The Sprite Forum

Brace yourself for the rush, just kidding You still got a few brave souls in vintage racing loyal to the 948, but most have gone to the 1275, but you find home for it with one of those guys.

Because the one I bought was on sale for three score and seventeen dollars.(77 bucks) The inline ones were closer to 300 bucks. I figured 20 minutes with a hacksaw and welder will save me a fair bit of coin. I shudda got 2.

Adrian

Yes it will fit 948, 1098 & 1275, but flow wise it is better on a 948. It locates on the left side of engine and exits towards rear without any alterations required.

If you must absolutely have a 948 c engine, get a 1273 and sleeve it. ¯\_(ツ)_/¯


Pete

OH, OK, a buddy, he's a member here, Mike Miller, used to buy the cheap Mini LCB from Mini Spares and make them into a racing thru-the-trans-tunnel exhaust for the Spridgets, by cutting them and turning the direction of the down pipe.

So... once I have my supercharged whiz bang 948/1050 what do I use for a clutch? Is the stock unit up to handling much added power? How much? Are there simple swaps/mods that a fella can do?

Adrian



Edited 2 time(s). Last edit at 2018-12-10 03:31 PM by pinkyponk.

I vintage race a 995cc Bug Eye with 80 to 90 HP and use a stock 1275 clutch and it has worked well over the past 10 years.

Adrian,

I used a 6.25/6.5" Hillman Imp 998 diaphragm clutch; about twice the clamp pressure of a competition 9 spring clutch as supplied by BMC Special Tuning back in the day. No flywheel redrilling required (as would be for the 1275 clutch cover) and perfectly roadable. Use with the 1275 Midget/Sprite driven plate. If you were to consider the 1275 clutch, you might as well go to town and lightweight the flywheel and redrill it for the Hillman Hunter 7.5/7.25" clutch (as I did for the 1275 flywheels) but that would be serious over-engineering. Heavier too!

Good luck with your choices!

Roger

Is there a Maxpeeding rod to fit my project?

Adrian

Nope. The only aftermarket options I’m aware of are Carrillo and Pauter.

Sorry... I should have been more specific. I should have asked if the 1275 ones will fit my 948. This ebay listing from Maxpeeding claims they do but I wanted to check with Hap on account of he recommended 1098 ones anyway. https://www.ebay.com/itm/For-Austin-Mini-Cooper-S-1275-A-series-Connecting-Rod-Conrod-Con-Rod-Rods-ARP-/151042374437

Adrian

No, they don’t fit the 948.

Hi,
if you get hold of some A+ rods from a later A series engine they also have the press fit pins and are much stronger. Just completed a 998 engine using Keith Calvers recommendations in the UK.

see this article, that inspired the build.

https://www.minimania.com/Engine___998_Tuning_Further_Options


Site info
https://www.calverst.com/webshop/cylinder-head/

Running in engines
https://www.calverst.com/technical-info/running-in-new-engines/

Inspiration for decision to increase capacity from 948 to 998

SPECIAL TUNING FOR THE MIDGET AND SPRITE- British Leyland- for period reference

Keith Calver 998 tuning, further options- 948 makes 43HP Std, Modified 68-72 HP ( 60%+)
Aim: To produce an engine that looks completely original but has been modified to provide reliable increased power and better drivability.
List of improvements carried out, most parts from Calver Special Tuning Ltd,
Specification
Cylinder Head: Stage 3 small-bore
998 +020” High Flat top Quality pistons Std size for press fit gudgen pin (10.3:1), Silicone Squeeze Cast
Steel Rocker assembly 1.3:1
Cam Followers- specially made, ground & hardened
Camshaft- Piper BP255 hi-torque
Duplex timing gear with IWIS chain (Simplex not used, although lighter)
Timing cover to match, 2nd hand
Special main cap hardened washers & centre main cap- ARP
Spin on oil filter housing- I have original if needed.
Blanking plate fitted where fuel pump was.

Work carried out by- Perret Engineering, Stalbridge, Dorset UK
Crankshaft reground, Machine rear main bearing cap to accept lip seal conversion
Reface flywheel to accept 1275 Clutch & fit new ring gear
Dynamically balance Crank, flywheel & clutch assembly- Sigma Engineering used (Local legend for classic race cars)
Chemically clean block, core plugs +oil gallery bungs, big end & main bearings +0.30” + Thrusts.
Re-bore, hone, reface block, fit a+ conrods, balance- to pistons provided.

Catch tank for breathing fitted
LCB manifold, stainless, insulated/Lava Wrap, Sports exhaust to match.

Distributor
Lucas 25D, upgraded with Accuspark Electronic ignition, sent to H&H ignition services, adjust curve to road sport spec (Calver recommended).
Carbs
HS2- completely overhauled, major repair kit from SU Burlen, Salisbury
Butterfly valve shaft bushes (line bored) Talon engineering Yeovil 240915
Inlet manifold matched to head
K&N Pancake air filters bought from USA
GearBox
Original smooth case sent to Heathrow Trans. To fit new 1098 gear set, much better than 948, retains outward appearance.


Hope this helps, a full race engine is good, for racing. The ultimate road engine has better drivability and a lot cheaper to build.


Good luck Paul

---

Paul Ross
Mk1 1959 stage 3 998
Mk3 1967 K series 1800, road race spec.
BT7 1960 289 65 Hipo RHD conversion

This sure looks like a Maxpeeding rod. https://selbyraceengines.com/selby-m7-connecting-rods/ They are a bit dear from this supplier.

The little end bush looks like the sticking point on the cheap Maxpeeding ones.

Adrian