16 replies to this topic

[pusb]

I have acquired an 1100 Clubman engine off a member on here for a very reasonable price. I want to eventually drop it into my City 850 for a bit of extra power, but for now the old 850 engine is running fine so I'm not in any hurry.

 

As I know nothing (yet) about rebuilding engines, I am just trying to build up my knowledge about what I need to do, and what I eventually want to end up with.

 

From what I can gather, an 1100 engine is not good at high RPM, but has good low end torque, which presumably makes it good for everyday city driving?

 

I am after advice on what sort of spec engine I can turn the old thing into. What I want is an engine that is reliable, reasonably easy for an idiot like me to put together and something that is lively as possible for an 1100 engine.

 

Also the 1100 head is missing (although did come with a 998 head), but from what I can see, on an engine rebuild the head looks the most complicated bit anyway! So I am looking at buying a complete head that I can just fit straight on. I will also need a gearbox to fit to it, I am assuming the box on my 850 wouldn't fit well to an 1100?

 

First thing I need to do, once I have stripped it down, is get the block cleaned up. It has its fair share of surface rust, and some stubborn grease/oil coatings, are there places you can have the engine chemically cleaned to remove all the rust and dirt?

 

Then I will need to start buying parts. I would like to hear peoples opinions on what components would make an 1100 engine run great as an everyday car, and what head and gearbox would match well to it?

[Cooperman]

First of all the 850 gearbox will fit straight on. However, with the much higher torque of the 1100 a higher final drive ratio would be a big advantage.

 

Now, engine re-building is never just a question of bolting it together with some 'better bits'. It requires a specification, a lot of measuring, some calculating, some machining, a trial build, possibly further machining, then, finally, very careful assembly.

 

The 1098 doesn't like revving at over 6000 rpm as a maximum sustainable figure, so you need a cam which gives best torque at around 3000 rpm and peak power at about 5500 rpm. Now you need to look at the Kent Cams data sheets ad see which cam meets these requirements. 

 

The best head is a 12G295, if you can find one, then do some mild gas-flowing, fit new valves & guides and measure the combustion chamber volumes.

 

For pistons a set of suitable flat-top ones will be best.

 

For carburation a pair of HS2 or a single HS4 would work Ok. The exhaust could be a 3-into-1 freeflow manifold with a twin box exhaust system at 1.75" bore. 

 

You will need a different advance curve on the distributor, so a different distributor needs to be specified.

 

You could lighten the flywheel a bit as well.

 

Obviously fit a new oil pump, water pump & timing chain.

 

Then after measuring, calculating, machining and checking, assemble it all very accurately, cleanly and carefully.

 

So start off with a written specification and post it on here. We can then comment and you might decide to alter it slightly.

[mk1leg]

beaten to it....lol great advice from the cooperman

[pusb]

Thanks Cooperman. You'll have to forgive my somewhat simplistic way of describing what I want to do! I know getting a job lot of bits and bolting them together would end in disaster! From what I have read, possibly the most important step is the measuring and machining. Due to the intricate nature of this, I think I will be handing it over to a machine shop for that part. I would like to do the assembly myself though.

 

I will take a look at Kent Cams and see what looks suitable. As for the carbs, would you say a pair of HS2's or a single HS4 is the better option? I could just use the HS4 off my 850 if that's the better option.

 

Dizzy and Flywheel are missing, so I will need new ones of those anyway. For the timing chain, are the duplex ones worth it?

[Cooperman]

You could use the HS4 with a suitable new needle, or a pair of HS2's would give better throttle response at mid-range.

As for a cam, be careful you don't get tempted to 'over-cam' it. You want the max power well before 6000 rpm and it looks as though a Kent 256 might be ideal.

If doing the assembly you will be advised to measure everything yourself. I once bought a fully gas-flowed head from a well-known Mini parts outlet and gave them the specification right to the chamber volumes. It was for a 1071 Cooper 'S' high-performance competition engine. It was a good job I checked the measurements as they had supplied it with chambers for a standard 1275 and had I fitted it my super 1071 engine would have ended up with about 8:1 C.R. an d I would have been very disappointed. I then had to strip and take it to my local friendly machine shop for correct skimming as I had lost trust in the supplier.

A duplex timing chain/sprockets is a good idea. You will need to time in the cam accurately using offset woodruff keys.

To measure everything accurately get yourself a 1" to 2" micrometer screw gauge, a digital vernier protractor, a DTI with a magnetic base, a crankshaft protractor and a set of feeler gauges.

Have the gearbox checked by an expert and fit a 3.44:1 crown-wheel & pinion. The higher torque of a 1098 will quickly show up any weaknesses in the transmission.

[pusb]

Thanks Cooperman. I have followed your advice and looked at the Kent 256, looks like it can do the business! Also what is an SW5 cam like? Another point, are aftermarket cams different on A to A plus engines?

 

Those 12G295 head's seem difficult to find! Are there any other suitable heads that are a bit more common?

[Cooperman]

I've never worked with an SW5 cam. I've heard good things about it, but I normally go with a Kent as their range is good and I know which ones do what. The 256 does look right for a 1098 and you won't be disappointed with it.

Al current cams are slot drive and will fit all A-series engines. Get a good oil pump - not a cheapie one.

The 12G295 head is indeed getting rare. You can get a standard 998 head and gas flow in so long as you are fitting flat-top pistons. It will need a lot of skimming after chamber re-profiling, but the 1098 is easier to get right in terms of C.R. because the chambers don't need to be as small. You can fit a 12G940 head from a 1275, but that can involve block pocketing and the lower available revs of the 1098 will make it not ideal, although it will work. You could go that route with a 940 with 33,5 mm inlet valves and so long as you measure accurately and do whatever that shows as necessary it will be fine.

[Spider]

Re: Measuring up 'stuff'. The machine shop can measure up some of the build, but unless they also do the assembly of it too, they can't measure everything, besides, it will be up to you to check their work, if you are doing the assembly. If you make an assumption that they have done everything right and say you seize a piston, they are only liable to correct the tight bore, not compensate you for a ruined engine. I would suggest you buy some basic measuring tool and get a feel for using them, suitable instruments won't cost that much (but read on in this regards).

 

I'd also suggest if you can find someone who is experienced to do your first build with you - there are just so many detailed and easily over looked 'things' that can easily be missed, some are just to get the best from your build and some are critical, but I don't believe that they can all be covered on the forum or in a publication, but only come from experience. They will also likely have all the measuring gear and show you how to use them and hoe the measure parts correctly, eg, how to measure a piston, it's just a round do-hicky isn't it?

 

Dwelling on this 'experience' bit, I've only been on this forum for just over a year (sorry every one!) and I've read a number of engine build threads, but I haven't yet read, though may have missed, anything in any of these threads about bore finish, con rod reconditioning, bearing nip, tunnel roundness, bore alignment, spot facing, etc etc, and these are just a very small sample of some of these detailed items that I was referring to in the paragraph above. This in no way is intended as a slur on any of the good, experienced, knowledgeable people on here, it's just way to much to cover in a forum posting.

 

If you are considering an 'out of the box Cam', can I suggest having a look at Piper Cams, the Kent Cams I've found are none too accurate. I'm sure Swifty's Cams would be first class quality, but they don't publish specs on them.

Edited by Moke Spider, 26 January 2016 - 07:00 PM.

[pusb]

Thanks both, all advice taken on board :)

[pusb]

After looking at the options, I think I will rebuild it to standard spec. Should still feel the difference over the 850 engine!

 

I suppose I could always stick a stage 1 kit on it afterwards.

Edited by pusb, 27 January 2016 - 08:22 PM.

[Spider]

A standard (high compression) 1100 engine, fitted with it's original 12G202 head will not disappoint. A fine motor, doesn't have to be pushed to be enjoyed, easy to drive, easy to live with.

 

What's more, come maintenance or tune up time, just get out the book and there's all the info.

Edited by Moke Spider, 28 January 2016 - 04:19 AM.

[timmy850]

A stock 1098 is worth about 45-50hp, with a stage one kit you'd be looking at 54-60hp. Rebuilt with a slightly better cam, head and higher compression ratio etc you'd have 60-70hp. That'd be a nice upgrade from an 850!

 

There is an article here by Calver using a SW5..

http://www.minimania...al_Tuning__1128

Which is worth reading after these ones

http://www.minimania...ONS__STAGE_ONE_

http://www.minimania...ER_OPTIONS_1100

 

[pusb]

Two decisions have been made on this! Firstly, as the sump plug on my current 850 engine is giving me trouble again, I want the new engine as quickly as possible!

 

Secondly, I have decided that the amount of time/effort/cost of building it myself isn't worth it. I probably won't ever build an engine again, so no point in learning a new skill to never use. So today I rang an engine builder to talk through having the work done with him.

 

He is going to put together a few options/prices for me, and then get back to me. Said there is a bit of a waiting list for work though (but that IMO is a good sign!).

 

He said his favoured set up would be this:

 

12g295 head

Kent 276 cam

Overbore + 0.20 or 0.40 (depending on the condition of the bores)

Duplex chain

HIF44 carb

 

He said he had an 1098 engine with that spec and it flew.

 

Happy to hear opinions on the spec :)

[Cooperman]

The 276 cam is far from ideal as it gives maximum power at 6100 rpm and that is a bit high for the lower revving 1098. That is known as over-campingood.
For what you want a 256, 266 or SW5 will be much better.

[pusb]

The 276 cam is far from ideal as it gives maximum power at 6100 rpm and that is a bit high for the lower revving 1098. That is known as over-campingood.
For what you want a 256, 266 or SW5 will be much better.

 

I did think that myself. He is going to call me back with a few different suggestions, so I'll see what he says then.