1152cc (+60)
12G295 Head - 1275 (1100S) 33mm inlets and stock 998/1098/Cooper 25.4mm exhausts.
Standard Pressed Rockers
RE-13 Cam
Lightened Flywheel + Backing Plate
40mm Dellorto
Pulsar Distributor
A+ Gearbox 3.44 Diff - Competition Diff Pin.


That's about it i think..Still going strong in the moke

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Starlet Conversion:
http://www.ausmini.com/forums/viewtopic.php?t=15484

Gafmo has a similar one in his car, except it's a well ported 202 head with these same size valves, and runs an HIF44 instead of Dellorto.
There is about 1HP (ATW) between these two, they are so close they trade places on dyno days.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Righty, taken a few days to meditate on information. Nearly made it through the big book of vizard now, i also watched the minifilms engine building DVD (dunno if anyone over there has seen it? Basicly a taped engine build) and for once everything clicked in my brain. So i think i've nearly got my head around engines properly.

The article by Graham Russel was also very good, i'll be using alot of his advice for my build i think.

I've been struggling to understand how compression works, but i think i understand it now.

So if the standard compression (i think, my memory may be wrong) is 8.3:1, and i wanted to raise it to Grahams 10.5:1, with a +30 (for example) piston, how would i do the maths to figure out compression? Can it even be done before assembling the engine?

Also, would anyone be able to comment on the pros/cons of flat-topped pistons? If i was to go the flat top route, it would certainly be using modified 998cc pistons. So if anyone happens to have tried it, it would be great to hear how it went

In regards to Carbs, i've found ebay over here often has 1 1/4" and 1 1/2" twin carbs on ebay for cheapish ($50 Aus Dollars) in need of light rebuilds, so they are within my budget. Seeing as i'd need to buy and refurb a carb anyway if i was going for a single, i might as well pay a little more for twins. I really need to read up on manifolds for twin SU's though, as all i've found so far are the Log type ones, which performed poorley if i remember rightly? In the GR article it seems a 1 3/4" carb came out on top, that RE 7 inlet manifold certainly looks like a good bit of kit.

Though, seeing as the only reason for me to fit twin carbs is to eliminate cylinder 1+4 running lean, can anyone give a rough idea on how badly they are effected? I'm just thinking ahead that getting both carbs to flow equally and setup correctly, which including fitting the custom "leaning device", it might be a huge hassle to get both carbs runing equally. If the leaning problem is only a negligable amount then it probly isnt worth me running twins.

And back to work being done to the head. After doing an aweful lot of reading, so far the modifcations to be made to the head are: re-shaped (unshrouded) chambers and bigger valves (chrome). I've been reading into "gas flowing" the head, but i'm not sure how much i would benifit from it. In theory it sounds great, the engine will flow better and thus increase power/economy, but i'm wondering if its super expensive and/or makes the head unreliable?

Those videos were great to watch, nippy little bugger

Righty then, thats my brain-dump for now, i think i went of on a bit of a rant with it, but hopefully i covered everything i needed to... for now

Thanks again to everyone, its been a big help

Yes you can machine tops off SOME 998 pistons to use a 1098 crank.
But- the amount involved is about 0.148" (ie 1/2 the stroke difference), many pistons won't stand this as it weakens the crown or the top ring land.
Be patient, GR has some flat top 1098s coming in +.080" and +.100" sizes.
Re determining the compression ratio, it's in Vizard's book better than I can explain...
formula is (SV + CV)/CV
where SV = swept volume of cylinder
CV = clearance volume = (combustion chamber vol + gasket vol + top ring land vol + deck height vol + piston crown vol).

read de book...

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Ah, well chopping 998cc pistons can go out the window then, thought there would be a catch.

Not sure i like the ides of +80 or +100 pistons though! Those must be pushing the bore thickness.

I see, compression is that simple eh... Back to vizards book i go.

GR has done one at .120" over....
I used to run a 1220, it was a 1098 block bored 0.135" over. (68.0mm).

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I'm buliding a 120 thou over 998 at the moment... the only issue I'm having with going that big is getting the block offset bored (to leave enough meat between the 'pairs' of cylinders so I won't have head gasket issues)... but at the end of it I'll have a 1096cc 998

Blimey, and i was thinking +60 was a push! I guess theres more in the little engines than i thought.

I'd imagine the reliability must be greatly reduced though?

Speaking of head gaskets, how do you make them fit after boring out the engine?

I'm using a 1275 turbo head gasket which looks as though it will work fine... anybody out there know any different?

It should work fine, with a 1275 head on it.
But, will probably not work with a smallbore head, as water holes in head are different to 1275 below the thermostat area. There is a BIG hole there on a smallbore head....

My 1220 way back then (1968) ran a copper 1275 gasket and a 1275 head.

Sit the 1275 gasket on the smallbore head and double check.

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DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

I have to agree with all the above that has been said already. Yep Josh and I and a couple of others have a good compertition between us tryinh to break 50bhp on a particular Dyno and I Bet one of us will very soon. This number does not sound big to waht you guys get over thier as the Dynoing is a little differnt but its good bhp and we should run them down the 1/4 really which would be interesting.
You have asked for economy and reliability

But the thing I will do Next time

Lighten Back plate and Flywheel and Balance together with Clutch and Crank (With the Crank get it Crack Tested and Ground to the next size up)

Bore to the Next size up and Piston's and Rings to Suit and maybe lighten the Rods a little. "Replace the Rod Bolts for New One's"

I love the RE13 Cam so I would not Change it

Head yep I will be staying with it. The one I have now has been Tickled but its been Shared to the Hell. I have another now and it will have a GR tickle only. Standard Rockers buit with double Vaulve Springs

Carb I'm staying with the HIF44 (or What ever you have) and get a good Manifilod. I got Mine from the UK 25 pound via Fleebay so just keep your eye out

As mentioned before..Sorry can't rember who...but get it put together by some one who knows what they are doing and you will get your economy and reliability once together get it Bench Dynoed and Run inn

Lastly..The Box..Get it Done once and once only

Our's Well the Wifes Daily Drive has had a few issue'd but nothin has broken and I give it a good run on the weekends

I think I have waffled on enough

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Stop Licking the Dog...I Don't Care Who Started It

I wasn't aware that bhp was measured differently? Is it sort of a metric/imperial kind of thing?

Either way, i've learnt fairley quickly that BHP doesn't really make an engine good, tourqe (or more accuratly, the tourqe curve) and gearing seem to effect engines much more than the bhp. Still doesn't stop all the local boys in their boy-racer cars shouting about how much BHP they have thanks to their 5" exhaust, but whatever...

I'm guessing "tickled" is slang for the head being "worked" a little bit?

I'll be putting the engine together myself, cheaper and i want the experience, but i'll certainly be getting it to a dyno or rolling road, depening if i finish the car or the engine first

Lucky for me, the engine i picked up for $5 came with a metro inlet manifold, good airflow and has the pipeing for water heating, which i'll need in the winter.

I've got nothing more to add yet, still wrapping my head around compression

Cactus,
My 1098 used one of the Metro water heated manifolds with a single 1.5" SU and the difference over the standard (i.e 1970s) manifold amazed the engine builder. Definitely use that one if you want to stick with a single carb setup.

The rest of the spec was 295 head with standard size valves, mild cam, 20+ overbore and it ran a 2.9 diff. This was a great cruising car on the highways, relatively quiet and plenty of torque for the hills and overtaking.