12 replies to this topic

[Jammy]

Not planning on getting any, was just interested in what people think about them. I know theres a few people who are unsure or don't use 1.5 rockers because of reliablility issues? I'm guessing 1.7 rockers are all out race use? Surely something like this would put alot of pressure on other components?

Link to MiniSports 1.71 rockers

[Pooky]

I don't really understand what those number mean!


Explain! :tongue:

[Jammy]

The number is the ratio of....the distance the pushrod pushes on end of the rocker to the distance the other end of the rocker pushes the valve (via the spring), but I'm probably wrong?!

[Guess-Works.com]

It's the ratio between the cam lift and hence pushrod lift, vs the lift which is applied to the valve bu the rocker..

As for 1.7's, way to harsh for my liking... just the thought of the amount of compression on the valve spring and push rods makes me wince :nugget:

[Jammy]

Oooo, I was pretty much there then!!

[wolfie]

Not planning on getting any, was just interested in what people think about them. I know theres a few people who are unsure or don't use 1.5 rockers because of reliablility issues? I'm guessing 1.7 rockers are all out race use? Surely something like this would put alot of pressure on other components?

Link to MiniSports 1.71 rockers

what reliability issues?

i have only ever hear chinese whispers obout problems with 1.5 ratio rockers and have never met anyone thats actually had a real problem

[jimbo_edmondo]

Yea i think I'll be purchasing some 1.5 ratios over the summer, not rollers though. I guess these will cause more side loading, than roller tips? The valves have got 220lb kent springs, so i guess they'll be ok?
You were thinking about some 1.5s weren't you jammy?

[Bluemini]

1.7's are for race use really. 1.5's are for your road/tuned engine and are very reliable and reduce side load on the valve - thats why they have the roller in them so it rolls over the top of the valve stem instead of dragging accross it.

[pdaykin]

I think reliability really means longevity

1.5 ratio rockers tend to shorten the lifespan of other components, eg cam/followers.

While I have heard stores of the needle roller bearings breaking in some roller rockers I have never actually met anyone where this happens - I think its more a case of a posibility (which doesnt exist with standard rockers) than a reality.

[Jammy]

Yea, I run 1.5 full roller rockers on my 1425, and I don't think any issues I've had have been caused by them. I agree with you Wolfie, never actually met anyone who has had problems with them, just lots of whispers.

[]GoD[Zander]

just put 1.7s in and see what happens and then post the pics

[Pavel]

Don't judge their condition or reliability by taking off the rocker cover and staring at them. Remove the cam, and post pictures of that. I'd like to see the "no ill effects" demonstrated by showing me pics of a cam that's been used with hi lift rockers for over 15000 miles

[Karl]

make sure you buy FULL roller rockers, not the cheaper crappy ones that always break just when you think you are alright. Trust me, for the £50ish extra its worth it.