34 replies to this topic

[gazza82]

MG 1300 is same as MkIII Cooper I think. Apart from final drive bet it's mainly the head ... need to check on Keith Claver's site

[postve]

MG 1300 is same as MkIII Cooper I think. Apart from final drive bet it's mainly the head ... need to check on Keith Claver's site

Thx gazza

Before I make the dive going to clean up the twin HS2-1.25 with new needles, springs and oil em up just to familiarize myself in advance of the following in spring;

- 2 - HS6 - 1.5
- new inlet manifold
- SW5-07 - swiftune
- 1.5 Roller Rockers - MED

Based on what I have so far above should do the trick- anyone again please advise if I am crazy

[Earwax]

postve

you are in the ball park for some good improvements, Always with a few individual preferences that people have experienced themselves. If you go old SU carbs you can go twin HS 4  or single HS6  , in the newer SU carb this is either single or twin Hif38 or single HIf44. ( 38 mm or 44 mm) you don't want twin HS 6....far too big ( my preference a single Hif44 or slightly less preferred HS6)

 

Without going into a whole world of differing opinions regarding porting and flowing a cylinder head. You may just check on the current inlet/exit valve sizes. Probably 33/29 mm is most likely and quite reasonable, but getting seats recut (or resized) and then blended and de-shrouded is a good compromise for hp VS cost, ( not as cheap as just bolted on 1.5 ratio rockers but still effective).. I have no idea on what Stage /performance level this equates to and in my opinion this Stage/level terminology is not helpful.

 

My thoughts are get new guides and reseat valves no matter what , and depending on what floats your boat some further enhancement work would sit well with your planned upgrades. happy decision making

[postve]

postve
you are in the ball park for some good improvements, Always with a few individual preferences that people have experienced themselves. If you go old SU carbs you can go twin HS 4 or single HS6 , in the newer SU carb this is either single or twin Hif38 or single HIf44. ( 38 mm or 44 mm) you don't want twin HS 6....far too big ( my preference a single Hif44 or slightly less preferred HS6)

Without going into a whole world of differing opinions regarding porting and flowing a cylinder head. You may just check on the current inlet/exit valve sizes. Probably 33/29 mm is most likely and quite reasonable, but getting seats recut (or resized) and then blended and de-shrouded is a good compromise for hp VS cost, ( not as cheap as just bolted on 1.5 ratio rockers but still effective).. I have no idea on what Stage /performance level this equates to and in my opinion this Stage/level terminology is not helpful.

My thoughts are get new guides and reseat valves no matter what , and depending on what floats your boat some further enhancement work would sit well with your planned upgrades. happy decision making

Thank you earwax as I am waffling and just read section in David's book and will go with the single 1.5 HIF44 - I can be indecisive now as nothing committed so you guys have been awesome as I prepare for the spring. Your last point - absolutely!!

[postve]

Earwax, one concern I have is I do not want to cut the good or anything for theHIF44 to fit - anyone put one in and can advise?

I see some with90 degree angle and thinking fitting issues

[Magneto]

The HIF44 is 1 3/4" not 1 1/2"....I have one my 89 Racing Green with a 1275 and it works well, plenty of midrange. But the single best thing you can do is the head - either buy one from Calver or at least DIY as it says in Vizard's book.....that will give you the most bang for the buck. I run MiniSpare's manifold, it fits fine and runs great and is inexpensive to boot. Make sure you have the right exhaust too a 13/4" Maniflow system or similar will help it breathe.....

[postve]

The HIF44 is 1 3/4" not 1 1/2"....I have one my 89 Racing Green with a 1275 and it works well, plenty of midrange. But the single best thing you can do is the head - either buy one from Calver or at least DIY as it says in Vizard's book.....that will give you the most bang for the buck. I run MiniSpare's manifold, it fits fine and runs great and is inexpensive to boot. Make sure you have the right exhaust too a 13/4" Maniflow system or similar will help it breathe.....

Thx again magneto

Which inlet manifold/head would you suggest??

[gazza82]

MG 1300 is same as MkIII Cooper I think. Apart from final drive bet it's mainly the head ... need to check on Keith Claver's site

Thx gazza

Before I make the dive going to clean up the twin HS2-1.25 with new needles, springs and oil em up just to familiarize myself in advance of the following in spring;

- 2 - HS6 - 1.5
- new inlet manifold
- SW5-07 - swiftune
- 1.5 Roller Rockers - MED

Based on what I have so far above should do the trick- anyone again please advise if I am crazy

I was right: from Keith's website

12G940 1.401"/35.6 1.15"/29.2 21.4 Stamped '12G1805' on flat area by thermostat - MG1300, 1300GT & Mk3 Cooper S

I was told these are probably best 'standard' head ... hope so .. one's going on my 1330 engine

Some conflicting feedback on 1.5:1 roller rockers ... try 'search'

[Earwax]

Regarding fitting a hif44, plenty of manifolds will do the job nicely.  the maniflow single SU carb inlet is a good one, but a lot of standard ones are good also ( just gave that example so you could look up the shape).  You wont need to modify the firewall , but you may have to jig around with spacers - and this is where it is better to have someone experienced to assist.  Reason - spacers for Hs 4  have two bolts, hiff44 have 4 ( i think)  - either phenolic (excuse spelling) or alloy will work- but again the width is critical---- i don't want to lead you astray - but i think mine on a hs6 is 15mm thick  ( check this with a known mini  with one fitted) - so please check this info for yourself

 

The other thing to watch is type and preference for airfilter.  Soft foam unifilter, or ramfilter type ones will fit but need the offset holes in the case- to help raise the filter body-  other types you will need to check for rubbing.

 

So as in all the mods considered above, it is best to match the components- or otherwise parts mismatch can be an expensive exercise.

 

Regarding the good advice about thinking twice about A) high lift rockers 1.5  and b) roller rockers  .  My thoughts - roller rockers are NOT really required but 1.5 lift rockers ( such as the keith dodd 1.5 forged) can be a good asset- so long as you know where your torque and rev bands are. If you final drive is tall and your cam is just standard - 1.5 lift rockers will push the torque band a bit higher-   not much good if the beastie comes to life at 5500 rpm when you spend 95% of the time at 4000rpm. I have a 1380 road motor that gets 1.5 rockers on track days, but is quite driveable on roads the rest of the time with 1.3  ,. ( I would look closely at the Keith Calver 1.4 rockers if doing it again ( they weren't around then)

[postve]

Regarding fitting a hif44, plenty of manifolds will do the job nicely.  the maniflow single SU carb inlet is a good one, but a lot of standard ones are good also ( just gave that example so you could look up the shape).  You wont need to modify the firewall , but you may have to jig around with spacers - and this is where it is better to have someone experienced to assist.  Reason - spacers for Hs 4  have two bolts, hiff44 have 4 ( i think)  - either phenolic (excuse spelling) or alloy will work- but again the width is critical---- i don't want to lead you astray - but i think mine on a hs6 is 15mm thick  ( check this with a known mini  with one fitted) - so please check this info for yourself

 

The other thing to watch is type and preference for airfilter.  Soft foam unifilter, or ramfilter type ones will fit but need the offset holes in the case- to help raise the filter body-  other types you will need to check for rubbing.

 

So as in all the mods considered above, it is best to match the components- or otherwise parts mismatch can be an expensive exercise.

 

Regarding the good advice about thinking twice about A) high lift rockers 1.5  and b) roller rockers  .  My thoughts - roller rockers are NOT really required but 1.5 lift rockers ( such as the keith dodd 1.5 forged) can be a good asset- so long as you know where your torque and rev bands are. If you final drive is tall and your cam is just standard - 1.5 lift rockers will push the torque band a bit higher-   not much good if the beastie comes to life at 5500 rpm when you spend 95% of the time at 4000rpm. I have a 1380 road motor that gets 1.5 rockers on track days, but is quite driveable on roads the rest of the time with 1.3  ,. ( I would look closely at the Keith Calver 1.4 rockers if doing it again ( they weren't around then)

 

Postve<> I have played around with the car for a but and found torque starts @2500 and reduces @4500-5000 and I did the wheel/crank ration twice and landed on 4.1 (strange as the car keeps pulling well into 90MPH) for the final gear ratio and quite sure the CAM is a standard 731.  I am leaning towards a costly but smart (I think) replacement to a SW5-07 CAM and match with the high gears I have.  SW5's from what I read  - a few times now and please do not ask me to show you - can be hard on stock lifters and strong suggestion is switch them out. I sent an email to Mr> Carver with my specs and plans to see what he says - thx again Earwax this is great reading and gives me a lot to compare before I make the jump. baby steps and first purchase - this week -

 

https://www.minispar...|Back to search

 

 

[postve]

 

 

MG 1300 is same as MkIII Cooper I think. Apart from final drive bet it's mainly the head ... need to check on Keith Claver's site

Thx gazza

Before I make the dive going to clean up the twin HS2-1.25 with new needles, springs and oil em up just to familiarize myself in advance of the following in spring;

- 2 - HS6 - 1.5
- new inlet manifold
- SW5-07 - swiftune
- 1.5 Roller Rockers - MED

Based on what I have so far above should do the trick- anyone again please advise if I am crazy

I was right: from Keith's website

12G940 1.401"/35.6 1.15"/29.2 21.4 Stamped '12G1805' on flat area by thermostat - MG1300, 1300GT & Mk3 Cooper S

I was told these are probably best 'standard' head ... hope so .. one's going on my 1330 engine

Some conflicting feedback on 1.5:1 roller rockers ... try 'search'

 

Postve<> the 12G940 is the early pre-smog version as mine is the 12G1316 - X (Smog) from what I read supposed to be good for mods. I will continue to review rollers but again read that the SW5-07 is hard on stock lifters.

 

 

 

[postve]

 

 

 

MG 1300 is same as MkIII Cooper I think. Apart from final drive bet it's mainly the head ... need to check on Keith Claver's site

Thx gazza

Before I make the dive going to clean up the twin HS2-1.25 with new needles, springs and oil em up just to familiarize myself in advance of the following in spring;

- 2 - HS6 - 1.5
- new inlet manifold
- SW5-07 - swiftune
- 1.5 Roller Rockers - MED

Based on what I have so far above should do the trick- anyone again please advise if I am crazy

I was right: from Keith's website

12G940 1.401"/35.6 1.15"/29.2 21.4 Stamped '12G1805' on flat area by thermostat - MG1300, 1300GT & Mk3 Cooper S

I was told these are probably best 'standard' head ... hope so .. one's going on my 1330 engine

Some conflicting feedback on 1.5:1 roller rockers ... try 'search'

 

Postve<> the 12G940 is the early pre-smog version as mine is the 12G1316 - X (Smog) from what I read supposed to be good for mods. I will continue to review rollers but again read that the SW5-07 is hard on stock lifters.

 

 

MiniMad,

 

Well one year or so later I think I hit it out of the park as performance is awesome and leveraged CST2001 from Keith.

 

HIF44 (BCE needle)

CST2001 - 12G940

1.4.1 rockers

etc.etc.

85-90HP

Tons of torque

 

 

[Turbo Phil]

If your running a standard head and valves, machine a 30deg back cut onto the valves. For the minimal work/cost involved this is the single most effective modification you can do to improve flow on an A-series cylinder head.
I charge £2.50 a valve.

Phil.

[postve]

Thx for the offer Phil and I would jump and do it if not for the distance as slightly beyond my capabilities to do the same

[Mini Manannán]

The APT Fast 266 is a belter of a grunty camshaft: https://www.aptfast....ategory=145605  I have the same cam in mine, it pulls from about 1500rpm until it (predictably) runs out of puff over 5000rpm.