8 replies to this topic

[mini_si]

Im building a daily driver / track day car and im wondering what cam upgrade would be best for the 1098 A series engine. Whats everyones thoughts on which one to use?

[mini7boy]

You might want to give these a read.

The first three, by Russell, don't have a lot of info on cams, but cover everything else very well and
have a discussion about adjusting valve clearances that is really critical information. You
might learn some other useful 1098 building tips that don't concern the cam.

The Calver article has better coverage of cam choices.

here's a three-part series of articles on the 1098 written by Aussie A-series ace Graham Russell.


http://www.minimania...81/ArticleV.cfm

http://www.minimania...82/ArticleV.cfm

http://www.minimania...92/ArticleV.cfm

Here's an article by Keith Calver on hopping up the 1098:

http://www.minispare...x?ty=ad&aid=174

This Minifinity forum entry is entitled "Best Cam for 1098"

http://www.minifinit...it=1098#p817341

[bigmotherwhale]

id go with swiftune sw5, kent cams also make nice camshafts just go for something tame if its a road car, race cams won be nice to drive and lumpy on idle. ive heard the megadyne cams are good but ive never really looked into it much

[bigmotherwhale]

i just read the minifinity article seems the sw5 wasnt a bad choice

[mini_si]

mmm the swift tune cam is looking a good bet for me. Has anyone got one in a 1098 engine, just so i can have a idea on how they perform in this engine.

[liirge]

I have one,
They have a tendancy to burn oil, alot of people comment on this, the other thing is that a 1098 doesnt rev due to longer stroke, so choose a cam that doesnt have all its power at the top end.
The 1098 has a noticably higher amount of torque low down than a 998, and they do sound very nice.

[Cooperman]

As had been said already, a 1098 lump won't rev, but it will burn oil. I wouldn't want to take a 1098 above about 6000 rpm sustained for fear of the crank breaking.
If you don't want to go to 1275, a really good option is a 998 bored to 1061 cc, that's +0.080". You can get some super quality flat-top pistons for that size of overbore. With a gas-flowed 12G295 head with slightly bigger inlet valves and a Kent 266 cam, together with a small-bore LCB, a decent carb like an HS6 or HIF44 on an alloy inlet and with a lightened flywheel plus a decent distributor like an Aldon 'Yellow' you'll have a superb engine. Such an engine will rev a lot higher, probably up to around 6800, than a 1098, as the stroke is so much less even though the capacity is not much different. That sort of set-up should yield about 70 bhp, thats up from 38 bhp for a basic 998 and 55 bhp for the original 998 Cooper. We have a similar one at 1061 with an HS4 and an original 510 Cooper 'S' cam. At 10.5:1 comp ratio it gives 66 bhp at 6000 rpm, is very driveable on the road and uses next to no oil. It's very smooth at the top end, especially when compared to my 1310 cc Cooper 'S' rally car.

[dannoodle]

if you read the vizzard books, he states that you can afford to use a longer duration cam in the 1098 without loosing too much low end grunt...makes sense to me, the pistons are traveling further up and down the bores so you've got more time in the combustion cycle

[mini7boy]

What's the reason for 1098s burning oil?