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MG Midget and Sprite Technical - SW05 cam

I have a SW05 cam in my 948 engine.
Valve clearance is specified as 0.016" however this was very noisy. Spoke to Swiftune and they said reduce clearance to 0.014" however this is still quite tappety.
I have read or heard somewher that this is typical.
Is there any improvement in fitting some sound dedening under the bonnet? What type is best?

Thanks

Les
Les Robinson

Les, for longer journeys of more than just a couple of miles I always wear ear plugs. Cheaper and much more effective than sound deadening under the bonnet. And you still get the roar from the exhaust and engine induction, which sounds great, but cut down on wind and mechanical clatter.
Guy

Had the same the sw5 can be a bit noisy
But it did not bother me for long as that engine was toast soon :(
Onno Könemann

I have a similar issue with my kent cam (.016") and high lift rockers (+extra .003"). I don't have a .019" feeler so I have adjusted them to .018. Still very noisy. Can I get away with less clearance?
Dave
D Brown

Dave, better not make the clearance smaller. The exhaust valve may get too hot then. You could make the inlet clearance a bit tighter though. I run a minispares EVO0001 cam with 0,40mm inlet and 0,45mm exhaust clearance.
I had the same SW05 cam as Onno (in fact his cam) and I didn't like it at all. Lots of noise and not the performance I expected.
Alex G Matla

As Trevor says....

Noisy valves are happy valves.

That said....yes there are some serious improvements in sound deading....but you have to look out side the proverbial box....check with stereo shops (car and home), home theater shops/installers, and new "green" insulation/specialty coating companys...

This field has really exploded in the past few years....the old dynamate stuff is now considerad antiuqe by todays Standareds of whats alvialbe
Prop

Dare I say that the SW5 is severely overrated...
Alex G Matla

" Is there any improvement in fitting some sound dedening under the bonnet? What type is best? "

Probably not. Stop one noise and you're likely to hear the next with greater clarity.

I "added quietness" with foil/bubble/foil insulation a few years ago, it has stayed put nicely and was inexpensive, but after things under the hood quieted down the wind and exhaust noises just got louder. Dubious benefit IMO.

Richard


Richard Reeves

Alex G... You are the very first person I've heard with a negative thought about the SW5....

Tell me what you felt was not good about it...

Was it possibly not suited to your application and what did you replace it with that was better...?

Cheers,
Mark.
M T Boldry

a few years ago, there were several that failed quickly, over at the minimania web site, in mini A series engines. A lot of discussion then about whether it was using that cam with high lift rockers, or if the proper ZDDP % was used for break in, or what

the concern, as I understood it, was the extremely fast valve opening speed (which was the point of that cam to improve breathing beyond other cams), the high loading lead to excessively high cam lobe loads and fast wear, if everything was not just right (some folks reported no trouble with it at all)

I am not a cam expert, just that is what I remember about the discussions about it, I am sure that others will chime in with more details, or will correct me if I've got it wrong.



Norm
Norm Kerr

Hi Mark

There are quite a few people not happy with tappet clatter ( clatter being very unusual on a series especially on the small bore engines which are usually like sewing machines). Excessive cam wear has been mentioned when used with higher ratio rockers.

The performance does not seem startling when in standard rocker application.

I haven't seen any worn cams but would be most interested to examine one or at least some piccies of exactly where the lobe damage occurred.

Peter
P Burgess

Out of interest - how long should a "performance" cam be expected to last? How would one tell it was wearing? I presume that when next checking the tappets l could measure valve lift with a dial gauge, but as l have not done this from new l am not sure that would tell me much. Unless l was getting a lot of variation between valves.
Guy

AIUI there's no spec provided with the SW5; so I wouldn't ever use one. That's a negative thought I expressed some years back!

It's like buying a modified cylinder head and not being told the valve sizes and CR. It could be anything - and different each time.

A
Anthony Cutler

Hi Guy

Billet cams, if bedded in correctly, will last a long time(at least the length of a piece of string).To be honest a well looked after billet cam should do the 100000 miles mark with no probs. Repro cams tend to 'go' around 20000 mark even when correctly bedded in. When we used repro csms for racing we had to renew them every season. With the billet cams we have run race engines to 30 hours with no apparent wear(that is approx 2500 miles flat out).

We have experienced Herzian failure on a lot of repro cams but never on a billet cam as yet. We have seen accompanying cam follower Herzian failure with repro cam use but not on billet cam cam followers.

The tip of the lobe tends to show wear patterns first.

Hi Anthony

It is interesting to note what you say about specs included with cam. With our Piper cams we get a spec sheet if current cam. When we order a specific cam such as the HR270/HR285 we do not get a sheet as we are working to old recipes, we check the cam then write the tappet and timing info on the box.

If you buy a Piper cam and it has an included spec sheet, use that info for timing etc as it may well be different from those advertised. Piper modify their current specs from time to time which is why you must follow the included info or check with the cam supplier who should know what is in the box they just sent you. All the Piper cam boxes now have job number info too.

We discovered some years back, there were 3 BP300 specs. To differentiate we tend to order on profile numbers and specifiy the inlet max lift. So a 191@104 is a 191 profile set to 104 max lift and is a very early spec BP300.

Just adds to the confusion for those wanting/expecting numbers to be absolute :) , which is why I am always saying don't try and read too much into what a cam will do based on spec sheets alone.

Armchair tuning can sometimes lead one astray.



Peter
P Burgess

Thanks Peter,
When I built my current road car engine I put in a Kent 276 (and yes, it also came with a spec sheet!). It was installed correctly and I followed the proper procedure (cam lube, 2500 rpm for 20 mins, no idling)

The engine has now done around 65,000. I have no particular reason to suspect cam wear - it was just that it seemed a logical question given the earlier discussion. I am not planning on changing it but did wonder how I might check it other than removing it to inspect the lobes. I am not inclined to tamper with it as it "ain't broke". Well, that is as far as I know!
Guy

I believe the earlier SW5s were ground on exsisting cams, ie reprofiled. However, into their production,they started using fresh blanks. In 2007, Swiftune introduced the SW5-07, a second generation version with improved tolerances and slightly better performance figures.
As with all manufacturers, R&D is ongoing and early production cams may have suffered premature failure or even unjust critisim.
I've used both the SW5 and the SW5-07 in many engines from 948cc to 1380cc all with great results for a ROAD engine. Make no mistake, it is NOT a race cam.

I know Keith Calver developed a camshaft with Piper that is very similar to the SW5 and I'm told is also very good.

As for cam specs, I'm sure the SW5 has been arround for long enough now that someone will have sat one on a 'cam-doctor' and taken some readings...?

Mark.
M T Boldry

my understanding is similar to marks...

swiftune purchased that big cam grindering/making machine that makes formula 1 camshafts and thats when the the sw5-07 came into existance and alot of the flaws removed

here is a site that has the sw5 specs and some of the other popular cam specs also... there are several of these sites but I cant find them right off.

http://www.theminiforum.co.uk/forums/index.php?showtopic=36988


Prop
Prop

Peter, i have a SW5 at home with a couple of destroyed lobes. Lots of swarf in the engine, block was toast, no oil pressure as oil pump was toast too. Hard for me to tell if the lobes disintegrating were the cause of the swarf but as far as I can recall there was nothing else in the engine that could have caused it. I'll dig it out and get some pics if I can remember.
Tarquin

Hiya

If you are ever passing it would be interesting to see the cam and followers. To be honest a design flaw should evidence itself on all the lobes ie all inlets or all exhausts or both if same profile.



Mark

We also have quite a few Mini owners wary of the cam, totally separate from midget threads.


Peter
P Burgess

Mark, right now I have a Minispares EVO001 with this spec:


Fast Road Evolution001 Minispares 264/268 6,71 7,3406 0,264 0,289 107,0 0,330 0,361 0,343 0,376 0,396 0,434 0,449 0,491 £47.38/- (minispares)

(Don't know if this has any use...)
It performs better IMHO as the SW5, despite the smaller inlet lift.

Even my trashed engine with C-AEG 643 cam performed better than the SW5.
Maybe it was just a negative feeling and impression with all the racket coming from under the hood.

Anyway, at silverstone I went on the rolling road and it gave something like 87 Bhp @ 5000 rpm, not completely broke in yet.

Alex G Matla

Maybe this is better to read:


Fast Road Mild Road
Evolution001 SW5
Minispares Swiftune
inl. Duration 264 244
exh. Duration 268,00 244
max lift inl. 0,264 0,281
max lift exh 0,289 0,281
full lift @ 107,0 108,0
Alex G Matla

Now im worried....

Im thinking i may have built my engine wrong...i dont have all that noise like you guys are describe...and im running the hhigh lift roller rockers....granted there is some noise....but nothing a radio or wind wont mask....certianly not louder then the old engine.....but it is a little chattery at idel, but no more then id expect to keep the valves happy

Any ideas what i may have done wrong...or what i need to do to make it run louder like its supposed to...my valve clearance are .18
Prop

Prop, c'mon, only .18? Slacken it to .36 minimum and drain the oil, go for a spin, like start the engine, turn on to the street and floor it! No, don't shift gears yet, first get to the 8000 rpm mark!. cruise the block like that, refill with oil, and presto: there's your genuine SW5 clatter :^P
Alex G Matla

Thank alex,

Ill certianly give that a try...just a thought i was thinking of porting my head this weekend using a new method i saw on the internet...you get fine sand, start the engine .... rev it up then pour the sand into the carbs ....it supposed to polish and reshape the inside of the head in a natral kind of way then The sand just pours out the exhauste tail pipe...they say the new performance effect is ...."indiscribable" and id be left speachless and amazed by what ive accomplished.

So what do you think, Should i do this new porting method before or after your suggestion of making the engine run more chattry like its supposed to?

Prop....if a little sand will work, then.....
Prop

Ha ha. do you need special sand for that method? Or is "scheveningen" sand ok? Cause then I can get on my bike and get a bucket.
Alex G Matla

Im thinking outside the box.... and going to try walnut media blast....has more cutting power. Which means More bang for the buck.
Prop

Last time I was in Nick Swift's workshop he didn't have a cam grinder - I don't know for certain, but would put money on Nicky getting his cams ground by Kent...
James B

Iirc they are ground by kent
Onno Könemann

I assume they are...arent kent and swiftune owned by the same person...

I maybe wrong on my terminogy...as to a cam grinder....but i do know they got a big piece of mechine that makes cams just like F1 .... its a staple of there advert on the swiftune website
Prop

'arent kent and swiftune owned by the same person...'

No - 2 seperate businesses - Nicky does mainly A series engines. Kent supply cams for many different engines. Swiftune is in Bethersden, Kent are based in Folkestone (as are Piper)
James B

Hi Prop

The website alludes to the cams being ground on a posh machine, I cannot see where it says they have one. One would assume the website would say 'all cams ground in house on our own superlobogrindo thingy' :)

Peter
P Burgess

I have the SW5O7 and have run that cam for over a year now. I like it. am I crazy?
S.A. Jones

So far no probs with my SW5-07 - its been in for over 3 years, about 10,000 miles
Mothy

Fitted with the correct valve springs and the engine set with a slightly high idle speed will ensure longer cam life....

Mark.
M T Boldry

This thread was discussed between 21/04/2011 and 04/05/2011

MG Midget and Sprite Technical index

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