget is around £500 (ish) with regards to the gearbox mine is sweet so just really need to get a 998 engine in decent condition then see what other parts I need
Thanks
I currently own a classic mini 1000 and wanted to give it a bit more pace
Basically it is currently running a 998cc engine standard apart from a bigger HS4 Carb from a 1275 on a minisport inlet that I had properly jetted and then a straight through 2.5" system that is probably sapping a lot of power...
Anyway I just want it to be a bit nippier and wondered the best way to go about this was!
The engine itself seems a bit tired it is on about 75,000 miles and doesn't really pull the car along that well at all (probably due to an exhaust) so think it would be better to get a new engine either way.
I already have a 12g295 head with double vale springs in good condition sat in the garage and believe this is the basis of a decent 998? It would be nice to see 60bhp as should be around 40bhp stock?
My budget is around £500 (ish) with regards to the gearbox mine is sweet so just really need to get a 998 engine in decent condition then see what other parts I need
Thanks
My Mini 1000 was measured at 62 BHP.
That is +40 thou flat top pistons, Mini Sport mild road cam, 12G2295 head cleaned up giving 9:1 compression, A series 1300 rockers (thats the pressed ovel head ones) Cleaned up standard carb and trumpet with standard air box with a bigger inlet pipe and K&N. Ali inlet manifold and 3 into 1 exhaust manifold with an RC40 exhaust, and lastly remove the vac pipe from the distributor to give faster advance. Hope this helps
That is +40 thou flat top pistons, Mini Sport mild road cam, 12G2295 head cleaned up giving 9:1 compression, A series 1300 rockers (thats the pressed ovel head ones) Cleaned up standard carb and trumpet with standard air box with a bigger inlet pipe and K&N. Ali inlet manifold and 3 into 1 exhaust manifold with an RC40 exhaust, and lastly remove the vac pipe from the distributor to give faster advance. Hope this helps
First of all your current engine is 'tired' so needs a complete rebuild. There is little point in putting a better head, or anything else for that matter, on an engine which is, basically, past its best. In fact, doing so would simply cause premature engine failure.
So best thing is to get it re-bored with new pistons, new main & big-end bearings on a re-ground crank, new oil pump, new crankshaft thrust bearings, new cam followers and any other worn parts.
You can use the 12G295 head, but will need to re-build it, carefully measure then have it machined to give the correct compression ratio. The 12G295 head was originally fitted to the 998 Cooper which had raised D-top pistons, so flat top or dished pistons with a 295 would result in a very low compression engine if the measurements, calculations and machining were not done properly.
Once the engine is re-built you can consider what to add to make the car not quite so slow, like a better cam, better inlet & exhaust system, better distributor, etc.
But, you won't even get the engine re-built back to standard for £500 unless you can do the entire build yourself and can buy the parts at a reduced price.
A 998 Cooper which had a better cam, higher compression ratio, twin HS2 carbs, 3 branch ex. manifold, proper diameter exhaust pipe, correct distributor and the 12G295 head gave 55 bhp and was very nice to drive.
If re-building and paying someone to do the complete build, to get to the 998 Cooper power would probably cost in the region of £1800, but that would be like a Cooper new unit.
A Mini is an old design classic car, so don't expect modern performance whatever you do to it. There are no 'fast road Minis', only 'not quite so slow' ones!
So best thing is to get it re-bored with new pistons, new main & big-end bearings on a re-ground crank, new oil pump, new crankshaft thrust bearings, new cam followers and any other worn parts.
You can use the 12G295 head, but will need to re-build it, carefully measure then have it machined to give the correct compression ratio. The 12G295 head was originally fitted to the 998 Cooper which had raised D-top pistons, so flat top or dished pistons with a 295 would result in a very low compression engine if the measurements, calculations and machining were not done properly.
Once the engine is re-built you can consider what to add to make the car not quite so slow, like a better cam, better inlet & exhaust system, better distributor, etc.
But, you won't even get the engine re-built back to standard for £500 unless you can do the entire build yourself and can buy the parts at a reduced price.
A 998 Cooper which had a better cam, higher compression ratio, twin HS2 carbs, 3 branch ex. manifold, proper diameter exhaust pipe, correct distributor and the 12G295 head gave 55 bhp and was very nice to drive.
If re-building and paying someone to do the complete build, to get to the 998 Cooper power would probably cost in the region of £1800, but that would be like a Cooper new unit.
A Mini is an old design classic car, so don't expect modern performance whatever you do to it. There are no 'fast road Minis', only 'not quite so slow' ones!
Hello Cooperman
I have decided to up the budget somewhat and build my own engine...
Anyway I have just purchased the A Series book by David Vizzard and plan to build a 1330 engine
I will sell my 12g295 head and keep the current 1000 lump in whilst I build up my new engine. To be honest the engine itself may not be that bad it will still pull 85 ish if required (normally do more like 55) I think it is just I am used to a 230hp GTI Golf!
What is a decent 12g295 head worth as a couple of people are after it it has never been skimmed and doesn't have any cracks after taking the valves out?
Engine Spec wise thinking of the below (copied from yourself on the miniforums):-
For a 1330 giving c.100 bhp you might like to consider the following:
Hepolite 21253 pistons - make sure you do a trial-build and deck the block to bring the pistons right to the top
Kent 286 cam
A big valve head, fully gas-flowed. Comp Ratio around 10.7:1
Twin HS4 carbs on a good alloy inlet manifold
Light-weight pre-Verto flywheel and clutch
LCB ex. manifold with a 1.75" int. dia. exhaust system - RC40 or Maniflow
Aldon 'Red' distributor, or a 'Megajolt'
Vernier timing gears
Metro Turbo oil pump
I have decided to up the budget somewhat and build my own engine...
Anyway I have just purchased the A Series book by David Vizzard and plan to build a 1330 engine
I will sell my 12g295 head and keep the current 1000 lump in whilst I build up my new engine. To be honest the engine itself may not be that bad it will still pull 85 ish if required (normally do more like 55) I think it is just I am used to a 230hp GTI Golf!
What is a decent 12g295 head worth as a couple of people are after it it has never been skimmed and doesn't have any cracks after taking the valves out?
Engine Spec wise thinking of the below (copied from yourself on the miniforums):-
For a 1330 giving c.100 bhp you might like to consider the following:
Hepolite 21253 pistons - make sure you do a trial-build and deck the block to bring the pistons right to the top
Kent 286 cam
A big valve head, fully gas-flowed. Comp Ratio around 10.7:1
Twin HS4 carbs on a good alloy inlet manifold
Light-weight pre-Verto flywheel and clutch
LCB ex. manifold with a 1.75" int. dia. exhaust system - RC40 or Maniflow
Aldon 'Red' distributor, or a 'Megajolt'
Vernier timing gears
Metro Turbo oil pump
Have come up with the following list of parts what stuff am I missing out of interest?
And what gear ratio would be best my wheels are 12 x 6 t
1330 Potential Engine Build
Pistons – Hepolite 21253 pistons = £180
http://www.minisport.com/87-524111-00set-slipper-p...
Camshaft – Kent 286 Cam = £220
http://www.minispares.com/Product.aspx?pid=36201
Engine Gasket Set = £10
http://www.minisport.com/geg206-engine-gasket-set-...
Head Gasket Set = £10
http://www.minisport.com/geg1140c-head-gasket-set-...
Metro Turbo Oil Pump = £50
http://www.retrominisltd.co.uk/index.php?main_page...
New Clutch Kit = £50
http://www.minisport.com/hk8855-3-piece-clutch-kit...
Vernier Timing Gear = £80
http://www.minisport.com/c-ajj3327-mini-sport-ligh...
Engine Re-Bore = £100
Block Re-Machine (after checking TDC) = £40
Crank Re-Grind = £50
Gearbox (Guessworks) = £400
Refurbished + New baulk ring + X-Pin Diff + Pick-up pipe
Twin - Carbs = £150
Donor 1275 = £175 ish
Headwork = £250?
Total = £1,765
Thanks a lot and sorry for the length of these two posts!
And what gear ratio would be best my wheels are 12 x 6 t
1330 Potential Engine Build
Pistons – Hepolite 21253 pistons = £180
http://www.minisport.com/87-524111-00set-slipper-p...
Camshaft – Kent 286 Cam = £220
http://www.minispares.com/Product.aspx?pid=36201
Engine Gasket Set = £10
http://www.minisport.com/geg206-engine-gasket-set-...
Head Gasket Set = £10
http://www.minisport.com/geg1140c-head-gasket-set-...
Metro Turbo Oil Pump = £50
http://www.retrominisltd.co.uk/index.php?main_page...
New Clutch Kit = £50
http://www.minisport.com/hk8855-3-piece-clutch-kit...
Vernier Timing Gear = £80
http://www.minisport.com/c-ajj3327-mini-sport-ligh...
Engine Re-Bore = £100
Block Re-Machine (after checking TDC) = £40
Crank Re-Grind = £50
Gearbox (Guessworks) = £400
Refurbished + New baulk ring + X-Pin Diff + Pick-up pipe
Twin - Carbs = £150
Donor 1275 = £175 ish
Headwork = £250?
Total = £1,765
Thanks a lot and sorry for the length of these two posts!
I have a 286 cam in my Cooper 'S' but that is a rally car with a SC CR gearbox and a 3.9:1 FDR.
Never would I ever fit one to a road car. The best road cam for a 1330 cc Mini is the Kent 266 (or MG Metro - they are very similar). For the road you need low to mid-range torque unless you intend keeping it revving at over 5000 rpm most of the time. Remember, a 286 gives peak power at 6400 rpm. You really don't want to be driving at those revs on the road all the time. Below about 4000 rpm the 266 will give better overall performance.
Never would I ever fit one to a road car. The best road cam for a 1330 cc Mini is the Kent 266 (or MG Metro - they are very similar). For the road you need low to mid-range torque unless you intend keeping it revving at over 5000 rpm most of the time. Remember, a 286 gives peak power at 6400 rpm. You really don't want to be driving at those revs on the road all the time. Below about 4000 rpm the 266 will give better overall performance.
Cooperman said:
I have a 286 cam in my Cooper 'S' but that is a rally car with a SC CR gearbox and a 3.9:1 FDR.
Never would I ever fit one to a road car. The best road cam for a 1330 cc Mini is the Kent 266 (or MG Metro - they are very similar). For the road you need low to mid-range torque unless you intend keeping it revving at over 5000 rpm most of the time. Remember, a 286 gives peak power at 6400 rpm. You really don't want to be driving at those revs on the road all the time. Below about 4000 rpm the 266 will give better overall performance.
Is they something inbetween like say a SW5? Or a 276?Never would I ever fit one to a road car. The best road cam for a 1330 cc Mini is the Kent 266 (or MG Metro - they are very similar). For the road you need low to mid-range torque unless you intend keeping it revving at over 5000 rpm most of the time. Remember, a 286 gives peak power at 6400 rpm. You really don't want to be driving at those revs on the road all the time. Below about 4000 rpm the 266 will give better overall performance.
The car is only used for a thrash at the weekends really and is by no means a daily drive
Also what is a good way of checking the health of an engine?
Think I may be being a little harsh on my 998 it pulls up to about an indicated 85 given the room and sure the xhaust is sapping a lot of power so tempted to fit the 12g295 head I have sat in the garage in the mean time
Thanks
In a 998 a 286 would be a nightmare. It would only work with a straight cut close ratio gearbox and something like a 4:1:1 final drive ratio which would give about 13 mph/1000 rpm in top gear, with 5000 rpm being 65 mph. You would also need to be revving at around 6500+ a lot of the time to make it go well.
Even a 276 would be a bit unpleasant.
For a good road 998 the Kent 266 or the MG Metro cam would be ideal.
I don't know much about SW cams as I always use Kent, but look at the timing & lift for the 266 and compare with any other make.
After almost 60 years of cam grindings for the A-series engine, the cams you can buy today are much of a much-ness and the minor differences were recently described to me as 'turd polishing' by the various manufacturers to win sales. True, you might gain a bhp or so at the top end with the loss of a bit lower down, but really unless you are racing and 1 bhp will make a difference to the lap time, then a good road cam is just that.
Even a 276 would be a bit unpleasant.
For a good road 998 the Kent 266 or the MG Metro cam would be ideal.
I don't know much about SW cams as I always use Kent, but look at the timing & lift for the 266 and compare with any other make.
After almost 60 years of cam grindings for the A-series engine, the cams you can buy today are much of a much-ness and the minor differences were recently described to me as 'turd polishing' by the various manufacturers to win sales. True, you might gain a bhp or so at the top end with the loss of a bit lower down, but really unless you are racing and 1 bhp will make a difference to the lap time, then a good road cam is just that.
I had a 1275 with a 286, I loved the sound of it and it went well above 5000rpm, but otherwise it was a big mistake for a road car. Don't get too concerned with power figures, torque is a lot more important in a road car. I now have a turbocharged 1293 which is fantastic, I'd reckon on £4k to build something similar, but I'd highly recommend looking at the turbocharged route, Vizard's book is out of date in that respect. You can have ample torque from 2000rpm while still having more power than you ever need.
greggy50 said:
Okay thanks turbo is an option as well
First step is going to get uni out the way but looking for a 1275 in need of rebuild atm and getting my 12g295 checked then sold as Dad who normally hates cara has decided would like to help me build an engine which is fantastic of him
Turbo option is cheaper on the head, but much more expensive on the transmission.First step is going to get uni out the way but looking for a 1275 in need of rebuild atm and getting my 12g295 checked then sold as Dad who normally hates cara has decided would like to help me build an engine which is fantastic of him
My brothers mini had around 65bhp on the dyno. That had +60 Powermax flat top pistons (IIRC this gives about 1050cc or thereabouts), a really nicely ported big valve 12G295, MG Metro cam and an HS4 with the obligatory Maniflow LCB and RC40. I think it ran an MG Metro inlet manifold as well, but it was a long time ago. I do remember that it went extremely well for a small bore engine.
Right well I have just purchased the following
A+ Block
Kent 276 Cam - done 2,000 miles
Forged Cooper Rockers
Omega 73.5mm Pistons with 11cc dish + standard rods - pistons are great condition and new rings
1275 Head
Down Draught Twin-Choke Webber on Manifold and ITG filter
Gearbox with standard Gearset
Few other bits to assemble
For £300 does this seem a good price?
I am guessing now need to source other parts main of these will be a crank how much should I be looking to pay for a decent one?
Also need to get (please add)
Clutch + Flywheel - any recommendations?
Gaskets
Timing Gear
Metro Turbo Oil Pump
Then presume need new bearings for the crank etc... - any specific ones needed?
Oh and finally will need help with the compression ratio nearer the time as the head will need skimming an stuff to bring it all in line
Also what should I be looking to do with the gearbox?
Do I need to go straight cut as heard that is bloody loud?
Or can I just get a centre oil pickup pipe + x pin diff?
Power wise not going mental guessing will be around 80 - 90hp? if that helps with regards to the box specification
Oh and finally ignore budget stuff mentioned earlier now secured a graduate job
Thanks a lot
A+ Block
Kent 276 Cam - done 2,000 miles
Forged Cooper Rockers
Omega 73.5mm Pistons with 11cc dish + standard rods - pistons are great condition and new rings
1275 Head
Down Draught Twin-Choke Webber on Manifold and ITG filter
Gearbox with standard Gearset
Few other bits to assemble
For £300 does this seem a good price?
I am guessing now need to source other parts main of these will be a crank how much should I be looking to pay for a decent one?
Also need to get (please add)
Clutch + Flywheel - any recommendations?
Gaskets
Timing Gear
Metro Turbo Oil Pump
Then presume need new bearings for the crank etc... - any specific ones needed?
Oh and finally will need help with the compression ratio nearer the time as the head will need skimming an stuff to bring it all in line
Also what should I be looking to do with the gearbox?
Do I need to go straight cut as heard that is bloody loud?
Or can I just get a centre oil pickup pipe + x pin diff?
Power wise not going mental guessing will be around 80 - 90hp? if that helps with regards to the box specification
Oh and finally ignore budget stuff mentioned earlier now secured a graduate job
Thanks a lot
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