distributor options

[andrew.searston]

hi everyone
getting my engine rebuilt soon, bored out ect.. was thinking of putting a performance coil and distributor to gain max power. currently running point at the moment, my question is what do i go for without breaking the bank??
and its a 948cc with standard carb

[bmcecosse]

No advantage going for a 'performance coil' etc - the standard coil is perfectly capable of giving you all the sparks you need. If rebuilding a 948 - consider boring to 65 thou and fitting Mini flat top (std) pistons and rods - to get 998 engine. Add a camshaft from a 1098 engine (AEA 300) and a head from a 1098 (12G 202) skimmed 40 thou with a 1 1/2" carb from a Mini - and you will have all the power of a 1098 - maybe a bit more, especially if you 'tidy' the head before fitting.

[andrew.searston]

want to keep it original looking and sounding, already has a 1098cc head (skimmed by 60 thou). if i did all as you said but kept the standard carb would their be much of an improvement?
would it run as smooth with a 1098 cam?

[bmcecosse]

Oh yes - you can keep the std carb if you so wish. The 1098 camshaft (or indeed cam from any late 1275 Mini - but note different oil pump required) will make a big difference - and is obviously not visible. Let's face it - the 1098 engine supposedly makes 48 bhp - and probably the carb is the limiting factor for that - so a good 948/998 engine will also make the same 48 bhp - but at higher revs of course - the air flow being the limiting factor. The larger carb would let it make the power at lower revs - it wouldn't have to 'suck' so hard.... You could always 'Vizardise' your carb to get a couple of extra bhps.....

[andrew.searston]

thanks for the info, will be going down that root. do you think it will tick over as smoothly with a 1098cc cam as it would standard?
also will the 60 thou skimmed head on it already will it be fine as you say skim it by 40. should have quite a bit of compression
the car has a oil bath air filter, so thats quite a restriction realy

[bmcecosse]

Depends if you go the 998 flat top pistons - then I would simply advise opening up the head around the inlet valves slightly - and removing a bit of the 'beak' - to drop the CR slightly. It will tick over just fine!

[andrew.searston]

thinking of keeping standard con rods and pistons, 1098 cam, 1098 head, duplex timing chain and standard carb. think this will make a little diffrence but nothing to serious and also keep cost down. will also do away with points

[bmcecosse]

Just thought you might pick up Mini pistons and rods cheaply. New 948 pistons are not inexpensive!

[philthehill]

Personally I would go for a + 060 thou oversize re-bore and leave it there. Pistons available from ESM Pt No: 9M122_60 £99.50. You already have the 1098cc head so it will breath better. Do not worry about the size of the carb/air cleaner they will allow more than enough air to pass through them for your needs and it will still look standard. The standard Minor cam shaft is also adequate for your needs (but could be improved upon I agree). If you upgrade the cam shaft to one which puts more load on the plain camshaft bearings you will need to fit white metal bearings (Pt No: 10M116) to compensate as per the 1098cc engine camshaft bearings.
My advice is to get you have working well and you will be surprised at the performance.

[bmcecosse]

The extra 5 thou bore allows use of cheap flat top Mini pistons! The 1098 cam will be fine in the cast bearings - it has v little more lift, and provided you don't fit silly 'strong' valve springs - it won't put any more load on the bearings than the normal pathetic cam. The 1098 cam is a GREAT improvement at this spec of modification. That is however the max cam to run without expensive cam bearings - that's the point to change to using a 1098 block.... Leyland found it wise to increase the carb size on the 998 engine to get a bit more power - so the standard 1 1/4" carb is v much a limitation - but I understand your enthusiasm to keep it looking standard - probably for insurance purposes..... It will go well enough - just perhaps slightly lower top speed - but how often do we ever run our cars at top speed anyway!

[philthehill]

I do not know about cheap 998cc pistons!
All I can find are about £38 plus P+P plus VAT.
Currently no S/H on 'e' bay either though I may be looking in the wrong place.
I do not know if I would trust a S/H set of pistons without first inspecting them before purchase.
Of course we do not know what wear is in the bore of Andrews engine so 0.005" extra bore may not be enough, therefore bore wear needs to be checked and until that is done all advice is presumption.

[andrew.searston]

do you think ill be able to use the 948 conrods with flat top mini pistons?

[bmcecosse]

No - you would need the Mini rods. The point would be to pick up a complete Mini block cheaply - frankly 998 engines are often given away free! I did a few years ago - unloved and unwanted - they all want to go 1275! Maybe not so many about these days. But I totally agree - unless you get a decent set very cheaply - it's not worth the hassle. And if your block is std bore - no point boring it out any more than necessary - it's certainly not worth it from an 'extra power' point of view - the few extra CCs are not going to make a significant difference. The important thing is the head and the cam change.

[MarkyB]

the few extra CCs are not going to make a significant difference

Don't go saying that in America! You'll get strung up

[bmcecosse]

Aye but here we are only talking about extra 50cc max - maybe 5% extra - so perhaps an extra 2 bhp..... It all counts - but it's not value for money power!

[MarkyB]

Is 50cc a cubic inch? That's what they really like

[bmcecosse]

Appears to be ~ 3 cubic inches!

[philthehill]

There is a 998cc A+ short motor for sale at Stratford on Avon, Not far from Kenilworth. On 'e' bay item No 181322741843, no bids and currently at £40 with an hour to go. Looks to be in reasonable condition. Worth a punt at £40 and could be collected to save on carriage.

[bmcecosse]

It sold for £40 - 1 bid.

[MarkyB]

Bargain!
Hard to see if the timing chain damper is present but it looks like the damper type bottom pully.
The crank and block could be sold on or just weighed in for beer money