Hi guys, someone suggested that i have a 998 pollution head on my 1100.

Is there any difference between a 998 pollution head, and a 1100 head? [with the external gear blanked off anyway]

And am I at any loss for having one on?



Cheers
Cal

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'63 850/1100 + more cooper goodies

Yeap, that is a pollution head. An 1100 (22G202) would be slightly better, but I wouldn't fret over it. Look like an english block right down to the engine number. Are you sure it is an 1100?

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Yes there is a heap of difference.
998 pollution head (CAM4004)- small round intake ports, 1.090" inlet valves, very shrouded chambers.
1098 head (12G202)- square intake ports, 1.156" inlet valves, less shrouded chambers.

Exhaust valve sizes are same on both.

You can port either of them out to the same sporty specs but the 998 one takes a heap more metal removal.

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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.

so if i pull the engine down would it be advantageous for me to replace it?

on another note to change the diff the motor would have to come out anyway??

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'63 850/1100 + more cooper goodies

If you are pulling it down for rebuild, yeah I'd change it. Plenty of 12G202s about, they were used on Morris 1100, 997 Cooper, 1098 Mini K & Clubby, and Mk2 Sprites.
[edit] here's a good one for sale- http://www.ausmini.com/forums/viewtopic.php?t=67794

A 12G295 head (998 Cooper, Mk2A Sprite) is even better if you find one, but rarer and $$$ier.

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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.

GT...... i would have no freaking idea lol

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'63 850/1100 + more cooper goodies

There was originally an alloy plate at back of block near the fuel pump mount.
If it was originally a 998 it will have 1000 on this plate.

To see what it is now:
1. Remove spark plugs.
2. Get a pencil.
3. Turn engine until pencil in #1 plug hole shows it is at TDC.
4. Mark pencil in #1 cylinder, at top of plug hole.
5. Put pencil into #2 cylinder. Mark again.
6. Measure between the 2 marks.
76.2mm = 998 crank.
83.7mm = 1098 crank

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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 would say that somone has put the engine number plate on that engine recently, as it lookd quite new. you can buy the plates and the correct rivits to hold them on off ebay.

If the alloy tag is still on the rear of the engine, it will tell you what it is, 1000/1100 etc

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