30 replies to this topic

[liirge]

Hey,
I was thinking about getting some roller rockers to reduce valve guide ware and frictional losses of Hp, and i was looking around at some prices, minispares used to sell a nice set, but not anymore the new ones are a little pricey for what im looking at.
However Minisport sell some nice 1.3:1 Rockers, but ive heard people having trouble with them, breaking at high revs? is this true?
Is anyone running them and noticed any problems with them, i think i wil ring up before i order and ask if they're actually in stock!! lol



So poeople thoughts and alternative suppliers at the same price range

Regards Alastair

[jaydee]

They break at high revs if the valve springs arent in good condition, so a minimal valve bounce takes the valve to hit the piston.
Fitting an high lift rocker to an high lift cam isnt a good deal, but the 1.3 arent excessive, so would work fine and give you a few more bhp.
The problem is that they cost a fortune and wear out the cam in a short time.

[liirge]

Hiya Jaydee thanks for your reply,
Just wondering, how do they wear the cam any quicker than normal rockers? i can understand on a 1.5 lift, but the 1.3 lift which is'nt too far off the standard 1275 ratio?

[jaydee]

Yah, but youre gonna use an SW10 with the 0.291" lift, and 1,5 litterally eats the standard cam in about 15k miles, so i guess the 1.3 can wear out an high lift cam.
For what they cost and whats the hassle of replacing a cam, i wouldnt take the risk.
Now, not totally sure and i may be mistaking, but as far as i remember, the cooper s eninges were fitted with an high lift cam similar to the kent 256, and rockers werent high lift.

[navyseal]

save your money and get some pressed steel rockers, good enough for upto 120bhp.

[liirge]

Ive got some pressed steel, ive heard they have a tendancy to brake at high revs.
The reaon why i didnt want to use them as they are already worn and may have changed there ratio due to this and may have worn in such away to cause excessive Guide ware in a matter of a few hundered miles.

[navyseal]

i had pressed steel on mine up until i was running the 7 port, and the 1380 i had before that was pushing 130bhp and they didnt break.
if they are work, re bush the shaft and get new pads, will still be cheaper than roller tip rockers.

[liirge]

Your engine, probably didnt have ALL its power really high up the rev range and therefore they werent under alot of strain alot of the time.

[navyseal]

Ive always been able to rev my engines to 8500rpm and they still pull, and when i drive it it gets a good thrashing as i sail about on a boat for 6 months of the year due to work.

[liirge]

Ok mate, did you weld the top Of them to strengthen them?

[navyseal]

nope. thats cooper s forged rockers you do that to isnt it? never heard anyone do that to the pressed steel ones.

[Racer_Pete]

Ive brought a set of 1.3:1 Minisport roller rockers, ive also heard they break at high revs but only heard about that happening once? hopefully wont hear about it again!!! soon find out once its run in.. lol. I decided on the 286 scatter, hopefully the 1.3:1's wont give any hassle at low revs with that cam, unlike 1.5:1's but i think it will be okay, if it does start giving me problems the standard A+ ones will be going back on.

[liirge]

Pretty sure its the pressed that are meant to have beads of weld put on the top to increase strengh at high rpms

[navyseal]

Pretty sure its the pressed that are meant to have beads of weld put on the top to increase strengh at high rpms

possibly. i know that people always did it to the forged cooper S rockers.

[liirge]

Ive brought a set of 1.3:1 Minisport roller rockers, ive also heard they break at high revs but only heard about that happening once? hopefully wont hear about it again!!! soon find out once its run in.. lol. I decided on the 286 scatter, hopefully the 1.3:1's wont give any hassle at low revs with that cam, unlike 1.5:1's but i think it will be okay, if it does start giving me problems the standard A+ ones will be going back on.

Hello pete good to hear from you on this one!
How did minisport do in terms of delivery i am familar with there customer service and delivery times!
Did you order online?
im sure the 1.3 will be ok, especially if your not to worried about revving to get power