1150 Stage 2 engine

[edd_barker]

Has anyone else seen these?

https://www.ebay.co.uk/itm/222279339464

I'd be interested to hear people's opinion. Quite expensive, but now that I know the costs of reconditioning and tuning these engines, and presuming these come with a guarantee, it's maybe not that bad!

Edd

[philthehill]

The overall price is reasonable for a company built engine to the spec quoted.
If you do decide to improve or tune a 1098cc engine the better bet is to use a 1098cc engine with the engine number prefixed by 10CC and which has 2" mains and is capable of being extensively tuned with little possibility of crankshaft failure.
My preference is to use the 948cc engine as it is a much sweeter engine and which is quite capable of being tuned to the same power output to the 1098cc being discussed without loosing tractability.
The better 948cc engine for tuning is the engine with the engine number prefixed by 9CG as the three camshaft bearings are fitted with white metal bearings.
If you take the 948cc engine out to 998cc (standard bore 2.543") plus 0.060" you will have the same capacity at 1150cc.
There is a lot of 948cc engine tuning information available on the web and in hard copy.
Good S/H tuning and improvement parts are available on the web at little cost so long as you are selective.
Phil

[liammonty]

If you take the 948cc engine out to 998cc (standard bore 2.543") plus 0.060" you will have the same capacity at 1150cc.

Hi Phil - I don't think the 60 thou overbore adds 152cc to a 998 does it?! Do you mean it takes it to 1050cc? It's to late for me to attempt to work it out exactly, but my 948 block is bored to 998 + 0.040", and that gives 1030cc.

[olderisbetter]

philthehill, thats interesting about the 948 as i have a 58 traveller and the engine is tired and in need of looking at, i am now wondering if it is a 948, it would be nice to keep it and get it going better, it is a goldseal so i know its not the original engine but it was put in as a replacement very early in its life.

[philthehill]

liamonty

The data on overbore engine size was taken from David Vizards book 'How To Modify Your Mini'.
Fig 3 page 87 'Displacement Increase With Boring' 1994 re-print.

998cc plus 0.020"......................1014.6 cc @ 76.2mm stroke.

998cc plus 0,040"......................1030.0 cc @ 76.2mm stroke.

998cc plus 0.060"......................1149.7 cc @ 76.2mm stroke.

In David Vizards book Tuning BL's 'A' Series he gives the capacity as 1046cc @ 76.2mm stroke. Page 386.

It looks like there is a mistake in his calculations or the printing

Phil

[philthehill]

olderisbetter
The old trusty 948cc is ripe for improvement and can be improved relatively cheaply.
BL improved the small block 'A' Series engines and called them the 'A' Plus incorporating lots of the modifications that had been developed over the years.
The most expensive items when boring out to 998cc plus are the pistons.
So long as you are selective you can pick up a set of 998cc pistons and fully floating gudgen pin con rods for about £30 plus the cost of a new set of rings - the cost of a set of good quality rings is about £70.
The con rods from a 1098cc Minor engine are suitable for use with 998cc pistons - I paid £5.80 for a set in good condition off 'e' bay.
I have a 948cc 'A' Series that I am re-building to 998cc specification but instead of my usual no expense spared re-build I am trying to do it as cheap as possible and use up some of the improved parts I have on the shelf.
Here is a picture of my original 1957 'A' Series improved 948cc engine bored to 998cc with a 12G295 head and 2A948 camshaft, lightened flywheel and duplex. The twin 1 12" carbs were a later addition as it originally ran with a 1 1/2" H4 SU on a Janspeed tubular inlet manifold and exhaust manifold. That engine was very tractable besides being quick.
Phil[frame][/frame]

[edd_barker]

Sounds great Phil!

I wonder if you will need an empty engine bay in which to place your engine when it is finished....

[liammonty]

liamonty

The data on overbore engine size was taken from David Vizards book 'How To Modify Your Mini'.
Fig 3 page 87 'Displacement Increase With Boring' 1994 re-print.

998cc plus 0.020"......................1014.6 cc @ 76.2mm stroke.

998cc plus 0,040"......................1030.0 cc @ 76.2mm stroke.

998cc plus 0.060"......................1149.7 cc @ 76.2mm stroke.

In David Vizards book Tuning BL's 'A' Series he gives the capacity as 1046cc @ 76.2mm stroke. Page 386.

It looks like there is a mistake in his calculations or the printing

Phil

Thanks Phil - good to know that even David Vizard (or his printers at least) get stuff wrong from time to time!!

Totally agree re the overbored 948 - mine is lovely to drive and I am very pleased with it.

[olderisbetter]

Phil, I would be very happy to build up my old 948 for hundreds rather than thousands and get more usable power from it and retain the engine that has been in the car most of its life, I think i will start keeping a look out for parts to do it with, What kind of power do you think your engine made with the HS4 on? i know its not always about numbers and as you say tractable is good.

[BLOWNMM]

Hi guys
I have been doing some calculations and I believe the following is correct:
A standard 948 with a bore of 62.9 and stroke of 76.2 has a displacement of 947.2 cc’s. If the bore is increased by 0.060” (1.524 mm.) then the displacement increases to 993.7 cc’s.
If this motor is then bored by a further 0.020” (0.508 mm.) the displacement increases to 1009.44 cc’s.
If the motor is bored by 0.040” (1.016 mm.) then the displacement would be 1025.29 cc’s.
If bored by 0.060” (1.524 mm.) then the displacement would be 1041.27 cc’s.
The +0.020", +0.040" and + 0.060" are over the bore of the 993.7 motor.
Bob

[liammonty]

Phil, I would be very happy to build up my old 948 for hundreds rather than thousands and get more usable power from it and retain the engine that has been in the car most of its life, I think i will start keeping a look out for parts to do it with, What kind of power do you think your engine made with the HS4 on? i know its not always about numbers and as you say tractable is good.

I know you asked Phil, but I'll tell you about mine anyway (!) as it's broadly a similar spec to the engine Phil described, with a + 0.030" overbore, 295 head, HIF 38, AC Dodd 'Road torque' cam and Maniflow exhaust system - gave up to a max of ~55 bhp on Southam Mini and Metro Centre's dyno when I took it to get the carb needle modified. How accurate their dyno is I can't say, though even if it's a little less than that figure, it's a huge improvement over the 37 bhp standard figure. It is livelier than a standard 1098, of course revs much more readily, and is smoother, although it doesn't have quite the low-down grunt, despite being very good. If you do go down this route, I would suggest not going for too wild a cam if you want to keep driveability - I tried a few, and the one I am currently using is great in that particular engine (in my opinion!).

[philthehill]

Olderisbetter
I was getting about 60 - 65 bhp at the flywheel with the 1 1/2" H4 SU.
To get there was quite easy and did not involve spending lots of money but a lot of effort was expended in getting everything just right and finding and using the right combination parts.

A good book to obtain and has lots of relative information to the 948cc in line 'A' Series engine is the Car and Car Conversions 'Tuning BMC Sports Cars' by Mike Garton published in 1969.

http://www.ebay.co.uk/itm/TUNING-BMC-SP ... SwnbZYF5fe

Every Minor owner who aspires to have an improved 'A' Series should have a copy on the shelf

Whilst David Vizards book on tuning the 'A' Series is excellent is does not include details relating to some aspects of tuning and improving the the 'A' Series when fitted in a BMC car fitted with a in line engine.
The Mike Garton book also covers the 'A' Series transmission.
Me and my tuned 948cc 'A Series circa 1969. The single H4 can be seen mounted on the Janspeed manifold.[frame][/frame]

[olderisbetter]

liammonty thanks, and phil those sort of power figures would be great and i don't mind spending time and having a plan as i have found in many projects of life always seems to get better results, and i have grabbed a copy of that book it seems an exelent reference point, my first move is to determine my engine is right for it and see what i already have sitting about.

[Mark Wilson]

Great photo Phil! I don't have a single photo of my first car, a 1957 I bought in 1970. You certainly wouldn't want to see a picture of me with my student long hair in 1969 - not a pretty sight.....

Mark

[philthehill]

Mark
That is and was my first car (circa 1966) and I have still got her - though even more modified now.
Phil

[olderisbetter]

Well i am pretty sure it is a 948 as it has 950 cast into the block and there seems to be a blank plate just by it where it looks like a fuel pump would have been maybe for another model, this could make a nice back burner project.

[philthehill]

If it has 950 cast into the block it started out as a 948cc/950 block.
It may have been re-bored but If it has been - no problem.
A nice back burner project to be done in slow time.
Phil

[olderisbetter]

Phil is is green like most blocks but you can see underneath in places it is gold and has the 8G number on the engine as goldseal often do so i think it has been rebuilt but unseure how far they went.

[philthehill]

I would suggest that you take the head off and see what size the pistons are and work from there.
Even if re-bored to plus 60thou so long as the bores/piston/rings are good it can still be improved.
The gold paint adds at least 0.008hp to the engine output

[olderisbetter]

I think head off if the best move, it rattles and smokes a fair bit so i am sure i cannot make it much worse, and i might make it a bit more useable while im thinking it through.