46 replies to this topic

[Madmax]

anyone know what difference 1.5:1 roller tip rockers will do compared to normal standard rockers, i know WHAT they do, but im interested in what kind of different 'feel' im going to get when i drive the car?

[clubman_dan]

i've heard that they ruin cams big time,

[TimS]

how do they manage that dan? after all they are designed for the enigne! and all they do is increase the valve lift! i can understand that they will multiply the valve spring force thus forcing the follower to rub against the cam lobes more increasing waer but this should not be drastic

[Madmax]

i have to admit i am slightly confused, i havebt heard them ruining cams as yet, why so?

[Madmax]

think im gonna go for em anyway considering what i know of them already

[P91MER]

I asked the same question on minifinity, well i asked on advice on fitting them. It got into a full debate between 2 professional engine tuners!

I am sticking with what Simon at morspeed said tho, that he has never seen them mess the cam up, and that he fits them onto all his race engines.

http://www.minifinit...=13646&start=40

On a standard engine you are looking at around 3Hp, on a tuned engine you are looking at up to 7HP!! which is definately worth while.

Was it you madmax that has ordered an engine from morspeed?

I ordered a Stg 3 head from him last week :D

Rich

[Madmax]

flappyplastic bits and i went down there to see him about flappys new 1340 he supplied, im off there thursday to have my flywheel lightened and tour the workshop, simons also whipping up a head for my specific engine too...

[TimS]

just read that post! i would agree with both in a way! obviously if you increase either the valve spring force or the ratio of rocker then you are going to apply more force on the folllower and wear the cam quicker. But i think the rate as which this is, is exadurated a little. There are thousands of A series engine out there running 1.5/1 rockers and iv not heard of any cases untill now of super high cam wear rates. After all other car using rockers often run higher ratios of rocker as std.


I must agree though when he says that it would b better to increase lift though the cam. As i see it this way yuo would be able to use a stiffer valve spring with roughly the same amount as rear. But this advantage would only be greatly seen on very high reving 850's or 998's not torquier lower reving big bore engines

[P91MER]

I must agree though when he says that it would b better to increase lift though the cam

Yes i agree totally, but if you are like me, and don't want to take engine out then higher ratio rockers are the way!!

Don't spose you know the waiting time for stuff from morspeed do ya?


Rich

[Woody]

I have a 1.5:1 roller rocker set on my 1275(non MG) mini , the diferance is very noticable over a standard 1.3 set ,
but it still is not as quick as my last engine (MG metro with standard rockers)
I would have liked to have tried the 1.5s on my MG engine :grin:

[Madmax]

i wasnt aware there was a waiting list p91lmer, everything weve got from him so far has been done on the day

[P91MER]

everything weve got from him so far has been done on the day

I mentioned a Stg 3 head to him the first week in jan, i actually ordered it last week and heard nuttin :sad:

I'm not really bothered tho, with the reviews i have heard about his products it will be worth the wait! Not going to rush they guy, he is a nice bloke!

Rich

[Madmax]

yeah ill second that

[TimS]

il third it

[Pavel]

I've seen 1.5 ruin cam lobes quite a bit, but given regular maintenance I don't see why you shouldn't fit them if they appeal to you.

I'd honestly fit 1.3 roller tips to my car. They will reduce wear on the valve stem and give that .05 of ratio more than standard. If I wasn't too fussed bout longevity of the engine before a check/rebuild, I'd use a set of 1.5 but only on the right engine.

They bring the power up about 500rpm (and torque), increasing power at the top, but robbing slightly from the bottom. Basically they have the same kind of effect as more overlap on a cam if that makes sense...