8 replies to this topic

[timothy]

Hi, I'm planning my engine build at the moment and looking at camshaft choices. What are peoples views on the swiftune sw5 camshaft for road use, as opposed to using a fast road cam from kent such as the 276 or 286? I want good midrange torque and fairly good topend, but as this is going in a road car i don't want to have to take it 7000 rpm to get power from it.

Cheers

Also what are peoples views on high compression pistons on a road engine? Are they necessary/will they provide a huge benefit over OE pistons in a 1330?

[fikus01]

the bigger the cc the bigger a cam you can make drivable!! does that hep you at all!!

for road engines aim for a compression ration no higher than about 10.5:1, 10 is good!!

the 286 can be lumpy with a 1275 but will be much smoother in a 1380!!

the 276 is specced to pull from 1000 - 7000rpm!! i found it to be fun and very drivable!!

the 286 is slightly madder!! found on the 1293 it didnt start pulling til about 2500rpm but it was stil going strong at 7000rpm think gearchange was best at 7500rpm!! it made more power than the 276 but at higher rpm!! and sacrifices lower drivability!!

tho as stated above bigger cc helps reduce the low down lumpyness!!

cant comment on the sw5!! heard lots of good things about it tho!!

dont forget the piper 255 or 285!

cylinder head choice will throw a whole bag of fun onto the equation too!! bigger ports and valves reduce drivability but increace torque and power at top end!!

anyone else??

[Guess-Works.com]

Personally I drive a 1330, running HC pistons, with a decked block and an Kent 290 cam, and to be honest below 3000 it's like driving a normal road car, just when you hit the power it goes banannas !!!

If you are in anyway subject to an emissions test for the MOT, then the SW5 is a good choice, but is a little mild for me...

Give you an idea of how quick it is, mine does 16.2 1/4 miles, it's doing over 80 at the end of the 1/4, 0-60 is considerably less than 10

[dklawson]

I can only compare the SW5 to the stock cam that came in my 1275. I find the SW5 very smooth and therefore suitable for my car (street only). It pulls well from somewhere around 1500 RPM up through the normal range I use. I can feel the improvement over the stock cam.

[timothy]

Ok cheers, I get the idea that the sw5 is a great cam for drivability, but not as good as something like a 286 at the top end. If I had a 1330 with a stage 4/trackday spec head, 1.3 roller rockers an HIF44 and an sw5 cam, am I right in thinking this would give about 85/90 bhp and about the same for torque? Are 1.5 ratio rockers neccessary for a build like this?

dklawson Posted Today, 12:59 PM
I can only compare the SW5 to the stock cam that came in my 1275. I find the SW5 very smooth and therefore suitable for my car (street only). It pulls well from somewhere around 1500 RPM up through the normal range I use. I can feel the improvement over the stock cam.

have you modified the head at all? What power and torque figures are you getting with that build?

Edited by timothy, 29 November 2006 - 04:30 PM.

[dklawson]

I wrote a reply but the board wouldn't take my post !!!

To paraphrase what I typed earlier....
I currently have a 12G940 big-valve head fitted. The ports were enlarged a bit to match the manifolds and the chambers were re-sized to match each other. I did very little serious porting of the head as I was doing this myself and didn't want to ruin it.

I have no dyno figures. Rolling roads are not common here, quite expensive, and the operator can't advise you one bit about how to improve the tuning on your British car. They may be able to say that you're timing is bouncing and/or that the mixture is rich or lean, but they wouldn't be able to tweak the car for you.

[fikus01]

i just tried a post too!!

i figured you'd be in the ball park of the bhp u quoted!! how close is one of those engine question marks that hangs over you til the day of your rolling road setup!!

if you've got your heart set on the sw5 cam and you're buying roller rockers then it would be worth getting the 1:5 rockers instead!! a little extra lift on what seems to be a good mildish cam like the sw5 cant hurt!! it'll probly give more mid - top end punch, i cant see it hurting the low down power by much really!!

[timothy]

I'm not sure what's going in with this post, but it's saying the last post was made yesterday which is strange considering I posted today.

Cheers for the advice, I think I will get 1.5 rockers and those along with a stage 4 head should give a bit more top-end to the sw5. I'm not heart set on this cam, just heard a lot of good things about it. I've heard a lot about hotter cams such as the Kent 286 resulting in poor drivability, but how poor is it? I use my mini everyday and am in traffic quite a lot so I can't really have a really lumpy idle, but I'm quite tolerable of a bit of a trade off it's still practical.

Thanks

Oh plus will what kind of power can the standard gearbox withstand? Would it be highly beneficial to fit s/c drop gears?

Sorry about the questions

[Guess-Works.com]

I run A Series Drops and a GT box on my 1330, so you're not going to have any problems with a std box/drops on yours especially if you use A+.

If you go for 1.5 rollers then get a kit which includes matched valve springs otherwise you'll be stressing the valve train and cam, Swifttune probably do a full kit with the cam, followers, rockers and spings..

If you fancy it to be a little more free revving I would suggest either a lightened or ultra-light flywheel and some vernier timing gear so you can get the cam timing spot on.