I have finally started rebuilding an 1100 engine for my Mini, so I figured I should start a thread to keep me motivated (and to ask questions in )

The car is a 1976 Clubby with a 998. Current mods are:

- extractors (don't know the brand, but it has 'wildcat' on the underside of the muffler)
- chopped standard intake manifold
- 1.5" SU with some internal mods
- Ramflo with aftermarket foam (I think it is unifilter foam, but it is quite thick)

The plan is to build up the new engine and then do an engine swap. I have a spare car which is (currently) running, so I won't have to rush the swap or anything.

I have a short block 1100 + 60 thou engine which has only done around 1500km since rebuild. Unfortunately it is in Perth at the moment and I am in Karratha in north-west WA (1600km from Perth). I am driving down there around Christmas time, so I will pick it up then, as well as a gearbox which may be better than the spare I have up here. I have enough to work on up here for the moment anyway.

Plans for the engine are:

- Wade 446b cam (already in the short block)
- new oil pump (already in the short block)
- dual row timing chain
- lightened flywheel (to Docs recommendations in other threads)
- 295 head modified to Vizard specs, possibly with oversized valves (more on that later)
- DHLA40 Dellorto
- Drmini Special Tuning stubstacks
- Ramflo with unifilter foam
- standard rockers (I think, or I may try to get a set of 1.3s)
- Extractors (the ones already on my car)

At the moment I am still looking for the dual row timing chain/gears and the manifold, but I'll just buy them new if I don't find any.

I currently don't plan on overhauling the gearbox because I have spares and I have a second car anyway. I will just clean up the gearbox I think is best, and check end floats and whatever else I can to make sure they are within spec. If I put it in and find that it is no good, I will overhaul another gearbox and do a swap.

The cylinder head I have has been crack tested and has inserts for the exhaust valves. The inlet valves have either had the seats re-cut bigger or have just become quite deeply recessed from a lot of use. Either way, I can't really use standard valves in its current condition because they are very deep in the head, and since I plan on running it on premium unleaded with no additives, I will need inserts anyway. So my question is - what size valves should I use? If I go up a bit in size from standard then they will start getting shrouded by the cylinder head wall, and this part of the wall can't be ground back very far. I looked around a bit and didn't find much info on here, apart from this thread:

http://www.ausmini.com/forums/viewtopic ... s&start=15

Would it be worth using 1275 inlets in this type of engine config? It will obviously require a bit more porting to try to de-shroud them, which means I will have to skim the head a little more. Is this likely to introduce the risk of pistons hitting valves? (I don't know if the pistons are flat-topped or dished). I will be buying new exhaust valves as well, so I may go up to 1+1/16" oversized valves so that I can get them up a little higher on the seats.

I am also thinking of getting some of these:

http://www.calverst.com/shop1/index.php ... ducts_id=5

which the Doc mentioned at some point as being superior to standard valve stem seals. Any opinions on this? I haven't owned Minis long enough to know how long valve stem seals are likely to last and whether it is worth stepping up to these.

sounds good - all the best with it



always buy new timing chain & gears, it's something like $140 for a nice rollmaster adjustable set, and any second hand ones you get will be rooted and not worth the hassle

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did I tell you that I won a trophy?

1100S inlets won't hit pistons or the block, but if you go over 1-1/16" (27mm) on the exhaust valves they can hit the block.

re those stem seals, they are lined with Viton A, not Teflon. They last forever compared to Mini or Metro ones. last time my motor was down for rebuild, I refitted the same ones.
One point- when fitting them put a smear of Loctite 262 on the outside of the valve guide first, and don't hit the seals on hard or you will make them loose. They have a brass body.

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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.

Block may have been rebuilt..was this done by you or some one else
if not by you the one thing I would surgest (if not by you) is to take the crank out and get it crack tested and rechecked.
Rockers I would recomend set of 1.3 asper Dr's Thread

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

ok. I will make sure I get it new. It will be handy to be able to adjust timing without needing offset keys as well (handy for the guy dynoing it, that is )



Any ideas on whether it is actually worth using 1100S inlets and oversize exhausts, Doc? I'm not sure at the moment whether I should go up to these sizes or go back to standard.

I will put an order in for the valve seals in the next week or so. Is Loctite 262 the same as 243, or close enough? I have a bottle of 243 here. I assume these seals sit down over the end of the valve guide?



It was done professionally by an engine builder. I may pull it apart for a quick check though since I don't really know the history of the engine.

And I'll keep my eyes peeled for a set of 1.3 rockers.

Graham Russell uses standard size 1100S inlets in his modified 202 and 295 heads, and 1100s exhausts too (but turned down to 1-1/16").

I did one for a 1220cc Sprite motor the same way, and I used Rover 998 unleaded inserts, bored out to 24mm before fitting.

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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.

Good luck with the build Richard and don't forget, plenty of piccy's please and your right mate getting the thread going is the best way ,(IMO) , to keep the motivation up and get heaps of help...

Cheers Gerg

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May the fork be with you.

if you go for a Russell Eng. cam (IE an RE13) he'll give you the angle it needs to be set at, big protractor and a dial indicator and off you go

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did I tell you that I won a trophy?

dude, good to hear your building up something..
60thou 1100's with 295 head and 446b cam is a great combination
the 202 head i did up

are you looking at rebuilding the gearbox aswell?? or you going cheep like normal??
i'd maybe fit a center oil pickup too

how is work goin for you way u north atm???

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- '74 Clubman Ute project

If you run into my cousin Zac in karratha tell him I said Hi!

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Noli Illegitimi Carborundum

Hopefully I will get some pics up in the next week or so, but at the moment there isn't a lot to look at because the short block is still in Perth and I haven't done any work on the head apart from disassembly, cleaning and measuring.

Clae - I won't be overhauling the gearbox, just cleaning it. I have spare a spare gearbox anyway, so if the one I put in there is no good then I will just overhaul the other one and swap it in. I am generally pretty kind to gearboxes anyway - no flatshifting, and double de-clutching when necessary - so I shouldn't have any dramas. I don't know about the central oil pickup. I have found a corner up here that I can't go fast around because my oil light comes on (only done that once), but apart from that I haven't had any problems. I have also heard bad things about central oil pickups - something about the filters being too small or not fine enough. Work up here is going well, pretty busy though. It is nice and warm up here too

benoz - I haven't met anyone called Zac yet. What is his surname?

Now time for a couple of questions - I have checked the valve springs and they are all different lengths so I am going to get some new ones. Any ideas what strength I should be getting? I am thinking of getting standard 998 Cooper double valve springs because I won't be able to rev the engine too highly because its an 1100. I'm thinking that the 998 Cooper springs should handle the revs.

I have decided to be grinding the head myself to Vizard specs. I got my sister to check the short block for me and it has dished pistons. If I grind the head as shown in Vizard's yellow book am I likely to run into problems trying to get high enough compression (I am aiming at about 10:1)? i.e. Will I run out of head to skim? I am thinking of sticking with standard sized valves, and that way I won't end up grinding out as much of the head and won't need to skim it as much. I also won't need to buy new retainers and get valves machined.

I will make sure I take some before and after photos on the head once I start work on it.

I have done some calcs and investigations and have kinda answered one of my questions.

I did some compression ratio calcs to see if I could get the compression ratio up to around 10:1. I made them really conservative, and followed the method/instructions on page 222/223 of the yellow Vizard book.

1100 + 0.060 = 1150cc = 387.5cc/cylinder

I assumed a dish of 8cc (can't measure it because the short block is in Perth, a ring land volume of 0.7cc, a gasket volume of 3cc, and a gap between piston and top of cylinder of 50 thou = 4.35cc.

Calculating this out using the formula gives a combustion chamber volume of about 16cc, which I don't think I can achieve without milling it too far and blowing head gaskets.

These calcs are really conservative though, and I can get the block decked slightly to make the pistons flush with the top of the block.

So, I figure as a best case scenario I will have 5cc of dish, ring land of 0.7cc and gasket volume of 2cc. This gives a combustion chamber volume of around 24cc. On page 221 of the book it says "When the engine concerned is 1100cc capacity, chamber volumes in the region of 21cc are required and represent no problem at all". So I guess in theory it is possible to make it work with this engine if I don't to any grinding on the combustion chamber.

Then I searched a bit on here, and found thread:

http://www.ausmini.com/forums/viewtopic ... sion+ratio

with this in particular:




So, I am thinking that it isn't going to work with dished pistons. I guess even if it does, it would be costing me a bit of horsepower because I won't be able to grind the head out at all. So now I have 2 choices:

1. Buy new flat-top pistons
2. Use a 202 head and grind it, then shave it back to get the compression ratio up.

Is option 2 feasible? Do 202 heads have a thicker deck, allowing them to withstand more milling? (this is mentioned as a possibility on the other thread). I know it will be a lot of work to do a 202 head (especially using a Dremel, which is what I will be using), but I don't mind that. I would probably prefer this option if it is going to hold head gaskets, because it will be cheaper and I will get some experience grinding heads.

Any opinions or advice on which option I should go for?

P.S. pics are hopefully going up tonight

I don't think a 202 is any thicker than a 12A1456 (998 one) or a 295.
Corrosion in there from 40 years use/non-use makes em thinner.

My solution on the Moke 1132: use Hypatec dished pistons, but a 1275 head, with the block notched. The chamber volume is only 21.4cc, and the deck is heaps thicker than smallbore heads.

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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.

For those who wanted pics:

My Mini (with the front up on the jack at the time of taking the photo):



The cylinder head - stock 12G295, hasn't been skimmed:



The valve springs - all sorts of different lengths:



Mmmmm, Dellorto:

Sorry whats all the white stuff over the chambers

I'm guessing a 40 Delly

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