11 replies to this topic

[Tinkerbelle]

Hello all,

Just wanted to know if anyone else has had a problem with Minisport roller tip rockers being noisy. I have had them for about a year but only just fitted them (c. 200 miles ago), so cannot really return them. They were always a bit loose feeling on the rocker bar!

I am running 1.3:1 on a 998 with an SW5 cam at 15 thou.

I don't really want to replace them as they aren't cheap. Can anyone suggest standard replacement ones which are 1.3:1?

I also checked out to see if they were hitting the rocker cover, but it doesn't seem that they are.

Help, I spent a fortune getting the engine sorted out and it sounds worse than my 105k miles 850!

[roofless]

Hello all,

Just wanted to know if anyone else has had a problem with Minisport roller tip rockers being noisy. I have had them for about a year but only just fitted them (c. 200 miles ago), so cannot really return them. They were always a bit loose feeling on the rocker bar!

I am running 1.3:1 on a 998 with an SW5 cam at 15 thou.

I don't really want to replace them as they aren't cheap. Can anyone suggest standard replacement ones which are 1.3:1?

I also checked out to see if they were hitting the rocker cover, but it doesn't seem that they are.

Help, I spent a fortune getting the engine sorted out and it sounds worse than my 105k miles 850!

definately all feeler-guaged up correctly? mine were pretty good, nice and quiet compared to what i had prior

[panelbeaterpeter]

Sounds like clearances. I had my 1:5 rockers setup with the suggested clearances for that setup, and it was quite noisy, so I turned them down a little. Still sounds noisier than before but not too bad. I think you have to keep them more open than standard to save wear on the cam or something? One for the tech dudes methinks.

Moved to Technical and Problems.

[Rosslin Racing]

do not forget that the roller system when using the feel gauge need to be measured from the side and not pushed in from the front.

[Tinkerbelle]

Yeah, I was measuring from front to back, I will try side to side.

I have always wondered what 'a good sliding fit meant', in terms of gapping the rockers in the first place. I go until the feeler gauge is just starting to be caught. Is this correct?

Thanks for that.

[panelbeaterpeter]

Yeah, I was measuring from front to back, I will try side to side.

I have always wondered what 'a good sliding fit meant', in terms of gapping the rockers in the first place. I go until the feeler gauge is just starting to be caught. Is this correct?

Thanks for that.

Sounds right to me.

[minipac]

I would contact minisport and ask what they would do, as I have just removed a pair of minisport rockers with a snapped shaft. on inspection the shaft was only half as thick as a pair I bought from mini spares. couldn't take the back dew to the length of time I have them before fitting them. it snapped while I was drive and I noticed it sounded very tappy, got home took rocker cover off and no.8 tappet almost fell off in my hand. lucky or what

[roofless]

I would contact minisport and ask what they would do, as I have just removed a pair of minisport rockers with a snapped shaft. on inspection the shaft was only half as thick as a pair I bought from mini spares. couldn't take the back dew to the length of time I have them before fitting them. it snapped while I was drive and I noticed it sounded very tappy, got home took rocker cover off and no.8 tappet almost fell off in my hand. lucky or what

that happened to alex also.

[Tinkerbelle]

Thanks for that,

I would rather remove them and fit some I will have better faith in. I might swap then for std ones whilst on the r/road next week and see if the is any difference at all between the std 1.22:1 and the 1.3:1! I will post the outcome.

I should have though that the swiftune of KAD ones should be better, but I don't think they do 1.3:1 for small bore heads. I only want them for the extra left anyway so maybe try and source some 1.3:1 oem std rockers, anyone know what they were fitted to Cooper s etc??

[JetBLICK]

The pressed steel type rockers with the oval pads are the closest std type rocker to 1.3 - keith calver did an experiment and measured the ratios of all the OEM rockers and these where the best, think they're 1-1.27 he said. The only aftermarket 1.3's are minisports roller tip rockers and the titan full roller rockers avaliable from minispares (which cost a fortune by the way)

You hear a lot of horror stories about the minisport rockers, the two most common things i've heard of is the pins that hold the rollers in have fallen out, and the shafts breaking. I dont think i could be persuaded to use a set after some of the stories i've heard. On the other hand the Titans are horrendously expensive, £340 or something, and are completely unnecessary for a little budget motor. I'd keep an eye out for some of pressed steel ones as mentioned before.

[Tinkerbelle]

Maybe I will try a new thread to see if anyone has fitted 1.3:1 rockers on there 998 and what difference it makes over std ones in terms of power.

I did a lot of work in one hit on my engine so too many variables to compare the rockers.

Anyone here got any comments e.g. are they necessary on a engine of my spec?

Thanks all for help.

[Tinkerbelle]

Anyone who is interested I have found something on roller rocker ratio etc from Keith Kalver.

http://www.minispare...le.aspx?aid=142

According to this the Minisport 1.3:1 are actually 1.27:1. Given this with my swiftune sw5 cam:-

Lobe lift of 0.281inch
Std 1.22:1 valve lift 0.343inch
1.3:1 valve lift 0.365inch
1.27:1 valve lift 0.357

Which is 14thou (0.36mm) more than std, doesn't sound like much. Atleast this means that I can replace the noisy roller rockers with Cooper S forged rockers and get the same ratio.

I would like to see some figures to see if this makes any difference!

Matt