19 replies to this topic

[valve bounce]

i about to start buliding a hot 1100 (295 head ported with bigger inlets, hif 38, stage 1 with janspeed exhaust manifold,striaght cut drop gears etc etc)
so what cam do i go for i was thinking sw5 but now kent 276/286 but the piper 270? please help me, i dont mind a lumpy idle but need a reasnable pickup as i tow a small carvan/trailer so pleanty of tourque would be great

[jaydee]

sw5 and kent 276 are totally different and piper cams usually wear down faster..
If you have to tow a caravan, nice torquey cams are the kent 246 and the kent 256 and i wouldnt fit an higher revving cam. The sw5 will certain give you better drivability, especially with the extra weight, but dont expect good power figures, if you want more the kent 256 and 266 are a good option. I dont know how a 276 can be on a small bore, but with the 286 you'll have drivability problems when towing the caravan.

[liirge]

sw5 and kent 276 are totally different and piper cams usually wear down faster..
If you have to tow a caravan, nice torquey cams are the kent 246 and the kent 256 and i wouldnt fit an higher revving cam. The sw5 will certain give you better drivability, especially with the extra weight, but dont expect good power figures, if you want more the kent 256 and 266 are a good option. I dont know how a 276 can be on a small bore, but with the 286 you'll have drivability problems when towing the caravan.

Right well this isnt 100% true im afraid, A cam such as a 286 will show very little cammyness in a 1098 especially with your over bore, and up'ed compression ratio seen on your project specs.
Now before people say anything, the longer stroke means that the 1098 engine is much better with longer duration cams upto about 280 degrees. Your choice of a 295 head is a very good one, as due to the smaller ports compared to the 940, you will gain more torque in the mid range than the use of a 940, but will lose some at the top end, but i wouldnt worry about that as the 1098 will never be a revvy motor. I would recomend a 10:1 Compression ratio at least.

[mk3 Cooper S]

Mild Road 2000-6500 6.67 8.12 252 Deg 16/5651/21 110 Deg 0.40 I 0.91mm CF1 / VS2
Part No Part Type Description
567 Camshaft Mild Road
Product: 567
--------------------------------------------------------------------------------

--------------------------------------------------------------------------------
This is a 998 Cooper replica CAM.
I have one in excellent condition for sale if you are interested?

[valve bounce]

thanks for the replies, just another quick one is the kent 266 the same a the mg metro cam?

[jaydee]

The MG metro cam is a cross of the old 731 ST cam for the exhaust and the cooper cam for the inlet.
Deg figures are:
MG metro- intake 252 exhaust 268 lift 0,263 overlap 0,054
Kent MD266- int 260 exhaust 270 lift 0,263 overlap 0,054

Edited by jaydee, 21 September 2009 - 08:09 PM.

[bmcecosse]

The standard 1098 cam (AEA 630) is actually not too bad. It's not a high revving engine - I would suggest either stick with that cam - or go to an MG MEtro cam absolute max. Main thing - stick a 12G940 head on it - it flies! That's my engine spec (not actually in a Mini - but same engine) and it pulls really well from low to decent revs - but best to not exceed 6000 if you want it to last!

[liirge]

The standard 1098 cam (AEA 630) is actually not too bad. It's not a high revving engine - I would suggest either stick with that cam - or go to an MG MEtro cam absolute max. Main thing - stick a 12G940 head on it - it flies! That's my engine spec (not actually in a Mini - but same engine) and it pulls really well from low to decent revs - but best to not exceed 6000 if you want it to last!

940 not the best on a 1098 engine due to the lack of revs and only advantage of this head over the 295 is the Top end power increase, for a road car the 295 will give better results.

Edited by liirge, 22 September 2009 - 12:44 AM.

[valve bounce]

i WILL NOT be using a 940 head they only work on small bores AT HIGH REVS THAT 1100S DONT DO!!!! so the 295 is best on a low reving 1100 and he 940 is better on a screaming 998

[mini7boy]

i WILL NOT be using a 940 head they only work on small bores AT HIGH REVS THAT 1100S DONT DO!!!! so the 295 is best on a low reving 1100 and he 940 is better on a screaming 998

good for you, valve bounce. It's good to see someone who's willing to think independently.

have you already seen these articles?

They were written by Graham Russell of Russell Engineering in Australia. He is one of the leading A-series experts in Australia
and his shop has: an engine dyno, chassis dyno, flowbench, cam grinder, balancer.

He grinds his own cams, ports cylinder heads and builds complete engines for road use as well as for front running Mini racecars.

http://www.minimania...?DisplayID=1881

http://www.minimania...?DisplayID=1882

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

he discusses cams in the first article.

take note of his clever valve adjusting method covered starting near the end of the second article.

Edited by mini7boy, 24 September 2009 - 11:41 PM.

[liirge]

i WILL NOT be using a 940 head they only work on small bores AT HIGH REVS THAT 1100S DONT DO!!!! so the 295 is best on a low reving 1100 and he 940 is better on a screaming 998

good for you, valve bounce. It's good to see someone who's willing to think independently.

have you already seen these articles?

They were written by Graham Russell of Russell Engineering in Australia. He is one of the leading A-series experts in Australia
and his shop has: an engine dyno, chassis dyno, flowbench, cam grinder, balancer.

He grinds his own cams, ports cylinder heads and builds complete engines for road use as well as for front running Mini racecars.

http://www.minimania...?DisplayID=1881

http://www.minimania...?DisplayID=1882

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

he discusses cams in the first article.

take note of his clever valve adjusting method covered starting near the end of the second article.

Hold on did you guys read my post saying NOT to use the 940 aswell...did you decide on a cam mate?

[valve bounce]

[/quote]
Hold on did you guys read my post saying NOT to use the 940 aswell...did you decide on a cam mate?
[/quote]

i didnt see that til after i posted actually but ive hreard you saying it before and agree, i havnt just decided on a cam yet but i thinking the kent md 266 is sounding the best really? any other opinions?

i have also read the chapter on cylinder heads in david vizzards book backward and forward about a dozen times, that also helped me decide on the head, also i already have the head on my old engine

[bmcecosse]

If yoiu haven't tried the 940 head on a 1098 engine - you aren't qualified to comment on it! I have such a thing - and it works beautifully - at ALL revs ! I replkaced a well worked295 with the slightly cleaned up 940 (standard small valve version) and the difference was amazing! Go for it!!

[valve bounce]

If yoiu haven't tried the 940 head on a 1098 engine - you aren't qualified to comment on it! I have such a thing - and it works beautifully - at ALL revs ! I replkaced a well worked295 with the slightly cleaned up 940 (standard small valve version) and the difference was amazing! Go for it!!

i think not, a 295 will be used on my build

[mini7boy]

If yoiu haven't tried the 940 head on a 1098 engine - you aren't qualified to comment on it! I have such a thing - and it works beautifully - at ALL revs ! I replkaced a well worked295 with the slightly cleaned up 940 (standard small valve version) and the difference was amazing! Go for it!!

i think not, a 295 will be used on my build

Gee whiz, valve bounce.

I don't know why you would take the words of Vizard(or Graham Russell for that matter) over the opinion of Roy.

c'mon now. Roy taught Vizard and Russell (almost) all they know.